M1A1 Abrams Ponderings
Christopher Stoner
From sto...@snake30.cs.wisc.edu (Christopher Stoner)
I've been reading two illuminating books on the Desert Storm campaign,
one is _Triumph Without Victory_ by the U.S. News and World Report staff and
the other is _From Shield to Storm_ by James Dunnigan. Both have some inter-
esting insights on the M1A1 Abrams during that campaign.
In TWV there are the standard accolades to the Abrams such as it's
superior fire-control and acquisition system (particularly the thermal sight
in the obscured visual environment) and the accuracy of the Rheinmetal 120mm
gun. The downside was viewed as fuel consumption (an armored brigade requiring
some 100,000 gallons of fuel per day) tied to a rapid advance and stretched
supply lines. The most interesting flaw, which is related to comfort while
operating in the drizzle experienced in the first two days of the land cam-
paign, is how often it is sited that the hatch seals of the M1A1 were so
poor that they leaked continuously (some drivers were described as sitting in
a pool of water in their seats). The M1A1 was brought to the theatre not only
because of it has superior armament to the M1's L-7 105mm gun but also because
it has an advanced overpressure NBC system (remember the chem war fears?).
The fact that the hatch seals were so leaky seems to indicate that it was a
good thing chem weapons were never used since the Abrams could hardly be con-
sidered to have NBC integrity!
My favorite Abrams story from the war comes from FSTS. It tells of a
bogged down M1A1 that had been left by it's unit to await a recovery team.
The tank was jumped by 2 Iraqi T-72s at nearly point-blank range. It was hit
at least twice by the T-72s but quickly dispatched them, including a hail-mary
shot that passed through a sand-dune before destroying an Iraqi tank. The
T-72 125mm hits mearly "dented" the Abrams' armor and it was sucessfully re-
covered. Another anecdote tells of a stuck Abrams that needed to be destroyed
in place. After the explosives went off it was found that the roof panels
in the turret had blown out and that the majority of the explosion had been
directed out through the hole. That tank was also successfully recovered and
repaired!
Iskandar Taib
From nt...@silver.ucs.indiana.edu (Iskandar Taib)
In article <C45Cs...@law7.DaytonOH.NCR.COM> sto...@snake30.cs.wisc.edu (Christopher Stoner) writes:
>Another anecdote tells of a stuck Abrams that needed to be destroyed
>in place. After the explosives went off it was found that the roof panels
>in the turret had blown out and that the majority of the explosion had been
>directed out through the hole. That tank was also successfully recovered and
>repaired!
Wouldn't this be bad for security? There'd be pieces of Chobham
armor lying around for everyone to see. I suppose that might be
worse than leaving an intact tank behind though...
As an aside, how many Abrams were lost during Desert Storm, and
to what causes or weapons? How many were lost to friendly fire,
and of those, to A-10 cannon?
--
-------------------------------------------------------------------------------
Iskandar Taib | The only thing worse than Peach ala
Internet: NT...@SILVER.UCS.INDIANA.EDU | Frog is Frog ala Peach
Bitnet: NTAIB@IUBACS !
sil...@cs.uiuc.edu
From sil...@cs.uiuc.edu
>As an aside, how many Abrams were lost during Desert Storm, and
>to what causes or weapons? How many were lost to friendly fire,
>and of those, to A-10 cannon?
I think that there were no Abrams lost. (There were some which were battlefield
KOs but were recovered and repairable.) I don't think that there were any
major friendly fire problems with Abrams as targets. Most of the problems had
to do with misidentification of LAVs, Bradleys or Warriors as Soviet made
APCs.
Don Johnson
From Don Johnson <joh...@amsaa-cleo.brl.mil>
In article <C4D8q...@law7.DaytonOH.NCR.COM> nt...@silver.ucs.indiana.edu (Iskandar Taib) writes:
>From nt...@silver.ucs.indiana.edu (Iskandar Taib)
>>In article <C45Cs...@law7.DaytonOH.NCR.COM> sto...@snake30.cs.wisc.edu (Christopher Stoner) writes:
>>Another anecdote tells of a stuck Abrams that needed to be destroyed
>>in place. After the explosives went off it was found that the roof panels
>>in the turret had blown out and that the majority of the explosion had been
>>directed out through the hole. That tank was also successfully recovered and
>>repaired!
>
>Wouldn't this be bad for security? There'd be pieces of Chobham
>armor lying around for everyone to see. I suppose that might be
>worse than leaving an intact tank behind though...
As has been discussed in this forum before, the Abrams series was designed
with crew survivability as a primary goal. The roof panels described above
are "blow off" panels in the roof of the ammo bustle. If an ammo event
occurs, the "blow off" panels will vent the explosion upward and away from
the crew. This in addition to the ballistic doors separating the crew from
the ammo bustle, allow the crew to live through a catastrophic event.
And if the TC is cool headed enough and swings the turret so the bustle
isn't over the engine deck, the driver may be able to move the tank to safe
territory.
I have never heard of any tank putting Chobham-type armor in roof sections.
If you have some info on this, I'd like to know about it.
--
O tempora! O mores!
W. Donald Johnson
Operations Research Analyst
joh...@amsaa-cleo.arl.mil
Curtis Fennell
From Curtis Fennell <ch...@harvey.gte.com>
In article <C4D8q...@law7.DaytonOH.NCR.COM> nt...@silver.ucs.indiana.edu (Iskandar Taib) writes:
>Wouldn't this be bad for security? There'd be pieces of Chobham
>armor lying around for everyone to see. I suppose that might be
>worse than leaving an intact tank behind though...
It's generally known that the Russians, at least, have the formula for
Chobham armor or at least enough information to recreate it. The
problem for the Russians (or anyone else who wants Chobham armor) is
not so much in having someone know how to make it, but rather in
having the ability to make it. Russian (formerly Soviet) technology
was far behind western technology in materials, especially in ceramics
and composites. Even if they did have the exact formula for Chobham
armor, they couldn't reproduce it in sufficient quantities to be a
threat.
As far as recovering the tank goes, the reason that they were going to
try to destroy the M1 in place was that during a fast moving mobile
operation like Desert Storm, they wouldn't have time to actually
recover the tank. So they probably removed as much of the equipment
as they could in a short period of time and used explosives to make
the tank as unuseable as possible. Then they got on with the attack.
Once the war was over, they went back, and after examining the tank
further, determined that it was salvageable.
Curt
Curt Fennell * ch...@gte.com
Unix System Administrator * (617) 466-2142
GTE Labs, 40 Sylvan Road * "One should forgive one's enemies,
Waltham, MA, 02254 * but not before they are hanged."
Dave Pierson
From Dave Pierson <pie...@cimill.enet.dec.com>
In article <C45Cs...@law7.DaytonOH.NCR.COM>, sto...@snake30.cs.wisc.edu
(Christopher Stoner) writes, in part:
> I've been reading two illuminating books on the Desert Storm campaign,
>The most interesting flaw, which is related to comfort while operating in the
>drizzle experienced in the first two days of the land campaign, is how often
>it is sited that the hatch seals of the M1A1 were so poor that they leaked
>continuously....
>...but also because it has an advanced overpressure NBC system (remember the
>chem war fears?). The fact that the hatch seals were so leaky seems to
>indicate that it was a good thing chem weapons were never used since the
>Abrams could hardly be considered to have NBC integrity!
"Advanced Over Pressure NBC System" _means_ it leaks. It Leaks OUT.
Outside air is drawn in thru a suitable filter/deactivation canister,
creating a moderate over pressure internally. It exits thru "leaks",
presumably designed in. To preserve the active material, the system is
kept switched off, except when needed. (I assume...).
This is no excuse for leaking water on the crew. There should have been
some means of preventing that. But the NBC integrity was not faulty,
based on what was said.
thanks
dave pierson |the facts, as accurately as i can manage,
Digital Equipment Corporation |the opinions, my own.
pie...@msd26.enet.dec.com |I am the NRA
"He has read everything, and, to his credit, written nothing." A J Raffles
ja...@cas.org
From ja...@cas.org
In article <C4GF...@law7.DaytonOH.NCR.COM>, you write:
|>
|> From sil...@cs.uiuc.edu
|>
|>
|>
|> >As an aside, how many Abrams were lost during Desert Storm...
|>
|> I think that there were no Abrams lost...
There seems to be have been a fair bit of downright astonishment
at the performance of the M1 in Desert Storm, especially at its
near-invulnerability. A discussion of the contest between the
T-72 and the M1 in "Military Technology" about a year ago was
extremely informative.
The strength of the armour was demonstrated by a story about
an M1 taking two hits from a T-72 at 500 yds. The driver thought
the first hit was a small mine. The second removed these doubts
and the T-72 was taken out before it could fire a third. There
wasn't even a momentary loss of electronics with either hit.
Another interesting point was gun performance. Although the T-72
gun has a higher muzzle velocity, the comparatively large cross-
section of the long rod penetrator of the APFSDS round lead to:
a. a rapid loss of kinetic energy through air resistance,
b. less force applied per unit area when the penetrator hits the
target.
The critique of Soviet tank design in the article was damning.
Alec Chambers
s...@email.sp.paramax.com
From s...@email.sp.paramax.com
nt...@silver.ucs.indiana.edu (Iskandar Taib) writes:
> Wouldn't this be bad for security? There'd be pieces of Chobham
> armor lying around for everyone to see. I suppose that might be
> worse than leaving an intact tank behind though...
As I recall, the deck and turret roof armor isn't Chobham,
it's normal armor steel. Until top-attack ATGM's become more
common, there's not much advantage to armoring the roof with Chobham,
and it's more expensive.
Scott
Alec Lee
From Alec Lee <al...@mnemosyne.cs.du.edu>
In article <C4IBF...@law7.DaytonOH.NCR.COM> Dave Pierson <pie...@cimill.enet.dec.com> writes:
[lotsa stuff deleted]
> presumably designed in. To preserve the active material, the system is
> kept switched off, except when needed. (I assume...).
There is no "active material" as such. The NBC system uses the turbine's heat
to superheat the incoming air which "burns" the impurities out fo the air. It
then is cooled back to the ambient temperature (or below) You can thus see
how the M1A1's "air conditioning" and "cool suits" were not difficult to
implement. . . but that's a different story.
Alec Lee
John Wesley Lewellen IV
From fa...@leland.Stanford.EDU (John Wesley Lewellen IV)
In article <C4LpC...@law7.DaytonOH.NCR.COM> Alec Lee <al...@mnemosyne.cs.du.edu> writes:
>
>From Alec Lee <al...@mnemosyne.cs.du.edu>
>
>There is no "active material" as such. The NBC system uses the turbine's heat
>to superheat the incoming air which "burns" the impurities out fo the air. It
>then is cooled back to the ambient temperature (or below) You can thus see
>how the M1A1's "air conditioning" and "cool suits" were not difficult to
>implement. . . but that's a different story.
>
>Alec Lee
>
That works fine for most of the bio weapons, and probably most of the chem.
weapons (I personally would worry a little about the combustion products;
in and of themselves they may not be too pleasant) but this system will
do absolutely nothing to help protect the crew against airborne
radiation. Of course, the tank armor is pretty good radiation shielding, but
burning radioactive dust simply gives you smaller radioactive dust particles.
- JWL IV
Iskandar Taib
From nt...@silver.ucs.indiana.edu (Iskandar Taib)
In article <C4IBG...@law7.DaytonOH.NCR.COM> Curtis Fennell <ch...@harvey.gte.com> writes:
>In article <C4D8q...@law7.DaytonOH.NCR.COM> nt...@silver.ucs.indiana.edu (Iskandar Taib) writes:
>>Wouldn't this be bad for security? There'd be pieces of Chobham
>>armor lying around for everyone to see. I suppose that might be
>>worse than leaving an intact tank behind though...
>It's generally known that the Russians, at least, have the formula for
>Chobham armor or at least enough information to recreate it. The
>problem for the Russians (or anyone else who wants Chobham armor) is
>not so much in having someone know how to make it, but rather in
>having the ability to make it. Russian (formerly Soviet) technology
>was far behind western technology in materials, especially in ceramics
>and composites. Even if they did have the exact formula for Chobham
>armor, they couldn't reproduce it in sufficient quantities to be a
>threat.
Hmmm interesting indeed..
I brought this up because a tanker posted a while back that
they were under orders to "not look, cover it up and report
immediately" if they inadvertantly broke into (!) one of the
Chobham armor boxes, so it is apparently sensitive informa-
tion. I was speculating that sundry infantrymen might drive
by the area and find chunks of Chobham lying around 9-)
I always thought that the latest Soviet tanks had Chobhamski
by now, but I guess I'm wrong 9-)
Is there *anything* that can kill an Abrams or any other
Chobham-protected tank with a direct hit on the front where
the armor is thickest? Another Abrams maybe?
Brian
From Brian <br...@coombs.anu.edu.au>
Curtis Fennell <ch...@harvey.gte.com> writes:
>From Curtis Fennell <ch...@harvey.gte.com>
>In article <C4D8q...@law7.DaytonOH.NCR.COM> nt...@silver.ucs.indiana.edu (Iskandar Taib) writes:
>>Wouldn't this be bad for security? There'd be pieces of Chobham
>>armor lying around for everyone to see. I suppose that might be
>>worse than leaving an intact tank behind though...
>It's generally known that the Russians, at least, have the formula for
>Chobham armor or at least enough information to recreate it. The
>problem for the Russians (or anyone else who wants Chobham armor) is
>not so much in having someone know how to make it, but rather in
>having the ability to make it. Russian (formerly Soviet) technology
>was far behind western technology in materials, especially in ceramics
>and composites. Even if they did have the exact formula for Chobham
>armor, they couldn't reproduce it in sufficient quantities to be a
>threat.
Here Curt I must beg to differ. Whilst the generally accepted
view is that the Russians (or as they were the Soviets) were always
far behind in nearly everything with comparison to the West, in the
field of armour composites and construction there is quite a bit of
evidence that they are in fact at least equal, if not actually leading
in certain areas.
As I've mentioned here before, when the then Soviets placed an
unsolicited bid into the British Challenger replacement tank competition
about 3 years ago (the winner was the Challenger II BTW) for the Brits
to purchase T80's they revealed that they were in the process of designing
and building protoypes of a new MBT which would utilise ceramics as
part of the main structure of the vehicle. This is far in advance of anything
which has thus far been attempted in the west with AFV design.
The advantages that utilising such a structure would have would be
considerable. Much lighter, much stronger and much easier to manufacture
(you'd basically mould the vehicle's main structure and then fire it
rather than building it up from sheets of steel) this would be a vehicle
which I suspect would, if provided with even comparable fire control
electronics and gun, would outperform (or at least give them more of a
run for their money than the past has shown) today's generation of
western MBT's.
Where though, I suspect that Soviets have encountered probles m
with fielding such a beastie is in the area of actually taking thie
concept from the protoype stage to the production stage along with the
prohibitive costs of developing an entirely new MBT when you have such
large numbers of the old still lying around basically unused.
--
Brian Ross___...@Coombs.anu.edu.au________________________________________
"Three discoveries are essential to the contented and civilised life -
sex, wine, and bookshops, by no means necessarily in that order."
_________________________________Tony Baker, Adelaide Review, October 1992____
Joshua Follick
From Joshua Follick <follick%hydra....@lynx.unm.edu>
I remember hearing that the reason western tanks in general,
and the M1 in particular have blocky profiles is because the
chobham armor used to protect them can only be formed in sheets,
not in rounded form. So i would expect that the blocky
turret of the M1, at least on the sides, is made of Chobham.
So if the sides of the turret are designed to blast out to protect the
crew, the concern of leaving chobham lying around is reasonable.
However, considering that our beloved military was ready to do anything
to avoid fighting anything but massive war in europe before the collapse
of the SU, I expect they weren't concerned at this possible problem.
--
Old Jedi Master: Ah Joshua, he's more machine now than man, twisted and evil.
Paintball is the sport of the 90s, and Lipservice Crew is the Team!!!
Team Lipservice Crew Motto:
"They Suck, We Rule"
Curtis Fennell
From Curtis Fennell <ch...@harvey.gte.com>
In article <C50t0...@law7.DaytonOH.NCR.COM> br...@coombs.anu.edu.au (Brian) writes:
>Curtis Fennell <ch...@harvey.gte.com> writes:
>>It's generally known that the Russians, at least, have the formula for
>>Chobham armor or at least enough information to recreate it. The
>>problem for the Russians (or anyone else who wants Chobham armor) is
>>not so much in having someone know how to make it, but rather in
>>having the ability to make it.
>
> Here Curt I must beg to differ. Whilst the generally accepted
>view is that the Russians (or as they were the Soviets) were always
>far behind in nearly everything with comparison to the West, in the
>field of armour composites and construction there is quite a bit of
>evidence that they are in fact at least equal, if not actually leading
>in certain areas.
Ah, if it isn't my old friend Brian! Well, he and I have "had at it"
a number of times, so I suppose it was destined to happen again. And
naturally, we disagree on this subject...
First off, during the period when there was a Soviet Union, the
tendancy among the Western Military Powers has been to overrate the
technological prowess of the Soviets rather than to underrate it.
Western "experts" were very surprised when Victor Belenko delivered
his Mig to Japan that the aircraft was as crude as it was. The
aircraft principally relied on the old Soviet method of brute force to
solve their military technological problems.
The Soviets (Russians) were (are) mostly behind the west in
technology. In some technologies, they were nearly equal, if not
ahead, but in others, notably materials, ceramics and composites, they
were woefully behind. In fact, their lack of materials technology is
part of the reason that their electronics were behind the west. Long
after the western military forces began using solid state electronics,
the Soviets were still using tube radios - not because the technology
required was "secret", but because their level of materials technology
wouldn't allow them to manufacture the components needed to construct
the devices.
But my point was not that the Soviets couldn't understand or use the
technology - but rather that they couldn't manufacture it in
sufficient quantities.
> As I've mentioned here before, when the then Soviets placed an
>unsolicited bid into the British Challenger replacement tank competition
>about 3 years ago (the winner was the Challenger II BTW) for the Brits
>to purchase T80's they revealed that they were in the process of designing
>and building protoypes of a new MBT which would utilise ceramics as
>part of the main structure of the vehicle.
First of all, the construction of a prototype does not mean that the
Russians would be capable of mass producing such a vehicle. Second of
all, in order to sell their new designs to the Brits, they may have
"overrated" their capabilities (a technique well known among western
defense contractors). Or they may have been lying entirely.
I know of no example of fielded weaponry that demonstrates that the
Russians are anywhere near our capability in materials, ceramics and
composites technology.
The Soviet design thrust in the late 70's and 80's for advanced
armored vehicles was based around reactive armor, at least partly
because they couldn't manufacture good ceramic-composite/chobham-type
armor.
Dan Sorenson
From Dan Sorenson <vik...@iastate.edu>
Joshua Follick <follick%hydra....@lynx.unm.edu> writes:
> I remember hearing that the reason western tanks in general,
>and the M1 in particular have blocky profiles is because the
>chobham armor used to protect them can only be formed in sheets,
>not in rounded form. So i would expect that the blocky
>turret of the M1, at least on the sides, is made of Chobham.
You're probably right on this. Generally, plastics and
ceramics that can withstand great shear force and heat are not
easily formed. I heard a similar statement regarding the "boxy"
cars that the USA is making today, as opposed to the flowing lines
of the late 60's-early-70's, due to the higher cost of manufacture
and the more brittle but lighter steel being used. Taken on the
whole, the trade-offs seem to be worthwhile.
>So if the sides of the turret are designed to blast out to protect the
>crew, the concern of leaving chobham lying around is reasonable.
One reason I suspect we're seeing these blocky profiles is
because of this reactive armor. It's better to take a HEAT round
and let the armor do its job than it is to try and deflect it with
a rounded turret and thus decrease the amount of armor able to react?
Anybody have anything on this that isn't still classified? One other
thing I suspect is that the tank will likely be utilized such that
hits from the side and rear will be minimized, thus sloping the
front is the primary problem and the sides can be slanted upwards
rather than being curved to deflect AP rounds.
This is, of course, just speculation. I'd like to know
if others have any data that would disagree with this. I just
remembered the flat slabs of steel making up a turret on a battleship.
Perhaps the smooth curves aren't the big criterion in deflecting
AP rounds either?
< Dan Sorenson, DoD #1066 z1...@exnet.iastate.edu vik...@iastate.edu >
< ISU only censors what I read, not what I say. Don't blame them. >
< USENET: Post to exotic, distant machines. Meet exciting, >
< unusual people. And flame them. >
212...@hydra.maths.unsw.edu.au
From <212...@hydra.maths.unsw.edu.au>
In article <C50s2...@law7.DaytonOH.NCR.COM> nt...@silver.ucs.indiana.edu (Iskandar Taib) writes:
>
>From nt...@silver.ucs.indiana.edu (Iskandar Taib)
>
>In article <C4IBG...@law7.DaytonOH.NCR.COM> Curtis Fennell <ch...@harvey.gte.com> writes:
>
>I always thought that the latest Soviet tanks had Chobhamski
>by now, but I guess I'm wrong 9-)
I have a book which makes the claim that the Russians have been putting
Composite (Chobham is a type of Composite) on Glacis plates of their tanks for
years. I believe it mentions that it is believed that T-64's and T-80's have
this fitted as well as (in some cases) Reactive Armour (mainly on the non-
composite armoured turrent).
>Is there *anything* that can kill an Abrams or any other
>Chobham-protected tank with a direct hit on the front where
>the armor is thickest? Another Abrams maybe?
I am told that the Americans have APDSFS-T round which will penetrate the
armour on any tank in the world. (By the way, APDSFS-T stands for *big breath*
Armour Piercing, Discarded Sabot, Fin Stabilised Tracer round.)
So it is safe to assume that other countries have it (or a version) by now.
>Iskandar Taib
Later, *Gonna ride the Wild Winds,
Matthew. *It aint dangerous,
212...@hydra.maths.unsw.edu.au *Enough for me. --- Queen.
Charlie
From Charlie <winc...@t9.cs.man.ac.uk>
>Is there *anything* that can kill an Abrams or any other
>Chobham-protected tank with a direct hit on the front where
>the armor is thickest? Another Abrams maybe?
>From the stories I have heard from the brithish tankers I've talked to,
you can't actually penetrate Chobham with a 120mm FIN (APFSDS) round,
let alone any type of HEAT/HESH round. This was supposed to be using a
Chobham protected turret as a target on the range, for test purposes...
As to secrecy. I know for a fact that on the Challenger I's, the Chobham
armour is bolted into place on the front of the talk, and that when the
tank goes in for its 5 year (I think..) major overhaul at the RAC HQ at
Bovington in Dorset, they REMOVE the Chobham plates, or whatever, from the
tank and store them in a locked safe room, to which only the high ranking
officers have access - likr the 2i/c of the REME detachment on the base
that actually serviced the beasts - a Lt. Col........
>--
>-------------------------------------------------------------------------------
>Iskandar Taib | The only thing worse than Peach ala
>Internet: NT...@SILVER.UCS.INDIANA.EDU | Frog is Frog ala Peach
>Bitnet: NTAIB@IUBACS !
--
--------------------------------------------------------------------------
| Charlie Winckless | "Yea, though I walk through the valley |
| (winc...@cs.man.ac.uk) | of the shadow of death I shall fear no |
| | evil for I am at angels eight zero and |
ErikTrimble
From ErikTrimble <tri...@alleg.edu>
[quotes are from nt...@silver.ucs.indiana.edu (Iskandar Taib) and Curtis
Fennell <ch...@harvey.gte.com> ]
> >
> >I always thought that the latest Soviet tanks had Chobhamski
> >by now, but I guess I'm wrong 9-)
>
> I have a book which makes the claim that the Russians have been
putting
> Composite (Chobham is a type of Composite) on Glacis plates of their
tanks for
> years. I believe it mentions that it is believed that T-64's and T-80's
have
> this fitted as well as (in some cases) Reactive Armour (mainly on the
non-
> composite armoured turrent).
More than likely, this came from the DoD book, Soviet Military Power,
which has a decided interest in overstating the capabilities of soviet (er
Russian) hardware. The "composite" armor that was quoted as being placed
on the T-64, T-72, and T-80 tanks behind the glacis turned out to be
another 6 inches of hardened armor plate. Effective, but hardly composite.
Yes the Soviets did being using reactive armor for many of the same
reasons the Israelis did: it's cheap, fairly effective, and a good way to
upgrade existing tanks that have fallen behind current state-of-the-art.
>
> >Is there *anything* that can kill an Abrams or any other
> >Chobham-protected tank with a direct hit on the front where
> >the armor is thickest? Another Abrams maybe?
>
> I am told that the Americans have APDSFS-T round which will penetrate
the
> armour on any tank in the world. (By the way, APDSFS-T stands for *big
breath*
> Armour Piercing, Discarded Sabot, Fin Stabilised Tracer round.)
> So it is safe to assume that other countries have it (or a version)
by now.
>
[.sigs deleted]
APDSFS-T rounds are for medium tanks and medium-hard targets. They use a
hardened tungsten penetrator. They are not terribly effective against
Chobham. Or even very thick steel armor or reinforced concrete, for that
matter.
The current anti-tank (MBT) round of the US army is the APFSDSDU round
(Armor-Piercing, Fin-Stabilized, Discarding Sabot, Depleted Uranium). The
penetrator uses U-238 mixed with used reactor fuel (U-235). The result is
a much denser penetrator than the tungsten one - thus, an much higher
inertia is generated. This shell will penetrate almost any known armor.
Chobham and similar composites of sufficient thickness (meaning, at least
8"+) can defeat a 120mm or 125mm round of this nature. Anything else is
toast. (Note: the soviets DID have this round).
However, the soviets did come up with a neat solution to defeating Chobham
and other composites: instead of a one-shot, one-kill round, they used
what amounts a solid steel cannonball. This was a 125mm in diameter solid
steel shot, which tended to fracture the armor on an M1 when it hit.
Rather than kill the tank, this shot effectively broke the composite armor
in the panel it hit. Any other hit in this quarter by any normal anti-tank
round would have a hit probability of a kill. As I said, not a single-shot
kill capacity, but an ingenious way to get around the problem,
non-the-less.
-Erik Trimble
tri...@lleg.edu
Isaac Kuo
From Isaac Kuo <isaa...@wish-bone.berkeley.edu>
In article <C54Gq...@law7.DaytonOH.NCR.COM> Dan Sorenson <vik...@iastate.edu> writes:
> One reason I suspect we're seeing these blocky profiles is
>because of this reactive armor. It's better to take a HEAT round
>and let the armor do its job than it is to try and deflect it with
>a rounded turret and thus decrease the amount of armor able to react?
>Anybody have anything on this that isn't still classified? One other
>thing I suspect is that the tank will likely be utilized such that
>hits from the side and rear will be minimized, thus sloping the
>front is the primary problem and the sides can be slanted upwards
>rather than being curved to deflect AP rounds.
Perhaps you are confusing reactive and composite armour. We are discussing
composite armour, which is a whole bunch of different layers of armour.
While the materials themselves might not be classified, the actual THICKNESSES
of the armour layers ARE. Why? Because otherwise, an enemy might just look
at those thicknesses, make a mock up armour plate a little thicker, and design
a weapon sure to penetrate it.
The boxy look is a result of several factors. First, it's easier to
manufacture. Second, the main threats to the tank are now HEAT and APFSDS
weapons, both of which can penetrate sloped armour almost as easily as non-
sloped armour. Third, putting the armour in "boxes" allows them to be replaced
when better armour is developed or needed. This has already happenned with the
M1A1 as all of the new M1A1's have a DPU layer designed to defeat APFSDS.
Unfortunately, the new armour box is a couple inches thicker than the old
anyway... Fourth, composite armour is very very thick. The M60's steel armour
had a frontal thickness of four inches. The M1A1 has frontal armour two feet
thick. It turns out that you get LESS protection from sloped armour from
attacks at a small angle off the front than from very straight armour:
60 degree front arc "Flat" armour Heavily sloped armour
\ / |==========| /===\ /
\ / |\......../| //...\\ /
\ / | \....../ | //.....\\ |/
\ / | \..../ | //.......\\ L_
TANK | \../ | /.........\ Direction "A"
The ... represents protected area. In order to have armour of the same weight,
the sloped sides of the sloped armour must be half as thick as the front side.
An attack from direction "A" will encounter less armour than a directly frontal
attack. An attack from dirction "A" will encounter about the same thickness
of armor against "Flat" armour.
>... I just
>remembered the flat slabs of steel making up a turret on a battleship.
>Perhaps the smooth curves aren't the big criterion in deflecting
>AP rounds either?
Battleship turrets, and the rest of the battleship, has two "orientations"
for armor: horizontal and vertical. These ARE sloped away from enemy shells
when the ship is in its zone of invulnerability. This zone is a washer shaped
area surrounding the enemy ship, and when the battleship is in this zone,
the enemy shells hit at an angle--too steep to penetrate the side armour
and too shallow to penetrate the deck armour. In the heyday of the big gun,
it was really hard to defend against close range, near horizontal fire, and
long range, plunging fire. Thus, the compromise...
--
*Isaac Kuo (isaa...@math.berkeley.edu) * _______
*"How lucky you English are to find the toilet so amusing.* _____(___o___)_____
* For us, it is a mundane and functional item. For you, *(==(_____________)==)
* the basis of an entire culture!" Manfred von Richtofen * \==\/ \/==/
Erik Svensson FOA2
From er...@lin.foa.se (Erik Svensson FOA2)
>From Curtis Fennell <ch...@harvey.gte.com>
(some stuff deleted)
>First off, during the period when there was a Soviet Union, the
>tendancy among the Western Military Powers has been to overrate the
>technological prowess of the Soviets rather than to underrate it.
>Western "experts" were very surprised when Victor Belenko delivered
>his Mig to Japan that the aircraft was as crude as it was. The
>aircraft principally relied on the old Soviet method of brute force to
>solve their military technological problems.
This really rather interesting. When ever the west has seen real evidence that
soviet stuff was crap there was always some kind of explanation that the stuff
the _soviets_ used was magnitude or more better. There has never been
any sort of support for this theory. Another theory was that that the new stuff
coming out sov factories was really hell on wheels, nothing like what we saw
now. There has never been any support for that either.
>I know of no example of fielded weaponry that demonstrates that the
>Russians are anywhere near our capability in materials, ceramics and
>composites technology.
Very true.
cheers
--
Erik Svensson
Research Officer National Defense Research Establishment (FOA)
Guided Weapons Division Stockholm, Sweden er...@sto.foa.se
NEW MAILING ADRESS: er...@sto.foa.se
"I like maxims that don't encourage behaviour modification." -- Calvin
Michael Gallagher
From Michael Gallagher <gall...@oasys.dt.navy.mil>
In sci.military, br...@coombs.anu.edu.au (Brian) writes:
> As I've mentioned here before, when the then Soviets placed an
>unsolicited bid into the British Challenger replacement tank competition
>to purchase T80's they revealed that they were in the process of designing
>and building protoypes of a new MBT which would utilise ceramics as
>part of the main structure of the vehicle. This is far in advance of anything
>which has thus far been attempted in the west with AFV design.
Actually, the USMC and US Army have built and tested four composite
hull combat vehicles.
The USMC has built and tested two composite M-113s, one of which
has gone through a simulated life of 20 years (2000 hours) and racked
up 32,000 miles without a composite failure. The USMC also has running
right now a 30 ton troop carrying composite hull assault amphibian
and does 20-25 knots over the water and land mobility comparable to.
the M1 and M2/M3.
The Army has built and tested to 6000 miles a Composite IFV (Bradely).
Both services are actively involved in composite research and have
been for close to two decades now. Everything from manufacturability,
armor protection, cost, repair, corrosion, attachments, etc. are vigorously
being assessed.
Most likely the next family of combat vehicles will be primarily
composite construction, just like the next class of military helicopters
will be.
Mike Gallagher,
Marine Corps Programs Office
Naval Surface Warfare Center - Carderock Division
Mark J. Stock
From "Mark J. Stock" <mst...@engin.umich.edu>
In article <C54Gv...@law7.DaytonOH.NCR.COM> ,
212...@hydra.maths.unsw.edu.au writes:
> I am told that the Americans have APDSFS-T round which will
>penetrate the armour on any tank in the world. (By the way, >APDSFS-T
stands for *big breath* Armour Piercing, Discarded Sabot, >Fin Stabilised
Tracer round.)
> So it is safe to assume that other countries have it (or a version)
>by now?
You think APFSDS-T is big, the russians like APFSDSDU-T (for depleted
uranium). They chose that stabiloy penetrator because of the great
reserves of heavy elements in their country. In America, because Uranium
is not quite as easy to get, they use Tungsten Carbide, a harder and just
as massive metal.
The russian!s penetrators are wider, but the US!s are longer (I think).
I also think that with the new tanks coming out, the American round will
travel faster, too.
BTW, the specific gravity of Uranium and Tungsten is 19, Gold being the
only other element as dense (19 too).
If someone know any of this for sure, please tell us!
Mark J.Stock
mst...@engin.umich.edu
University of Michigan, Aerospace and Mechanical Engineering
"I am the Occam's Razor, I am the Steppenwolf"
Ethan L Mckinney
From Ethan L Mckinney <mcki...@athena.mit.edu>
In article <C56BH...@law7.DaytonOH.NCR.COM>, ErikTrimble <tri...@alleg.edu> writes:
[bunches of stuff deleted]
|> However, the soviets did come up with a neat solution to defeating Chobham
|> and other composites: instead of a one-shot, one-kill round, they used
|> what amounts a solid steel cannonball. This was a 125mm in diameter solid
|> steel shot, which tended to fracture the armor on an M1 when it hit.
|> Rather than kill the tank, this shot effectively broke the composite armor
|> in the panel it hit. Any other hit in this quarter by any normal anti-tank
|> round would have a hit probability of a kill. As I said, not a single-shot
|> kill capacity, but an ingenious way to get around the problem,
|> non-the-less.
|>
|> -Erik Trimble
|> tri...@lleg.edu
|>
The question is, is this realistic? I'm no physicist or materials scientist, but
it seems to me that an APFSDS round packs the same kinetic energy as "cannonball"
round (that is, regular AP solid shot). It just applies it in a smaller area.
Why shouldn't this shatter Chobam just as well?
Now, when the reports on "cannonball" rounds came out, they said it was *100mm*
ammo for older T-54, -55, 62s which had no hope of penetrating with APFSDS. I
have a different take on this. I suspect that the Soviets just decided to
equip their second- and third-rate tanks with cheap ammunition which would be
perfectly effective against APCs, IFVs, and MBT side/rear armor. They'd save
lots of money and sacrifice only a tiny amount of combat effectiveness.
Opinions, anyone? (Like I need to ask!)
E
Brian Douglass
From Brian Douglass <anasaz!bri...@anasazi.com>
er...@lin.foa.se (Erik Svensson FOA2) writes:
>From er...@lin.foa.se (Erik Svensson FOA2)
>>From Curtis Fennell <ch...@harvey.gte.com>
>(some stuff deleted)
>This really rather interesting. When ever the west has seen real evidence that
>soviet stuff was crap there was always some kind of explanation that the stuff
>the _soviets_ used was magnitude or more better. There has never been
>any sort of support for this theory. Another theory was that that the new stuff
>coming out sov factories was really hell on wheels, nothing like what we saw
>now. There has never been any support for that either.
Because, in the intelligence game, you never, ever, EVER want to
underestimate the Enemy. Obviously Pearl Harbor is the prime example of a
failure to adequately estimate a potential enemies' abilities, much less to
overestimate their abilities. Pearl is also the prime motivation for the
the consistent overestimation of Soviet capabilities. To overestimate and
be found out wrong, you look stupid. To underestimate and be find out your
wrong, you're probably dead.
>--
> Erik Svensson
> Research Officer National Defense Research Establishment (FOA)
> Guided Weapons Division Stockholm, Sweden er...@sto.foa.se
>NEW MAILING ADRESS: er...@sto.foa.se
>"I like maxims that don't encourage behaviour modification." -- Calvin
--
Brian Douglass bri...@anasazi.com
602-870-3330 X657
eric remy
From edr...@leland.Stanford.EDU (eric remy)
In article <C5DL4...@law7.DaytonOH.NCR.COM> "Mark J. Stock" <mst...@engin.umich.edu> writes:
>
>From "Mark J. Stock" <mst...@engin.umich.edu>
>
>
> You think APFSDS-T is big, the russians like APFSDSDU-T (for depleted
>uranium). They chose that stabiloy penetrator because of the great
>reserves of heavy elements in their country. In America, because Uranium
>is not quite as easy to get, they use Tungsten Carbide, a harder and just
>as massive metal.
> The russian!s penetrators are wider, but the US!s are longer (I think).
>I also think that with the new tanks coming out, the American round will
>travel faster, too.
> BTW, the specific gravity of Uranium and Tungsten is 19, Gold being the
>only other element as dense (19 too).
> If someone know any of this for sure, please tell us!
>
>Mark J.Stock
Most of this has been corrected in other posts, but here goes.
Modern american sabot rounds are all depleted uranium, mostly due to
low cost and pyrophoricity. (Also makes it very easy to identify
friendly fire in wars like the Persian Gulf- just check for
radioactivity in the dead vehicle.) Uranium is dense, but by no means
the densest metal. (Osmium, 22.57 g/cc, or iridium 22.61-there's some
disagreement. Both are too expensive and too brittle for use as weapons.)
It's hard to compare length/diameter of the rounds, partly because
the dimensions of the US rounds are secret. (My FM 17-12-3 gives the
data on rounds up to two before the most modern.) The Soviet's tend
to be much more crude than the americans- the 105 on the M60 and M1
outperforms the 125 on the T-64/72/(74)80 class, while the German 120
on the Leopard II and M1A1 is better yet. Muzzle velocities are
fairly constant with the newer rounds, possibly because they are
beginning to push the limits of the older tanks. The M60A3 can't fire
the M900 sabot round because the recoil mechanism can't handle the
force, and I doubt they'll be upgraded. Current velocities are in the
1500m/s range for the 105: the older tungsten carbide rounds are
actually slightly faster than the newer DU ones. (I don't have any
data, but I suspect that the penetrator is slightly larger/heavier in
the new rounds.)
(If anyone is curious about what these rounds look like, the current
issue of Armor magazine has a beautiful photo of a 120mm training
round being fired with sabot petals separating from the penetrator.)
--
Eric R. edr...@d31ha0.Stanford.EDU Department of Chemistry
-1/2\nabla^2\psi_{T-72}
Bertil Jonell
From Bertil Jonell <d9be...@dtek.chalmers.se>
In article <C5FKB...@law7.DaytonOH.NCR.COM> edr...@leland.Stanford.EDU (eric remy) writes:
>Modern american sabot rounds are all depleted uranium, mostly due to
>low cost and pyrophoricity.
I belive DU is also much easier to machine than tungsten: Tungsten
has a so high melting point that tungsten penetrators has to be made
through sintering and they are thus more brittle than DU. This brittleness
also makes tungsten unsuitable for extremely slender penetrators.
>Eric R. edr...@d31ha0.Stanford.EDU Department of Chemistry
> -1/2\nabla^2\psi_{T-72}
-bertil-
--
"It can be shown that for any nutty theory, beyond-the-fringe political view or
strange religion there exists a proponent on the Net. The proof is left as an
exercise for your kill-file."
Arno Hahma
From Arno Hahma <aha...@utu.fi>
In article <C5DL4...@law7.DaytonOH.NCR.COM> "Mark J. Stock" <mst...@engin.umich.edu> writes:
>reserves of heavy elements in their country. In America, because Uranium
>is not quite as easy to get, they use Tungsten Carbide, a harder and just
>as massive metal.
I don't think anyone uses carbides, as they are very brittle. Using a
metal alloy is a better choice.
> The russian!s penetrators are wider, but the US!s are longer (I think).
Possible. The russian penetrators I have seen were all much wider than
the western counterparts. The russian projectiles were of a
significantly lower quality material, too.
>I also think that with the new tanks coming out, the American round will
>travel faster, too.
I doubt. The Rheinmetall 120 mm gun fires at about 1650 m/s while the
125 mm russian gun fires at 1890 m/s. There is quite a difference
there. The ammo weight is very close to each other.
> BTW, the specific gravity of Uranium and Tungsten is 19, Gold being the
>only other element as dense (19 too).
> If someone know any of this for sure, please tell us!
While the theoretical densities of those two metals are almost equal,
it is an entirely different matter, what the densities are in the
projectile. Tungsten, being a very high melting metal, can only be
fabricated by powder metallurgy. That means, you _never_ reach the
theoretical density. In addition, pure tungsten is soft, just like
construction steel, you can file it, cut it etc. Despite of that, it
is brittle - just try how weak a lamp filament is compared to a wire
of the same thickness and made of say, copper or steel. Tungsten is by
no means an ideal material.
To correct the problem, you have to get the material more ductile or
harder or both. This is done by alloying. If you choose anything less
dense than tungsten itself as the additive, you end up with an alloy
less dense. Unfortunately, there are barely choices denser than
tungsten, so you have to compromise. The final density will be
something in the order of 11 to 15 g/ccm. The russians are closer to
the lower and the western closer to the upper limit.
With uranium, you can do it much easier: by casting. Uranium melts
relatively low and certainly dissolves suitable additives to reach
enough hardness. Uranium is also very ductile by itself, so you only
have to worry about keeping that property, not gaining it. As a
result, it is easy to reach densities in excess of 15 g/ccm, despite
of problems with the casting process (such as keeping the air out of
it). I think uranium has not been introduced earlier, as they have not
found good additives for getting it tough enough. As a pure metal, it
is soft like lead, which is really not strong enough for the
accelerations needed.
I have these nice, cylindrical paperweights on my table, shaped,
strangely enough, ogivally at one end. One is supposed to contain
about 90 % W and the rest something ferrous and it also has some odd,
5-pointed star shaped stamps on its ogival end. It's quite heavy,
density as high as 11,7 g/ccm and da** hard. Then there is this other
paperweight, without the mentioned stamps and much smoother and nicer
looking and extremely hard - it even scratches quartz!. It seems to
contain 89 % of W, 10 % of Ni, the rest being too long to write in
this limited bandwidth. The other weight is also very heavy having a
density of 14,8 g/ccm. Then there's this third one, which I don't have
on my desk... ;->.
>Mark J.Stock
ArNO
2
Joshua Follick
From Joshua Follick <follick%hydra....@lynx.unm.edu.unm.edu>
If the AS-6 does go Mach-3, I think the soviets have a
better idea than we do. Sub-mach cruise missiles are
relatively foolishly easy to shoot down. Considering that
we could make a high mach missile and we haven't, instead choosing
the all too-slow Tomahawk, I think we have chosen poorly.
Mars, the Bringer of War
From "Mars, the Bringer of War" <ja...@virginia.edu>
While I agree in some way with you, I disagree in others.
While the AS-6 can indeed go Mach 3, it is a generally high
flight profile missile, whilch is easilly detected, and is a
fairly large target for SAMs. The advantage, of course, is its
fairly long range (200nm+ according to Janes) and its short
time in the SAM envelope. The US Tomohawk, on the other hand,
can have a much greater range, and is so much slower because of
that. In compensation, however, it is very difficult to
detect, and its low altitude makes shooting it down more
difficult as well. As to which philosophy works better in
actual combat, one hopes we'll never have to find out.
Justin
Paul Stacy
From Paul Stacy <jfr...@helena.stat.uga.edu>
With all the recent talk here of Soviet missiles being easier to detect
that western ones, why do all the navy people and othersr keep saying
theya re worried about having only a few seconds to detect and attemp
to intercept them?
A Mach 3 missile moves much faster than our Harpoons and Tomahawks, which
would cut travel time greatly.
Paul "Joe Friday" Stacy (not net.police) Buffalo State College, New York
STA...@SNYBUFVA.BITNET (Buffalo State College VAX) JUST THE
jfr...@marie.stat.uga.edu (Univ. of Georgia (Athens) UNIX) "VAX", MA'AM!
aa...@freenet.buffalo.edu (Buffalo FreeNet)
Disclaimer: This isn't the opinion of the school, police, Chief of Detective
Staff Brown, Planet Spaceball, Starfleet Command, or the Pentagon.
Irving Lachow
From Irving Lachow <il...@andrew.cmu.edu>
>From Paul Stacy <jfr...@helena.stat.uga.edu>
>
>With all the recent talk here of Soviet missiles being easier to detect
>that western ones, why do all the navy people and othersr keep saying
>theya re worried about having only a few seconds to detect and attemp
>to intercept them?
>
>A Mach 3 missile moves much faster than our Harpoons and Tomahawks, which
>would cut travel time greatly.
The Navy is worried about low-altitude supersonic ASCMs. Such missiles
would combine the best characteristics of U.S. missiles with the speed
of Soviet missiles. Because the radar horizon of a ship-borne radar is
only a few kilometers against a sea-skimming missile, an air defense
system would have no time to react to a supersonic ASCM coming over the
horizon (even if it were already being tracked by a Hawkeye--the Aegis
radars still have to pick up the track). In contrast, current Soviet
ASCMs fly high enough to extend the radar horizon of the Aegis far
enough to give it enough time to track the target and fire. This is
what happened in Desert Storm with the Patriots: they were fed info from
our sats so they knew where to look for the Scud RVs, but they only had
a few seconds to fire in order to intercept the Scuds above the minimum
engagement altitude (and the Patriots were able to see the Scuds more
than 100 km away).
Irving Lachow
C.M.U.