QF 3.7 inch AA gun
stu...@animats.net
I am currently in the process of writing a piece of interactive
fiction based in Darwin, Australia during the February 1942 raids. The
player starts the game in the role of a gunner as part of a crew
operating a QF 3.7 anti aircraft gun. I have read quite a few books
now that give me a good general view of the period, but I am now
looking for some detailed information on the operating procedures of
this gun, particularly the earlier models with manual fuze setting and
loading. I would like to make the story as accurate and detailed as
possible, but I'm struggling to find the information I need.
Is there anybody familiar with the operation of the early model of
this gun and the Kerrison Predictor who is able to help me?
Thanks in advance,
Stuart
euno...@yahoo.com.au
I'm sorry I can't help you but I've been looking for some related info
on this gun. Although the 3.7" (94mm) gun was introduced first in
1938 at some point during the second world war an automatic loader to
ram the round into the breech was introduced with an automatic fuze
setter to set the fuze a fraction of a second before ramming. This
was the "Mollins Fuze setter" MFS No 11 and guns so equiped were
called designated the Mk IIIa.
If you find our what the date of entry of service of this guns was
please get back to this new group.
Without an fully automatic fuze setter it was done either manually by
a soldier/sailor with a spanner who would prop the shell on its based
between his legs or by a manual fuze setter: or alternatively by a
machine which might hold a pair of shells nose down so that they might
be picked up at any time while an operator continuously adjusted the
delay time according to a an instrument dial.
The UK Army appears to have been well ahead of the RN in radar and
gunnery. In fact the RN AAA was the most retarded of any major
combatant.
There is a picture of the formidable agglomerations this produced on
this web site:
http://riv.co.nz/rnza/hist/local/qf37aa3.htm
http://www.57regtraclub.com/id6.html
"During the war an automatic fuze-setter (MFS No 11) and an automatic
loader were fitted. These not only speeded up the rate of fire, but by
eliminating variations in time taken by individuals in loading and
fuze-setting, enabled guns to follow data supplied by predictor more
closely. Thus the new machinery not only increased the rate of fire
from 10 to 20 rpm, but also improved accuracy. Guns so equipped were
designated Mark 3A."
Also
http://.co.nz/rnza/hist/local/qf37aa.htm
http://australianartilleryassociation.com/regiments/regiments_9haapg002.htm
stu...@animats.net
> "During the war an automatic fuze-setter (MFS No 11) and an automatic
> loader were fitted. These not only speeded up the rate of fire, but by
> eliminating variations in time taken by individuals in loading and
> fuze-setting, enabled guns to follow data supplied by predictor more
> closely. Thus the new machinery not only increased the rate of fire
> from 10 to 20 rpm, but also improved accuracy. Guns so equipped were
> designated Mark 3A."
>
Thanks for the extra information. I'll keep looking around and try to
contact some of the authors of the the books I have read, too. I'll be
sure to post anything interesting I find out on this group.
Thanks again,
Stuart
ken...@cix.compulink.co.uk
<0873a2aa-bd8b-41a9...@c23g2000hsa.googlegroups.com>,
euno...@yahoo.com.au () wrote:
> In fact the RN AAA was the most retarded of any major
> combatant.
The RN was behind the USN with heavy AA but ahead in light AA at the
start of the war. The RN was probably ahead of Germany, Italy and Japan
in naval AA. Besides you seem to be comparing RN AA in 1938 or so with
the USN in 1945.
Ken Young
euno...@yahoo.com.au
> In article
> <0873a2aa-bd8b-41a9-8e51-6d9f9508d...@c23g2000hsa.googlegroups.com>,
>
> eunome...@yahoo.com.au () wrote:
> > In fact the RN AAA was the most retarded of any major
> > combatant.
>
> The RN was behind the USN with heavy AA but ahead in light AA at the
> start of the war.
The RN may have had better guns but it didn't not have better fire
control for light guns. The latter matters more I think. In both
cases the RN and USN gravitated towards the Bofors 40mm. It's true
that the RNs 2-pdr [4 cm/39 (1.575")] Mark VIII was superior to the
US 1.1 inch gun but the US moved rapidly and more thorougly to the
40mm Bofors pointed by the Mk 51 FCS (fire control system) complete
with remote power control.
> The RN was probably ahead of Germany, Italy and Japan
Nope the RN was well behind the German Navy which actually had quite
good systems available and also behind Japan and Italy. Not until the
introduction of radar did the gap begin to close.
> in naval AA. Besides you seem to be comparing RN AA in 1938 or so with
> the USN in 1945.
No, I'm not. the US 5 inch mounts and its associated tachimetric
fire control system has a history going back to 1932 when development
of the Sperry Mk 1 computer was begun as part of the Mk 37 fire
control system for the 5"/38 DP mount about the same time the RN was
developing the HACS. The RN simply got it totally wrong and had to
live with the consequences. The Ford Mk 1A computer was complete by
1935; this unit added rate information for height changes thus
providing a complete solution for targets moving over 400mph. these
computers were not only used in US capital ships but destroyers as
well.
The RN almost certainly had the worst AAA systems of any of the
combatents at the start of the war: worse than US, German, Italian
and Japanese and never really solved all their its problems until 1945
since the existing systems were resistant to modification since they
had been designed on the incorrect premises. The German navy was
second behind the US and certainly well ahead in regards to the
sophistication of its AAA systems on its larger ships though a few
errors such as using open mounts meant that the sophisticated control
gear was compromised by sea water ingress far to frequently.
I'm not trying to 'dump' on the British or RN but this is a case when
a group of people got it wrong.
First of all the German computer systems were fully tachimetric:
something which can't be said of the HACS in any way so the German
systems produced a far better firing solution and they did so
continuously.
Basically in the RN's HACS system an officer "the control officer"
had to estimate the targets speed and feed it manually into the
computer which then used the current position and the estimated speed
to calculate a firing solution inclusive of the considerable dead time
required to manually set the fuze and load the gun. The HACS was
incapable of calculating the speed directly using information from the
director and optical range finders and apparently never gained this
ability though it eventually gained this via the use of additional
circuits added to radar when radar became available. It initially
also lacked the ability to engage diving and maneuvering targets.
Since the germans (ju 87 and ju 88) and Japanese were rather good at
dive bombing this was a serious problem. It was designed to deal
with level bombers. When microwave radar became available the radars
circuits were finally able to provide this information automatically
but not via the optical systems. In the German system the this
velocity information however could be calculated from the optical
systems; so the German Navy was closer in this regard to the USN's
sophisticated system than to the HACS of the RN.
You can read about HACS here: http://www.navweaps.com/index_tech/tech-066.htm
Secondly the German mounts, as far as larger ships are concerned,
were aimed by remote power control direct from the predictor at least
as far as elevation of the gun was concerned and the setting of the
fuze which was automatic and direct from the predictor via a fuze
setting mechanism adjacent to the gun breech. The round still had to
be manually transfered into the gun at which point continuously
running rollers pulled the round in.
In all of the RN's systems this was done manually until the second
half of the war when radar and electronics allowed a sort of partial
bypass of these problematic systems since circuits added to the radars
could give good position and rate information. In the RN's system
the fuze delay time was set by a man with a spanner or by a fuze
setting machine in which the delay was entered into the machine
manually after having been read from guages. RPC was only added
later to the RN's systems.
You can see an explanation of one of the german systems here:
http://www.navweaps.com/Weapons/WNGER_41-65_skc33.htm
http://www.navweaps.com/Weapons/WNGER_41-65_skc33_pics.htm
http://dcoward.best.vwh.net/analog/ford.htm
http://www.navweaps.com/index_tech/tech-013.htm
German electrical engineers and scientists had perfected an amplifying
device called the 'magnetic amplifier' today refered to as a saturable
reactor. This rugged device made possible the Fi.103/B1, A4/V2 and
for the german navy remote power driven turrets free from the fear of
thermionic vacuum tube failure. The systems of the Prinz Eugen
rather surprised the USN and untill the mid to late 1950s
revolutionized power electronics until the event of solid state power
electronics. Another unique aspect of the German systems was the
large number of computers/directors which allowed the ships to engage
a larger number of targets. Due to the restrictions of the Versailes
treaty and the fear of war with Poland in the 1930s the Germans saw
fire control as a manner of improving the odds.
(The bismark had these systems but the front set of 4 turrets had been
upgraded to a faster traversing design while the rear had not, when
the Swordfish approached the Fire Control Systems did not take into
account the slower traversing units, thus the swordfish got through
the heavy FLAK at which point the inferior German medium 37mm let them
through)
The lack of Duel Purpose (eg 5 inch guns) on German capital ships
which used sperate 6 inch (presumably to deal with the fear of on
rushing destroyers) and 4 inch guns (for FLAK) shows I feel perhaps a
doctrinal problem of immaturity from lack of experience but a fear of
on rushing destroyers and saturation attacks that comes from expecting
to be the numerically inferior force.
Where the German navy fell behind was in high frequency radar or and
something called 'lobe switching' which German officers had been
offered in 1935 but had rejected. However around 1942/43 Telefunken
engineers succeeded in a revolutionary improvements in powerful high
frequency disk triodes able to produced high power outputs (50kw) in
the 10-27cm range which while not in the league of the magnetron in
high frequency was enough to aim guns by with modest antenna the final
system allowed slaving of remotely power guns to the FuMO 231 Euklid
fire control system intended for the Z55 class of destroyers that had
very sophisticated AAA defenses.
Smaller German ships lacked the the remote power control however the
directors appear to have been fully tachimetric the problem with HACS
was the lack of support for full velocity calculation and the rougher
firing solution rather than the lack of remote power control for the
guns in most early British Navy heavy AAA.
In my opinion the British Army was the Cinderella of the services:
its 3.7 inch QF gun showed that a good job could be gun when the
automatic fuze setter and power loader was added and latter remote
power control. The Royal Navies radars were also based on the UK
Armies AMES radars.
The RN simply seems to have gotten it wrong and then, having not
cultivated the skills and manufacturing industry to make the control
gear necessary found it difficult to improve its systems in the
quantities required.
>
> Ken Young
Tero P. Mustalahti
> The UK Army appears to have been well ahead of the RN in radar and
> gunnery. In fact the RN AAA was the most retarded of any major
> combatant.
I really doubt it was more "retarded" than Japanese Army AAA and from
everything I have read, and not significantly worse than the Japanese
Navy AAA practices. Perhaps marginally worse. I agree with you that the
Kriegsmarine was ahead of the RN in optically controlled AAA. I do not
know much about Italian Navy AAA methods, let alone the Italian army. Do
you have information which leads you to believe that the RN was behind
the Italians as well? You also seem to have forgotten the Soviets
completely...
Tero P. Mustalahti
Geoffrey Sinclair
news:6f78b388-e576-4c03...@j20g2000hsi.googlegroups.com...
> On Jan 27, 6:29 am, ken...@cix.compulink.co.uk wrote:
>> In article
>> <0873a2aa-bd8b-41a9-8e51-6d9f9508d...@c23g2000hsa.googlegroups.com>,
>>
>> eunome...@yahoo.com.au () wrote:
>> > In fact the RN AAA was the most retarded of any major
>> > combatant.
>>
>> The RN was behind the USN with heavy AA but ahead in light AA at the
>> start of the war.
>
> The RN may have had better guns but it didn't not have better fire
> control for light guns.
The trouble here is of course that things changed over the course of the
war and it seems the worst of the RN is being selected as the base
comparison.
Anyway so now it seems we have RN better guns but lacked
the fire control for light guns, so I presume the better guns are
the light stuff only.
> The latter matters more I think.
Good, then you would know the RN had fire control for their light
AA pieces before the USN, since the idea of the multiple 2 pounder
was to justify the cost of the control.
> In both
> cases the RN and USN gravitated towards the Bofors 40mm. It's true
> that the RNs 2-pdr [4 cm/39 (1.575")] Mark VIII was superior to the
> US 1.1 inch gun but the US moved rapidly and more thorougly to the
> 40mm Bofors pointed by the Mk 51 FCS (fire control system) complete
> with remote power control.
So by the end of the war the US had the better light AA fire control,
after being behind for the period 1939 to 1942, when the US began
adopting the 40mm and associated fire control. With the USN always
being ahead for heavy AA fire control.
The USN began fitting the mark 51 director in mid 1942 about
6 months after the first twin bofors mounts had been made.
>> The RN was probably ahead of Germany, Italy and Japan
>
> Nope the RN was well behind the German Navy which actually had quite
> good systems available and also behind Japan and Italy. Not until the
> introduction of radar did the gap begin to close.
This is quite funny really.
IJN the type 94 fire control has all the nice descriptions, tachymetric,
triaxial director and a resolver for deck tilt, solutions could be given
for non level flight from the computer in the transmitting station. The
trouble was the computer took too long to come up with a solution.
The system was modified to basically do some initial by eye shooting
to at least provide some opposition.
The poor performance at Midway meant some modifications had
to be made, but no better system was developed during the war.
And some IJN ships, including the Haruna had the older type 91,
which was inferior to the type 94.
The above for the heavy AA, the IJN used the French Navy Le Prieur
sights for light AA, along with the Ward Leonard remote power system
for the triple 25mm guns. Production difficulties lead to the abandonment
of the remote power option.
And you should note the elevation of the IJN Dual purpose 5 inch guns
was 55 degrees in most pre war destroyers.
Italian AA had the same problem, as the Japanese, slow resolution of the
data, and did not have gyrosights and so on for the light AA guns.
>> in naval AA. Besides you seem to be comparing RN AA in 1938 or so with
>> the USN in 1945.
>
> No, I'm not.
You are the one who is talking light AA above, now we jump back
to the heavy AA
>the US 5 inch mounts and its associated tachimetric
> fire control system has a history going back to 1932 when development
> of the Sperry Mk 1 computer was begun as part of the Mk 37 fire
> control system for the 5"/38 DP mount about the same time the RN was
> developing the HACS.
Like the fact the RN had HACS in service before 1932 you mean?
> The RN simply got it totally wrong and had to
> live with the consequences. The Ford Mk 1A computer was complete by
> 1935; this unit added rate information for height changes thus
> providing a complete solution for targets moving over 400mph. these
> computers were not only used in US capital ships but destroyers as
> well.
The mark 37, the ship borne gold standard of heavy AA for WWII
did its tests in 1939. Those two extra years of peace made a big
difference to the standards the USN could adopt in WWII, coupled
with the combat reports it received.
> The RN almost certainly had the worst AAA systems of any of the
> combatents at the start of the war: worse than US, German, Italian
> and Japanese and never really solved all their its problems until 1945
> since the existing systems were resistant to modification since they
> had been designed on the incorrect premises.
So the idea is the RN was inferior to the IJN and RM in both heavy
and light AA systems for the entire war, or will we have more switching
between heavy AA and light AA to suit the comparisons.
It will be interesting to see what the superior IJN and RM systems
look like.
> The German navy was
> second behind the US and certainly well ahead in regards to the
> sophistication of its AAA systems on its larger ships though a few
> errors such as using open mounts meant that the sophisticated control
> gear was compromised by sea water ingress far to frequently.
Take a look at how the German Naval 37mm gun worked at the
start of the war, nothing like a single shot light AA weapon. This
rather compromised the effort into making the better fire controls.
They needed an upgrade from the 37mm AA gun developed
for non ship use.
And yes the German naval AA mountings and fire controls were
overall better than the RN at the start of the war.
> I'm not trying to 'dump' on the British or RN but this is a case when
> a group of people got it wrong.
However "they got it wrong" will be repeated several times.
I do note the usual praise of the Germans, including what the
might/cloud have done, they were significantly ahead of the RN
in fire control in 1939. I do note however that nothing is actually
mentioned about the claimed superior Japanese and Italian systems.
> First of all the German computer systems were fully tachimetric:
> something which can't be said of the HACS in any way so the German
> systems produced a far better firing solution and they did so
> continuously.
Yes.
> Basically in the RN's HACS system an officer "the control officer"
> had to estimate the targets speed and feed it manually into the
> computer which then used the current position and the estimated speed
> to calculate a firing solution inclusive of the considerable dead time
> required to manually set the fuze and load the gun.
Actually read the HACS reference provided, the bit about most
larger ships used fuse setting machines?
> The HACS was
> incapable of calculating the speed directly using information from the
> director and optical range finders and apparently never gained this
> ability though it eventually gained this via the use of additional
> circuits added to radar when radar became available.
So let me understand this it never gained it but it gained it?
> It initially
> also lacked the ability to engage diving and maneuvering targets.
> Since the germans (ju 87 and ju 88) and Japanese were rather good at
> dive bombing this was a serious problem.
Actually the German dive bombers needed more practice to hit
moving ships and it took a while to figure it out. Things like
Gloucester and Fiji being sunk after they were out of main AA
ammunition indicate things were a little different to that being
claimed.
> It was designed to deal
> with level bombers. When microwave radar became available the radars
> circuits were finally able to provide this information automatically
> but not via the optical systems.
So the British jumped over optical and went straight to the
first "modern" systems, that is radar controlled. While
being able to take a good look at the state of the art in
heave AA fire control from the US and things like good
light AA mountings from the Dutch.
> In the German system the this
> velocity information however could be calculated from the optical
> systems; so the German Navy was closer in this regard to the USN's
> sophisticated system than to the HACS of the RN.
As expected the pre war ideas simply had no information on this
new radar thing and what it could do.
> You can read about HACS here:
http://www.navweaps.com/index_tech/tech-066.htm
It helps clear up the wrong claims being made.
> Secondly the German mounts, as far as larger ships are concerned,
> were aimed by remote power control direct from the predictor at least
> as far as elevation of the gun was concerned and the setting of the
> fuze which was automatic and direct from the predictor via a fuze
> setting mechanism adjacent to the gun breech. The round still had to
> be manually transfered into the gun at which point continuously
> running rollers pulled the round in.
Hey the Germans had a fuse setting machine beside their gun, just like
the RN ones. Though the RN ones look to be inferior.
> In all of the RN's systems this was done manually until the second
> half of the war when radar and electronics allowed a sort of partial
> bypass of these problematic systems since circuits added to the radars
> could give good position and rate information.
Try again, the RN had remote power control, its weight and cost
being a reason not to fit it to destroyers, as it would push up their
size, complexity and cost.
> In the RN's system
> the fuze delay time was set by a man with a spanner or by a fuze
> setting machine in which the delay was entered into the machine
> manually after having been read from guages. RPC was only added
> later to the RN's systems.
Note the man with a spanner line, it will be repeated because it
makes them sound so bad, you know like the Luftwaffe 88mm
fuse setting arrangement as of pre war.
> You can see an explanation of one of the german systems here:
> http://www.navweaps.com/Weapons/WNGER_41-65_skc33.htm
Limited RPC.
> http://www.navweaps.com/Weapons/WNGER_41-65_skc33_pics.htm
The above is pictures.
> http://dcoward.best.vwh.net/analog/ford.htm
The Ford URL is a US system.
> http://www.navweaps.com/index_tech/tech-013.htm
This above URL rather puts a dampener on the wonder German
electronics in the Prinz Eugen.
Yes the advertising for the Germans is in full swing, no Italians
or Japanese make the cut though.
The 1931 German AA fire control version required some 20 minutes
to spin up the main gyros, they were so big it was a dockyard job to
replace them, a counter to the advantage of them providing a good
artificial horizon.
The 1933 version came in at 40.4 tons, up from the 21 tons of
the 1931 version, the big gyro rotors coming in at 260 Kg each.
The director weight excludes the amplifiers and generators.
The 1937 version, for Bismarck, Tirpitz and Prinz Eugen eliminated
the big gyros but then needed 5 tons of ballast to maintain centre
of gravity, overall weight was dropped to 36 tons. (All metric tons).
A trouble with all the above designs was the gimbal rings forming
the gun angle converter also carried the weight of the director, which
was an obstacle to eliminating vibrations.
When it came to AA radar fire control the navy adopted the Luftwaffe's
Wurzburg system but this was too heavy for most ships. Tirpitz and
some of the AA ships were given sets.
> German electrical engineers and scientists had perfected an amplifying
> device called the 'magnetic amplifier' today refered to as a saturable
> reactor. This rugged device made possible the Fi.103/B1, A4/V2 and
> for the german navy remote power driven turrets free from the fear of
> thermionic vacuum tube failure.
Ah yes, we are pausing for the advertising break.
> The systems of the Prinz Eugen
> rather surprised the USN and untill the mid to late 1950s
> revolutionized power electronics until the event of solid state power
> electronics.
Actually what the USN looked at closely was the passive sonar
on board the cruiser, in particular things like wavelengths.
> Another unique aspect of the German systems was the
> large number of computers/directors which allowed the ships to engage
> a larger number of targets. Due to the restrictions of the Versailes
> treaty and the fear of war with Poland in the 1930s the Germans saw
> fire control as a manner of improving the odds.
The Bismarck class carried 6 directors for 8 AA turrets, the
Hippers 4 directors for 6 AA turrets.
The RN went with 4 directors for it main ships, 2 turrets per
director, the USN battleships also went with 4 directors.
Ark Royal and the Illustrious class actually had more main AA
directors than the standard US carrier.
> (The bismark had these systems but the front set of 4 turrets had been
> upgraded to a faster traversing design while the rear had not, when
> the Swordfish approached the Fire Control Systems did not take into
> account the slower traversing units, thus the swordfish got through
> the heavy FLAK at which point the inferior German medium 37mm let them
> through)
The idea the wild weather with its bad visibility had nothing to
do with the situation is remarkable. Bismarck was actually sailing
through a weather front when the second Swordfish strike tried
to attack, the aircraft were split up, sections attacking individually,
which should maximise AA effectiveness.
There was no saturation of the defences.
> The lack of Duel Purpose (eg 5 inch guns) on German capital ships
> which used sperate 6 inch (presumably to deal with the fear of on
> rushing destroyers) and 4 inch guns (for FLAK) shows I feel perhaps a
> doctrinal problem of immaturity from lack of experience but a fear of
> on rushing destroyers and saturation attacks that comes from expecting
> to be the numerically inferior force.
Or perhaps the same reason the RN went to the 5.25 inch gun for
its battleship secondary armament, the need for a shell to make a big
mess of any attacking destroyer meant 4 inch guns were simply too
light.
The one criticism of the USN 5 inch 38 was "lightness", when
dealing with ships, hence the idea of the USN 5 inch 51 calibre.
And as for Bismarck there is simply the way it was an updated
Baden class, with an AA suite added.
> Where the German navy fell behind was in high frequency radar or and
> something called 'lobe switching' which German officers had been
> offered in 1935 but had rejected.
Somehow the Germans always seem to do it but never actually use it.
> However around 1942/43 Telefunken
> engineers succeeded in a revolutionary improvements in powerful high
> frequency disk triodes able to produced high power outputs (50kw) in
> the 10-27cm range which while not in the league of the magnetron in
> high frequency was enough to aim guns by with modest antenna the final
> system allowed slaving of remotely power guns to the FuMO 231 Euklid
> fire control system intended for the Z55 class of destroyers that had
> very sophisticated AAA defenses.
What we have here is the Germans are allowed what they are supposed
to built past war as proof of german technology. The RN is restricted to
only the wartime systems it used.
In which case note the RN mark VI fire control, it just made WWII.
The Z55 class were a paper project. It will be interesting to see how
many of these revolutionary electronic devices made it into service.
The problem with radar fire control is the width of its beam, the
smaller the wavelength the smaller the width, and so the lower the
chance the radar is tracking a nearby aircraft, not the one the guns
are trying to shoot at. Of course larger antenna arrays can reduce
the beam width but that costs weight.
The 1944 USN mark 61 for the 40 mm projected the radar display
onto the sight's field of view to help solve this problem.
It should be noted the light AA directors did not have to be as
sophisticated as the main gun directors, the ranges were that
much shorter, errors mattered less and speed of solution was
important given the speed of the aircraft, so you could "cut
corners".
And of course it was things like proximity fuses that enabled
the heavy AA guns a real chance against rapidly closing aircraft.
> Smaller German ships lacked the the remote power control however the
> directors appear to have been fully tachimetric the problem with HACS
> was the lack of support for full velocity calculation and the rougher
> firing solution rather than the lack of remote power control for the
> guns in most early British Navy heavy AAA.
The German destroyers never mounted DP guns, pre war their
AA was four 37mm pieces. The Germans then went to the
5.9 inch gun as the destroyer armament.
It was not until the never completed Z46 class that the new
5.1 inch gun in twin DP mounts was projected as the main
armament, together with six improved 37 mm pieces and
eight 20mm guns.
Even the pre war torpedo boats, despite mounting the 4.1 inch
gun, restricted maximum elevation to 50 degrees.
> In my opinion the British Army was the Cinderella of the services:
> its 3.7 inch QF gun showed that a good job could be gun when the
> automatic fuze setter and power loader was added and latter remote
> power control. The Royal Navies radars were also based on the UK
> Armies AMES radars.
This is interesting, what ever happened to the RAF systems. The RN
and RAF were both experimenting with radar pre war. Then the
British hit a jackpot with the cavity magnetron.
> The RN simply seems to have gotten it wrong and then, having not
> cultivated the skills and manufacturing industry to make the control
> gear necessary found it difficult to improve its systems in the
> quantities required.
Of course this ignores the long development times involved in
actually creating sophisticated fire controls, and the fact that
not even the US had spare fire controls for the RN indicates
the manufacturing effort.
And of course the RN did improve the systems, more gyro controls
and of course radar which provided a short cut, given the size and
development time of any new mechanical computers. (Hint, the USN
mark 37 computer was so big it needed to be below decks, and this
made it hard to fit to older ships). The cavity magnetron meant
smaller radars, less weight, and narrower beams, good for fire
control.
The lack of heavy AA in the RN destroyers can be seen by the
decisions to mount twin 4 inch or single 4 inch AA guns on some
destroyers, as well as the experimental 4.7 inch mounting. See
the L, M, O and P classes. It was not until the S class the standard
RN 4.7 inch destroyer armament had 55 degree elevation.
Geoffrey Sinclair
Remove the nb for email.
ken...@cix.compulink.co.uk
<479e1106$0$9759$5a62...@per-qv1-newsreader-01.iinet.net.au>,
gsinc...@froggy.com.au (Geoffrey Sinclair) wrote:
> The 1931 German AA fire control version required some 20 minutes
> to spin up the main gyros,
Also there were roll and pitch limits. If the gimbals hit the ship
structure it took time to recover. Germany was the only nation I know of
to try and stabilise the entire director.
> It was not until the never completed Z46 class that the new
> 5.1 inch gun in twin DP mounts was projected as the main
> armament,
That was the existing 128mm Luftwaffe AA gun in new triaxial mountings.
The war ended before development was complete and any production
mountings built. Priority was low because the RN and RAF had made the KM
a wreck and the land situation was becoming critical anyway.
Ken Young
David Thornley
Geoffrey Sinclair <gsinc...@froggy.com.au> wrote:
><euno...@yahoo.com.au> wrote in message
>And you should note the elevation of the IJN Dual purpose 5 inch guns
>was 55 degrees in most pre war destroyers.
>
says that the destroyer 5" guns were too slow moving to be effective
as AA weapons.
Aside from the old flush-deckers and a couple of leader classes,
all US destroyers had usable dual-purpose main armament. British
destroyers also had sufficiently handy main guns, so the ones
that could elevate far enough were quite useful.
>> The systems of the Prinz Eugen
>> rather surprised the USN and untill the mid to late 1950s
>> revolutionized power electronics until the event of solid state power
>> electronics.
>
>Actually what the USN looked at closely was the passive sonar
>on board the cruiser, in particular things like wavelengths.
>
Not to mention trying to keep the engines going.
Not all German innovations worked well.
>> The lack of Duel Purpose (eg 5 inch guns) on German capital ships
>> which used sperate 6 inch (presumably to deal with the fear of on
>> rushing destroyers) and 4 inch guns (for FLAK) shows I feel perhaps a
>> doctrinal problem of immaturity from lack of experience but a fear of
>> on rushing destroyers and saturation attacks that comes from expecting
>> to be the numerically inferior force.
>
>Or perhaps the same reason the RN went to the 5.25 inch gun for
>its battleship secondary armament, the need for a shell to make a big
>mess of any attacking destroyer meant 4 inch guns were simply too
>light.
>
Unfortunately, the 5.25" was a disappointment as an AA gun, although
it might have been considerably improved in HMS Vanguard.
It turned out that the AA role was much more important than the
anti-destroyer role, and so it happened that the British backed
the wrong horse in this case.
>The one criticism of the USN 5 inch 38 was "lightness", when
>dealing with ships, hence the idea of the USN 5 inch 51 calibre.
I think you mean 54 caliber, easy to get confused with USN
5" guns. The 51 caliber was anti-surface, and used primarily
in the older battleships as anti-destroyer armament. The 54
wasn't used by the end of the war, and was dual-purpose. I
don't know how well it would have done as an AA gun.
>It was not until the never completed Z46 class that the new
>5.1 inch gun in twin DP mounts was projected as the main
>armament, together with six improved 37 mm pieces and
>eight 20mm guns.
>
That was a good gun, being the 12.8cm AA gun moved to a naval
setting.
The mounting was at least ambitious, which had potential for
good or bad things. The mounting is as important as the gun.
It's quite likely that cramped mountings played an important
role in slowing the ROF of the British 5.25" guns.
I dislike evaluating a weapon that was never actually built.
I never know what's going to come up in practice.
Therefore, I'm dubious about German dual-purpose destroyer
main guns. I know how the US ones worked (well). I know how
the Japanese ones worked (badly). I know how the British
ones worked (well), although not as widely used.
Since by that time the British would have been using the
quite serviceable dual-purpose 4.5" gun on all their destroyers,
it seems quite likely that the German weapon would have been
inferior.
>The lack of heavy AA in the RN destroyers can be seen by the
>decisions to mount twin 4 inch or single 4 inch AA guns on some
>destroyers, as well as the experimental 4.7 inch mounting. See
>the L, M, O and P classes. It was not until the S class the standard
>RN 4.7 inch destroyer armament had 55 degree elevation.
>
Late war RN destroyers had 4.5" guns, which worked well. Since
the discussion seems to be jumping all around the wartime years,
it seems only fair to mention the good stuff they wound up using.
--
David H. Thornley | If you want my opinion, ask.
da...@thornley.net | If you don't, flee.
http://www.thornley.net/~thornley/david/ | O-
ken...@cix.compulink.co.uk
<479e1106$0$9759$5a62...@per-qv1-newsreader-01.iinet.net.au>,
gsinc...@froggy.com.au (Geoffrey Sinclair) wrote:
> The USN began fitting the mark 51 director in mid 1942 about
> 6 months after the first twin bofors mounts had been made.
I missed this the first time round. The US Mk 51 director was a RN gyro
site with correction for gun displacement from line of sight. Like the
RN sights it relied on angular displacement until radar was added and
then there was the problem of making sure the sight and the radar were
tracking the same target.
OF course the credit for the Bofors should go to the British Army. That
was the first Allied force to adopt the Bofors and the first to use gyro
sights. However those sights were developed from ones intended from
fighters, US use was it seems restricted to bomb sights at the time. The
USN not only had the benefit of two years extra development time it also
got the benefits of reverse Lend Lease and a lot more industrial
capacity. The proximity fuse was a British invention built by Americans.
Ken Young
euno...@yahoo.com.au
wrote:
> <eunome...@yahoo.com.au> wrote in message
>
> news:6f78b388-e576-4c03...@j20g2000hsi.googlegroups.com...
>
> > On Jan 27, 6:29 am, ken...@cix.compulink.co.uk wrote:
> >> In article
> >> <0873a2aa-bd8b-41a9-8e51-6d9f9508d...@c23g2000hsa.googlegroups.com>,
>
> >> eunome...@yahoo.com.au () wrote:
> >> > In fact the RN AAA was the most retarded of any major
> >> > combatant.
>
> >> The RN was behind the USN with heavy AA but ahead in light AA at the
> >> start of the war.
>
> > The RN may have had better guns but it didn't not have better fire
> > control for light guns.
>
> The trouble here is of course that things changed over the course of the
> war and it seems the worst of the RN is being selected as the base
> comparison.
First of all several posters made the claim that the RN was behind the
USN but ahead of all of the Axis in AAA Fire Control.
This is most certainly not correct, especially for the German systems
and it seems the Japanese and the Italians systems were more thorough
in some areas and it can be plausibly argued were better as well.
Certainly that is the statement made by the author of this article.
http://www.navweaps.com/index_tech/tech-066.htm
The context (check my post) being the more sophisticated systems for
bigger guns HACS, Mk 37, the German Dop L32 mounts.
In terms of the Medium AAA my comparison was purely within the USN/
RN. The Germans having a good stabalised mount but with a 37mm gun
that had good ballistics and and power but very poor rate of fire.
Now, HACS or 'High Angle Control System' as opposed to the 'Low Angle
system' used against surface targets was a key system for RN ships
from destroyers to battle ships since it controlled destroyer main
armament and heavy ship secondary armament (i.e. anything in the range
4.0, 4.5, 4.7, 5.2) when used in the AAA role.
The RN was the largest or second largest navy.
The HACS was certainly the more primitive system out of the equivalent
German and American systems so it's a good "base" for comparison.
I also argue that Modifications really improve HACS as much as you
infer either, as I will explain. Perhaps deficiencies with HACS were
filled in by good medium AAA.
Looking at the German systems one can see that eventually they had
either 20mm or 105mm guns with little sophistication in between.
Consider the challenge of long range AAA and how HAACs worked.
First of all the bearing and range of the target needs to be known.
This is fairly easy using an optical sight and stereo optical or
coincidence range finder.
Secondly its velocity (speed and heading) needs to be ascertained so
that this can be used in conjunction with ballistics data to solve
simultaneous differential equations so that an firing solution
( intercept point) and fuze setting time is calculated. Since the
shell might be in flight for several seconds during which the aircraft
might move around 1.5km this velocity estimate needs to be
accurate.
This is where HACS was very poor, yes modifications with radar were
made but they corrected only one of the two core limitations. At
least the final limitation wasn't resolved till 1945.
With HACS speed and heading had to be 'estimated' rather than
calculated automatically as full 'tachyometry' of continuously
measuring bearing, elevation and range in respect of time and a stable
gyroscopic reference to derive velocity were not inplemented in HACS,
not doubt there were instruments and techniques to assist the HACS
control officer in doing this but it got down to an estimate and but
in practice it seems to have been impossible to keep track of the
velocity changes of WW2 aircraft. HACS kept track of the aircraft
using the estimated data in case the ship turned or the aircraft
passed into clouds.
The USN and Kriegsmarine systems were fully "Tachymetric" ie velocity
measuring not just position measuring. The RN HACS at the beginning
of the war seems to have lacked rate gyros so that as the ship turned
accurate angular rate measurements could therefore not be made. Yes it
was able to plot on a graph paper the target aircrafts calculated
bearing during ships manoeuvres using the velocity estimate that had
been manually entered while the aircraft became obscured by cloud but
that was only after the uncompensated speed 'estimate' had been made.
To repeat the system was unable to take speed measurements by simply
tracking the range and bearing of the target or to calculate them as
it lacked the compensating gyro rate reference to do this as well as
the calculating mechanisms.
Later GR (Gyro Rate) Units and GRUB (Gyro Rate Unit Boxes: quaint RN
talk for the associated basic computer) were added. These took
inputs from the optical sight and combined it with range readings from
the 50cm wavelength type 285 radar that were semiautmatically entered
into the system to calculate speed and heading. (note the type 285
radar couldn't track the target it could only range it so optical
tracking was still necessary. The HAACS system still was unable to
automatically integrate optical range measurements into the GR/GRUB
though the use of radar range measurements bypassed this need in most
cases.
The lack of pure optical tachyometry probably would be a problem in
the case of effective jamming or littoral clutter or during amphibious
support.
Now there is another problem not dealt with by the 285 Radar and GR
Units/GRUB which now could calculate speed and the radar apart from
the fact that an all optical solution was not possible and this is
that the HACS and its new GRUB still can't directly calculate and
track height changes, the whole core system wasn't designed to do
that. In effect it could be said that HACS was 2 dimensional instead
of 3 dimensional system.
So this vertical dimension is where the 'fully tachymetric' US and
German systems are still ahead and it seems even the Italian and
Japanese ones as well.
It seems that it was 1944 or 1945 that some ships (one Ibelieve) with
HACS had the type 275 microwave track locking radar added to replace
the range only 285 50cm unit and this is what finally allowed a
complete solution.
Note the problem with HACS has nothing to do so far with the lack of
Remote Power Control for pointing of the guns directly or automatic
fuze setting machines. That's another problem area.
>
> Anyway so now it seems we have RN better guns but lacked
> the fire control for light guns, so I presume the better guns are
> the light stuff only.
The best british light weapon would have been the 40mm 2 pdr 'pom pom'
on a power driven quad or octouple mount. This weapon had a heavy
projectile but very low muzzle velocity of 650m/s that made it short
ranged and inaccurate at ranges neccesary to deter an attacker.
Remote power control didn't appear till mid 1943 and gyro sights till
1945 while higher muzzle velocity version with new amunition were also
introduced late war. Prior to this aiming appears to have been by the
estimated deflection being entered manually into the gunner sighting
system. The round lacked a tracer so it could not easily be aimed.
The standard US weapon was the 1.1 inch 28mm gun which had a high
muzzle velocity and came in quad mounts that were remote power driven
and aimed remotely by a 'dummy sight' ie a sight without any computing
capability or gyros. The gun had a good muzzle velocity of around
900m/s but fired a low rate (the quad mount was chosen to match the
0.5 calibre browning in cadence) and the projectile was considered a
little light.
In other words both the USN's and the RN's light AAA was considered to
have serious deficiencies.
>
> > The latter matters more I think.
>
> Good, then you would know the RN had fire control for their light
> AA pieces before the USN, since the idea of the multiple 2 pounder
> was to justify the cost of the control.
I question that widely made claim about the pom pom as I see little
evidence of particualry wide deployment or sophistication of the 2
pounder pom pom system. The sighting arrangments were quite crude.
It also somewhat irrelevant to the 'war'; the US Mk 51 fire control
system for the 40mm bofors, which incorporated the K14 gyro site was
in mass production and widely equipping ships before perl harbour and
the US entry into war. The Charles Stark Draper developed k14 gyro
sight on its own was used to equip 20mm canon and other small mounts
(eg the 1.1 inch gun) when supplies of compressed air (for gyro spin)
and electrical power made this possible. Gryo sights on their own are
really hard to use: you have to keep track of the range by a
stediometric range finder (enclosing the aircrafts known dialled in
wing span) while simultaneously tracking the recticle that moves
around to display the correct ofset. At least with the Mk51 the lead
angle was added in by the computer to the guns rather than the gunner
having to deflect the site with the complete gun.
I also doesn't seem that the pom pom gun in its quad mount and or its
fire control was all that effective or ahead of the US systems at the
beginning of the war. The US systems were RPC albeit with a dummy non
computing sight.
I would like to know what this advance fire control system that was in
service in 1940-1942 actually was.
http://en.wikipedia.org/wiki/QF_2_pounder_naval_gun
"An advanced weapon when introduced, by the outbreak of World War II
advances in aircraft had effectively made it obsolete. It was intended
that the curtain of fire it threw up would be sufficient to deter
attacking aircraft but lack of a suitable tracer round meant that the
barrage was unseen and so the deterrence factor was prevented from
being effective. It had a low velocity due to the relatively short
barrel and small charge, the fuse mechanism was unsatisfactory, the
weapons were extremely complex and prone to jamming, and the mountings
were enormously heavy and complicated and could not be produced
quickly enough or fitted widely enough. When HMS Prince of Wales was
attacked and sunk by Japanese aircraft near Singapore the subsequent
report judged that the single 40 mm Bofors gun, mounted on the
quarterdeck, had been a more effective anti-aircraft weapon than the
entire battery of multiple pom-pom mounts. Nevertheless, it was a
ubiquitous weapon that was never entirely displaced by the Bofors gun
during World War II. Later innovations such as remote power control
(RPC) coupled to an effective radar-equipped tachymetric (speed
predicting) director increased the accuracy enormously, and problems
with the fuses and reliability were also addressed. The single
mountings received a reprieve towards the end of the war, as the 20 mm
Oerlikon guns had insufficient stopping power to counter Japanese
Kamikaze aircraft and there were insufficient numbers of Bofors guns
to go round."
So the advanced light AA was unable to do much for HMS "Prince of
Wales" presumably because it wasn't advanced enough to make a
difference.
>
> > In both
> > cases the RN and USN gravitated towards the Bofors 40mm. It's true
> > that the RNs 2-pdr [4 cm/39 (1.575")] Mark VIII was superior to the
> > US 1.1 inch gun but the US moved rapidly and more thorougly to the
> > 40mm Bofors pointed by the Mk 51 FCS (fire control system) complete
> > with remote power control.
>
> So by the end of the war the US had the better light AA fire control,
> after being behind for the period 1939 to 1942, when the US began
> adopting the 40mm and associated fire control. With the USN always
> being ahead for heavy AA fire control.
I would say by the beginning of US involvement in the war in December
1942 its own light/medium AA was ahead of everyone's as well. Its
legacy 1.1 inch guns were maybe a bit weak but even they were upgraded
with gyro sights.
In the period 1939-42 it might be argued that the RN's medium AAA was
better but does that matter since although at that time the pom poms
were better but still inadequate for anything but a biplane torpedo
bomber itself. It's like saying a morris minor is ahead of a model T
ford for requirements of Indianapolis racing.
The 1.1 inch gun doesn't sound a soft touch either.
>
> The USN began fitting the mark 51 director in mid 1942 about
> 6 months after the first twin bofors mounts had been made.
>
> >> The RN was probably ahead of Germany, Italy and Japan
>
> > Nope the RN was well behind the German Navy which actually had quite
> > good systems available and also behind Japan and Italy. Not until the
> > introduction of radar did the gap begin to close.
>
> This is quite funny really.
I can hear you tittering. the fact however is that the HACS was well
behined the German systems at the start of the war.
>
> IJN the type 94 fire control has all the nice descriptions, tachymetric,
> triaxial director and a resolver for deck tilt, solutions could be given
> for non level flight from the computer in the transmitting station. The
> trouble was the computer took too long to come up with a solution.
> The system was modified to basically do some initial by eye shooting
> to at least provide some opposition.
>
> The poor performance at Midway meant some modifications had
> to be made, but no better system was developed during the war.
So, no doubt modifications eventually allowed faster calcuation of
target aircrafts velocity.
>
> And some IJN ships, including the Haruna had the older type 91,
> which was inferior to the type 94.
The advanced state of the Japanese navy and its size at the beginning
of the war and its failure to then maintain and keep pace with
developments is well known. There was a lot of old 'crap' in the RN
as well.
So the Type 94 had problems dealing with fast aircraft as did HACS, at
least it dealt with the full range of manovers. HACS continued to
require manual spoofing to cope with diving targets as well in this
case to overcome not a lack of computer speed but the lack of
provision of the basic mechanisms to begin with.
Presumably the Japanese attempted to address the 'speed issue'. The
challenge for the Japanese engineers and trades people was keeping
enough from being drafted.
>
> The above for the heavy AA, the IJN used the French Navy Le Prieur
> sights for light AA, along with the Ward Leonard remote power system
> for the triple 25mm guns. Production difficulties lead to the abandonment
> of the remote power option.
>
> And you should note the elevation of the IJN Dual purpose 5 inch guns
> was 55 degrees in most pre war destroyers.
Just over 40 degrees for the early RN systems, 80 or 85 degrees for
the better German systems, which weren't usually considered DP (except
on the Prinz Eugen where the 105MM flak was effectively DP) but
dedicated FLAK.
German destroyers tended to be larger than their British counterparts
and probably could afford to carry more FLAK.
>
> Italian AA had the same problem, as the Japanese, slow resolution of the
> data, and did not have gyrosights and so on for the light AA guns.
>
> >> in naval AA. Besides you seem to be comparing RN AA in 1938 or so with
> >> the USN in 1945.
>
> > No, I'm not.
>
> You are the one who is talking light AA above, now we jump back
> to the heavy AA
My context was the expensive FCS for heavy AA, note I'm talking
about RN HACS vs USN Mk 37 and 5 inch DP and the equivalent German
systems.
>
> >the US 5 inch mounts and its associated tachymetric
> > fire control system has a history going back to 1932 when development
> > of the Sperry Mk 1 computer was begun as part of the Mk 37 fire
> > control system for the 5"/38 DP mount about the same time the RN was
> > developing the HACS.
>
> Like the fact the RN had HACS in service before 1932 you mean?
Ok, but the US contempoaries to the UK's HACS ; in other words the
'range keeping' precurors to the Mk 37 were already tachymetric,
though not able to deal with diving aircraft.
SNIP
>
> The mark 37, the ship borne gold standard of heavy AA for WWII
> did its tests in 1939. Those two extra years of peace made a big
> difference to the standards the USN could adopt in WWII, coupled
> with the combat reports it received.
Prior to the Mark 37 FCS with its Mk 1A computer the US already had
some tachometric FCS systems for heavy AAA so much of the
infrastructure such as AC power etc was already in place. Likewise
the infrastructure as measured by human knowledge base, specialist
engineers, technicians, craftsmen had been built up by the prior
efforts likewise for provision of the necccesary services such as AC
power as well as actually having room in the turrets for the necessary
equipement.
There is actually an intelligent and insightful question to ask: why
did the RN get stuck with HACS which is being obscured by your frantic
desire to prove my anti British but pro German (and pro American
bias.)
The reality is that the RN grossly underestimated what would be needed
to deal with modern aircraft and paid a price for it.
>
> > The RN almost certainly had the worst AAA systems of any of the
> > combatants at the start of the war: worse than US, German, Italian
> > and Japanese and never really solved all their its problems until 1945
> > since the existing systems were resistant to modification since they
> > had been designed on the incorrect premises.
>
> So the idea is the RN was inferior to the IJN and RM in both heavy
> and light AA systems for the entire war, or will we have more switching
> between heavy AA and light AA to suit the comparisons.
I switched to light AAA only in response to another poster. RN light
AAA is normally lauded.
>
> It will be interesting to see what the superior IJN and RM systems
> look like.
The Japanese had superior optics to any othe combatent. Specialist
machinary is an Italian Forte' I would not be suprised if they
produced a competent result in fire control.
>
> > The German navy was
> > second behind the US and certainly well ahead in regards to the
> > sophistication of its AAA systems on its larger ships though a few
> > errors such as using open mounts meant that the sophisticated control
> > gear was compromised by sea water ingress far to frequently.
>
> Take a look at how the German Naval 37mm gun worked at the
> start of the war, nothing like a single shot light AA weapon. This
> rather compromised the effort into making the better fire controls.
> They needed an upgrade from the 37mm AA gun developed
> for non ship use.
I have not problem with acknowleging the poor rate of fire of the
German 37mm gun.. The German naval single shot 37mm gun was the
German disaster as it was another factor that may have cost the
Bismark. A good powerfull round with good ballistics in a reliable
weapon that however had to be individually loaded and so could only
fire 30 rpm. It was on a gyro stabilised mount.
>
> And yes the German naval AA mountings and fire controls were
> overall better than the RN at the start of the war.
The core HACS "may" I emphasise "may" have improved ahead of the
German systems by the end of the war as the RN was able to integrate
radar with add on gyros to sort of automatically spoof the limted core
system to bypass one of its two shortcomings. If we include what
radar made possible then this is more certain to be true.
However German system were fully tachymetric to start with:- it should
have been relatively easy for them to inject the range data from their
Hohtenweil or late model Seetakt radars in lieu of the optical range
finder thus achieving the same effect as HACS (no GR or GRUB ie
Gyro's needed to be added as thety were already integrated.)
Photographs show FuMO 26 antena on the Prinz Eugen with a height
finding antena added to the directors radar.
I have no source of whether this is indeed what was done, but it is
highly plausible as the radar was warning of airborn threats and
providing range and bearing information.
>
> > I'm not trying to 'dump' on the British or RN but this is a case when
> > a group of people got it wrong.
>
> However "they got it wrong" will be repeated several times.
Yep, that's simply part of prosecuting an argument: you argue the
point from several perspectives to cover all bases. Its not a sign of
excess bias just thoroughness.
That is the point of this subthread and the consensus. There were no
doubt individuals within the RN raising alarm bells but they were
unable to push through their point and were simply ignored.
>
> I do note the usual praise of the Germans, including what the
> might/cloud have done, they were significantly ahead of the RN
> in fire control in 1939. I do note however that nothing is actually
> mentioned about the claimed superior Japanese and Italian systems.
At least two posters in this thread made the erroneous claim that the
RN was ahead of all of the axis in naval fire controls, the context
clearly being the sophisticated and expensive fire controls required
for effective heavy AAA. That is simply an in correct belief with a
wide body of writing pointing to the limitation assumptions and
therefore primitive nature of HACS and the legacy it left those trying
to make it work against modern ww2 aggressor aircraft.
It seems in your characteristically reflexive defence of a British
cock-up you would have me not argue my point to satisfy your
preferences.
My WW2 topic might be German electronics but it is not a bias in
argument but a bias in focus; specialisation. The problem with being
a 'pro' or 'anti' person is that it makes for poor understanding of
history.
>
> > First of all the German computer systems were fully tachymetric:
> > something which can't be said of the HACS in any way so the German
> > systems produced a far better firing solution and they did so
> > continuously.
>
> Yes.
OK, so we have that in agreement, for early war HACS at least.
>
> > Basically in the RN's HACS system an officer "the control officer"
> > had to estimate the targets speed and feed it manually into the
> > computer which then used the current position and the estimated speed
> > to calculate a firing solution inclusive of the considerable dead time
> > required to manually set the fuze and load the gun.
>
> Actually read the HACS reference provided, the bit about most
> larger ships used fuse setting machines?
There are two types of fuze setting machines: those that are manual in
which a human reads a gauge from the FCS and then manualy adjusts a
dial accordingly which then sets the fuze or those that are automatic
in which the fuze mechanism is set directly from the predictors
output.
I read that the fuze setting machines in the RN capital ships were
manual and separate from any power loading device.
The ideal placement of the fuze setting machine was as an integral
part of a power feeding system. I know of only 3 guns that achieved
this; the US 90mm, the German 128mm FLAK 40 and the latter versions
of UK 3.7 inch from the Mk 3a onwards.
The US twin 5"/38 incorporated automatic fuze setting into the
munitions hoist so that the rounds fuze could be set and power ramed
moments after release.
>
> > The HACS was
> > incapable of calculating the speed directly using information from the
> > director and optical range finders and apparently never gained this
> > ability though it eventually gained this via the use of additional
> > circuits added to radar when radar became available.
>
> So let me understand this it never gained it but it gained it?
It never gained the ability to calculate velocity by optical means
alone; that's actually clear from my sentence.
It sounds like what happened is that when the GRUBs were added they
calculated the velocity of the target using a hybrid optical-radar
system referenced to gyroscopes that compensated for turning of the
ship and then entered it where the control officer used to put his
manual estimate.
Now the HACS is getting accurate and timely velocity information from
the type 285 & GRUB in the horizontal plane and tracking it but it
was not set up to handle the vertical plane ie height changes.
AFAIKT the Germans mainly attacked ships with torpedo bombers or dive
bombers or slant bombers. Level bombers were only used with guided
weapons at least in the latter stages of the war.
>
> > It initially
> > also lacked the ability to engage diving and maneuvering targets.
> > Since the germans (ju 87 and ju 88) and Japanese were rather good at
> > dive bombing this was a serious problem.
>
> Actually the German dive bombers needed more practice to hit
> moving ships and it took a while to figure it out. Things like
> Gloucester and Fiji being sunk after they were out of main AA
> ammunition indicate things were a little different to that being
> claimed.
Between 21st May and 1st June 1941, during the battle and evacuation
of Crete, the Royal Navy suffered 3 Cruisers and 6 Destroyers sunk, 1
Carrier, 2 Battleships, 5 Cruisers and 5 Destroyers damaged, out of
the 1 Carrier, 4 Battleships, 10 Cruisers and 30 Destroyers deployed.
So the losses are altogether 11 out of 30 destroyers, 8 out 10
Cruisers, 2 out of 4 BBs, 1 out of 1 CA were neutrilized (sank or
damaged) in about a week by the LW... admitedly, with not much
opposition from the air.
And we are talking about a single Fliegerkorps, not 3 entire
Luftflotten, as during the Battle of Britian.
Fiji incidently was effectively sunk by a lone Me 109 which dove out
of clouds and delivered a direct hit.
>
> > It was designed to deal
> > with level bombers. When microwave radar became available the radars
> > circuits were finally able to provide this information automatically
> > but not via the optical systems.
>
> So the British jumped over optical and went straight to the
> first "modern" systems, that is radar controlled.
Not quite, they substituted radar range measurement for the lack
backup facilities for using stereoscopic range and rate measurment and
added gyroscopes and computers to establish the level speed of the
aircraft.
Optical sighting was still necessary. In the case of diving aircraft
individual aimed shots were no longer possible and barrage fire had to
be used. That lone Me 109 still stood a chance.
HACS was still not tachymetric and still had lmitations.
SNIP
>
> > You can read about HACS here:
>
> http://www.navweaps.com/index_tech/tech-066.htm
>
> It helps clear up the wrong claims being made.
What wrong claims?
Basically HACS was limited till 1945 irrespcetive of whether it had
the 285 50cm radar integrated or not. When the type 275 centric
radar replaced the 285 decometric set it seems to have been 1945 or
late 1944 in limited FKC form and essentially bypassed what was left
of HACS.
By this time the German Navy had ordered about 150 FuMO 231 track
locking radars to direct their guns, this was more or less a 50% scale
Manheim radar it had a 1.5m diameter dish and opperated at 27cm
intially, 3cm later. One was installed on a German destroyer that
never left the docks.
>
> > Secondly the German mounts, as far as larger ships are concerned,
> > were aimed by remote power control direct from the predictor at least
> > as far as elevation of the gun was concerned and the setting of the
> > fuze which was automatic and direct from the predictor via a fuze
> > setting mechanism adjacent to the gun breech. The round still had to
> > be manually transfered into the gun at which point continuously
> > running rollers pulled the round in.
>
> Hey the Germans had a fuse setting machine beside their gun, just like
> the RN ones. Though the RN ones look to be inferior.
Fuze setting machines need to be fast inoder to deal with close,
manouvering targets. The requirement is relaxed when dealing with
level bombers which is what the 88mm land based FLAK 37 could afford
to do; you know level bombers like B-17 and Lancasters were its
primary target.
>
> > In all of the RN's systems this was done manually until the second
> > half of the war when radar and electronics allowed a sort of partial
> > bypass of these problematic systems since circuits added to the radars
> > could give good position and rate information.
>
> Try again, the RN had remote power control, its weight and cost
> being a reason not to fit it to destroyers, as it would push up their
> size, complexity and cost.
Lack of RPC was however not the main issue, lack of tachyometry was.
>
> > In the RN's system
> > the fuze delay time was set by a man with a spanner or by a fuze
> > setting machine in which the delay was entered into the machine
> > manually after having been read from guages. RPC was only added
> > later to the RN's systems.
>
> Note the man with a spanner line, it will be repeated because it
> makes them sound so bad, you know like the Luftwaffe 88mm
> fuse setting arrangement as of pre war.
The reality remains that a man with a spanner set the fuzes on British
destroyers, unlike in the American system.
Remember this started out as a comparison between British and US ship
building efficiency.
Now, as you bringing up the pre war FLAK 18 (early 88mm.) : Fuze
setting machines need to be fast inoder to deal with close,
manouvering targets that ships face.
The German ground based FLAK guns performed a different job to that of
a naval gun; they could truely afford to be specialised in high
altitude level bombers becuase that's how Lancaster and B-17's
attacked. This is not the situation for ships AA defences on a
ship. Nor did they need a stable gyroscopic reference.
Having said that; the German gound based predictors did not have the
limitations of the HACS even if the 88 gun whether FLAK 18 or upgraded
FLAK 36 or FLAK 37 were manually trained.
>
> > You can see an explanation of one of the german systems here:
> >http://www.navweaps.com/Weapons/WNGER_41-65_skc33.htm
>
> Limited RPC.
This is what "Limited RPC" means. Automatic remote power control was
applied to
1 elevation of the gun, which would need to change rapidly in oder to
accomodate to fast approaching targets with the setting passed
directly from the FLAK director.
2 Automatic triaxial stabalisation of the gun directly from gyroscopes
and compass i.e stabalisation of elevation, cross leveling and taverse
were all remote power driven
3 fuze setting from predictor.
The traverse of the gun was power driven but NOT linked diretly to the
predictor but note that gyrostablisation was applied to the traverse.
RPC on the traverse did not contribut much as the other angles were
the more serious contraints. Gunners merely used the 'match the dial'
method but did not have to worry about ships movements or cranking and
handle.
The alternative to gyrostabalisation was to have a man peering at the
horizon through a sight whose job it was to either act as a gyroscope
by keeping fixed to the horrison or fire the guns at the peak or crest
of the waves.
>
> >http://www.navweaps.com/Weapons/WNGER_41-65_skc33_pics.htm
>
> The above is pictures
Yes, you can see the auto loaders and the fuze setting machines
>
> >http://dcoward.best.vwh.net/analog/ford.htm
>
> The Ford URL is a US system.
>
> >http://www.navweaps.com/index_tech/tech-013.htm
>
> This above URL rather puts a dampener on the wonder German
> electronics in the Prinz Eugen.
It does no such thing, anywhere.
It notes that the US had superior radar systems by the end of the war.
By the end of the war the German technology was catching up after its
neglect of the high frequency radar field.
Optivally in terms of sights, range finders, stabalized optics,
computing accuracy the German systems were first rate.
They had superior night vision optics and range finders and even had
passive infrared systems on their capital ships.
As I pointed out about 150 x FuMO 231 Euklid radar lock directors
had been ordered and delivery was starting. So it can be said that
both the Germans and British were behined the US untill 1945 when
the British started to catch up with the type 275 radar while the
Germans
were introducing the Euklid FuMO 231 running a few months behined the
British. An academic exercise due to the end of the war approaching.
The German Seetakt radar (13kW) however was behined the British 274
and 275 radar
(25kW and later 125kW) in transimission power which meant that the
British radar consistently picked
up the German opponent first even though both were limited by the
horizon.
The Germans company GEMA raised power to 125kW and 400kW but far to
late to
see service at sea, only on land.
>
> Yes the advertising for the Germans is in full swing, no Italians
> or Japanese make the cut though.
The Italians were out of action by 1943 so comparison isn't possible.
The Japanese I rather suspect improved their gear.
>
> The 1931 German AA fire control version required some 20 minutes
> to spin up the main gyros, they were so big it was a dockyard job to
> replace them, a counter to the advantage of them providing a good
> artificial horizon.
It's not a good counter.
The value of the FCS is that despite its weight it dramatically
improves the effectiveness of the ships armament by making its fire
accurate.
>
> The 1933 version came in at 40.4 tons, up from the 21 tons of
> the 1931 version, the big gyro rotors coming in at 260 Kg each.
> The director weight excludes the amplifiers and generators.
>
> The 1937 version, for Bismarck, Tirpitz and Prinz Eugen eliminated
> the big gyros but then needed 5 tons of ballast to maintain centre
> of gravity, overall weight was dropped to 36 tons. (All metric tons).
>
> A trouble with all the above designs was the gimbal rings forming
> the gun angle converter also carried the weight of the director, which
> was an obstacle to eliminating vibrations.
You appear to be refering to the main directors of capital ships.
The gunnery they produced
was accurate enough: Scharnhorst achieved the longest recodered hit at
26,000 yards using this
technology despite the possibility that the whole director had the
pickoffs mounted on the massive gimballs.
There was plently of respect for the German cruisers abilities to
achieve hits when their optical systems
could be used.
>
> When it came to AA radar fire control the navy adopted the Luftwaffe's
> Wurzburg system but this was too heavy for most ships. Tirpitz and
> some of the AA ships were given sets.
They presumably used optical aiming with radar ranging using the
Seetakt style FuMO 26 and FuMO 27; this didn't require a Wurzburg or
Manheim radar which were both full gunlaying radars and could track a
target in 3 dimensions and pass data directly to the predictor, the
Mannheim even having a track lock function.
>
> > German electrical engineers and scientists had perfected an amplifying
> > device called the 'magnetic amplifier' today refered to as a saturable
> > reactor. This rugged device made possible the Fi.103/B1, A4/V2 and
> > for the german navy remote power driven turrets free from the fear of
> > thermionic vacuum tube failure.
>
> Ah yes, we are pausing for the advertising break.
It's a matter of historical fact that the servo technology developed
in Germany was appreciated and used by the allies post war: untill the
development of transitors in the mid 1950s and early 1960s the
magnetic amplifier was the only solid state device around. It made
possible large gyro stabalised missiles and was used throughout the
USN post war and turned up in such things as the B-47 tail turret.
>
> > The systems of the Prinz Eugen
> > rather surprised the USN and untill the mid to late 1950s
> > revolutionized power electronics until the event of solid state power
> > electronics.
>
> Actually what the USN looked at closely was the passive sonar
> on board the cruiser, in particular things like wavelengths.
And the magnetic amplifiers.
>
> > Another unique aspect of the German systems was the
> > large number of computers/directors which allowed the ships to engage
> > a larger number of targets. Due to the restrictions of the Versailes
> > treaty and the fear of war with Poland in the 1930s the Germans saw
> > fire control as a manner of improving the odds.
>
> The Bismarck class carried 6 directors for 8 AA turrets, the
> Hippers 4 directors for 6 AA turrets.
Indicating a well founded fear of saturation attacks.
>
> The RN went with 4 directors for it main ships, 2 turrets per
> director, the USN battleships also went with 4 directors.
> Ark Royal and the Illustrious class actually had more main AA
> directors than the standard US carrier.
>
> > (The bismark had these systems but the front set of 4 turrets had been
> > upgraded to a faster traversing design while the rear had not, when
> > the Swordfish approached the Fire Control Systems did not take into
> > account the slower traversing units, thus the swordfish got through
> > the heavy FLAK at which point the inferior German medium 37mm let them
> > through)
>
> The idea the wild weather with its bad visibility had nothing to
> do with the situation is remarkable. Bismarck was actually sailing
> through a weather front when the second Swordfish strike tried
> to attack, the aircraft were split up, sections attacking individually,
> which should maximise AA effectiveness.
>
> There was no saturation of the defences.
There was a dispersal of the defences and the approach was from where
the guns
had not been properly set up to use the directors.
>
> > The lack of Duel Purpose (eg 5 inch guns) on German capital ships
> > which used sperate 6 inch (presumably to deal with the fear of on
> > rushing destroyers) and 4 inch guns (for FLAK) shows I feel perhaps a
> > doctrinal problem of immaturity from lack of experience but a fear of
> > on rushing destroyers and saturation attacks that comes from expecting
> > to be the numerically inferior force.
>
> Or perhaps the same reason the RN went to the 5.25 inch gun for
> its battleship secondary armament, the need for a shell to make a big
> mess of any attacking destroyer meant 4 inch guns were simply too
> light.
The Germans went for 150mm guns in order to try and gain an advantage;
also because Polish destroyers had been exceding treaty calibres with
the use of 135mm or 140mm guns.
The Narvick class destroyers 6 inch 150mm guns had sufficient
elevation for them to be used in the FLAK role.
>
> The one criticism of the USN 5 inch 38 was "lightness", when
> dealing with ships, hence the idea of the USN 5 inch 51 calibre.
>
> And as for Bismarck there is simply the way it was an updated
> Baden class, with an AA suite added.
The myth, normally repeated with the claimed 'fact' that the German
battleships had their FCS above the armour belt has been dismissed by
examination of the wrekage of the Bismark.
See http://en.wikipedia.org/wiki/German_battleship_Bismarck, the ship
was far more than a 'Baden' class and its armour appears to have not
failed despite the lack of the 'all or nothing' armour concept.
>
> > Where the German navy fell behind was in high frequency radar or and
> > something called 'lobe switching' which German officers had been
> > offered in 1935 but had rejected.
>
> Somehow the Germans always seem to do it but never actually use it.
In this case they did and could have done it much earlier.
Lobe switching was demonstated in 1935 at GEMA and incorporated as a
retrofittable item to GEMA's Seetakt radars delivered to the Germany
Navy. It was incorporated into GEMA's Freya radars delivered to the
Luftwaffe as well as Lichtenstein radars. It was a stodgy procurment
decision only by the German Navy. Fritz Trenke, a German WW2 radar
expert, describes it being incorporated from 1940 so maybe the it was
only lower radar power that put the German ships at an disadvantage.
Doctrinally the German navy believed that radar would disclose the
position of a ship and should only be used for ranging in combat or as
a navigation aid. Night vision optics and passive infrared imaging
and ranging systems were thus developed and deployed. Of course
radar outperformed the optical systems at night and in bad weather.
The PPI version of Hohtenweil could also use lobe switching and
despite its 53cm wavelenght could still find a life raft or a
periscope.
> > However around 1942/43 Telefunken
> > engineers succeeded in a revolutionary improvements in powerful high
> > frequency disk triodes able to produced high power outputs (50kw) in
> > the 10-27cm range which while not in the league of the magnetron in
> > high frequency was enough to aim guns by with modest antenna the final
> > system allowed slaving of remotely power guns to the FuMO 231 Euklid
> > fire control system intended for the Z55 class of destroyers that had
> > very sophisticated AAA defenses.
>
> What we have here is the Germans are allowed what they are supposed
> to built past war as proof of german technology. The RN is restricted to
> only the wartime systems it used.
Early 1945 the RN introduces track locking AAA radar. Around the
same time the German start production of the same thing. A few months
lag in serive intorduction at most. It was 1943 before even a PPI
centrimentric set became available to the convoy escorts and british
warships.
The USN was clearly ahead. The RN not so much at all.
>
> In which case note the RN mark VI fire control, it just made WWII.
>
> The Z55 class were a paper project. It will be interesting to see how
> many of these revolutionary electronic devices made it into service.
They were being fitted out in the docks. They were not a paper
project. Euklid had been built, tested and production had started
and one seems to have been fitted.
The guns were proably similar to the FLAK 40 with power drawn in and
intergral fuze setting. At 5 inches/127mm and 45 calibres it was
proably more powerfull than the US 5"/38 and had a better fuze setting
mechanism.
You can see the round in the fuze setter here:
http://www.missing-lynx.com/library/german/flakarticle_dmouritzsen12.jpg
It shows a shell in the fuze setter ready to be flipped into the
ramming position.
Note the use of single piece amunition as oppsed to the seperate
propellent cartridge.
>
> The problem with radar fire control is the width of its beam, the
> smaller the wavelength the smaller the width, and so the lower the
> chance the radar is tracking a nearby aircraft, not the one the guns
> are trying to shoot at. Of course larger antenna arrays can reduce
> the beam width but that costs weight.
Indeed, though the problems of tracking and acquistion with a narrow
beam introduces new issues that were intially hard to solve.
>
> The 1944 USN mark 61 for the 40 mm projected the radar display
> onto the sight's field of view to help solve this problem.
I believe it entered service in 1944.
>
> It should be noted the light AA directors did not have to be as
> sophisticated as the main gun directors, the ranges were that
> much shorter, errors mattered less and speed of solution was
> important given the speed of the aircraft, so you could "cut
> corners".
Actually I think that 'cutting corners' was a result of the technolgy
to produce a miniturised fcs was just not there yet.
The B-29 had a better FCS then most naval guns.
>
> And of course it was things like proximity fuses that enabled
> the heavy AA guns a real chance against rapidly closing aircraft.
Even without proximity fuzes radar proper radar directed (M9 director
and SCR584) gun fire was quite effective. FuMO 231 would have also
produced a big increase in effectiveness.
Note during the Anzio landings in 1943 the Germans effectively jamed
the US armies SCR-284gun director radars with noise jamming and duppel
(window) and the SCR 584microwave radar had to be rushed.
>
> > Smaller German ships lacked the the remote power control however the
> > directors appear to have been fully tachimetric the problem with HACS
> > was the lack of support for full velocity calculation and the rougher
> > firing solution rather than the lack of remote power control for the
> > guns in most early British Navy heavy AAA.
>
> The German destroyers never mounted DP guns, pre war their
> AA was four 37mm pieces. The Germans then went to the
> 5.9 inch gun as the destroyer armament.
The 5.9 inch guns of the Narvik class had a resonable high elevation
capability, enough to be used a FLAK
>
> It was not until the never completed Z46 class that the new
> 5.1 inch gun in twin DP mounts was projected as the main
> armament, together with six improved 37 mm pieces and
> eight 20mm guns.
The intention was that EUKLID FuMO 231 director would be used and the
37mm pieces would have been replaced by the 5.5cm Garaet 58 'one hit
to kill' weapon while the 2.0cm pieces would be replaced by 30mm guns
based on the Luftwaffes Mk 103. A gun with much higher cadence, throw
weight and better ballistics than the quadvierling.
>
> Even the pre war torpedo boats, despite mounting the 4.1 inch
> gun, restricted maximum elevation to 50 degrees.
>
> > In my opinion the British Army was the Cinderella of the services:
> > its 3.7 inch QF gun showed that a good job could be gun when the
> > automatic fuze setter and power loader was added and latter remote
> > power control. The Royal Navies radars were also based on the UK
> > Armies AMES radars.
>
> This is interesting, what ever happened to the RAF systems. The RN
> and RAF were both experimenting with radar pre war.
The good stuff, pre microwave, came out of the Armies 50cm work AMES
radars this includes chain home low and the Type 284 and 285.
> Then the
> British hit a jackpot with the cavity magnetron.
Indeed, luckily for them someone recognised its value.
>
> > The RN simply seems to have gotten it wrong and then, having not
> > cultivated the skills and manufacturing industry to make the control
> > gear necessary found it difficult to improve its systems in the
> > quantities required.
>
> Of course this ignores the long development times involved in
> actually creating sophisticated fire controls, and the fact that
> not even the US had spare fire controls for the RN indicates
> the manufacturing effort.
It doesn't ignore the long development times involved. It does quite
the opposite.
The failure to plan a succesor for HACS early enough created many
problems.
>
> And of course the RN did improve the systems, more gyro controls
> and of course radar which provided a short cut, given the size and
> development time of any new mechanical computers. (Hint, the USN
> mark 37 computer was so big it needed to be below decks, and this
> made it hard to fit to older ships). The cavity magnetron meant
> smaller radars, less weight, and narrower beams, good for fire
> control.
The RN habbit of revamping old ships into new ones to circumvent naval
limitations treaties undoutably contributed to this.
Tero P. Mustalahti
> On Jan 29, 6:17 am, "Geoffrey Sinclair" <gsinclai...@froggy.com.au>
> wrote:
> The Japanese had superior optics to any othe combatent.
Better than German optics? That sounds pretty surprising, since in
general Germany was the world leader in optics at the time.
> I have not problem with acknowleging the poor rate of fire of the
> German 37mm gun.. The German naval single shot 37mm gun was the
> German disaster as it was another factor that may have cost the
> Bismark. A good powerfull round with good ballistics in a reliable
> weapon that however had to be individually loaded and so could only
> fire 30 rpm. It was on a gyro stabilised mount.
The Germans probably believed that the excellent ballistics would
compensate for the poor rate of fire. This is understandable from a
theoretical point of view (lower time of flight makes calculations
easier), but it did not work very well in practice.
> However German system were fully tachymetric to start with:- it should
> have been relatively easy for them to inject the range data from their
> Hohtenweil or late model Seetakt radars in lieu of the optical range
> finder thus achieving the same effect as HACS (no GR or GRUB ie
> Gyro's needed to be added as thety were already integrated.)
> Photographs show FuMO 26 antena on the Prinz Eugen with a height
> finding antena added to the directors radar.
>
> I have no source of whether this is indeed what was done, but it is
> highly plausible as the radar was warning of airborn threats and
> providing range and bearing information.
Some ships were fitted with Würzburg-C or Würzburg-D for AAA control.
Well, at least the Tirpitz was. It was also fitted to the dedicated AAA
ships and floating batteries (most of them could not move under their
own power). The AAA radar setup of the Prinz Eugen was probably
experimental and may not have worked very well, since it was later removed.
> The ideal placement of the fuze setting machine was as an integral
> part of a power feeding system. I know of only 3 guns that achieved
> this; the US 90mm, the German 128mm FLAK 40 and the latter versions
> of UK 3.7 inch from the Mk 3a onwards.
Interestingly the Germans still concluded that simply firing shells with
simple contact fuses at maximum rate of fire was the most effective way
even for the 128 mm guns. That was never fully implemented at doctrinal
level, since it was a relatively late conclusion, but in 1945 there were
plans to stop using time fuses in heavy AAA guns.
> The Narvick class destroyers 6 inch 150mm guns had sufficient
> elevation for them to be used in the FLAK role.
But not training rates or rates of fire.
> Doctrinally the German navy believed that radar would disclose the
> position of a ship and should only be used for ranging in combat or as
> a navigation aid.
And they were right, but ahead of their time. In WW2 the possibility of
being detected by passive radar detectors was not very significant, but
of course today it is extremely significant part of naval tactics. It is
notable though that the Germans developed many passive radar detectors
themselves.
ken...@cix.compulink.co.uk
<390dfe37-5d40-4725...@f47g2000hsd.googlegroups.com>,
euno...@yahoo.com.au () wrote:
> First of all several posters made the claim that the RN was behind the
> USN but ahead of all of the Axis in AAA Fire Control.
Everybody except you in fact.
> and it seems the Japanese and the Italians systems were more thorough
> in some areas and it can be plausibly argued were better as well.
Not in any written source I have seen though of course they were in
English and may have been prejudiced.
> The Germans having a good stabalised mount
Neither the Italian or German stabilised mounts seem to have been
weather proof.
> The HACS was certainly the more primitive system out of the equivalent
> German and American systems so it's a good "base" for comparison.
Well that is what you are claiming. However considering results makes
for a different argument. At Crete most if not all of the ships sunk by
the Luftwaffe had actually run out of AA ammunition.
> I also argue that Modifications really improve HACS as much as you
> infer either, as I will explain.
Pardon, should that be do not?
> Looking at the German systems one can see that eventually they had
> either 20mm or 105mm guns with little sophistication in between.
Really, what makes you think that? The KM adopted the Army 37mm guns
and produced single Bofors based on a Norwegian model. By 1944 the 2cm
was only considered useful in quad mounts.
> The HAACS system still was unable to
> automatically integrate optical range measurements into the GR/GRUB
> though the use of radar range measurements bypassed this need in most
> cases.
So you are arguing that the fact that Radar measurements removed the
requirement for measuring speed by optical methods was a fault. It was
something the Germans never managed as far as I know.
> The lack of pure optical tachyometry probably would be a problem in
> the case of effective jamming or littoral clutter or during amphibious
> support.
I am sure you can come up with cases where that happened.
> and this is what finally allowed a
> complete solution.
So the RN solved the problem.
> This weapon had a heavy
> projectile but very low muzzle velocity of 650m/s
Where did you get this from? The 2pdr came in two velocities with the
original being 622m/s and the wartime model firing a lighter shell at
732 m/s.
> Remote power control didn't appear till mid 1943 and gyro sights till
> 1945
No. You are right about RP but the UK started the war with Gyro sights.
> The round lacked a tracer so it could not easily be aimed.
Wrong again.
> It also somewhat irrelevant to the 'war'; the US Mk 51 fire control
> system for the 40mm bofors, which incorporated the K14 gyro site was
> in mass production and widely equipping ships before perl harbour and
> the US entry into war.
Now that was a good trick since the Bofors was first mounted aboard US
ships in June 1942
> An advanced weapon when introduced, by the outbreak of World War II
> advances in aircraft had effectively made it obsolete.
It was however kept in service throughout the war and I do not consider
Wikpedia a reliable source. True given the same number of barrels and
the same fire control the Bofors was more effective.
> I would say by the beginning of US involvement in the war in December
> 1942
You really meant to say that?
> The 1.1 inch gun doesn't sound a soft touch either.
The 1.1 is generally acknowledged as one of the bigger US mistakes on
the same lines as their torpedoes.
> German destroyers tended to be larger than their British counterparts
> and probably could afford to carry more FLAK.
Well no, German destroyers were overarmed and had similar AA armament
to RN ships but heavier surface armament.
> My context was the expensive FCS for heavy AA, note I'm talking
> about RN HACS vs USN Mk 37 and 5 inch DP and the equivalent German
> systems.
The USN Mk37 had two more years of peace time development than any RN
system, the Germans never got a DP gun into service and their AA systems
were not that impressive in combat results.
Given time I may be able to come up with a complete list of RN combat
losses but from memory more were lost to surface action, mines and
submarines than to aircraft attack. Certainly if RN AA was as bad as you
make it out to be the Luftwaffe and the Italian air force have to have
been totally incompetent to have failed to sink the entire fleet.
The USN adopted the Bofors because Britain was using it for both the
army and the RN. The Bofors gyro sight used by the RN and the USN was
developed due to British army orders. Britain invented the gyro sight
initially for fighters. Light AA did not need range finders but relied
on rate of change of angular momentum which was why gyro sights were
used anyway.
Ken Young
ken...@cix.compulink.co.uk
Mustalahti) wrote:
> That was never fully implemented at doctrinal
> level, since it was a relatively late conclusion, but in 1945 there
> were plans to stop using time fuses in heavy AAA guns.
That was actually as a result of statistical research and only applied
to land AA see Hogg Anti-Aircraft. The Allies of course had the
proximity fuse instead.
Ken Young
Tero P. Mustalahti
>
> That was actually as a result of statistical research and only applied
> to land AA see Hogg Anti-Aircraft.
Yes, by 1944 the Germans did not do much sea AA, so land AA was implied.
It was supposed to work against large bomber formations and not against
much smaller naval attack aircraft.
> The Allies of course had the
> proximity fuse instead.
Yes.
Tero P. Mustalahti
Geoffrey Sinclair
news:390dfe37-5d40-4725...@f47g2000hsd.googlegroups.com...
> On Jan 29, 6:17 am, "Geoffrey Sinclair" <gsinclai...@froggy.com.au>
> wrote:
>> <eunome...@yahoo.com.au> wrote in message
>>
>> news:6f78b388-e576-4c03...@j20g2000hsi.googlegroups.com...
>>
>> > On Jan 27, 6:29 am, ken...@cix.compulink.co.uk wrote:
>> >> In article
>> >> <0873a2aa-bd8b-41a9-8e51-6d9f9508d...@c23g2000hsa.googlegroups.com>,
>>
>> >> eunome...@yahoo.com.au () wrote:
>> >> > In fact the RN AAA was the most retarded of any major
>> >> > combatant.
>>
>> >> The RN was behind the USN with heavy AA but ahead in light AA at the
>> >> start of the war.
>>
>> > The RN may have had better guns but it didn't not have better fire
>> > control for light guns.
>>
>> The trouble here is of course that things changed over the course of the
>> war and it seems the worst of the RN is being selected as the base
>> comparison.
>
> First of all several posters made the claim that the RN was behind the
> USN but ahead of all of the Axis in AAA Fire Control.
This is then an excuse for making another incorrect claim?
> This is most certainly not correct, especially for the German systems
I have no problem the German heavy AA fire control systems were
superior to the RN in providing gun laying data, the problem is the
major weight penalty the directors imposed.
> and it seems the Japanese and the Italians systems were more thorough
> in some areas and it can be plausibly argued were better as well.
Actually no. That is the reality and I note no evidence has been
presented to back the claim yet again.
> Certainly that is the statement made by the author of this article.
> http://www.navweaps.com/index_tech/tech-066.htm
Perhaps a quote about how much better the Italian and Japanese
systems from the article would be in order. Since the Italians
are not mentioned and the Japanese are mentioned in the context
of their batch of destroyers with 75 degree elevation guns, ignoring
the following designs had reduced elevations.
> The context (check my post) being the more sophisticated systems for
> bigger guns HACS, Mk 37, the German Dop L32 mounts.
Oh yes, the context here is the light AA guns, see above. And note the
first Eunometic clam, the RN AAA was the most retarded, not heavy
AA. Just watch getting the DOP mounting wet as they had weather
problems.
> In terms of the Medium AAA my comparison was purely within the USN/
> RN.
So why do the Italians and Japanese appear above?
> The Germans having a good stabalised mount but with a 37mm gun
> that had good ballistics and and power but very poor rate of fire.
Hand feeding single rounds tends to do this.
> Now, HACS or 'High Angle Control System' as opposed to the 'Low Angle
> system' used against surface targets was a key system for RN ships
> from destroyers to battle ships since it controlled destroyer main
> armament and heavy ship secondary armament (i.e. anything in the range
> 4.0, 4.5, 4.7, 5.2) when used in the AAA role.
>
> The RN was the largest or second largest navy.
Largest in 1939 as its building program had started earlier than the
USN, but the USN was rapidly catching up plus the RN started taking
losses.
> The HACS was certainly the more primitive system out of the equivalent
> German and American systems so it's a good "base" for comparison.
Again no one is claiming the RN was ahead of the Germans or the
USN in heavy AA, it appears to be ahead of the Italians and Japanese.
> I also argue that Modifications really improve HACS as much as you
> infer either, as I will explain. Perhaps deficiencies with HACS were
> filled in by good medium AAA.
This is good, medium AAA? Filled in? Perhaps?
I presume the idea is to claim it was not as improved as claimed.
What is medium AA?
> Looking at the German systems one can see that eventually they had
> either 20mm or 105mm guns with little sophistication in between.
Which was a problem given the 20mmm was becoming too light
as the war progressed and the Germans lacked proximity fuses.
In any case the navy simply used the much better 37mm gun of the
land based flak units.
> Consider the challenge of long range AAA and how HAACs worked.
This should be fun.
> First of all the bearing and range of the target needs to be known.
> This is fairly easy using an optical sight and stereo optical or
> coincidence range finder.
This is a problem given the errors in optical rangefinders and the
speed of the aircraft.
> Secondly its velocity (speed and heading) needs to be ascertained so
> that this can be used in conjunction with ballistics data to solve
> simultaneous differential equations so that an firing solution
> ( intercept point) and fuze setting time is calculated.
Director time and mechanical computers take time to solve
the problem.
> Since the
> shell might be in flight for several seconds during which the aircraft
> might move around 1.5km this velocity estimate needs to be
> accurate.
Lets see now 600 km per hour is 1 km per 6 seconds, or 1 mile
every 10 or so seconds. At muzzle velocities of around 800 metres
per second (5 inch 38) the round is going to reach out to 8 km,
or around 9,000 yards.
> This is where HACS was very poor, yes modifications with radar were
> made but they corrected only one of the two core limitations. At
> least the final limitation wasn't resolved till 1945.
I like the way the idea is to say only one or two of the core
limitations were fixed.
> With HACS speed and heading had to be 'estimated' rather than
> calculated automatically as full 'tachyometry' of continuously
> measuring bearing, elevation and range in respect of time and a stable
> gyroscopic reference to derive velocity were not inplemented in HACS,
> not doubt there were instruments and techniques to assist the HACS
> control officer in doing this but it got down to an estimate and but
> in practice it seems to have been impossible to keep track of the
> velocity changes of WW2 aircraft. HACS kept track of the aircraft
> using the estimated data in case the ship turned or the aircraft
> passed into clouds.
Actually HACS seems to have been able to track aircraft moving
in a straight line at fixed altitude quite well. For example fuse data
was continually transmitted.
And yes it continuously measured bearing, elevation and range.
And news for all the errors in optical systems meant there were
estimates in all solutions, there were less errors in radar systems.
> The USN and Kriegsmarine systems were fully "Tachymetric" ie velocity
> measuring not just position measuring.
No HACS measures velocity.
> The RN HACS at the beginning
> of the war seems to have lacked rate gyros so that as the ship turned
> accurate angular rate measurements could therefore not be made.
The various gyro units were added during the war as it became
clear the ship needed to dodge bombs and change course to
upset the aircraft attack.
> Yes it
> was able to plot on a graph paper the target aircrafts calculated
> bearing during ships manoeuvres using the velocity estimate that had
> been manually entered while the aircraft became obscured by cloud but
> that was only after the uncompensated speed 'estimate' had been made.
I like this, how exactly are the superior optical systems of other navies
going to see through the cloud?
> To repeat the system was unable to take speed measurements by simply
> tracking the range and bearing of the target or to calculate them as
> it lacked the compensating gyro rate reference to do this as well as
> the calculating mechanisms.
In other words the HACS used people when the USN and Germans
had used machines to do some of the work.
> Later GR (Gyro Rate) Units and GRUB (Gyro Rate Unit Boxes: quaint
> RN talk for the associated basic computer) were added.
Try early in the war.
> These took
> inputs from the optical sight and combined it with range readings from
> the 50cm wavelength type 285 radar that were semiautmatically entered
> into the system to calculate speed and heading.
This sounds like all the other early directors having radar added, the
full integration took time.
> (note the type 285
> radar couldn't track the target it could only range it so optical
> tracking was still necessary.
Try the 285 could give range, rate and bearing. Controlled blind
fire was not around until 1944/45 for anybody.
> The HAACS system still was unable to
> automatically integrate optical range measurements into the GR/GRUB
> though the use of radar range measurements bypassed this need in most
> cases.
So rather than rework the system the RN bypassed it with a better
one, simple it seems.
> The lack of pure optical tachyometry probably would be a problem in
> the case of effective jamming or littoral clutter or during amphibious
> support.
Ah yes, when in doubt create a worst case scenario for the bad guys.
> Now there is another problem not dealt with by the 285 Radar and GR
> Units/GRUB which now could calculate speed and the radar apart from
> the fact that an all optical solution was not possible and this is
> that the HACS and its new GRUB still can't directly calculate and
> track height changes, the whole core system wasn't designed to do
> that. In effect it could be said that HACS was 2 dimensional instead
> of 3 dimensional system.
By the way going to mention the GRU, the Gyro Rate Unit, the
device that was designed to measure vertical and lateral rates
even when the target was not in level flight?
Oh and yes the system could easily calculate height changes if
they were constant. Like your dive bomber after pushing over.
> So this vertical dimension is where the 'fully tachymetric' US and
> German systems are still ahead and it seems even the Italian and
> Japanese ones as well.
So give us the Italian systems and note the Japanese system was
in theory better but too slow.
> It seems that it was 1944 or 1945 that some ships (one Ibelieve) with
> HACS had the type 275 microwave track locking radar added to replace
> the range only 285 50cm unit and this is what finally allowed a
> complete solution.
Anson as built, Ontario and Superb as built certainly received the mark
VI director with type 275 radar. Superb was post war.
> Note the problem with HACS has nothing to do so far with the lack of
> Remote Power Control for pointing of the guns directly or automatic
> fuze setting machines. That's another problem area.
I know it had problems, I am just impressed by how exaggerated
someone can make them.
>> Anyway so now it seems we have RN better guns but lacked
>> the fire control for light guns, so I presume the better guns are
>> the light stuff only.
By the way my text above is in reply to the Eunometic claim of
"The RN may have had better guns but it didn't not have better fire
control for light guns."
> The best british light weapon would have been the 40mm 2 pdr 'pom pom'
> on a power driven quad or octouple mount. This weapon had a heavy
> projectile but very low muzzle velocity of 650m/s that made it short
> ranged and inaccurate at ranges neccesary to deter an attacker.
Oh good another Eunometic declared result, the gun is downgraded
and you sort of wonder how any RN ship survived an air attack.
You know fiction is being written when it is realised Illustrious had the
mark IVA* mountings in 1940 with the 732 meres per second guns.
> Remote power control didn't appear till mid 1943 and gyro sights till
> 1945 while higher muzzle velocity version with new amunition were also
> introduced late war.
The mark IV director for the 2 pounder with Gyros was in service in
1940, still hand worked by the end of the war most had Remote
Power Control.
It would seem Anson appeared in 1942 with the remote power
mountings.
The RN was trying to use the USN mark 51 sight for bofors guns
but, inadequate supply lead to a British production, the austerity
sight, which was in service in 1945, but no details yet of an
introduction date. The lack of supply is an indictor of how long
it took for the USN to equip its ships.
By the way for a good 1 volume book on WWII naval weapons check
out Naval Weapons of World War II by John Campbell. His main
problem for me is the RN is the standard to measure others by, which
can jar at times.
> Prior to this aiming appears to have been by the
> estimated deflection being entered manually into the gunner sighting
> system. The round lacked a tracer so it could not easily be aimed.
The whole point of the multiple mountings was they justified a director.
And there was 2 pounder tracer.
> The standard US weapon was the 1.1 inch 28mm gun which had a high
> muzzle velocity and came in quad mounts that were remote power driven
> and aimed remotely by a 'dummy sight' ie a sight without any computing
> capability or gyros. The gun had a good muzzle velocity of around
> 900m/s but fired a low rate (the quad mount was chosen to match the
> 0.5 calibre browning in cadence) and the projectile was considered a
> little light.
Lets see now real muzzle velocity 823 meters per second, rate of fire
150 rounds per minute, given the ammunition was supplied in 8 round
clips.
Aiming was via a ring sight and use of tracer.
By the way if the USN gun was poor note the IJN 25 mm gun had
a muzzle velocity of 900 metres per second and effective rate of
fire was 110 rounds per minute.
When the USN attacked the centre force at Leyte they lost some
18 aircraft, on a clear, still day with the IJN in relatively sheltered
waters so not much swell. With hundreds of 25 mm guns on board
the IJN warships.
> In other words both the USN's and the RN's light AAA was considered to
> have serious deficiencies.
Everyone's light AA at the start of WWII had serious deficiencies.
>> > The latter matters more I think.
>>
>> Good, then you would know the RN had fire control for their light
>> AA pieces before the USN, since the idea of the multiple 2 pounder
>> was to justify the cost of the control.
>
> I question that widely made claim about the pom pom as I see little
> evidence of particualry wide deployment or sophistication of the 2
> pounder pom pom system. The sighting arrangments were quite crude.
It is quite simple the RN actually had fire controls for their main light
AA weapon, the USN did not. The USN used purely visual aiming.
This was the 1939 situation, by 1942 the USN was fitting light AA
sights and rapidly pulled ahead.
For Illustrious to report defects in her light AA directors she had
to have some.
> It also somewhat irrelevant to the 'war'; the US Mk 51 fire control
> system for the 40mm bofors, which incorporated the K14 gyro site was
> in mass production and widely equipping ships before perl harbour and
> the US entry into war.
The USN began fitting the mark 51 director in mid 1942 about
6 months after the first twin bofors mounts had been made.
Please let us know the large number of ships fitted with the
improved sight in 1941 if the above statement is wrong.
> The Charles Stark Draper developed k14 gyro
> sight on its own was used to equip 20mm canon and other small mounts
> (eg the 1.1 inch gun) when supplies of compressed air (for gyro spin)
> and electrical power made this possible.
And many to most 20mm were by eye shooters.
> Gryo sights on their own are
> really hard to use: you have to keep track of the range by a
> stediometric range finder (enclosing the aircrafts known dialled in
> wing span) while simultaneously tracking the recticle that moves
> around to display the correct ofset.
So in other words they are not some sort of cure all.
> At least with the Mk51 the lead
> angle was added in by the computer to the guns rather than the gunner
> having to deflect the site with the complete gun.
As noted before the mark 51 was a 1944 arrival and used mainly
for 5 and 3 inch guns.
The mark 63 was the improved sights for the bofors.
> I also doesn't seem that the pom pom gun in its quad mount and or its
> fire control was all that effective or ahead of the US systems at the
> beginning of the war. The US systems were RPC albeit with a dummy non
> computing sight.
Let us see now, beginning of war was September 1939, in reality
the USN started fitting light AA directors in mid 1942, in Eunometic
fiction it was about a year earlier, but the RN light AA fire control is
said to be inferior in 1939. The directors were better than by eye
aiming.
Very good, more time travel history.
> I would like to know what this advance fire control system that was in
> service in 1940-1942 actually was.
It was the mark III and mark IV directors, better than the by eye method
but not good enough for WWII.
> http://en.wikipedia.org/wiki/QF_2_pounder_naval_gun
(snip the PoW poor AA results etc. see the above URL)
As for the 2 pounder being obsolete in 1939 the RN rated the
bofors as twice as good, all other things being equal.
> So the advanced light AA was unable to do much for HMS "Prince of
> Wales" presumably because it wasn't advanced enough to make a
> difference.
It is really simple if we are in the 1939 to 1941 period we need to
compare the results of the RN light AA with other navies. The
quickest example I can find is the USN AA returns for the late
Pacific war fighting. The 1.1 inch shot down 1 kamikaze at about
the same rounds per aircraft as the 40mm used in shooting down
114 (there were lots more bofors). When it came to conventional
attacks the 1.1 inch scored no kills from about twice the number
of rounds used versus Kamikazes, the bofors scored 46 kills at
3,361 rounds per kill versus 2,272 when stopping kamikazes.
Think the 1.1 inch was so good now? Given it presumably had
better fire controls in 1944/45.
>> > In both
>> > cases the RN and USN gravitated towards the Bofors 40mm. It's true
>> > that the RNs 2-pdr [4 cm/39 (1.575")] Mark VIII was superior to the
>> > US 1.1 inch gun but the US moved rapidly and more thorougly to the
>> > 40mm Bofors pointed by the Mk 51 FCS (fire control system) complete
>> > with remote power control.
>>
>> So by the end of the war the US had the better light AA fire control,
>> after being behind for the period 1939 to 1942, when the US began
>> adopting the 40mm and associated fire control. With the USN always
>> being ahead for heavy AA fire control.
>
> I would say by the beginning of US involvement in the war in December
> 1942 its own light/medium AA was ahead of everyone's as well. Its
> legacy 1.1 inch guns were maybe a bit weak but even they were upgraded
> with gyro sights.
Except to make this claim the USN production program is advanced
by around a year.
And the US joins the war a year later than historical.
Understand the US started fitting the fire controls in mid 1942.
> In the period 1939-42 it might be argued that the RN's medium AAA was
> better but does that matter since although at that time the pom poms
> were better but still inadequate for anything but a biplane torpedo
> bomber itself. It's like saying a morris minor is ahead of a model T
> ford for requirements of Indianapolis racing.
It would be good to define medium AA for a start, 2, 3 or 4 inch?
And I note the reality is the RN guns abilities are given incorrectly
in order to actually come to the conclusion.
> The 1.1 inch gun doesn't sound a soft touch either.
Ah, the RN is to be attacked, so puff up "competitors".
>> The USN began fitting the mark 51 director in mid 1942 about
>> 6 months after the first twin bofors mounts had been made.
But Eunometic claims around a year before hand apparently.
>> >> The RN was probably ahead of Germany, Italy and Japan
>>
>> > Nope the RN was well behind the German Navy which actually had quite
>> > good systems available and also behind Japan and Italy. Not until the
>> > introduction of radar did the gap begin to close.
>>
>> This is quite funny really.
>
> I can hear you tittering. the fact however is that the HACS was well
> behined the German systems at the start of the war.
Yes folks, the IJN and Italians go missing. We rush back to the Germans.
>> IJN the type 94 fire control has all the nice descriptions, tachymetric,
>> triaxial director and a resolver for deck tilt, solutions could be given
>> for non level flight from the computer in the transmitting station. The
>> trouble was the computer took too long to come up with a solution.
>> The system was modified to basically do some initial by eye shooting
>> to at least provide some opposition.
>>
>> The poor performance at Midway meant some modifications had
>> to be made, but no better system was developed during the war.
>
> So, no doubt modifications eventually allowed faster calcuation of
> target aircrafts velocity.
Yes folks Eunometic does not know if the Japanese improved their
systems, it is assumed they did, but the Japanese are still superior,
well they are granted superiority. Not only that but the post mid
1942 Japanese systems will be used to compare to the 1939 RN
systems.
Is the RN that good these sorts of comparisons need to be done?
In case people are wondering no new HA fire control systems were
introduced into the IJN, one of the low angle directors was modified
to a combined director but with unsatisfactory results.
>> And some IJN ships, including the Haruna had the older type 91,
>> which was inferior to the type 94.
>
> The advanced state of the Japanese navy and its size at the beginning
> of the war and its failure to then maintain and keep pace with
> developments is well known. There was a lot of old 'crap' in the RN
> as well.
Ah yes, but the IJN is ruled superior, and granted further superiority
above.
> So the Type 94 had problems dealing with fast aircraft as did HACS, at
> least it dealt with the full range of manovers.
Correct, unfortunately with too long a time lag and tracking
speed problems.
> HACS continued to
> require manual spoofing to cope with diving targets as well in this
> case to overcome not a lack of computer speed but the lack of
> provision of the basic mechanisms to begin with.
In case people are wondering the IJN directors managed 8 degrees
a second elevation and 16 degrees a second training. Which was
simply not fast enough in WWII. Another basic mechanism problem.
> Presumably the Japanese attempted to address the 'speed issue'. The
> challenge for the Japanese engineers and trades people was keeping
> enough from being drafted.
The issue was noted but no results were obtained.
>> The above for the heavy AA, the IJN used the French Navy Le Prieur
>> sights for light AA, along with the Ward Leonard remote power system
>> for the triple 25mm guns. Production difficulties lead to the
>> abandonment
>> of the remote power option.
>>
>> And you should note the elevation of the IJN Dual purpose 5 inch guns
>> was 55 degrees in most pre war destroyers.
>
> Just over 40 degrees for the early RN systems, 80 or 85 degrees for
> the better German systems, which weren't usually considered DP (except
> on the Prinz Eugen where the 105MM flak was effectively DP) but
> dedicated FLAK.
Note by the way rather than deal with the IJN gun elevation problems
we jump back to other people's elevation problems and in a non surprise
the Germans "win".
The IJN pre war destroyers had better main gun elevation than the RN.
It took until mid war for the standard new RN destroyer to match the IJN.
Neither elevation could handle dive bomber attacks.
> German destroyers tended to be larger than their British counterparts
> and probably could afford to carry more FLAK.
And had low angle main guns only and had comparable light AA
guns pre war and had more top weight problems than the RN ships
which limited additions like radar and AA guns.
>> Italian AA had the same problem, as the Japanese, slow resolution of the
>> data, and did not have gyrosights and so on for the light AA guns.
No reply here.
>> >> in naval AA. Besides you seem to be comparing RN AA in 1938 or so with
>> >> the USN in 1945.
>>
>> > No, I'm not.
>>
>> You are the one who is talking light AA above, now we jump back
>> to the heavy AA
>
> My context was the expensive FCS for heavy AA, note I'm talking
> about RN HACS vs USN Mk 37 and 5 inch DP and the equivalent German
> systems.
So now FCS is expensive, whatever that means.
I have no problems the RN was behind the USN and Germans in
heavy AA directors.
>> >the US 5 inch mounts and its associated tachymetric
>> > fire control system has a history going back to 1932 when development
>> > of the Sperry Mk 1 computer was begun as part of the Mk 37 fire
>> > control system for the 5"/38 DP mount about the same time the RN was
>> > developing the HACS.
>>
>> Like the fact the RN had HACS in service before 1932 you mean?
>
> Ok, but the US contempoaries to the UK's HACS ; in other words the
> 'range keeping' precurors to the Mk 37 were already tachymetric,
> though not able to deal with diving aircraft.
So far almost every Eunometic given date I have checked is wrong.
The USN mark 19 tachymetric linear rate fire control for 5 inch guns
was at sea in 1928, then came the mark 28 but it was too heavy for
the provided hand training, then came the mark 33, available for
Ranger, Quincy, Farragut etc. Allowed aircraft top speed was 275
knots, improved to 320 knots, then to 400 knots with some ability
against diving targets.
> SNIP
(it appears the RN simply got it totally wrong claim has been deleted)
>> The mark 37, the ship borne gold standard of heavy AA for WWII
>> did its tests in 1939. Those two extra years of peace made a big
>> difference to the standards the USN could adopt in WWII, coupled
>> with the combat reports it received.
>
> Prior to the Mark 37 FCS with its Mk 1A computer the US already had
> some tachometric FCS systems for heavy AAA so much of the
> infrastructure such as AC power etc was already in place.
No problems here.
> Likewise
> the infrastructure as measured by human knowledge base, specialist
> engineers, technicians, craftsmen had been built up by the prior
> efforts likewise for provision of the necccesary services such as AC
> power as well as actually having room in the turrets for the necessary
> equipement.
AC experience can come from the electricity industry. The specialists
need to be quantified, and the room in turrets is fun given the directors
were away from the turrets and becoming very heavy.
I just like the way the hurdle is made so big. The RN can be excused
then because there was not the resources?
As opposed to needing those extra years to catch up after funds became
available?
> There is actually an intelligent and insightful question to ask: why
> did the RN get stuck with HACS which is being obscured by your frantic
> desire to prove my anti British but pro German (and pro American
> bias.)
Oh I know the Eunometic bias is pro German, the British rate last but
there is no pro American. I like the frantic bit, Eunometic likes to
editorialise.
The RN was stuck with HACS for the same reason most air forces
were still turning out biplane fighters in the late 1930's. The rate of
change had accelerated but the time to devise new weapons had
increased. The RN made assumptions about the type of attack they
would face and were proved wrong and were not able to create a
first class optical AA system but then used radar to move to the
more accurate radar guided directors.
> The reality is that the RN grossly underestimated what would be needed
> to deal with modern aircraft and paid a price for it.
All navies did, as the lack of good light AA proved. Heavy AA was
also a problem, given the need for time fused shells, the proximity
fuse was a major repayment in USN faith in heavy AA gun directors.
>> > The RN almost certainly had the worst AAA systems of any of the
>> > combatants at the start of the war: worse than US, German, Italian
>> > and Japanese and never really solved all their its problems until 1945
>> > since the existing systems were resistant to modification since they
>> > had been designed on the incorrect premises.
>>
>> So the idea is the RN was inferior to the IJN and RM in both heavy
>> and light AA systems for the entire war, or will we have more switching
>> between heavy AA and light AA to suit the comparisons.
>
> I switched to light AAA only in response to another poster. RN light
> AAA is normally lauded.
So the idea is the RN was inferior to the IJN and RM in both heavy
and light AA systems for the entire war, or will we have more switching
between heavy AA and light AA to suit the comparisons.
>> It will be interesting to see what the superior IJN and RM systems
>> look like.
>
> The Japanese had superior optics to any othe combatent.
Really, perhaps their director optics can be detailed? The IJN are
supposed to have lookouts chosen for their night vision but other
references dismiss that as a myth.
> Specialist
> machinary is an Italian Forte' I would not be suprised if they
> produced a competent result in fire control.
Ah yes the Eunometic creed, the good guys must have done it,
the bad guys could not do it.
No evidence, just preferred outcomes.
>> > The German navy was
>> > second behind the US and certainly well ahead in regards to the
>> > sophistication of its AAA systems on its larger ships though a few
>> > errors such as using open mounts meant that the sophisticated control
>> > gear was compromised by sea water ingress far to frequently.
>>
>> Take a look at how the German Naval 37mm gun worked at the
>> start of the war, nothing like a single shot light AA weapon. This
>> rather compromised the effort into making the better fire controls.
>> They needed an upgrade from the 37mm AA gun developed
>> for non ship use.
>
> I have not problem with acknowleging the poor rate of fire of the
> German 37mm gun.. The German naval single shot 37mm gun was the
> German disaster as it was another factor that may have cost the
> Bismark. A good powerfull round with good ballistics in a reliable
> weapon that however had to be individually loaded and so could only
> fire 30 rpm. It was on a gyro stabilised mount.
>
>>
>> And yes the German naval AA mountings and fire controls were
>> overall better than the RN at the start of the war.
>
> The core HACS "may" I emphasise "may" have improved ahead of the
> German systems by the end of the war as the RN was able to integrate
> radar with add on gyros to sort of automatically spoof the limted core
> system to bypass one of its two shortcomings. If we include what
> radar made possible then this is more certain to be true.
Which is in effect what the RN did, it came in late to optical AA
directors, and had the radar sets to enable it to bypass them in
favour of the better radar guided ones.
As to who was best at the end of the war is this development,
in production, or oldest or what? The German AA defences of
their convoys do not seem to have been effective in stopping
convoy attacks by Coastal Command. And it could be the
Beaufighter/Mosquito combination in 1944/45 was taking fewer
losses per ship sunk than the Blenheim attacks in 1941.
> However German system were fully tachymetric to start with:- it should
> have been relatively easy for them to inject the range data from their
> Hohtenweil or late model Seetakt radars in lieu of the optical range
> finder thus achieving the same effect as HACS (no GR or GRUB ie
> Gyro's needed to be added as thety were already integrated.)
I know the Germans had the better optical system but it appears
they did not integrate radar into the directors.
Note the wavelength problem in terms of ensuring the radar was
tracking the right aircraft.
> Photographs show FuMO 26 antena on the Prinz Eugen with a height
> finding antena added to the directors radar.
Later removed, not a good sign that it worked well.
> I have no source of whether this is indeed what was done, but it is
> highly plausible as the radar was warning of airborn threats and
> providing range and bearing information.
As far as the references I have are concerned the answer is no.
Radar was not integrated.
No light AA directors were fitted during the war. Any aiming
intelligence was on the mount.
>> > I'm not trying to 'dump' on the British or RN but this is a case when
>> > a group of people got it wrong.
>>
>> However "they got it wrong" will be repeated several times.
>
> Yep, that's simply part of prosecuting an argument: you argue the
> point from several perspectives to cover all bases. Its not a sign of
> excess bias just thoroughness.
Yes folks repeating they got it wrong is being thorough, not bias.
Eunometic is wrong
Eunometic is wrong
Eunometic is wrong.
Just being thorough.
> That is the point of this subthread and the consensus.
No, we have someone dumping fiction to over prove a point.
> There were no
> doubt individuals within the RN raising alarm bells but they were
> unable to push through their point and were simply ignored.
I gather the idea is to remain ignorant of RN developments, like
the improvements to HACS, it was up to mark IV in 1939.
>> I do note the usual praise of the Germans, including what the
>> might/cloud have done, they were significantly ahead of the RN
>> in fire control in 1939. I do note however that nothing is actually
>> mentioned about the claimed superior Japanese and Italian systems.
>
> At least two posters in this thread made the erroneous claim that the
> RN was ahead of all of the axis in naval fire controls, the context
> clearly being the sophisticated and expensive fire controls required
> for effective heavy AAA.
So inject another false claim in to balance things right?
Also the time needs to be quantified given the radar advantage
of the RN in the mid to late war.
> That is simply an in correct belief with a
> wide body of writing pointing to the limitation assumptions and
> therefore primitive nature of HACS and the legacy it left those trying
> to make it work against modern ww2 aggressor aircraft.
Yes folks, HACS now becomes primitive and we are now
covering WWII and yet we know the RN fire controls were much
better in 1945, thanks to radar.
So when someone makes an incorrect statement just add another
one is the Eunometic creed.
> It seems in your characteristically reflexive defence of a British
> cock-up you would have me not argue my point to satisfy your
> preferences.
Let's see, most dates wrong, adjectives scattered about to praise
the good guys and denigrate the bad guys and so on. Perhaps it
would be best to show the British as wrong in this case, rather
than writing fiction. It is relatively easy to do when it comes to
RN fire controls, yet the faults have to be exaggerated.
Since the German navy did not ship any light AA directors can we
call them primitive as well?
> My WW2 topic might be German electronics but it is not a bias in
> argument but a bias in focus; specialisation.
No, we have someone with incorrect information and telling us they
are going to assume the right result when facts are lacking trying to
make a case.
The RN heavy AA fire controls were inferior to the Germans and
the USN. The fun bit starts with attempt to prove "primitive". The
RN then closed the gap using radar.
> The problem with being
> a 'pro' or 'anti' person is that it makes for poor understanding of
> history.
People have been trying to tell Eunometic this for years.
>> > First of all the German computer systems were fully tachymetric:
>> > something which can't be said of the HACS in any way so the German
>> > systems produced a far better firing solution and they did so
>> > continuously.
>>
>> Yes.
>
> OK, so we have that in agreement, for early war HACS at least.
>
>>
>> > Basically in the RN's HACS system an officer "the control officer"
>> > had to estimate the targets speed and feed it manually into the
>> > computer which then used the current position and the estimated speed
>> > to calculate a firing solution inclusive of the considerable dead time
>> > required to manually set the fuze and load the gun.
>>
>> Actually read the HACS reference provided, the bit about most
>> larger ships used fuse setting machines?
>
> There are two types of fuze setting machines: those that are manual in
> which a human reads a gauge from the FCS and then manualy adjusts a
> dial accordingly which then sets the fuze or those that are automatic
> in which the fuze mechanism is set directly from the predictors
> output.
>
> I read that the fuze setting machines in the RN capital ships were
> manual and separate from any power loading device.
I simply note yet again the story shifts and now we have the two
fuse setting machines. Like maybe feeding the shell into a machine
that sets the fuse then you hand load it?
> The ideal placement of the fuze setting machine was as an integral
> part of a power feeding system. I know of only 3 guns that achieved
> this; the US 90mm, the German 128mm FLAK 40 and the latter versions
> of UK 3.7 inch from the Mk 3a onwards.
So the USN 5 inch mounts lacked this, correct?
> The US twin 5"/38 incorporated automatic fuze setting into the
> munitions hoist so that the rounds fuze could be set and power ramed
> moments after release.
So the USN set fuses in the munitions hoist, which would be rather
fun if the round prematured. So why was there a fuse setters seat
between the guns and a fuse setting indicator regulator near the seat?
And how were any ready use shells set?
>> > The HACS was
>> > incapable of calculating the speed directly using information from the
>> > director and optical range finders and apparently never gained this
>> > ability though it eventually gained this via the use of additional
>> > circuits added to radar when radar became available.
>>
>> So let me understand this it never gained it but it gained it?
>
> It never gained the ability to calculate velocity by optical means
> alone; that's actually clear from my sentence.
So in other words it gained it, the RN took the radar shortcut.
> It sounds like what happened is that when the GRUBs were added they
> calculated the velocity of the target using a hybrid optical-radar
> system referenced to gyroscopes that compensated for turning of the
> ship and then entered it where the control officer used to put his
> manual estimate.
No the GRUB which is trying to plot course appears to be optical.
The radars doing the range finding.
> Now the HACS is getting accurate and timely velocity information from
> the type 285 & GRUB in the horizontal plane and tracking it but it
> was not set up to handle the vertical plane ie height changes.
Which is where the GRU came in.
> AFAIKT the Germans mainly attacked ships with torpedo bombers or dive
> bombers or slant bombers. Level bombers were only used with guided
> weapons at least in the latter stages of the war.
You mean those He111 strikes against RN ships early in the war
before the invasion of Norway were dive bombers? And the
torpedo bombers were diving during their attacks?
>> > It initially
>> > also lacked the ability to engage diving and maneuvering targets.
>> > Since the germans (ju 87 and ju 88) and Japanese were rather good at
>> > dive bombing this was a serious problem.
>>
>> Actually the German dive bombers needed more practice to hit
>> moving ships and it took a while to figure it out. Things like
>> Gloucester and Fiji being sunk after they were out of main AA
>> ammunition indicate things were a little different to that being
>> claimed.
>
> Between 21st May and 1st June 1941, during the battle and evacuation
> of Crete, the Royal Navy suffered 3 Cruisers and 6 Destroyers sunk, 1
> Carrier, 2 Battleships, 5 Cruisers and 5 Destroyers damaged, out of
> the 1 Carrier, 4 Battleships, 10 Cruisers and 30 Destroyers deployed.
>
> So the losses are altogether 11 out of 30 destroyers, 8 out 10
> Cruisers, 2 out of 4 BBs, 1 out of 1 CA were neutrilized (sank or
> damaged) in about a week by the LW... admitedly, with not much
> opposition from the air.
Ah so in order to make the Luftwaffe look good we count damaged
as lost and pretend the Italians were not around.
Of course the HMS York being hit by an explosive MTB and beached
is going to be ignored, plus the fact it was nearly refloated despite the
air attacks. Imperial had to be scuttled as its steering gear had been
disabled and it had no air cover. Killed by the threat of air attack.
> And we are talking about a single Fliegerkorps, not 3 entire
> Luftflotten, as during the Battle of Britian.
Actually we are talking around 650 combat aircraft including
150 dive bombers. Or around 25% the Battle of Britain force
in numbers and around a third the dive bombers.
The Luftwaffe units involved had lost 259 aircraft, of which
121 were transports with 48 of them to accident. There were
311 dead and missing aircrew, of which Fliegerkorps XI (not X)
lost around 185.
So what is that 138 combat types for Crete and 9 RN ships
sunk? Given the lack of AA guns on Crete is the idea the
Luftwaffe losses were to non RN AA gun causes?
> Fiji incidently was effectively sunk by a lone Me 109 which dove out
> of clouds and delivered a direct hit.
And I note the fact Gloucester and Fiji were run out of AA
ammunition is being ignored. Fiji had to be immobilised for the
bombers to start hitting it.
>> > It was designed to deal
>> > with level bombers. When microwave radar became available the radars
>> > circuits were finally able to provide this information automatically
>> > but not via the optical systems.
>>
>> So the British jumped over optical and went straight to the
>> first "modern" systems, that is radar controlled.
>
> Not quite, they substituted radar range measurement for the lack
> backup facilities for using stereoscopic range and rate measurment and
> added gyroscopes and computers to establish the level speed of the
> aircraft.
Actually they added the relevant gyro units and radar.
> Optical sighting was still necessary.
Full blind fire appeared in 1944 and 1945.
> In the case of diving aircraft
> individual aimed shots were no longer possible and barrage fire had to
> be used. That lone Me 109 still stood a chance.
Lone aircraft in a cluttered environment always do.
> HACS was still not tachymetric and still had lmitations.
This is known, and it is amusing to see it continually repeated.
> SNIP
>
>>
>> > You can read about HACS here:
>>
>> http://www.navweaps.com/index_tech/tech-066.htm
>>
>> It helps clear up the wrong claims being made.
>
> What wrong claims?
They were detailed in the previous post with more in this post.
> Basically HACS was limited till 1945 irrespcetive of whether it had
> the 285 50cm radar integrated or not. When the type 275 centric
> radar replaced the 285 decometric set it seems to have been 1945 or
> late 1944 in limited FKC form and essentially bypassed what was left
> of HACS.
Oh I have no trouble the HACS was limited, the primitive tag is
the oversell.
> By this time the German Navy had ordered about 150 FuMO 231 track
> locking radars to direct their guns, this was more or less a 50% scale
> Manheim radar it had a 1.5m diameter dish and opperated at 27cm
> intially, 3cm later. One was installed on a German destroyer that
> never left the docks.
You see folks the idea here is the British actually do something the
Germans are going to do something, in theory anyway, and that
makes the two the same.
By the way going to compare the never used German system to the
RN type 262 auto lock and follow up radar, using the 3cm band?
They appeared at the same time, and neither saw wartime use.
>> > Secondly the German mounts, as far as larger ships are concerned,
>> > were aimed by remote power control direct from the predictor at least
>> > as far as elevation of the gun was concerned and the setting of the
>> > fuze which was automatic and direct from the predictor via a fuze
>> > setting mechanism adjacent to the gun breech. The round still had to
>> > be manually transfered into the gun at which point continuously
>> > running rollers pulled the round in.
>>
>> Hey the Germans had a fuse setting machine beside their gun, just like
>> the RN ones. Though the RN ones look to be inferior.
>
> Fuze setting machines need to be fast inoder to deal with close,
> manouvering targets.
So the non answer means the German fuse setting machines are
about the same. Glad to have that cleared up.
> The requirement is relaxed when dealing with
> level bombers which is what the 88mm land based FLAK 37 could afford
> to do; you know level bombers like B-17 and Lancasters were its
> primary target.
With horrendous results in terms of shells fired per shoot down.
>> > In all of the RN's systems this was done manually until the second
>> > half of the war when radar and electronics allowed a sort of partial
>> > bypass of these problematic systems since circuits added to the radars
>> > could give good position and rate information.
>>
>> Try again, the RN had remote power control, its weight and cost
>> being a reason not to fit it to destroyers, as it would push up their
>> size, complexity and cost.
>
> Lack of RPC was however not the main issue, lack of tachyometry was.
I like this, whenever the RN has an ability it keeps being defined
as not as important. The things the RN did wrong are classified
as the important ones.
>> > In the RN's system
>> > the fuze delay time was set by a man with a spanner or by a fuze
>> > setting machine in which the delay was entered into the machine
>> > manually after having been read from guages. RPC was only added
>> > later to the RN's systems.
>>
>> Note the man with a spanner line, it will be repeated because it
>> makes them sound so bad, you know like the Luftwaffe 88mm
>> fuse setting arrangement as of pre war.
>
> The reality remains that a man with a spanner set the fuzes on British
> destroyers, unlike in the American system.
The reality is a man with a spanner set most AA fuses in WWII or
else the shell was fed into a machine by hand to set the fuse then
into the gun, fully automatic was rare.
> Remember this started out as a comparison between British and US ship
> building efficiency.
Which has nothing to do with the AA fire controls nor the number
of spanner men on board.
> Now, as you bringing up the pre war FLAK 18 (early 88mm.) : Fuze
> setting machines need to be fast inoder to deal with close,
> manouvering targets that ships face.
This is really quite funny, given the bombers are heading straight
for the ship and land AA batteries can be a considerable distance
from the target, making the land based gun problems when it
comes to courses slightly harder.
> The German ground based FLAK guns performed a different job to that of
> a naval gun; they could truely afford to be specialised in high
> altitude level bombers becuase that's how Lancaster and B-17's
> attacked. This is not the situation for ships AA defences on a
> ship. Nor did they need a stable gyroscopic reference.
This is fun, the size of a gun directly impacted on its training and
elevation limits, which in turn created the minimum effective range.
The bigger the gun the bigger the minimum. So the under 4 inch
88 mm gun is set up to have a bigger minimum effective range than
the 4 and above inch naval guns, and this is deliberate? Try in
WWII the heavy AA guns over Germany spent a lot of time shooting
at high flying 4 engined types, but not the flak guns deployed outside
of Germany
Land based guns do not need their stable elements unless there are
lots of earthquakes.
> Having said that; the German gound based predictors did not have the
> limitations of the HACS even if the 88 gun whether FLAK 18 or upgraded
> FLAK 36 or FLAK 37 were manually trained.
Yes thought so after dismissing the need comes the they were better
anyway.
>> > You can see an explanation of one of the german systems here:
>> >http://www.navweaps.com/Weapons/WNGER_41-65_skc33.htm
>>
>> Limited RPC.
>
> This is what "Limited RPC" means.
What I like is the web site can tell you. So I will snip it.
> RPC on the traverse did not contribut much as the other angles were
> the more serious contraints. Gunners merely used the 'match the dial'
> method but did not have to worry about ships movements or cranking and
> handle.
So match the pointer was effective, just as long as the training and
elevation
rates were acceptable.
> The alternative to gyrostabalisation was to have a man peering at the
> horizon through a sight whose job it was to either act as a gyroscope
> by keeping fixed to the horrison or fire the guns at the peak or crest
> of the waves.
So gyros are not the be all, you can use people to compensate.
>> >http://dcoward.best.vwh.net/analog/ford.htm
>>
>> The Ford URL is a US system.
>>
>> >http://www.navweaps.com/index_tech/tech-013.htm
>>
>> This above URL rather puts a dampener on the wonder German
>> electronics in the Prinz Eugen.
>
> It does no such thing, anywhere.
Try and read it again instead of hoping.
> It notes that the US had superior radar systems by the end of the war.
So much for the Prinz Eugen's radars being a revelation then.
> By the end of the war the German technology was catching up after its
> neglect of the high frequency radar field.
Yes folks, the Germans are allowed to almost catch up.
The RN stays primitive.
> Optivally in terms of sights, range finders, stabalized optics,
> computing accuracy the German systems were first rate.
No problems there.
> They had superior night vision optics and range finders and even had
> passive infrared systems on their capital ships.
I thought the IJN was supposed to have the superior optics when
mentioned above?
> As I pointed out about 150 x FuMO 231 Euklid radar lock directors
> had been ordered and delivery was starting.
Yes folks, they almost did it, and that counts, the RN has to do it.
> So it can be said that
> both the Germans and British were behined the US untill 1945 when
> the British started to catch up with the type 275 radar while the
> Germans
> were introducing the Euklid FuMO 231 running a few months behined the
> British. An academic exercise due to the end of the war approaching.
By the way the RN was a few months behind the USN, that is rated
important, the Germans being a few months behind the RN is not
important.
Eunometic prefers adjectives rather than numbers for obvious reasons.
> The German Seetakt radar (13kW) however was behined the British 274
> and 275 radar
> (25kW and later 125kW) in transimission power which meant that the
> British radar consistently picked
> up the German opponent first even though both were limited by the
> horizon.
The earth's curve has a tendency to limit radar range.
> The Germans company GEMA raised power to 125kW and 400kW but
> far to late to see service at sea, only on land.
Yes folks end of war German stuff counts, no checking similar
situations for other people. (Japanese radar was quite good
using the Eunometic rules).
>> Yes the advertising for the Germans is in full swing, no Italians
>> or Japanese make the cut though.
>
> The Italians were out of action by 1943 so comparison isn't possible.
> The Japanese I rather suspect improved their gear.
I like the way the original comparison was in the 1939 to 1942 period
but that is deleted now, anything but detail the claimed better Italian
systems.
>> The 1931 German AA fire control version required some 20 minutes
>> to spin up the main gyros, they were so big it was a dockyard job to
>> replace them, a counter to the advantage of them providing a good
>> artificial horizon.
>
> It's not a good counter.
This has been noted.
> The value of the FCS is that despite its weight it dramatically
> improves the effectiveness of the ships armament by making its fire
> accurate.
And the weight drives up the ship size and causes growth problems.
There is always a trade off. Hipper and co were 40% bigger than
a county class for more directors, and 4 more heavy aa guns and
less reliable machinery.
>> The 1933 version came in at 40.4 tons, up from the 21 tons of
>> the 1931 version, the big gyro rotors coming in at 260 Kg each.
>> The director weight excludes the amplifiers and generators.
>>
>> The 1937 version, for Bismarck, Tirpitz and Prinz Eugen eliminated
>> the big gyros but then needed 5 tons of ballast to maintain centre
>> of gravity, overall weight was dropped to 36 tons. (All metric tons).
>>
>> A trouble with all the above designs was the gimbal rings forming
>> the gun angle converter also carried the weight of the director, which
>> was an obstacle to eliminating vibrations.
>
> You appear to be refering to the main directors of capital ships.
No the AA guns.
> The gunnery they produced
> was accurate enough: Scharnhorst achieved the longest recodered hit at
> 26,000 yards using this
Or Warspite in the Mediterranean.
> technology despite the possibility that the whole director had the
> pickoffs mounted on the massive gimballs.
In other words the design had a flaw.
> There was plently of respect for the German cruisers abilities to
> achieve hits when their optical systems could be used.
No one is disputing the accuracy, I am noting the cost.
By the way how often did German cruisers shoot at allied warships
in WWII? Hipper was quite bad and quite good at Barents Sea.
>> When it came to AA radar fire control the navy adopted the Luftwaffe's
>> Wurzburg system but this was too heavy for most ships. Tirpitz and
>> some of the AA ships were given sets.
>
> They presumably used optical aiming with radar ranging using the
> Seetakt style FuMO 26 and FuMO 27;
No it is using Wurzburg as the available solution but only for
big ships.
> this didn't require a Wurzburg or
> Manheim radar which were both full gunlaying radars and could track a
> target in 3 dimensions and pass data directly to the predictor, the
> Mannheim even having a track lock function.
Yes folks, somehow the size of the radar needed to do this is going
to be ignored, the 3 metre mirror on the Mannheim for example.
And how well it tracked needs to be noted.
>> > German electrical engineers and scientists had perfected an amplifying
>> > device called the 'magnetic amplifier' today refered to as a saturable
>> > reactor. This rugged device made possible the Fi.103/B1, A4/V2 and
>> > for the german navy remote power driven turrets free from the fear of
>> > thermionic vacuum tube failure.
>>
>> Ah yes, we are pausing for the advertising break.
>
> It's a matter of historical fact that the servo technology developed
> in Germany was appreciated and used by the allies post war: untill the
> development of transitors in the mid 1950s and early 1960s the
> magnetic amplifier was the only solid state device around. It made
> possible large gyro stabalised missiles and was used throughout the
> USN post war and turned up in such things as the B-47 tail turret.
Like I said we pause for the advertising break.
>> > The systems of the Prinz Eugen
>> > rather surprised the USN and untill the mid to late 1950s
>> > revolutionized power electronics until the event of solid state power
>> > electronics.
>>
>> Actually what the USN looked at closely was the passive sonar
>> on board the cruiser, in particular things like wavelengths.
>
> And the magnetic amplifiers.
So far it seems the sonar was the target.
to quote the web site,
"The German system used "magnetic amplifiers" which were also a kind
of AC electric transformer, but did not use any vacuum tubes to amplify
the leverage (voltage) of the control circuits--they acted more like the
nested coils in the ignition system of automobiles. They seem to have
been quite satisfactory and U.S. ordnance designers studied them
carefully during and after WWII. In some functions, the German
developed magnetic amplifiers turned out to be best and the U.S. Navy
adopted them after WWII, but synchroes seem to have been best for
raw power output for controlling weapon train and elevation machinery
and are still used in many cases by many navies, though digital computer
controls are gradually replacing them today. "
Eunometic translates this to revolutionised.
>> > Another unique aspect of the German systems was the
>> > large number of computers/directors which allowed the ships to engage
>> > a larger number of targets. Due to the restrictions of the Versailes
>> > treaty and the fear of war with Poland in the 1930s the Germans saw
>> > fire control as a manner of improving the odds.
>>
>> The Bismarck class carried 6 directors for 8 AA turrets, the
>> Hippers 4 directors for 6 AA turrets.
>
> Indicating a well founded fear of saturation attacks.
Or an early appreciation the directors were important and there
was a need for redundancy.
>> The RN went with 4 directors for it main ships, 2 turrets per
>> director, the USN battleships also went with 4 directors.
>> Ark Royal and the Illustrious class actually had more main AA
>> directors than the standard US carrier.
Somehow this is not evidence of fearing saturation attacks but rather
the appreciation of the need for director controlled fire.
>> > (The bismark had these systems but the front set of 4 turrets had been
>> > upgraded to a faster traversing design while the rear had not, when
>> > the Swordfish approached the Fire Control Systems did not take into
>> > account the slower traversing units, thus the swordfish got through
>> > the heavy FLAK at which point the inferior German medium 37mm let them
>> > through)
>>
>> The idea the wild weather with its bad visibility had nothing to
>> do with the situation is remarkable. Bismarck was actually sailing
>> through a weather front when the second Swordfish strike tried
>> to attack, the aircraft were split up, sections attacking individually,
>> which should maximise AA effectiveness.
>>
>> There was no saturation of the defences.
>
> There was a dispersal of the defences and the approach was from where
> the guns had not been properly set up to use the directors.
The Swordfish attacked in sequence, enabling concentration on
each sub attack. This is not dispersal of the defences. That would
have happened if the original attack plan had worked.
And I like the idea the directors could not control the guns.
Tell us which arcs were blind spots for the director controlled guns?
Really smart design.
>> > The lack of Duel Purpose (eg 5 inch guns) on German capital ships
>> > which used sperate 6 inch (presumably to deal with the fear of on
>> > rushing destroyers) and 4 inch guns (for FLAK) shows I feel perhaps a
>> > doctrinal problem of immaturity from lack of experience but a fear of
>> > on rushing destroyers and saturation attacks that comes from expecting
>> > to be the numerically inferior force.
>>
>> Or perhaps the same reason the RN went to the 5.25 inch gun for
>> its battleship secondary armament, the need for a shell to make a big
>> mess of any attacking destroyer meant 4 inch guns were simply too
>> light.
>
> The Germans went for 150mm guns in order to try and gain an advantage;
> also because Polish destroyers had been exceding treaty calibres with
> the use of 135mm or 140mm guns.
The Poles were not bound by any treaty and they were heavily
outnumbered. Seems rather strange so few destroyers with
only one port to shelter in are so important.
Try the heavier shells are the ones to stop attacking destroyers.
> The Narvick class destroyers 6 inch 150mm guns had sufficient
> elevation for them to be used in the FLAK role.
Yes joke time again. Note their elevation and training rates. Plus
the fire controls used.
>> The one criticism of the USN 5 inch 38 was "lightness", when
>> dealing with ships, hence the idea of the USN 5 inch 51 calibre.
>>
>> And as for Bismarck there is simply the way it was an updated
>> Baden class, with an AA suite added.
>
> The myth, normally repeated with the claimed 'fact' that the German
> battleships had their FCS above the armour belt has been dismissed by
> examination of the wrekage of the Bismark.
Is FCS supposed to be fire control system? Like in all those
director hoods seen around the superstructure. Or is the idea
to note the computer was below the armoured deck and then claim
the entire system was. Rather hard to take a range from below deck.
One of the things the design apparently did was have the
communications lines above the armoured deck.
> See http://en.wikipedia.org/wiki/German_battleship_Bismarck, the ship
> was far more than a 'Baden' class and its armour appears to have not
> failed despite the lack of the 'all or nothing' armour concept.
Simply put it was based on the Baden class. And I am not very
worried whether the belt armour was penetrated or not certainly the
turret armour was.
>> > Where the German navy fell behind was in high frequency radar or and
>> > something called 'lobe switching' which German officers had been
>> > offered in 1935 but had rejected.
>>
>> Somehow the Germans always seem to do it but never actually use it.
>
> In this case they did and could have done it much earlier.
Oh good, at least they did something this time.
> Lobe switching was demonstated in 1935 at GEMA and incorporated as a
> retrofittable item to GEMA's Seetakt radars delivered to the Germany
> Navy. It was incorporated into GEMA's Freya radars delivered to the
> Luftwaffe as well as Lichtenstein radars. It was a stodgy procurment
> decision only by the German Navy. Fritz Trenke, a German WW2 radar
> expert, describes it being incorporated from 1940 so maybe the it was
> only lower radar power that put the German ships at an disadvantage.
So the idea is it was around in 1940 and helped overcome the limits
of larger wavelengths, correct?
> Doctrinally the German navy believed that radar would disclose the
> position of a ship and should only be used for ranging in combat or as
> a navigation aid.
In other words the same radio silence ideas that limited radio and
radio beacons on board ships.
> Night vision optics and passive infrared imaging
> and ranging systems were thus developed and deployed. Of course
> radar outperformed the optical systems at night and in bad weather.
Once radar was demonstrated funds were directed there.
> The PPI version of Hohtenweil could also use lobe switching and
> despite its 53cm wavelenght could still find a life raft or a
> periscope.
Welcome to 1945 German radar in limited production, with a resolution
of 3 degrees, 20 km range in a surface ship, 53 cm wavelength made it
hard to pick up periscopes.
>> > However around 1942/43 Telefunken
>> > engineers succeeded in a revolutionary improvements in powerful high
>> > frequency disk triodes able to produced high power outputs (50kw) in
>> > the 10-27cm range which while not in the league of the magnetron in
>> > high frequency was enough to aim guns by with modest antenna the final
>> > system allowed slaving of remotely power guns to the FuMO 231 Euklid
>> > fire control system intended for the Z55 class of destroyers that had
>> > very sophisticated AAA defenses.
>>
>> What we have here is the Germans are allowed what they are supposed
>> to built past war as proof of german technology. The RN is restricted to
>> only the wartime systems it used.
>
> Early 1945 the RN introduces track locking AAA radar.
Actually it appears to be earlier than 1945.
And the German developments are as usual over praised.
> Around the
> same time the German start production of the same thing.
With zero deployments.
> A few months lag in serive intorduction at most.
Oh sorry it is just that those "few months" are longer than a few and
the measurement is few if German and many if RN etc.
> It was 1943 before even a PPI
> centrimentric set became available to the convoy escorts and british
> warships.
Not the bigger warships, the convoy escorts had to wait.
And compared to 1945 for the Germans you mean?
> The USN was clearly ahead. The RN not so much at all.
So the USN is presumed to have track locking radar in 1944 or
earlier I presume. Sort of ignores the trading of information between
the RN and USN.
>> In which case note the RN mark VI fire control, it just made WWII.
>>
>> The Z55 class were a paper project. It will be interesting to see how
>> many of these revolutionary electronic devices made it into service.
>
> They were being fitted out in the docks. They were not a paper
> project.
Where do all these junk claims come from. None of the ships
were launched and they were cancelled in 1944/45.
>Euklid had been built, tested and production had started
> and one seems to have been fitted.
Oh yes again one set is good enough. Going to note the RN
and USN one only sets in 1944 and 1945?
> The guns were proably similar to the FLAK 40 with power drawn in and
> intergral fuze setting. At 5 inches/127mm and 45 calibres it was
> proably more powerfull than the US 5"/38 and had a better fuze setting
> mechanism.
Yes folks, the Germans never did it but hey they would have
yet again eventually.
> You can see the round in the fuze setter here:
> http://www.missing-lynx.com/library/german/flakarticle_dmouritzsen12.jpg
> It shows a shell in the fuze setter ready to be flipped into the
> ramming position.
And this is supposed to show what, as long as the Germans have
a prototype it counts? So the RN prototype guided missiles count
as WWII weapons?
> Note the use of single piece amunition as oppsed to the seperate
> propellent cartridge.
Which is what AA guns wanted in order to avoid extra delays.
>> The problem with radar fire control is the width of its beam, the
>> smaller the wavelength the smaller the width, and so the lower the
>> chance the radar is tracking a nearby aircraft, not the one the guns
>> are trying to shoot at. Of course larger antenna arrays can reduce
>> the beam width but that costs weight.
>
> Indeed, though the problems of tracking and acquistion with a narrow
> beam introduces new issues that were intially hard to solve.
So those wonder 1942 USN sights were not that good in 1942?
>> The 1944 USN mark 61 for the 40 mm projected the radar display
>> onto the sight's field of view to help solve this problem.
>
> I believe it entered service in 1944.
I like this, the 1944 mark 61 entered service in 1944.
>> It should be noted the light AA directors did not have to be as
>> sophisticated as the main gun directors, the ranges were that
>> much shorter, errors mattered less and speed of solution was
>> important given the speed of the aircraft, so you could "cut
>> corners".
>
> Actually I think that 'cutting corners' was a result of the technolgy
> to produce a miniturised fcs was just not there yet.
No, it is the reality cutting corners cut down complexity, time
delays and weight, not manufacturing problems.
> The B-29 had a better FCS then most naval guns.
Given the problems involved and how late it was developed
this would not be surprising.
>> And of course it was things like proximity fuses that enabled
>> the heavy AA guns a real chance against rapidly closing aircraft.
>
> Even without proximity fuzes radar proper radar directed (M9 director
> and SCR584) gun fire was quite effective.
So now we are on land it seems.
> FuMO 231 would have also produced a big increase in effectiveness.
Again the Germans would have.
> Note during the Anzio landings in 1943 the Germans effectively jamed
> the US armies SCR-284gun director radars with noise jamming and duppel
> (window) and the SCR 584microwave radar had to be rushed.
Interesting if true. Since the references I have do not mention the
fact I am assuming a Eunometic exaggeration again.
Particularly as SCR-284 was a voice radio. SCR-584 was a
gun laying radar.
>> > Smaller German ships lacked the the remote power control however the
>> > directors appear to have been fully tachimetric the problem with HACS
>> > was the lack of support for full velocity calculation and the rougher
>> > firing solution rather than the lack of remote power control for the
>> > guns in most early British Navy heavy AAA.
>>
>> The German destroyers never mounted DP guns, pre war their
>> AA was four 37mm pieces. The Germans then went to the
>> 5.9 inch gun as the destroyer armament.
>
> The 5.9 inch guns of the Narvik class had a resonable high elevation
> capability, enough to be used a FLAK
What a joke, 8 degrees a second training and elevation in the twin
mount, despite the 65 degree maximum elevation, one round per
7.5 seconds.
So far no good information on the single mountings.
>> It was not until the never completed Z46 class that the new
>> 5.1 inch gun in twin DP mounts was projected as the main
>> armament, together with six improved 37 mm pieces and
>> eight 20mm guns.
>
> The intention was that EUKLID FuMO 231 director would be used and the
> 37mm pieces would have been replaced by the 5.5cm Garaet 58 'one hit
> to kill' weapon while the 2.0cm pieces would be replaced by 30mm guns
> based on the Luftwaffes Mk 103. A gun with much higher cadence, throw
> weight and better ballistics than the quadvierling.
Yes the idea here is to use things the Germans never built or were still
in the laboratory as proof of their skill.
Meantime the RN is confined to systems in production, the wonder
is why anyone thinks the Germans were that bad they need this sort
of rigging.
>> Even the pre war torpedo boats, despite mounting the 4.1 inch
>> gun, restricted maximum elevation to 50 degrees.
No reply here.
>> > In my opinion the British Army was the Cinderella of the services:
>> > its 3.7 inch QF gun showed that a good job could be gun when the
>> > automatic fuze setter and power loader was added and latter remote
>> > power control. The Royal Navies radars were also based on the UK
>> > Armies AMES radars.
>>
>> This is interesting, what ever happened to the RAF systems. The RN
>> and RAF were both experimenting with radar pre war.
>
> The good stuff, pre microwave, came out of the Armies 50cm work AMES
> radars this includes chain home low and the Type 284 and 285.
Ah I see, some of the RN and RAF radars were based on British
army work, which became all RN radars were based on the work.
In other words the services swapped information and came up with
improvements, whereas in the early development the German navy
and air force went their own ways.
>> Then the
>> British hit a jackpot with the cavity magnetron.
>
> Indeed, luckily for them someone recognised its value.
Ah yes, allies are lucky, Germans are just good.
>> > The RN simply seems to have gotten it wrong and then, having not
>> > cultivated the skills and manufacturing industry to make the control
>> > gear necessary found it difficult to improve its systems in the
>> > quantities required.
>>
>> Of course this ignores the long development times involved in
>> actually creating sophisticated fire controls, and the fact that
>> not even the US had spare fire controls for the RN indicates
>> the manufacturing effort.
>
> It doesn't ignore the long development times involved. It does quite
> the opposite.
I note the development times were not mentioned, instead the RN
lacks skills and the British manufacturing industry. Amazing that,
in two sentences the British are just lucky, then stupid and weak.
> The failure to plan a succesor for HACS early enough created many
> problems.
Sort of like Hitler starting his 1944/45 war in 1939 caused all sorts of
problems for the German navy?
Perhaps the pace of rearmament had its usual logic, better was the
enemy of many?
>> And of course the RN did improve the systems, more gyro controls
>> and of course radar which provided a short cut, given the size and
>> development time of any new mechanical computers. (Hint, the USN
>> mark 37 computer was so big it needed to be below decks, and this
>> made it hard to fit to older ships). The cavity magnetron meant
>> smaller radars, less weight, and narrower beams, good for fire
>> control.
>
> The RN habbit of revamping old ships into new ones to circumvent naval
> limitations treaties undoutably contributed to this.
What a really strange reply, perhaps examples of this revamping
could be given?
Also the whole point about the mark 37 upgrade is that it required
a significant refit, probably major structural work to create the space
in the ship to mount the new equipment. So the ship needed to have
the ability to carry the extra weight and volume, the older cruisers and
destroyers were not likely to have the margin and the USN could not
afford the ships being out of action for the refit periods.
When the Savannah was upgraded it was blistered, adding about 8
feet to the beam, the alternative was surrendering a main gun turret.
ken...@cix.compulink.co.uk
<47c506e9$0$27303$5a62...@per-qv1-newsreader-01.iinet.net.au>,
gsinc...@froggy.com.au (Geoffrey Sinclair) wrote:
> Oh good another Eunometic declared result, the gun is downgraded
Besides as I said in my last post no 2pdr had a MV of 650m/s anyway.
> It would be good to define medium AA for a start, 2, 3 or 4 inch?
Medium AA was defined as weapon to fill the gap between the maximum
effective height of light AA and below the point where heavy AA
mountings lacked the angular speed to track aircraft. Both Britain and
Germany tried to build this but failed to produce satisfactory weapons.
Britis development was based on the 47mm (6pdr) coastal artillery
weapon. Germany produced guns in 50 and 55mm calibres. IIRC the Germans
mounted a few single 50mm mounts on ships. The 3 inch AA gun was
designated as heavy AA in British records.
By accepted definitions nobody had medium AA in general service during
WW2, god knows what Eunomotic thinks medium AA was.
> Ah I see, some of the RN and RAF radars were based on British
> army work, which became all RN radars were based on the work.
All British RADARS were developed by the same organisation starting
with the Chain Home at the experimental station at Bawdsey. As a result
there was a lot of overlap between Naval and Army equipment. Come to
that there was overlap between Navy and RAF systems. This was mainly in
transmitters and recievers.
> What a really strange reply, perhaps examples of this revamping
> could be given?
Presumably he is refering to the rebuilds on some BB due to the
extension of the building holiday in 1930. The County class crusers were
also rebuilt to take advantage of the fact they came out underweight
with aircraft facilities and extra AA added.
Things he has failed to mention was that the heavy and light AA fitted
to RN ships at the start of the war was much the same for ship size as
that on KM ships. The 4.5 inch fired the same weight shell and had a
better performance than the US 5/38 and German triaxial mountings did
not take kindly to shipping water.
Ken Young
Geoffrey Sinclair
news:390dfe37-5d40-4725...@f47g2000hsd.googlegroups.com...
(On RN Fire controls)
The most comprehensive set of figures for naval AA
performance I can easily find is the set relating to the
USN in the period 1 October 1944 to 31 January 1945,
broken down into Kamikaze and non Kamikaze attacks, then
by 5 inch common shells, 5 inch proximity fuse, 3 inch,
40 mm, 1.1 inch, 20 mm and 0.50 inch.
The following table is weapon or shell, (kills /
ammunition use per kill for Kamikaze) / then for non
Kamikaze actions.
5 inch common / (19/1,162) / (33.5/960)
5 inch proximity / (24.5/310) / (20/624)
3 inch / (6.5/710) / (4/752)
40 mm / (114/2,272 / (46/3,361)
1.1 inch / (1/2231) / (no kills/4,764)
20 mm / (62.5/8,972) / (50.5/7,152)
0.50 inch / (2.5/28,069) / (3/15,139)
To emphasise the way these are a guide the figures also
give monthly average expenditure per kill, so for 5 inch
common in non Kamikaze actions the figures range from
748 in October to 2,601 in November 1944. The Kamikaze
actions vary even more so, minimum 493 in December 1944
and maximum 2,675 in January.
It is interesting to note the way 5 inch proximity fuses
were much better against Kamikazes nearly 4 times as good
on average than the 5 inch common but only about 1.5 times
as good for conventional attacks, showing the speed of the
Kamikaze attack was stretching the fire controls. The way
the Kamikazes came closer to the ships helps explain the
improvement in 3 inch and 40 mm kill rates, but the reverse
is true of the 20 mm and 0.50 inch presumably for the
reasons mentioned in many references, by the time the
lighter guns were in action the need was to destroy the
aircraft, not bring it down and they were too light.
The above figures do not give the other factor which is
the ratio of damaged to shot down attackers. The figures
in Mighty Eighth War Diary are a guide, though of course
the aircraft involved were much more damage resistant than
anything the Japanese had and they were much higher in the
sky, making them harder to hit. On the other hand the flak
concentrations around the oil refineries were heavy.
In the following examples I am using oil targets on days
when visual bombing was done and the bombers reported
zero or a few air to air kills.
So when 262 the 8th Air Force B-17s hit mainly oil targets
on 20 July 1944 2 were lost and 153 damaged. The raid on
Politz by 142 bombers saw 17 shot down and 106 damaged.
The raid by 209 bombers on Zeitz and Rositz lost 6 bombers
and had another 88 damaged. So AA fire was clearly hitting
many more bombers than shooting them down.
As an aside the 28 July 1944 raid on Leuna by 652 bombers
plus another 62 attacking other targets used radar bombing,
claimed 1 kill and lost 7 bombers plus 217 damaged.
Anyway with that in mind we turn to force Z versus the IJN
in December 1941. The main reference being used is
Battleship my Middlebrook and Mahoney, which uses the
Japanese official history as the source for Japanese losses.
The weather was clear, the sea calm.
8 level bombers, Prince of Wales initially plotted them at
range 16,500 yards assuming the enemy altitude was 10,000
feet and speed 200 mph, "really reliable" range at about
12,000 yards which was when firing began. The system was
the gunnery officer pressed a button and the guns were then
automatically fired at the correct time for the fuse settings.
Repulse opened up at 11,000 yards, the attack was made on
Repulse but the aircraft flew over Prince of Wales.
Prior to the attack Admiral Phillips had ordered a 30
degree turn to starboard then as the guns were firing a
50 degree turn to starboard. The result was the AA guns
on each side of the ships were able to fire, then masked
then able to fire. With gaps between masking an unmasking.
The light AA guns were not within range of the attack.
One bomb hit. 108 5.25 inch and 36 4 inch rounds were fired
hitting 5 of the 8 aircraft, two of which immediately aborted.
Second attack by 9 torpedo aircraft, initially flying at about
7,000 feet but diving, aiming for Prince of Wales, the attacks
were delivered at 150 knots and 33 metres in height. Torpedoes
released at 1,500 to 600 metres, the longer ranged ones possibly
due to HMS Express being in the way. Twelve 5.25 inch salvoes
had been fired before going over to barrage fire. The pom
poms were suffering ammunition problems, causing one to jam
12 times and another 8 times. The aircraft swept over Prince
of Wales machine gunning it. One aircraft was shot down just
after torpedo release, 3 others sustained minor damage.
Two torpedo hits, the killer was aft near the propeller shaft,
dropping speed to 15 knots and causing at least an 11.5 degree
list. With the stern now 2 feet above water level, not the
usual 24 feet. Most of the AA guns lost power for a while.
Third attack by 7 torpedo aircraft on Repulse, coming in
at over 200 knots, Repulse had the same pom pom ammunition
problems and one if its mounts had lost power because of the
bomb hit. (There is a contradiction in the records here,
the Japanese claim another 8 torpedo bombers attacked as
well but the British do not record it, this second squadron
reported no aircraft damaged for 4 hits) Also 6 level bombers
attacked, the remainder of the original bomber formation dropping
their second bomb. Two of the 7 torpedo aircraft had hang ups,
one did a lone attack to release it, four of the seven received
light damage.
All up according to Japanese sources 8 bombers and 24 torpedo
aircraft had attacked claiming some bomb and 7 torpedo hits on
Repulse for 1 aircraft lost, 2 seriously damaged and 10 slightly
damaged. So far Repulse had taken one bomb hit and Prince of
Wales two torpedo hits and men had been lost to machine gun fire.
Prince of Wales lost all power the aft part of the ship, making
the aft heavy AA guns effectively useless, the list meant the
forward heavy AA guns could be elevated but not trained.
The next attack was by 26 torpedo bombers, one squadron attacked
scoring 4 hits on Prince of Wales from 6 torpedoes fired. A second
took on Repulse scoring 1 hit and the final 9 did the best attack of the
day, losing two aircraft and scoring 3 hits on Repulse, which also
took a long range strike from one of the second squadron to attack.
All up some 2 aircraft were shot down, 3 seriously damaged and 5
slightly damaged during this attack. One of the pom pom crew
recorded the torpedoes were being launched out of effective range
of the pom poms, so they shot down the aircraft crossing the ship
instead of switching fire as per doctrine to aircraft that had not
attacked yet.
Final bombing attack 8 level bombers, target Prince of Wales,
two heavy AA turret could shoot but the their range taker had
been wounded. The second round of torpedo strikes had solved
the list problem. One bomb hit scored for 5 damaged bombers.
By the looks of things Force Z expended under 400 rounds of
heavy AA ammunition plus plenty of light AA rounds. For 3
kills, 5 heavily damaged and 20 lightly damaged. Out of 72
attacks (22 bomber, 50 torpedo) noting 6 aircraft did two
attacks, so 66 aircraft.
People can decide for themselves how good the above
results were, with the additional note as the first torpedo
strike came in Admiral Phillips was certain it was not
a torpedo strike.
One final point attacking aircraft need to be flying straight
for a time before releasing their weapon. Slips or skids will
skew the aim. Dive bombers are at a constant speed losing
height at a constant rate. Torpedo bombers want to avoid
tossing the torpedo or causing it to dive further than normal
when entering the water so try to be in level flight.