Anti-ship missiles vs. ship's armor?

[Gil W. Lau]

From "Gil W. Lau" <bp...@cleveland.freenet.edu>

I was reading a book on fleet tactics and was surprised to hear
the author comment that anti-ship missiles, in general, can't
penetrate a battleship's armor. I never really thought about
armor piercing characteristics of ASMs. I guess the point is almost
moot as no modern warship really is armored like old battlewagons.
However, just out of curiosity, does anyone have any data
pertaining to AP stats of modern ASMs?

-- Gil

[Michael Holbrook]

From Michael Holbrook <mh6...@cutter.ship.edu>

Gil W. Lau (bp...@cleveland.freenet.edu) wrote:

: From "Gil W. Lau" <bp...@cleveland.freenet.edu>

: -- Gil

Hmmm, I would like to add another question to this one. In light of all
of the advances made in tank armour, why do we not see any armour on
modern fighting ships? Certainly much is to be said about the
effectiveness of missles like the Standard and systems like CIWS and
Goalkeeper, but wuld it not also be cost-effective to actually armour
ships? Or do missiles these days simply pack so much wallop that they
would go through armour like the proverbial knife through butter? If
that is so, then why the "impenetrability" of the Iowa class's armour?
Also, how thick was the armour of the Soviet "Sverdlov" class cruises?
Could it withstand an ASM?
Cheerio,
Michael Holbrook

[Jerry Prather]

From Jerry Prather <pra...@infi.net>

Michael Holbrook (mh6...@cutter.ship.edu) wrote:

: From Michael Holbrook <mh6...@cutter.ship.edu>

: : -- Gil

OK, let's get real. The ship's made to fight in WWII were made to face
surface ship combat. That means, at the least they were supposed to cope
with 8" armour piercing projectiles, whether by dint of armour, speed, or
outer layer defense. Modern ships, including crusiers have been built
without any semblance (sp?) of armour, at least up to the USS Belknap (I
should point out that I am reflecting my ex-USN bias, and only refering to
the USN). After near destruction in a fire after a collision, it was rebuilt
with Kevlar armor around its critical wireways (mast to radar, etc.). Later
ships, including most (all?) the Ticos have been given similar protection.

Note that I am not talking about armour in the classical sense. A WWII AP
projectile would pass through the hull of a CG-47 class cruiser without ever
exploding. The Kevlar armour protects wireways, not structures.

Why were battleships brought back to the USN? Because they could take all
the non-nuclear cruise missiles fired at them and shrug them off without
sustaining a mission kill. To cope with an Iowa class battleship an enemy
with a modern conventional missile would have to get 25+ hits and also be
lucky.

--
Jerry Prather pra...@infi.net
Consult Computer Concepts! Voice (804) 486-0602, Fax by appointment
3512 Sandy Point Key (These are my opinions, but you can
Virginia Beach, VA 23452 borrow them if you wish.)

[Richard Bell]

From rlb...@coulomb.uwaterloo.ca (Richard Bell)

Missiles do not punch through armor, because most ships are unarmored.
Ships are unarmored because they must float. The Iowa's, Yamato's,
Bismark's, and King George V's could be heavily armored and float, because
of their emmense size. If I have to chose between an armored deck for
my destroyer (which may stop an air dropped bomb), and a SAM ( which can
shoot down the bomber), I will install the SAM.

Russian carrier-killing ASM's perform quite well against all targets because
even the Iowa has difficulty arguing with 1000 kg warheads; although, it
still takes multiple hits. Other anti-shipping missiles only carry 100 to
400 kg warheads.

[sch...@cbnewse.att.com]

From sch...@cbnewse.att.com

>From article <Cwsqq...@ranger.daytonoh.ncr.com>, by Michael Holbrook <mh6...@cutter.ship.edu>:

I would like to comment on this. I'm sorry, I can't site the sources,
but I can't remember exactly where, but if I remember correctly, the
US Navy did some tests with a number of WWII heavy cruisers.

All typical ASM just exploded and burned, causing the loss of exterior
items like radio antennas, radar masts, etc. But no real damage was
caused by the HIT.

The modern missile does NOT consist of 2,000 lbs of explosive. It
is much smaller, though it "burns" hotter [whatever that means]

My son, a "battleship sailor", sez that there is no missile short
of nuke, that would hurt the "Mighty Mo"!

Richard C Schmidt

--
=============================================================
Richard C Schmidt Work: sch...@rcdlsvr.attmail.com
Home: r...@fafnir.atl.ga.us
Opinions are mine alone - I sometimes have trouble even doing that

[-D.WELLS]

From drw...@hogpg.ho.att.com (-D.WELLS)

In article <Cwr4r...@ranger.daytonoh.ncr.com>,

Gil W. Lau <bp...@cleveland.freenet.edu> wrote:
>
>I was reading a book on fleet tactics and was surprised to hear
>the author comment that anti-ship missiles, in general, can't
>penetrate a battleship's armor. I never really thought about
>armor piercing characteristics of ASMs. I guess the point is almost
>moot as no modern warship really is armored like old battlewagons.
>However, just out of curiosity, does anyone have any data
>pertaining to AP stats of modern ASMs?
>

I don't have any stats handy, but I think you'll find that most,
if not all, have HE warheads. Today, that is exactly what you want,
since few modern warships have much armor. Also, keep in mind that
NO merchant ships have armor. If your goal is to cut off your opponent's
merchant shipping, (this CAN work in some cases, just ask the Japanese!)
then you really don't want to bother with AP warheads.
I think that the French may make a small ASM that has an AP
warhead. It may be an anti-tank missile adapted for naval use.
I'll see if I can get more data on this.

David R. Wells

"There seems to be something wrong | David R. Wells
with our bloody ships today" | AT&T Bell Labs, Holmdel, NJ
Adm. D. Beatty, May 31, 1916 | Email: drw...@hogpa.att.com

DISCLAIMER: I don't speak for AT&T, and they don't speak for me.

[Andrew Clark Toppan]

From Andrew Clark Toppan <el...@wpi.edu>

Michael Holbrook (mh6...@cutter.ship.edu) wrote:

: Hmmm, I would like to add another question to this one. In light of all

: of the advances made in tank armour, why do we not see any armour on
: modern fighting ships? Certainly much is to be said about the
: effectiveness of missles like the Standard and systems like CIWS and
: Goalkeeper, but wuld it not also be cost-effective to actually armour
: ships? Or do missiles these days simply pack so much wallop that they
: would go through armour like the proverbial knife through butter? If
: that is so, then why the "impenetrability" of the Iowa class's armour?
: Also, how thick was the armour of the Soviet "Sverdlov" class cruises?
: Could it withstand an ASM?
: Cheerio,
: Michael Holbrook

Well, to armor modern ships on the scale of the Iowa class BB's would
be rather expensive. Even if modern armoring techniques and materials
could reduce the thickness (and weight) of the armor by half, the
ships would have to be incredibly large to accomodate it. I'm no
expert, but to armor a CVN on that scale would probably require nearly
doubling the size of the ship, if the original capabilities of the
vessel were to be retained. For every ton of armor added a ton af
something else must be removed, or else the ship must be enlarged,
wich in turn requires more armor. To armor something like a cruiser
on that scale would be impossible. The cost for any ship would be
astronomical. The ships probably would be missile-proof, though.
Someone said that the average modern ASM warhead packs a punch no
larger that that of an 8" shell. Certainly far less that what the
Iowas were built to withstand. But, a large percentage of the Iowa's
displacement is armor (i'd guess about 25%). Modern ships do have
some armor around vital spaces, etc., but far less that a WWII ship.
It is mean to protect primarily against fragments etc., not direct
hits.
el...@wpi.edu

[John Schilling]

From John Schilling <schi...@spock.usc.edu>

Michael Holbrook <mh6...@cutter.ship.edu> writes:

>From Michael Holbrook <mh6...@cutter.ship.edu>

>: -- Gil

Many modern warships do have some degree of armor (steel or kevlar) around
vital areas. And many antiship missiles have "semi-armor-piercing"
warheads, essentially thick-cased HE or thin-walled APHE depending on
your point of view. Right now, the advantage is pretty clearly with
the missiles.

Changing this requires really, really tough armor. Something like the
frontal armor of a tank over the entire hull of a ship, or WWII battleship
armor. And there simply aren't any rolling mills capable of making that
sort of armor any more. Nor any production facilities for modern tank-style
compund armor on the necessary scale.

It would take an enormous capital investment before you could turn out
even one missile-proof ship, and by the time you did so any prospective
enemy would have refitted his missiles with the appropriate warheads.
A 500-lb shaped charge warhead might not be as destructive against
soft targets as a normal Exocet or Harpoon head, but no armor belt
on Earth will stand up to it.

Now, if you just happen to have a few old ships from the thick-armor days
lying around, and the means to refit them with modern weapons, that's another
matter. But building new BB's or CA's from the keel up, just isn't going
to happen.

--
*John Schilling * "You can have Peace, *
*Member:AIAA,NRA,ACLU,SAS,LP * or you can have Freedom. *
*University of Southern California * Don't ever count on having both *
*Aerospace Engineering Department * at the same time." *
*schi...@spock.usc.edu * - Robert A. Heinlein *
*(213)-740-5311 or 747-2527 * Finger for PGP public key *

[Bleyle]

From Bleyle <ble...@infi.net>

Graham J Bricknell (g...@zoo.bt.co.uk) wrote:

: From Graham J Bricknell <g...@zoo.bt.co.uk>

: On this topic it is worth noting that if a projectile hits a ship,
: but does not sink it due to any armour it might have, it will still
: have a significant impact upon the ships ability to operate. This
: is because sensors etc.. remain fragile.

The Navy calls this "mission-kill" - ie, the ship may physically still be
there, but its ability to function as a warship has been destroyed.

--

*********************
* Bleyle *
* ble...@infi.net *
*********************

[Bleyle]

From Bleyle <ble...@infi.net>

Mike Fischbein (m...@panix.com) wrote:

: From Mike Fischbein <m...@panix.com>

: On Wed, 28 Sep 1994 18:43:08 GMT, Andrew Clark Toppan (el...@wpi.edu) wrote:

: Actually, CVs and CVN are the only modern ships with protection
: approaching that of an old BB. The weight isn't much of a problem;
: after you design a flight deck and the structure to hold it up, and
: cram everything you can fit in that cubic, you need a couple of
: thousand tons of mass for balance -- might as well put in armor.

: Instead of one thick homogenous mild steel layer, however, the CVs are
: large enough to use a layered approach. Some relatively thin
: steel, a water filled tank, some more steel, an air void, a
: high-strength armor layer, and so on. The flight deck and transom,
: of course, are armored to take aircraft crashes.

Seems like you're talking about the CV/N's ability to absorb damage rather
than prevent it. True, the massive size of a carrier, its integrated damage
control systems, and its compartmentalization make it a survivable platform.
But I wouldn't call it "armored". The characteristics you call armor are
really incidental to the primary design goal. Maybe semantics, maybe not...
Regards, Mike.

[-D.WELLS]

From drw...@hogpg.ho.att.com (-D.WELLS)

In article <Cwsqq...@ranger.daytonoh.ncr.com>,

Michael Holbrook <mh6...@cutter.ship.edu> wrote:
>
>
>Hmmm, I would like to add another question to this one. In light of all
>of the advances made in tank armour, why do we not see any armour on
>modern fighting ships?

Why not indeed? Regular readers may recall that this debate springs up
frequently on this newsgroup. I, of course, side with those who would
like to see more armor on modern warships. Others, of course, take the
contarary position.

>Certainly much is to be said about the
>effectiveness of missles like the Standard and systems like CIWS and
>Goalkeeper, but wuld it not also be cost-effective to actually armour
>ships?

The anti-missile defenses are quite nice, but we know for certain that
they sometimes fail. Armor is a nice backup. Yes, it does tend to make
the ship larger, but that is not always a disadvantage. A large ship
can take advantage of certain economies of scale. A large ship can also
have better torpedo protection.

>Or do missiles these days simply pack so much wallop that they
>would go through armour like the proverbial knife through butter?

I would say not. Others disagree.

>If that is so, then why the "impenetrability" of the Iowa class's armour?

The armor on the Iowas is not impenetrable, just very rugged. I suppose
that a GBU-28 could get through it, but of course, a GBU-28 is not a
long-range anti-ship missile. Large Soviet-designed ASMs tend to have
1000kg high explosive warheads. I tend to doubt that these could get
through the heavy armor on an Iowa. For example, the belt armor on
an Iowa is about 310mm (a little over a foot) thick. Assuming that the
missile hits the belt, (which is not a totally unreasonable assumption,
since many missiles are programmed to hit low and amidships), an Iowa
should be able to ride out the hit without too much difficulty. I could
cite a few instances of battleships in World War II being hit by similarly
sized HE bombs and surviving, if given time to look them up.

>Also, how thick was the armour of the Soviet "Sverdlov" class cruises?

According to my '89-'90 Janes, they have (had?) 100-125 mm on the belt,
40-50mm on the decks, 125mm on the turrets, and 150mm on the conning tower.

>Could it withstand an ASM?

It would depend on the ASM, on where it hit, and on just plain luck.
I would give a Sverdlov a pretty good chance of surviving a hit by
and Exocet, or a Harpoon. When you get into big, Soviet style ASMs,
or multiple hits by smaller missiles, the picture gets complicated.
Personally, if given the choice, I'd go after a Sverdlov (or a BB
for that matter) with submarines and torpedoes rather than ASMs.

[patterson,george r]

From "patterson,george r" <pat...@cc.bellcore.com>

In article <Cwurz...@ranger.daytonoh.ncr.com>,
<sch...@cbnewse.att.com> wrote:

>My son, a "battleship sailor", sez that there is no missile short
>of nuke, that would hurt the "Mighty Mo"!

He's probably correct. A kamikaze plowed into her side during WWII and
did no damage. The pilot's body, on the other hand, killed some people
at one of the 40mm stations.

Nearly all warships have some degree of side armor. In the old days, It
would be possible for ships to get close enough for shells to hit the
side. I don't have the figures handy, but, if memory serves correctly,
the Iowas had side armor above the waterline that could take about 3/4
of the penetration force of the deck armor. That makes them invulnerable
to anything less than a 14" AP shell.

There is, of course, a good reason why they used to call destroyers "tin
cans".

-----------------------------------------------------------------------
|
George Patterson - | I don't know if I believe in love at first sight.
| I've never seen a Porshe full of money.
|
-----------------------------------------------------------------------

[Andrew Clark Toppan]

From Andrew Clark Toppan <el...@wpi.edu>

Mike Fischbein (m...@panix.com) wrote:

: Actually, CVs and CVN are the only modern ships with protection
: approaching that of an old BB. The weight isn't much of a problem;
: after you design a flight deck and the structure to hold it up, and
: cram everything you can fit in that cubic, you need a couple of
: thousand tons of mass for balance -- might as well put in armor.

: Instead of one thick homogenous mild steel layer, however, the CVs are
: large enough to use a layered approach. Some relatively thin
: steel, a water filled tank, some more steel, an air void, a
: high-strength armor layer, and so on. The flight deck and transom,
: of course, are armored to take aircraft crashes.

Yes, but the armor strength does not even approach the thick belts
that old BB's had, especially in terms of horizontal (side) armor.
The Iowas were armored against 16" projectiles. I doubt any ship in
any navy is that well protected.

el...@wpi.edu

[John Schilling]

From John Schilling <schi...@spock.usc.edu>

drw...@hogpg.ho.att.com (-D.WELLS) writes:

>The armor on the Iowas is not impenetrable, just very rugged. I suppose
>that a GBU-28 could get through it, but of course, a GBU-28 is not a
>long-range anti-ship missile. Large Soviet-designed ASMs tend to have
>1000kg high explosive warheads. I tend to doubt that these could get
>through the heavy armor on an Iowa. For example, the belt armor on
>an Iowa is about 310mm (a little over a foot) thick. Assuming that the
>missile hits the belt, (which is not a totally unreasonable assumption,
>since many missiles are programmed to hit low and amidships), an Iowa
>should be able to ride out the hit without too much difficulty.

Big problem: Large Soviet-designed ASMs are among the few generally
*not* programmed to hit low and amidships. Some of the later models
have an sea-skimming option, but the default (and only, for early models)
trajectory is high-altitude cruise followed by a diving attack.

That 1000-kg warhead, attached to a 2000+kg airframe, is going to be
hitting the BB's deck, not the belt. And most likely at something over
1500 knots.

Depending on case thickness and fuse delay, it could well cause some severe
damage to an Iowa.

[Michael R Haenggi]

From Michael R Haenggi <mhae...@maroon.tc.umn.edu>

scott david orr (sdo...@mik.uky.edu) wrote:

: One simple reason: you cna't put armor on a radar. Without radars for
: detection and fire control, a ship is utterly helpless. Hence, there's no
: point to armoring a ship--it's not the structural damage that kills you, it's
: the damage to your detection and weapons systems.

How about for the silly ol' purpose of saving the crew? Sure the ship
will be rendered ineffective, but doesn't the crew count for anything? At
least it might give them a chance to find a lifeboat. Seems to me thats
like saying there's no point in putting an ejection seat in an aircraft
because the plane will be wrecked anyway.

****************************************************************************
Mike Haenggi Don't take life so seriously...
mhae...@maroon.tc.umn.edu Its only a temporary situation.

[Bob Lyle]

From Bob Lyle <madr...@metronet.com>

I think the Swedes use Hellfires for coastal defense. Assuming a
state-of-the art, 6" warhead that should punch through 25" of homogenous
steel - at least.

Of course, it is really designed to shred thew superstructure of a fast
attack boat.

Bob Lyle

[Ed Rudnicki]

From Ed Rudnicki <erud...@pica.army.mil>

In article <Cwurz...@ranger.daytonoh.ncr.com> drw...@hogpg.ho.att.com (-D.WELLS) writes:
>In article <Cwr4r...@ranger.daytonoh.ncr.com>,
>Gil W. Lau <bp...@cleveland.freenet.edu> wrote:
>>I was reading a book on fleet tactics and was surprised to hear
>>the author comment that anti-ship missiles, in general, can't
>>penetrate a battleship's armor. I never really thought about
>>armor piercing characteristics of ASMs. I guess the point is almost
>>moot as no modern warship really is armored like old battlewagons.
>>However, just out of curiosity, does anyone have any data
>>pertaining to AP stats of modern ASMs?
>>
>
> I don't have any stats handy, but I think you'll find that most,
>if not all, have HE warheads. Today, that is exactly what you want,
>since few modern warships have much armor. Also, keep in mind that
>NO merchant ships have armor. If your goal is to cut off your opponent's
>merchant shipping, (this CAN work in some cases, just ask the Japanese!)
>then you really don't want to bother with AP warheads.

Most missile warheads should be rated at least as SAP, in order to
retain their structural integrity long enough to enter the target
ship prior to detonation. This is one of the reasons the 20mm
Phalanx CIWS is considered marginal by some - the penetrators cannot
pass through the warhead casing and detonate the filler.

> I think that the French may make a small ASM that has an AP
>warhead. It may be an anti-tank missile adapted for naval use.
>I'll see if I can get more data on this.

Is this the AS-15TT fired from the Dauphin?

Ed Rudnicki erud...@pica.army.mil All disclaimers apply

[John F Carr]

From John F Carr <j...@athena.mit.edu>

In article <CwwGD...@ranger.daytonoh.ncr.com>,
scott david orr <sdo...@mik.uky.edu> wrote:

>One simple reason: you can't put armor on a radar.

Why not? 12 inches of steel on top of the radar wouldn't work but that's
not the only way to do it.

You could make the radar transmitter out of thick steel plates (as thick
as you can make them without upsetting the ship's balance). I expect the
radar would be less sensitive but it would be more survivable. Anything
other than a direct hit will do little damage; after the computer
recalibrates the radar to comensate for damaged or misaligned transmitter
segments it would be nearly as good as new.

You could cover the radar with (nearly) radio transparent armor like
kevlar and composites. Only a direct hit destroys the radar; a miss sends
fragments into the armor instead of the radar.

You could not armor the radar and instead put short range backup radar and
communications systems well separated from the main radar. If the radar
is destroyed but you still have fire control systems use the backup radar
to engage incoming missles and link to another ship to get target data for
cruise missiles. The damaged ship isn't effective on its own but would
still function as part of a task force.

--
John Carr (j...@mit.edu)

[Frank Kastenholz]

From Frank Kastenholz <kas...@lard.ftp.com>

>From drw...@hogpg.ho.att.com (-D.WELLS)

>>If that is so, then why the "impenetrability" of the Iowa class's armour?
>

>The armor on the Iowas is not impenetrable, just very rugged. I suppose
>that a GBU-28 could get through it, but of course, a GBU-28 is not a
>long-range anti-ship missile. Large Soviet-designed ASMs tend to have
>1000kg high explosive warheads. I tend to doubt that these could get
>through the heavy armor on an Iowa. For example, the belt armor on
>an Iowa is about 310mm (a little over a foot) thick. Assuming that the
>missile hits the belt, (which is not a totally unreasonable assumption,
>since many missiles are programmed to hit low and amidships), an Iowa

>should be able to ride out the hit without too much difficulty. I could
>cite a few instances of battleships in World War II being hit by similarly
>sized HE bombs and surviving, if given time to look them up.

My impression from reading Dulin & Garzke and Freidman is that a
major factor in damage to BBs is not punching holes through the armor
plate, but rather shock damage that does things like popping seals
and glands (ala PoW), causing joints in the armor plate to open up
(if I recall, this was a major failing in one of the Japanese BBs),
and then generally shaking up the internal equipment so that the crew
were hampered in the DC efforts.

I would imagine that a 1000kg HE warhead would cause significant
shock damage to an Iowa. After all, it took only about a half-dozen
330kg torpedos to sink the PoW and the only penetration of her
citadel (that I recall) was the glands and stuffing boxes destroyed
by the prop-shaft bent by one of the torpedos...

--
Frank Kastenholz

[-D.WELLS]

From drw...@hogpg.ho.att.com (-D.WELLS)

In article <CwwGG...@ranger.daytonoh.ncr.com>,

Graham J Bricknell <g...@zoo.bt.co.uk> wrote:
>
>On this topic it is worth noting that if a projectile hits a ship,
>but does not sink it due to any armour it might have, it will still
>have a significant impact upon the ships ability to operate. This
>is because sensors etc.. remain fragile.
>

While this is entirely true, most anti-ship missiles are programmed
to hit amidships, fairly low. If you look at pictures of the Sheffield
or the Stark, you'll see what I mean. But you'll note that in both cases
the radar antennae were left intact.

Actually, considering the lack of armor on ships today, this is a good
idea, since it is likely that a hit in this area will hit CIC, or a forward
magazine. Also, if you hit low, the ship is more likely to take water
and sink. Of course, on an armored ship, you'd be hitting the belt armor.

[Vivendum]

From vive...@aol.com (Vivendum)

In article <Cx3w...@ranger.daytonoh.ncr.com>, John Schilling
<schi...@spock.usc.edu> writes:

After all, the deck armor, I imagine, would be easily penetrated by most
ASM's.

[Michael Holbrook]

From mh6...@cutter.ship.edu (Michael Holbrook)

-D.WELLS (drw...@hogpg.ho.att.com) wrote:

: From drw...@hogpg.ho.att.com (-D.WELLS)

: In article <Cwsqq...@ranger.daytonoh.ncr.com>,
: Michael Holbrook <mh6...@cutter.ship.edu> wrote:

: >
: >
: Why not indeed? Regular readers may recall that this debate springs up

: frequently on this newsgroup. I, of course, side with those who would
: like to see more armor on modern warships. Others, of course, take the
: contarary position.

: The anti-missile defenses are quite nice, but we know for certain that

: they sometimes fail. Armor is a nice backup. Yes, it does tend to make
: the ship larger, but that is not always a disadvantage

: The armor on the Iowas is not impenetrable, just very rugged. I suppose

: that a GBU-28 could get through it, but of course, a GBU-28 is not a
: long-range anti-ship missile. Large Soviet-designed ASMs tend to have
: 1000kg high explosive warheads. I tend to doubt that these could get
: through the heavy armor on an Iowa. For example, the belt armor on
: an Iowa is about 310mm (a little over a foot) thick. Assuming that the
: missile hits the belt, (which is not a totally unreasonable assumption,
: since many missiles are programmed to hit low and amidships), an Iowa
: should be able to ride out the hit without too much difficulty. I could
: cite a few instances of battleships in World War II being hit by similarly
: sized HE bombs and surviving, if given time to look them up.

: David R. Wells

: "There seems to be something wrong | David R. Wells
: with our bloody ships today" | AT&T Bell Labs, Holmdel, NJ
: Adm. D. Beatty, May 31, 1916 | Email: drw...@hogpa.att.com

: DISCLAIMER: I don't speak for AT&T, and they don't speak for me.

It is nice to find someone who favours armouring ships. In spite of all
that I've heard (and almost all of it quite well thought out) I still
believe that armouring ships is more intelligent than not. Basically,
the arguments tend to break down along these lines:

1. It is cost prohibitive. The steel armour (or even chobham or some
other sort of exotic armour) simply costs too much.

2. It would tend to increase the size (and hence costs of ships).

3. Does not protct radars (hence would do little to prevent a mission-kill).

4. Would cause an arms-race scenario, with one side armouring its ships,
the other developing better missiles, then the first side rearmouing its
ships, then the other developing better missiles...

All of these are true. But I think that the benefits outweigh these costs.
If I may, I would like to present some counterarguments to these points.

1. We have sunk billions of dollars into active missile defense systems
like CIWS and Standard. They work, you could even say they work well,
but they are not 100% effective. It seems to be very cost-effective to
have a nice, non-technical, breakdown-proof backup in the form of a few
inches of hardened steel plate, just in case the technology craps out.
The cost of armouring ships could not possibly approach the cost of
arming them with the sensitive, fragile, and complex electronic suites
that we use to shoot down incoming missiles. I am not saying that armour
should be used instead of these systems. Most certainly not. But it
would be nice to have an Aegis cruiser with some armour. I cannot believe
that a few inches of steel plate over vital areas (a belt amidships, an
armoured deck, maybe some conning tower armour, but maybe not, because
the concussion would probably kill the SPY radar anyway) would even
approach the cost of the most basic NATO shipbourn SAM system (like, say,
Sea Sparrow, which is not the most effective system in the world,
anyway). You see, it need not be everywhere on the ship in order to
armour it. We discovered back in the early part of this century that an
all-or-nothing armour scheme, in which vital areas are protected and
non-vital areas are not, is very effective, both in terms of fulfilling
its purpose and keeping costs down.

2. The size of ships probably would get larger. There is not much to say
here, except that the use of missiles has already caused ship size to
inflate dramatically. A Spruance class destroyer is as large as a WWII
cruiser. Probably most of the cost in armouring ships would come in the
form of having to make them larger in order to keep all of that heavy
armour afloat.

3. The mission kill argument is another good one, but I believe that it
has a fatal flaw. The argument is that the radars are vulnerable, so
armour will not halp them. Therefore, if a ship is hit by an ASM, it is
as good as killed even if it is armoured. Well, maybe in the terms of a
scenario, yes. But not if a whole war is looked at, or even if something
as simple as the bottom line is looked at. An armoured Aegis that is
nailed by, say, an Exocet, is mission-killed. It is out of the fight,
and its armour did not help. But its armour WOULD help keep that very
expensive ship afloat. No penetration at waterline here, folks. That
ship is steaming back to port (or being towed, but I'd put my money on
steaming, er, or are they turbing powered? Tangent anyway) and will have
another radar installed on her, and her damage repaired. On the other
hand, an unarmoured ship might end up singing the blues with Davy Jones
and the boys at the bottom of the sea. This includes radar, missile
system, engines, hull, ammunition, and lives. All gone. The bottom line
is that the armour saved millions of dollars.

4. The arms race argument is also specious IMHO. We already build
missile systems to foil incoming ASMs, and the bad guys (and us) build
ASMs to beat the defense systems. Adding armour protection is simply
adding another dimension to the game. Its not like the world is going to
be plunged into a race "to make ships missile proof" as one gentleman
asserted. We're already there. We just choose to do it with even more
expensive electronics instead of boring, inert metal. It looks better on
the defense contracts. Armour wouldn't "missile-proof" ships anyway,
just make them more missile resistant.

Well, thats my longwinded $0.02. Hey, to the guy who said that the
rolling mills simply aren't there anymore, what a way to revitalize the
U.S. Steel industry! :)

Let me know what you think.

Cheerio,
Mike Holbrook

[Bertil Jonell]

From d9be...@dtek.chalmers.se (Bertil Jonell)

In article <Cx3w...@ranger.daytonoh.ncr.com>,

Bob Lyle <madr...@metronet.com> wrote:
>I think the Swedes use Hellfires for coastal defense. Assuming a
>state-of-the art, 6" warhead that should punch through 25" of homogenous
>steel - at least.

No, Bofors made a (SAP?) HE warhead for them to fit instead of
the standard shaped charge.

>Bob Lyle

-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."

[scott david orr]

From scott david orr <sdo...@mik.uky.edu>

In article <Cx3w...@ranger.daytonoh.ncr.com> Michael R Haenggi <mhae...@maroon.tc.umn.edu> writes:
>
>
>scott david orr (sdo...@mik.uky.edu) wrote:
>
>: One simple reason: you cna't put armor on a radar. Without radars for
>: detection and fire control, a ship is utterly helpless. Hence, there's no
>: point to armoring a ship--it's not the structural damage that kills you, it's
>: the damage to your detection and weapons systems.
>
>How about for the silly ol' purpose of saving the crew? Sure the ship
>will be rendered ineffective, but doesn't the crew count for anything? At
>least it might give them a chance to find a lifeboat. Seems to me thats
>like saying there's no point in putting an ejection seat in an aircraft
>because the plane will be wrecked anyway.
>

No. If I (as a designer) have a choice between armoring a ship "to save teh
crew", on the one hand, or adding more defensive systems and/or weapons
systems that have the potential to destroy the enemy before the enemy
launches his attack, on the other hand, I wil choose the second, because it
has a far greater chance of actually saving the crew. Your point about
ejections seats is well-taken, but ejection seats, unlike armor, do not
take up a large percentage of the space and weight available on the platform
in question.

Scott Orr

[Michael A. Chance]

From mch...@crl.com (Michael A. Chance)

John Schilling <schi...@spock.usc.edu> writes:

>That 1000-kg warhead, attached to a 2000+kg airframe, is going to be
>hitting the BB's deck, not the belt. And most likely at something over
>1500 knots.

A cruise missile hitting at Mach 2, with a half-ton warhead? Are you
sure? It takes a lot of effort to push a warhead that big that fast.
The US cruise missiles top out at about 650.

>Depending on case thickness and fuse delay, it could well cause some severe
>damage to an Iowa.

Maybe. Remember, they had a MAJOR explosion in one of the turrets,
and it just blew off the dust covers of the guns. The Iowa are pretty
well compartmentalized.

--
Michael A. Chance St. Louis, Missouri, USA "At play in the fields
Work: mc3...@sw1stc.sbc.com of St. Vidicon"
Play: mch...@crl.com
mch...@nyx.cs.du.edu

[Matthew L. Ward]

From war...@picard.cig.mot.com (Matthew L. Ward)

>From Frank Kastenholz <kas...@lard.ftp.com>

[Stuff from drw...@hogpg.ho.att.com Deleted]

>My impression from reading Dulin & Garzke and Freidman is that a
>major factor in damage to BBs is not punching holes through the armor
>plate, but rather shock damage that does things like popping seals
>and glands (ala PoW), causing joints in the armor plate to open up
>(if I recall, this was a major failing in one of the Japanese BBs),
>and then generally shaking up the internal equipment so that the crew
>were hampered in the DC efforts.
>
>I would imagine that a 1000kg HE warhead would cause significant
>shock damage to an Iowa. After all, it took only about a half-dozen
>330kg torpedos to sink the PoW and the only penetration of her
>citadel (that I recall) was the glands and stuffing boxes destroyed
>by the prop-shaft bent by one of the torpedos...

The damage caused by a Torpedo or other underwater explosion is magnified
by the so-called "water hammer" effect. Billy Mitchell first used this effect
to sink the Ostfreisland (sp?).

I believe that the effect is caused by the propagation of concussive forces
into the area of least density. This an air-filled hull would get the bulk
of the explosive force.

With an explosive in the air, even with shaped charges, a substantial portion
of the explosive force is bleed off by the gases expanding into (literally)
thin air.

------------------------------------------------------------------------------
Matthew Ward, Motorola Personal Digitial Cellular, APPLE ][ FOREVER !
Arlington Heights, IL. USA - My words are not Motorola's
_______________________________________________________________________________
For a good time call: The Capitol Hill Switchboard: 1-800-768-2221
and ask for the office of your Senator or Representative
(don't think of it a toll-free call, you already paid dearly for it)
-------------------------------------------------------------------------------

[patterson,george r]

From pat...@cc.bellcore.com (patterson,george r)

In article <Cx3w...@ranger.daytonoh.ncr.com>,

John Schilling <schi...@spock.usc.edu> wrote:
>drw...@hogpg.ho.att.com (-D.WELLS) writes:

>>The armor on the Iowas is not impenetrable, just very rugged. I suppose
>>that a GBU-28 could get through it, but of course, a GBU-28 is not a
>>long-range anti-ship missile. Large Soviet-designed ASMs tend to have
>>1000kg high explosive warheads. I tend to doubt that these could get
>>through the heavy armor on an Iowa.

>That 1000-kg warhead, attached to a 2000+kg airframe, is going to be

>hitting the BB's deck, not the belt. And most likely at something over
>1500 knots.
>Depending on case thickness and fuse delay, it could well cause some severe
>damage to an Iowa.

True. The original specs on the deck armor were "as necessary to give
protection at an outer limit of 30,000 yards against 16" 45 caliber
2,240 lb. armor piercing projectiles". The belt armor was designed to
give protection from the same projectile at 18,000 yards at 90 degree
target angle.

Muzzle velocity of such a shell is 2425 fps. The 2,240 lb. shell weight
mentioned above is the entire weight. I can't find an exact reference,
but I believe the actual warhead charge is a little over 600 pounds.

So the ship is designed to withstand a 300kg warhead, attached to a
700+kg "airframe", hitting at something less than 1500 knots.

Even if the missile described above hit the belt, would *you* like to
bet your life on that armor taking three times its design load?

Reference: _The Iowa Class Battleships_, Muir.

-----------------------------------------------------------------------
| Love, n; A form of temporary insanity curable either
| by marriage or by removal of the afflicted from the
George Patterson | conditions under which he incurred the condition. It
| is occasionally fatal, but more often to the physician
| than to the patient. - The Devil's Dictionary -
-----------------------------------------------------------------------

[Paul F Austin]

From pau...@ic1d.harris.com (Paul F Austin)

Jerry Prather <pra...@infi.net> writes:

>: : From "Gil W. Lau" <bp...@cleveland.freenet.edu>

>: : I was reading a book on fleet tactics and was surprised to hear
>: : the author comment that anti-ship missiles, in general, can't
>: : penetrate a battleship's armor. I never really thought about
>: : armor piercing characteristics of ASMs. I guess the point is almost
>: : moot as no modern warship really is armored like old battlewagons.
>: : However, just out of curiosity, does anyone have any data
>

>Why were battleships brought back to the USN? Because they could take all

>the non-nuclear cruise missiles fired at them and shrug them off without
>sustaining a mission kill. To cope with an Iowa class battleship an enemy
>with a modern conventional missile would have to get 25+ hits and also be
>lucky.
>

Not exactly. While the Iowas would pipe Sweepers after a Exocet or Harpoon
attack, Russian ASMs were and are entirely different kettles of fish.

A typical Russian ASM (AS6) packs a 1 tonne warhead and has terminal velocity
about Mach 2.5 with a high angle trajectory. Does this sound rather like a 16
inch projectile? If the penetrator of one of these ASMs is armored (no
information) then certainly the deck armor of an Iowa could be penetrated.

I think this is why the USN went away from armored ships, with a decision
based on Kamikaze experience that the only hope was to prevent impact in the
first place. If you can't prevent a hit, then you can't prevent a kill. I
think this logic is flawed since armor is cheap and gives the defense systems
more margin but I think that this is the logic.

"Peace is the ideal that we infer from the fact that there are periods between wars" Jerry Pournelle
Paul Austin

[Ed Rudnicki]

From Ed Rudnicki <erud...@pica.army.mil>

In article <Cx3w...@ranger.daytonoh.ncr.com> Bob Lyle <madr...@metronet.com> writes:
>I think the Swedes use Hellfires for coastal defense. Assuming a
>state-of-the art, 6" warhead that should punch through 25" of homogenous
>steel - at least.
>
>Of course, it is really designed to shred thew superstructure of a fast
>attack boat.

I thought that the coast defense Hellfire had a blast-frag warhead
in lieu of HEAT. They do advertise it as the "Hellfire Modular
Missile System" :)

[Frank Kastenholz]

From kas...@lard.ftp.com (Frank Kastenholz)

>From mh6...@cutter.ship.edu (Michael Holbrook)

> 2. The size of ships probably would get larger. There is not much to say
> here, except that the use of missiles has already caused ship size to
> inflate dramatically. A Spruance class destroyer is as large as a WWII
> cruiser. Probably most of the cost in armouring ships would come in the
> form of having to make them larger in order to keep all of that heavy
> armour afloat.

The issue isn't so much physical size as it issues of displacement,
desired speed, and engine size. Everything else being equal, engine
power needed to move a given at a given speed goes up much more than
linearly as the displacement goes up. So, to add more displacement
(eg for armor) to a ship requires also adding more power, or more or
larger engines.

Putting in bigger engines is not a great win since then you also have
to put in larger auxiliary equipment to support the engines. If the
engines are more powerful then they are physically bigger (more
displacement, start the cycle over!) need more structure to support
them (more displacement, start the cycle over!!) and take up more
physical space, which means that the engineering spaces are not as
well subdivided as you might like -- actually reducing survivability.

Or you could add additional engines. This, of course, leads to
additional weight, structure, and so on, again. It also means that
you need more engineering crew to run them (more space and weight for
crew spaces and supplies!) AND possibly more prop-shafts (more
weight) which put vulnerable holes in the armor.

And of course, all this additional engine power means that you need
more fuel relative to an unarmored ship. More fuel means more
fuel-tanks (which can be used for torpedo protection). More fuel
tanks takes volume from the ship and adds weight for the machinery
and, of course, the fuel (go back to step 1 where more weight
requires bigger engines!).

>3. The mission kill argument is another good one, but I believe that
>it has a fatal flaw. The argument is that the radars are vulnerable,

>so armour will not help them. ... An armoured Aegis that is nailed
>...is mission-killed. It is out of the fight, and its armour did not

>help. But its armour WOULD help keep that very expensive ship afloat

>... steaming back to port and will have another radar installed on

>her, and her damage repaired.

The argument is that once all the external sensors are knocked out,
the ship becomes a sitting duck and can then be destroyed by the
enemy. Once you take out a ship's radar and the other soft stuff,
then the ship can't detect incoming missiles and planes and can't
launch/guide her own SAMs or use her anti-missile systems. Even
though this ship may be afloat, she can't fire back. She then becomes
nothing more than a practice target and can be sent to the bottom at
the enemy's pleasure.

>4. The arms race argument is also specious IMHO. We already build
>missile systems to foil incoming ASMs, and the bad guys (and us) build
>ASMs to beat the defense systems.

The arms race wasn't so much with the other countries better weapons
(and vice versa). It was with the laws of physics and hydrodynamics
and so on and the conflicting needs of engines, machinery, operating
economics...

> Well, thats my longwinded $0.02. Hey, to the guy who said that the
> rolling mills simply aren't there anymore, what a way to revitalize the
> U.S. Steel industry! :)

Hmmm. Let's assume that we armor each new ship. This is what, a
handfull of Burke's a year? Let's say it's 6. Let's be real silly
here and add 15,000 tons of armor to each one (roughly the amount on
an Iowa -- I said I'd be silly!) 6 * 15,000 tons is 90,000 tons of
armor a year. Out of a total US steel production of ~80,000,000 tons
a year; 00.11%. Oh well.... :-)

--
Frank Kastenholz

[Frank Kastenholz]

From kas...@lard.ftp.com (Frank Kastenholz)

>From war...@picard.cig.mot.com (Matthew L. Ward)
>
>>From Frank Kastenholz <kas...@lard.ftp.com>
>

>>I would imagine that a 1000kg HE warhead would cause significant
>>shock damage to an Iowa. After all, it took only about a half-dozen
>>330kg torpedos to sink the PoW
>

>The damage caused by a Torpedo or other underwater explosion is magnified
>by the so-called "water hammer" effect.
>

>I believe that the effect is caused by the propagation of concussive forces
>into the area of least density. This an air-filled hull would get the bulk
>of the explosive force.
>
>With an explosive in the air, even with shaped charges, a substantial portion
>of the explosive force is bleed off by the gases expanding into (literally)
>thin air.

All true. But there's also a 3:1 difference in quantity of HE
invovled (1000kg for the ASM, 330 for the torpedos) as well as a
possible difference in the quality of the HE. That is, do modern HE's
give more bang for the kilo than 1930's vintage? All of these
questions require someone with a more quantitative knowledge than I.

Anyway, the main point of my posting was that it isn't always
necessary for the weapons to actually penetrate any armor. There are
already ample holes in it when the ship leaves the builder's dock.
Sometimes, all that's needed is to shake it up a bit...

--
Frank Kastenholz

[John Stoffel]

From jo...@avante.WPI.EDU (John Stoffel)

george> From pat...@cc.bellcore.com (patterson,george r)

george> In article <Cx3w...@ranger.daytonoh.ncr.com>,

george> John Schilling <schi...@spock.usc.edu> wrote:
>> drw...@hogpg.ho.att.com (-D.WELLS) writes:

>>> The armor on the Iowas is not impenetrable, just very rugged. I suppose
>>> that a GBU-28 could get through it, but of course, a GBU-28 is not a
>>> long-range anti-ship missile. Large Soviet-designed ASMs tend to have
>>> 1000kg high explosive warheads. I tend to doubt that these could get
>>> through the heavy armor on an Iowa.

>> That 1000-kg warhead, attached to a 2000+kg airframe, is going to be
>> hitting the BB's deck, not the belt. And most likely at something over
>> 1500 knots.
>> Depending on case thickness and fuse delay, it could well cause some severe
>> damage to an Iowa.

george> True. The original specs on the deck armor were "as necessary
george> to give protection at an outer limit of 30,000 yards against
george> 16" 45 caliber 2,240 lb. armor piercing projectiles". The belt
george> armor was designed to give protection from the same projectile
george> at 18,000 yards at 90 degree target angle.

george> Muzzle velocity of such a shell is 2425 fps. The 2,240
george> lb. shell weight mentioned above is the entire weight. I can't
george> find an exact reference, but I believe the actual warhead
george> charge is a little over 600 pounds.

george> So the ship is designed to withstand a 300kg warhead, attached
george> to a 700+kg "airframe", hitting at something less than 1500
george> knots.

george> Even if the missile described above hit the belt, would *you*
george> like to bet your life on that armor taking three times its
george> design load?

This is a fallacious arguement for a fairly simple reason which you
state yourself in your first paragraph. The big Russion ASMs are HE
warheads, which means they have zero to low armour piercing ability.
And if you can't pentrate the armour, then you can't really do much
except ding it alittle and cause incidental damamge.

As I remember from Friedman's "US Naval Weapons" the standard 16" AP
shell had only about 50lbs or so of HE in it, the rest of it was all
metal and used to punch through the opposing metal so the HE could
penetrate to the vitals of the ship.

One good example of this is the Japanese Kamakaze which hit a US
battleship around the end of WWII. Those planes had around 1000kg war
heads as I remember, and all it did when it hit the main belt was to
scratch the paint a bit. I'd have to look in Friedman's "US
Battleships" for more details.

John

John F. Stoffel - jo...@wpi.edu - 508-831-5512 - FL 111F
Workstation Specialist - Worcester Polytechnic Institute College Computer Ctr.
Kill your television

[Damian Kneale]

From dam...@uniwa.uwa.edu.au (Damian Kneale)

One important facet of armouring ships that no-one has mentioned is that
along with making ships bigger, they will also become slower, and at the
same time more expensive. With most country's navies being cost driven
to a large extent, this is a drawback. It seems that the economy of the
situation says that buying 5 unarmoured ships is better than buying 3 or
4 armoured ones for the same price.

This is not quite as callous as it sounds. The 5 ships are not
undefended, just basically unarmoured. The theory is that it is better
to sink money into one good defense system than split it between two and
have a compromise. Judge for yourself whether or not it's a good idea.

Damian.

--
Damian Kneale | Last of the Romantics
dam...@ucc.gu.uwa.edu.au | @---}----
dam...@uniwa.uwa.edu.au | Smile, it could be worse!

[Steve Wall]

From Steve Wall <smw...@pica.army.mil>

In article <Cx6Is...@ranger.daytonoh.ncr.com>, mch...@crl.com (Michael
A. Chance) wrote:

>
> Maybe. Remember, they had a MAJOR explosion in one of the turrets,
> and it just blew off the dust covers of the guns. The Iowa are pretty
> well compartmentalized.
>

But that "explosion" only involved propellant burning in a partially
unconfined space. Devastating to the gun crew without a doubt,
but not the effect that a few hundred pounds of TNT inside a steel
shell would cause. I don't think any shells cooked off in the turret.

--
Steve Wall

[Ed Rudnicki]

From Ed Rudnicki <erud...@pica.army.mil>

In article <Cx7JF...@ranger.daytonoh.ncr.com> kas...@lard.ftp.com (Frank Kastenholz) writes:
>All true. But there's also a 3:1 difference in quantity of HE
>invovled (1000kg for the ASM, 330 for the torpedos) as well as a
>possible difference in the quality of the HE. That is, do modern HE's
>give more bang for the kilo than 1930's vintage? All of these
>questions require someone with a more quantitative knowledge than I.

It wouldn't be that much more. Typical torpedo fills were aluminized
TNT, for enhanced blast. In an ASM warhead that big, cost of the
filler and producibility would be factors. And even aluminized RDX
would not be that much of an improvement. Of course I can't comment
without knowing what the filler is. The warhead is big enough to
make the more exotic fillers seen in smaller missiles likely to be
cost-prohibitive.

[Adam]

From acge...@taco.engr.ucdavis.edu (Adam)

patterson,george r (pat...@cc.bellcore.com) wrote:

: True. The original specs on the deck armor were "as necessary to give

: protection at an outer limit of 30,000 yards against 16" 45 caliber
: 2,240 lb. armor piercing projectiles". The belt armor was designed to
: give protection from the same projectile at 18,000 yards at 90 degree
: target angle.

: Muzzle velocity of such a shell is 2425 fps. The 2,240 lb. shell weight
: mentioned above is the entire weight. I can't find an exact reference,
: but I believe the actual warhead charge is a little over 600 pounds.

: So the ship is designed to withstand a 300kg warhead, attached to a
: 700+kg "airframe", hitting at something less than 1500 knots.

: Even if the missile described above hit the belt, would *you* like to
: bet your life on that armor taking three times its design load?

: Reference: _The Iowa Class Battleships_, Muir.

I believe the flaw in this argument is the fact that the Soviet
ASM's do not have armor-piercing warheads. You noted in your design
specifications that the armor was designed to ward off 16" AP shells.
Now the big SS-N-20's ("Shipwreck" I believe the NATO nomenclature is)
have HE warheads, not AP.
I'm pretty sure that it is simple kinetic energy which carries
the ASM through the ship, rather than any sort of "semi-armor piercing"
design. Can someone confirm or deny from Jane's?
At any rate, AP warheads almost certainly have more than 3 times the
armor penetration of HE warheads. This would imply that the deck armor
would indeed be sufficient.

--
+-------------+---------------------------------------------------------------+
|Adam Getchell|acge...@taco.engr.ucdavis.edu | ez00...@othello.ucdavis.edu |
| acgetchell |"Invincibility is in oneself, vulnerability is in the opponent"|
+-------------+---------------------------------------------------------------+

[-D.WELLS]

From drw...@hogpg.ho.att.com (-D.WELLS)

In article <Cx6It...@ranger.daytonoh.ncr.com>,
Paul F Austin <pau...@ic1d.harris.com> wrote:

>
> Jerry Prather <pra...@infi.net> writes:
>
>
>>Why were battleships brought back to the USN? Because they could take all
>>the non-nuclear cruise missiles fired at them and shrug them off without
>>sustaining a mission kill. To cope with an Iowa class battleship an enemy
>>with a modern conventional missile would have to get 25+ hits and also be
>>lucky.
>
>Not exactly. While the Iowas would pipe Sweepers after a Exocet or Harpoon
>attack, Russian ASMs were and are entirely different kettles of fish.

Same kettle, just a bigger fish (with different swimming habits) ;-)

>A typical Russian ASM (AS6) packs a 1 tonne warhead and has terminal velocity
>about Mach 2.5 with a high angle trajectory. Does this sound rather like a 16
>inch projectile?

Maybe just a bit, but keep in mind that BBs were designed to take multiple
hits from such projectiles, and we KNEW that these projectiles would be
armor piercing.

>If the penetrator of one of these ASMs is armored (no
>information) then certainly the deck armor of an Iowa could be penetrated.

I really have to believe that the warhead is just normal HE. (OK, MAYBE
SAP) There just isn't any need for anything else these days. Why waste
weight on a penetrator, which is only necessary for a very few ships, when
you could just put in more explosives, or more fuel, which will help
against all the rest? When the AS-6, SS-N-12, et al were designed, I
seriously doubt that the Soviets were concerned about the threat from
battleships. The same holds today. Why bother, when there are only four
ships that it would be useful against, and they are all in reserve!

>I think this is why the USN went away from armored ships, with a decision
>based on Kamikaze experience that the only hope was to prevent impact in the
>first place. If you can't prevent a hit, then you can't prevent a kill. I
>think this logic is flawed since armor is cheap and gives the defense systems
>more margin but I think that this is the logic.

I think that the rationalization for moving away from armored ships was
nuclear weapons. The theory was that no armor would stand up to a nuke.
Future wars will be nuclear, therefore no armor is needed. Keep in mind
that several Kamikazes hit US battleships, (most notably the Missouri,
but also one of the New Mexicos, perhaps others as well) and a British CV
(HMS Illustrious?) which had an armored flight decks. None of these ships
was seriously damaged.

The kamikaze analogy is a good one, in my opinion, however we must keep
in mind that these modern cruise missiles are much faster, and have
more kinetic energy. Still, I am not at all convinced that they'll go
through heavy armor.

[Dan Schulz]

From schu...@gold.tc.umn.edu (Dan Schulz)

>>On this topic it is worth noting that if a projectile hits a ship,
>>but does not sink it due to any armour it might have, it will still
>>have a significant impact upon the ships ability to operate. This
>>is because sensors etc.. remain fragile.
>>
> While this is entirely true, most anti-ship missiles are programmed
>to hit amidships, fairly low. If you look at pictures of the Sheffield
>or the Stark, you'll see what I mean. But you'll note that in both cases
>the radar antennae were left intact.

You almost put your finger on it. Reprogramming a missle is easy. The
reason modern ships don't employ heavy armor is that it is easily defeated.
Why spend lots of money of armor (which requires larger hulls, and will
generally slow you down) when your enemy can develope a counter to it
_for_a_lot_less_money_.

And I still think that a strike package compossed of A6's and F18's will put
any BB to the bottom (it'll be a flaming wreck at least), assuming it is
alone with no screening escort. The military will tell you anything to get
your moral up. Its the KEY :)

[-D.WELLS]

From drw...@hogpg.ho.att.com (-D.WELLS)

In article <Cx6Is...@ranger.daytonoh.ncr.com>,

Michael A. Chance <mch...@crl.com> wrote:
>
>John Schilling <schi...@spock.usc.edu> writes:
>
>>That 1000-kg warhead, attached to a 2000+kg airframe, is going to be
>>hitting the BB's deck, not the belt. And most likely at something over
>>1500 knots.
>
>A cruise missile hitting at Mach 2, with a half-ton warhead? Are you
>sure? It takes a lot of effort to push a warhead that big that fast.
>The US cruise missiles top out at about 650.

Yup, they're that big and that fast. And it's a metric ton (about 2200 lbs
for the big ones), not a half ton. (well, OK, they do have some in the 1100
lb/500kg range too) Now, I'm still an advocate of armor, but some of the big
xUSSR cruise missiles really are that big.

Of course, because they're so big, and as someone else pointed out, these
are among the few that do come in high, you get a fairly good amount
of warning that they're coming in, and your friendly neighborhood
AA ship (Ticonderoga, Burke, whatever) will get the a few chances to shoot
at it.

>>Depending on case thickness and fuse delay, it could well cause some severe
>>damage to an Iowa.
>
>Maybe. Remember, they had a MAJOR explosion in one of the turrets,
>and it just blew off the dust covers of the guns. The Iowa are pretty
>well compartmentalized.

This is actually somewhat instructive, although not conclusive.

The explosion on the Iowa did more than just "blow off the dust covers".
The inside of the turret was gutted. It seems that the breech block of one
of the guns got blown off, and it went straight back into that old,
obsolescent, (still effective though) irreplacable analog fire control
computer. I'm afraid that this turret will never fire another round.
(It would take extensive repairs that the Government will not pay for)

On the other hand, that huge explosion didn't even damage the roof armor
on the turret. I saw the Iowa just recently, and there was no damage
visible from the outside. If I'm not mistaken, the roof armor on the
turrets is not that much thicker than the total armor on the decks.
(If memory serves, the turret roof has 7", the decks total about 6")
I could look up the exact weight of the explosives involved in the
Iowa disaster. If it's in the same league as the warhead on an SS-N-12,
I'd say that it's a pretty good indication that an Iowa's deck armor
could survive a hit by an SS-N-12.

[Michael Holbrook]

From mh6...@cutter.ship.edu (Michael Holbrook)

Paul F Austin (pau...@ic1d.harris.com) wrote:

: From pau...@ic1d.harris.com (Paul F Austin)

: Jerry Prather <pra...@infi.net> writes:

: >: : From "Gil W. Lau" <bp...@cleveland.freenet.edu>

: >: : I was reading a book on fleet tactics and was surprised to hear
: >: : the author comment that anti-ship missiles, in general, can't
: >: : penetrate a battleship's armor. I never really thought about
: >: : armor piercing characteristics of ASMs. I guess the point is almost
: >: : moot as no modern warship really is armored like old battlewagons.
: >: : However, just out of curiosity, does anyone have any data

: >

: I think this is why the USN went away from armored ships, with a decision

: based on Kamikaze experience that the only hope was to prevent impact in the
: first place. If you can't prevent a hit, then you can't prevent a kill. I
: think this logic is flawed since armor is cheap and gives the defense systems
: more margin but I think that this is the logic.

If so, then they were foolish to base the move on this information. Take
the experiences of the US Navy's carriers late in the pacific campaign
and contrast them to the Royal Navy's carrier experiences at that same
period. The limies had a saying: "If a US carrier is hit by a kamikaze,
six months in port with fire damage. If a Brit carrier gets hit, time to
fetch the brooms". This was ENTIRELY because of the armour that the
British afforded their carriers, armour that the American carriers
lacked. And the deck armour of an I-class carrier was not really that
thick. Indeed, the US navy learned from the British and placed deck
armour on the Midway class.

The US navy may have very good reasons for abandoning armour, but the
kamikaze experience isn't one of them.

Cheerio,
Mike Holbrook

[Michael Holbrook]

From mh6...@cutter.ship.edu (Michael Holbrook)

Frank Kastenholz (kas...@lard.ftp.com) wrote:

: From kas...@lard.ftp.com (Frank Kastenholz)

: >From mh6...@cutter.ship.edu (Michael Holbrook)

: > 2. The size of ships probably would get larger.

: The issue isn't so much physical size as it issues of displacement,

: desired speed, and engine size. Everything else being equal, engine
: power needed to move a given at a given speed goes up much more than
: linearly as the displacement goes up. So, to add more displacement
: (eg for armor) to a ship requires also adding more power, or more or
: larger engines.

: Putting in bigger engines is not a great win since then you also have
: to put in larger auxiliary equipment to support the engines. If the
: engines are more powerful then they are physically bigger (more
: displacement, start the cycle over!) need more structure to support
: them (more displacement, start the cycle over!!) and take up more
: physical space, which means that the engineering spaces are not as
: well subdivided as you might like -- actually reducing survivability.

: Or you could add additional engines. This, of course, leads to
: additional weight, structure, and so on, again. It also means that
: you need more engineering crew to run them (more space and weight for
: crew spaces and supplies!) AND possibly more prop-shafts (more
: weight) which put vulnerable holes in the armor.

: And of course, all this additional engine power means that you need
: more fuel relative to an unarmored ship. More fuel means more
: fuel-tanks (which can be used for torpedo protection). More fuel
: tanks takes volume from the ship and adds weight for the machinery
: and, of course, the fuel (go back to step 1 where more weight
: requires bigger engines!).

True, but lets not forget that we have aircraft carriers that can haul
butt at circa 30 knots. Certainly anything cruiser-sized and up would
almost have to be a nuke. Sure, it would be more expensive, but it would
also be more survivable.

: >3. The mission kill argument...
: The argument is that once all the external sensors are knocked out,

: the ship becomes a sitting duck and can then be destroyed by the
: enemy. Once you take out a ship's radar and the other soft stuff,
: then the ship can't detect incoming missiles and planes and can't
: launch/guide her own SAMs or use her anti-missile systems. Even
: though this ship may be afloat, she can't fire back. She then becomes
: nothing more than a practice target and can be sent to the bottom at
: the enemy's pleasure.

That's an assumption that I'd not be prepared to make. Certainly it
could happen, but remember that ships can recieve guidance and search
data from other vessels (that's part of the point of Aegis). If the ship
is alone, then she's a duck. If she has escorts, or other undamaged
peers, then she is a drake (and I mean the big red mythical firebreathing
kind). Ships that are still afloat in a task force may be a liability,
but I'd rather have a damaged ship that can fight again than a sunk
ship. If she is not alone, then she cannot be "sunk at the enemy's
pleasure".

: >4. The arms race argument is also specious IMHO. We already build

: >missile systems to foil incoming ASMs, and the bad guys (and us) build
: >ASMs to beat the defense systems.

: The arms race wasn't so much with the other countries better weapons
: (and vice versa). It was with the laws of physics and hydrodynamics
: and so on and the conflicting needs of engines, machinery, operating
: economics...

true, always has been, always will.

: Hmmm. Let's assume that we armor each new ship. This is what, a

: handfull of Burke's a year? Let's say it's 6. Let's be real silly
: here and add 15,000 tons of armor to each one (roughly the amount on
: an Iowa -- I said I'd be silly!) 6 * 15,000 tons is 90,000 tons of
: armor a year. Out of a total US steel production of ~80,000,000 tons
: a year; 00.11%. Oh well.... :-)

well, lets not forget that we're talking about DESTROYERS here, not BBs!
And I was responding to a guy that said that the US stell industry
"couldn't handle it".

Cheerio,
Mike Holbrook

[Nigel Tzeng]

From ni...@access.digex.net (Nigel Tzeng)

In article <Cx6It...@ranger.daytonoh.ncr.com>,

[snip]

>Not exactly. While the Iowas would pipe Sweepers after a Exocet or Harpoon
>attack, Russian ASMs were and are entirely different kettles of fish.
>
>A typical Russian ASM (AS6) packs a 1 tonne warhead and has terminal velocity
>about Mach 2.5 with a high angle trajectory. Does this sound rather like a 16
>inch projectile? If the penetrator of one of these ASMs is armored (no
>information) then certainly the deck armor of an Iowa could be penetrated.
>
>I think this is why the USN went away from armored ships, with a decision
>based on Kamikaze experience that the only hope was to prevent impact in the
>first place. If you can't prevent a hit, then you can't prevent a kill. I
>think this logic is flawed since armor is cheap and gives the defense systems
>more margin but I think that this is the logic.

I think that one thing we are forgetting is that if we had a
significant number of armored combatants we'd force the opponent to
use AS6 sized weapons as opposed to Exocet sized weapons. While this
sounds like a losing proposition for the pro-armor group (after all
bigger missiles do exist) you'd have to consider that the best way of
penetrating an Aegis defended fleet is to saturate the AAW
defenses... and that a lot harder if you halve or quarter the number
of missiles you can carry on your aircraft because they have to be
bigger. Reduce that number enough and they wont get any hits because
the AAW umbrella can target incomming missles with enough overkill to
stop the attack cold (hopefully).

Add in the fact that the you're probably forced to use something the
size of a Backfire instead of a Mirage the odds are you have fewer
aircraft to boot. Not that many countries can support a multi
regiment bomber group dedicated to anti-shipping and pay for a
credible fighter force at the same time. Another plus is a Backfire
is easier to see and kill than a Mirage with an exocet or harpoon on
it.

Does the AS6 even fit on a fighter? I don't think so but...

>
>Paul Austin
>

Nigel Tzeng

[Michael Holbrook]

From mh6...@cutter.ship.edu (Michael Holbrook)

John Schilling (schi...@spock.usc.edu) wrote:

: From John Schilling <schi...@spock.usc.edu>

: drw...@hogpg.ho.att.com (-D.WELLS) writes:

: >The armor on the Iowas is not impenetrable, just very rugged. I suppose
: >that a GBU-28 could get through it, but of course, a GBU-28 is not a
: >long-range anti-ship missile. Large Soviet-designed ASMs tend to have
: >1000kg high explosive warheads. I tend to doubt that these could get

: >through the heavy armor on an Iowa. For example, the belt armor on
: >an Iowa is about 310mm (a little over a foot) thick. Assuming that the
: >missile hits the belt, (which is not a totally unreasonable assumption,
: >since many missiles are programmed to hit low and amidships), an Iowa
: >should be able to ride out the hit without too much difficulty.

: Big problem: Large Soviet-designed ASMs are among the few generally
: *not* programmed to hit low and amidships. Some of the later models
: have an sea-skimming option, but the default (and only, for early models)
: trajectory is high-altitude cruise followed by a diving attack.

: That 1000-kg warhead, attached to a 2000+kg airframe, is going to be

: hitting the BB's deck, not the belt. And most likely at something over
: 1500 knots.

: Depending on case thickness and fuse delay, it could well cause some severe
: damage to an Iowa.

Damn right it could. But remember, almost anything else would be reduced
to metal filings. Also, it bears mentioning that the big soviet ASMs were
not the most accurate of weapons (some of the later models excepted), and
the whole point of a deck hit is moot if the missile decides to bugger a
cloud of chaff of the ocean's surface instead. Also, CIWS could probably
hit a monster like the KITCHEN or SHIPWRECK easier then it could an exocet
(that, however, is just a guess). Even the deck armour of an Iowa would
probably fare well against something like a harpoon or exocet, and lets
face it, that is what most of the navies that the US will be facing will
be using.

Cheerio,
Mike Holbrook

PS actually, most of the navies that we'll be facing in the near future
will be using harsh language only. But we can't afford to bank on it.
-H

[John Schilling]

From John Schilling <schi...@spock.usc.edu>

mch...@crl.com (Michael A. Chance) writes:

>From mch...@crl.com (Michael A. Chance)

>John Schilling <schi...@spock.usc.edu> writes:

>>That 1000-kg warhead, attached to a 2000+kg airframe, is going to be
>>hitting the BB's deck, not the belt. And most likely at something over
>>1500 knots.

>A cruise missile hitting at Mach 2, with a half-ton warhead? Are you
>sure? It takes a lot of effort to push a warhead that big that fast.
>The US cruise missiles top out at about 650.

As for size and speed, I am indeed certain. Checked the descriptions for the
SS-N-12 and AS-6 from _Jane's Weapon Systems_. The Russians have always
liked brute force. They did give up a lot in terms of launch weight,
range, and stealth, to achieve such performance.

What is not entirely clear is the construction of the warhead; most sources
do not distinguish between various types of conventional warheads. Anything
not nuclear or chemical tends to get lumped into a generic "HE" category

But, since these missiles were designed for use against CVs with armored
flight decks, it is unlikely that they are thin-skinned, point-detonating
types. Circumstantial evidence does suggest an SAP design.

>>Depending on case thickness and fuse delay, it could well cause some severe
>>damage to an Iowa.

>Maybe. Remember, they had a MAJOR explosion in one of the turrets,
>and it just blew off the dust covers of the guns. The Iowa are pretty
>well compartmentalized.

Granted, a single hit will not sink an Iowa. But it will very likely
wreck whatever turret or compartment is in the missile's path. Multiple
hits probably will put the ship out of operation fairly quickly.

--
*John Schilling * "You can have Peace, *
*Member:AIAA,NRA,ACLU,SAS,LP * or you can have Freedom. *
*University of Southern California * Don't ever count on having both *
*Aerospace Engineering Department * at the same time." *
*schi...@spock.usc.edu * - Robert A. Heinlein *
*(213)-740-5311 or 747-2527 * Finger for PGP public key *

[Ed Rudnicki]

From Ed Rudnicki <erud...@pica.army.mil>

In article <Cx9Er...@ranger.daytonoh.ncr.com> John Schilling <schi...@spock.usc.edu> writes:
>What is not entirely clear is the construction of the warhead; most sources
>do not distinguish between various types of conventional warheads. Anything
>not nuclear or chemical tends to get lumped into a generic "HE" category
>
>But, since these missiles were designed for use against CVs with armored
>flight decks, it is unlikely that they are thin-skinned, point-detonating
>types. Circumstantial evidence does suggest an SAP design.

Given the size of the warhead, I'd make a bet on a multi-P charge
type warhead, as used on the German Kormoran. Inside a large ship a
large number of big frags would be more damaging than mere blast.
Inside a smaller ship there'd be little to choose.

This warhead would by nature have substantial structural integrity
vis a vis a pure blast type.

Ed Rudnicki
All disclaimers apply

[Bob Lyle]

From madr...@metronet.com (Bob Lyle)

Michael Holbrook (mh6...@cutter.ship.edu) wrote:

: well, lets not forget that we're talking about DESTROYERS here, not BBs!

: And I was responding to a guy that said that the US stell industry
: "couldn't handle it".

Actually, there is a real lack of steelworks capable of large castings.
If my informants are correct, there are onlt two in the USA that can cast
even tank turrets. Rolled plates od armor quality are nearly as hard to get.

Bob Lyle

[Daniel Pawtowski]

From dpaw...@access.digex.net (Daniel Pawtowski)

In article <Cx9Eq...@ranger.daytonoh.ncr.com>,

Michael Holbrook <mh6...@cutter.ship.edu> wrote:
>
>
>PS actually, most of the navies that we'll be facing in the near future
>will be using harsh language only. But we can't afford to bank on it.

I suppose the "low intensity" type of fights the US keeps getting into
nowadays actually support the concept of having a little armor.

Suppose a couple big-muscled thugs in Hati decided to go out in a rowboat
and fire an old .50 caliber machine gun or a cheap LAW-style antitank
missile into the side of a passing US destroyer. They'd likely punch a
hole through and kill someone before the destroyer blew them away, whereas
a WWII-era US warship had enough armor to shrug off small arms.

Or in high-tension zones where permission to shoot is a heavily loaded
political hotbed, passive defenses can be a nice plus. All the AA missiles
in the world won't help you if you're not allowed to fire them.

Daniel Pawtowski
dpaw...@vt.edu

[Rob S. Rice]

From rr...@netnews.upenn.edu (Rob S. Rice)

[deletions for brevity]
: If so, then they were foolish to base the move on this information. Take

: the experiences of the US Navy's carriers late in the pacific campaign
: and contrast them to the Royal Navy's carrier experiences at that same
: period. The limies had a saying: "If a US carrier is hit by a kamikaze,
: six months in port with fire damage. If a Brit carrier gets hit, time to
: fetch the brooms". This was ENTIRELY because of the armour that the
: British afforded their carriers, armour that the American carriers
: lacked. And the deck armour of an I-class carrier was not really that
: thick. Indeed, the US navy learned from the British and placed deck
: armour on the Midway class.

True enough--in fact the tactic evolved of using the Limey carriers
as Kamikaze bait, BUT...there's always a trade off. 1)His
majesty's aircraft carriers could carry nought but HALF the plane load
of the American ships, hence the incredible size of the Midway
and later classes--jets and armor, 2)If the British carriers got
hulled, they took an immediate and severe list. I can still
remember the picture of the _Ark Royal_ going down off Gibraltar with
her aircraft unable to get off her tilting deck.

: Cheerio,
: Mike Holbrook

Rob S. Rice
rr...@ccat.sas.upenn.edu

[Lars Henrik Bxler Olafsen]

From la...@ifi.uio.no (Lars Henrik Bxler Olafsen)

In article <Cx7JF...@ranger.daytonoh.ncr.com> jo...@avante.WPI.EDU (John Stoffel) writes:
>This is a fallacious arguement for a fairly simple reason which you
>state yourself in your first paragraph. The big Russion ASMs are HE
>warheads, which means they have zero to low armour piercing ability.
>And if you can't pentrate the armour, then you can't really do much
>except ding it alittle and cause incidental damamge.

What about pressure? Wouldn't the poor sods inside feel the effects of
a 1 ton TNT charge detonating on the other side of a steel wall?
I know that tanks can be taken out this way. Wouldn't it be possible
to take out i.e the bridge or a gun turret in this manner?

-Lars

[-D.WELLS]

From drw...@hogpg.ho.att.com (-D.WELLS)

In article <Cx7JF...@ranger.daytonoh.ncr.com>,

Frank Kastenholz <kas...@lard.ftp.com> wrote:
>
>> 2. The size of ships probably would get larger. There is not much to say
>> here, except that the use of missiles has already caused ship size to
>> inflate dramatically. A Spruance class destroyer is as large as a WWII
>> cruiser. Probably most of the cost in armouring ships would come in the
>> form of having to make them larger in order to keep all of that heavy
>> armour afloat.
>
>The issue isn't so much physical size as it issues of displacement,
>desired speed, and engine size. Everything else being equal, engine
>power needed to move a given at a given speed goes up much more than
>linearly as the displacement goes up. So, to add more displacement
>(eg for armor) to a ship requires also adding more power, or more or
>larger engines.

This is clearly untrue. I can cite historical examples, if necessary.
I don't have my reference books with me, but I recall a certain modern
frigate needing about 70,000 SHP to move about 4000 tons at 27 knots.
The Yamato needed 150,000 SHP to move 72,000 tons at 27 knots.

Similarly, let's assume that a Spruance and a Nimitz can make about the
same speed, flat out. (yeah, "In Excess of 30 knots". Let's assume that
they make the same amount in excess of 30 knots. From what I understand,
that's tolerably close to reality) A Spruance officially puts out about
80,000 SHP. A Nimitz officially puts out about 280,000 SHP. While I
admit that both figures are probably lower than reality, let's assume that
they're proportionally lower. 3.5 times the power moves 10 times the
displacement.

I would say that from these real-world examples, the power needed to move a
given displacement ship at a given speed increases much less than linearly
as displacement goes up.

This actually makes sense. Drag is proportional to the drag coefficient
times the cross-sectional area. The cross sectional area is going to
go up with the square of the spatial dimensions, whereas the displacement
goes up with the cube of spatial dimensions. (this assumes that you're
increasing all spatial dimensions at the same rate, a far worse assumption
than reality) It seems then, that larger ships should actually have an
advantage in top speed.

Think of it this way: Which is faster, an SR-71 (relatively big) or an
F-5 (relatively small)? It's that way for a reason.

[patterson,george r]

From pat...@cc.bellcore.com (patterson,george r)

In article <Cx7JF...@ranger.daytonoh.ncr.com>,
John Stoffel <jo...@avante.WPI.EDU> wrote:

>One good example of this is the Japanese Kamakaze which hit a US
>battleship around the end of WWII. Those planes had around 1000kg war
>heads as I remember, and all it did when it hit the main belt was to
>scratch the paint a bit. I'd have to look in Friedman's "US
>Battleships" for more details.

Please do. The only kamikaze of which I'm aware that hit an Iowa class
ship was a Zero with a 250lb (est.) bomb attached. The ship was the
Missouri, and a photo exists of the plane at the moment of contact. None
were ever hit by a "Baka bomb", which I assume is the aircraft to which
you refer. The "bakas" took out several destroyers and one cruiser -
that's all.

Note in the above that a 250lb bomb does not carry 250lbs of explosive.

References: _The Iowa Class Battleships_ and _The Divine Wind_.

-----------------------------------------------------------------------
| The use of euphemism is the fine art of lying
| while telling the truth. For example, one
George Patterson - | airline, in an annual report to stockholders,
| referred to the crash of one of its airplanes as
| an "involuntary conversion of a 727".
-----------------------------------------------------------------------

[Robert Wunderlick]

From wun...@oasys.dt.navy.mil (Robert Wunderlick)

In sci.military, Ed Rudnicki <erud...@pica.army.mil> writes:
>
>Most missile warheads should be rated at least as SAP, in order to
>retain their structural integrity long enough to enter the target
>ship prior to detonation. This is one of the reasons the 20mm

An example of one of the exceptions would be a shaped charge warhead
( a la SS-N-2), for which you would want to initiate the fusing external
to the ship to allow for proper formation of the jet.

Bob Wunderlick
David Taylor Model Basin
Carderock Division HQ, Naval Surface Warfare Center
Bethesda, MD 20084-5000 (DTMBCDHQNSWC - whew!)

[David A Stephenson]

From da...@christa.unh.edu (David A Stephenson)

In article <Cx9EM...@ranger.daytonoh.ncr.com> dam...@uniwa.uwa.edu.au (Damian Kneale) writes:
>
>From dam...@uniwa.uwa.edu.au (Damian Kneale)
>
>One important facet of armouring ships that no-one has mentioned is that
>along with making ships bigger, they will also become slower, and at the
>same time more expensive. With most country's navies being cost driven
>to a large extent, this is a drawback. It seems that the economy of the
>situation says that buying 5 unarmoured ships is better than buying 3 or
>4 armoured ones for the same price.
>

The newest class of US Navy destroyer has steel armor (I think), I
wounder if experiences such as the USS Stark and Royal Navy's HMS
Sheffield (both used aluminum for armor) had anything to do with the
Arleigh-Burke's design? Besides where is the eceonomy in buying weapons
platforms that won't survive long enough to engage the enemy?

David

da...@christa.unh.edu

[Paul F Austin]

From pau...@ic1d.harris.com (Paul F Austin)

madr...@metronet.com (Bob Lyle) writes:

>Actually, there is a real lack of steelworks capable of large castings.
>If my informants are correct, there are onlt two in the USA that can cast
>even tank turrets. Rolled plates od armor quality are nearly as hard to get.

You're correct about limited production capacity for thick plate, but it's not
that limited. Plates for submarine hull sections are quite thick and the
thickness of tank glacises (glaci?) are comparable to that of barbettes in BB
(I can't say that twice, fast)

In any case, if the market were there, production capacity would emerge.

"Peace is the ideal that we infer from the fact that there are periods between wars" Jerry Pournelle
Paul Austin

[-D.WELLS]

From drw...@hogpg.ho.att.com (-D.WELLS)

In article <Cx9Er...@ranger.daytonoh.ncr.com>,

John Schilling <schi...@spock.usc.edu> wrote:
>
>But, since these missiles were designed for use against CVs with armored
>flight decks, it is unlikely that they are thin-skinned, point-detonating
>types. Circumstantial evidence does suggest an SAP design.

Does it? Why bother with a SAP for use against carriers? Flight decks are
full of easily damaged/destroyed aircraft, some fully fueled, plus very
often, armament for the aircraft. Hit some of that stuff, start a fire,
and the carrier is mission killed. Remember the Forrestal?

[-D.WELLS]

From drw...@hogpg.ho.att.com (-D.WELLS)

In article <Cx9Eq...@ranger.daytonoh.ncr.com>,

Michael Holbrook <mh6...@cutter.ship.edu> wrote:
>
>to metal filings. Also, it bears mentioning that the big soviet ASMs were
>not the most accurate of weapons (some of the later models excepted), and
>the whole point of a deck hit is moot if the missile decides to bugger a
>cloud of chaff of the ocean's surface instead. Also, CIWS could probably
>hit a monster like the KITCHEN or SHIPWRECK easier then it could an exocet

Actually, it's not that obvious. There's been some speculation that the
CIWS might not be powerful enough to stop one of the big xSoviet ASMs or
SSMs. The theory is that it is fairly unlikely that the CIWS will detonate
the warhead, and even if some critical part of the missile is hit, the
missile will still have enough inertia to get to hit the ship. Keep in
mind that the range of the CIWS is pretty short. It's hard for those of
us with no access to classified data to tell for sure, but the theory
seems plausible enough to keep up the sales of Goalkeepers and Bredas.

>(that, however, is just a guess). Even the deck armour of an Iowa would
>probably fare well against something like a harpoon or exocet, and lets
>face it, that is what most of the navies that the US will be facing will
>be using.
>
>Cheerio,
>Mike Holbrook
>
>PS actually, most of the navies that we'll be facing in the near future
>will be using harsh language only. But we can't afford to bank on it.

Would that this were true! I hear that our old friends the Iranians are
buying Backfires and AS-16s. (no 1000 kg warheads on those, but you
can fit more of them on a Backfire) As Mike says, we can't afford to
bank on it.

David R. Wells

[-D.WELLS]

From drw...@hogpg.ho.att.com (-D.WELLS)

In article <Cx6Is...@ranger.daytonoh.ncr.com>,
scott david orr <sdo...@mik.uky.edu> wrote:
>
>In article <Cx3w...@ranger.daytonoh.ncr.com> Michael R Haenggi <mhae...@maroon.tc.umn.edu> writes:
>>
>>How about for the silly ol' purpose of saving the crew? Sure the ship
>>will be rendered ineffective, but doesn't the crew count for anything? At
>>least it might give them a chance to find a lifeboat. Seems to me thats
>>like saying there's no point in putting an ejection seat in an aircraft
>>because the plane will be wrecked anyway.
>
[some stuff deleted]
>has a far greater chance of actually saving the crew. Your point about
>ejections seats is well-taken, but ejection seats, unlike armor, do not
>take up a large percentage of the space and weight available on the platform
>in question.

I think that this is turning into a bad analogy. Space & weight are factors
in the design of ships, but they are not as critical as they are in
aircraft. Ships don't have to worry quite so much about providing enough
lift to support the weight. It's easier to use buoyancy in water than
aerodynamic lift in air to support large weights.

[Michael Holbrook]

From mh6...@cutter.ship.edu (Michael Holbrook)

John Schilling (schi...@spock.usc.edu) wrote:

: As for size and speed, I am indeed certain. Checked the descriptions for the

: SS-N-12 and AS-6 from _Jane's Weapon Systems_. The Russians have always
: liked brute force. They did give up a lot in terms of launch weight,
: range, and stealth, to achieve such performance.

: Granted, a single hit will not sink an Iowa. But it will very likely

: wreck whatever turret or compartment is in the missile's path. Multiple
: hits probably will put the ship out of operation fairly quickly.

Ah, but FIRST you have to get those hits. There is an old english maxim
found in the recipe for hare stew: "First, catch your hare". A very good
point, that I had not considered, was made a few posts back.

Big missiles are expensive. Both because they are larger, but also
because they require more capable aircraft to get them to the launch
point, and because less missiles can be carried on an aircraft. Lets
look at the situation: A Mirage can carry how many exocets? A few. Ah,
but how many KITCHENS can it carry? KANGAROOs? (I'm not sure if these
designations are exactly right, but you get the point). These missiles
are BIG. So an effective exocet attack can be launched by say, five
mirages. How many BACKFIRES doest it take to put an equivalent number of
Big ASMs in the air? Quite a few more, I should suspect. Remember, those
planes don't come anywhere near as cheap as a Mirage. And also remember,
exocets get through active air defenses much better than Big ASMs, so
you'd have to put still more missiles in the air. What countries can
afford to do THAT?

So, chances are that only a few would be launched in the first place,
most would fall to the Standards, and that one or two lone missiles would
damage, but not sink an armoured platform. Ah, but image what would
happen to a Tico if a SHIPWRECK were to plow into her...

Cheerio,
Mike Holbrook

[James Dusek]

From du...@cadsun.corp.mot.com (James Dusek)

In article <Cx3wA...@ranger.daytonoh.ncr.com>, Frank Kastenholz
<kas...@lard.ftp.com> wrote:
> From Frank Kastenholz <kas...@lard.ftp.com>
> >From drw...@hogpg.ho.att.com (-D.WELLS)
> >>If that is so, then why the "impenetrability" of the Iowa class's armour?

> >The armor on the Iowas is not impenetrable, just very rugged. I suppose
> >that a GBU-28 could get through it, but of course, a GBU-28 is not a
> >long-range anti-ship missile. Large Soviet-designed ASMs tend to have

> shock damage to an Iowa. After all, it took only about a half-dozen
> 330kg torpedos to sink the PoW and the only penetration of her
> citadel (that I recall) was the glands and stuffing boxes destroyed
> by the prop-shaft bent by one of the torpedos...

The only reason the PoW sunk was because the prop shaft warped, and
tore open a hole that let water flood the ship. A lucky hit by a torp.

Which leads to another point, even if the ship is missle proof, torps
will still ruin its day, esp. the Russian torps. We all know the soviets
had plenty of submarines.

--------------------------------------------------------------------
| James Dusek | If the Goverment prints the money, |
| Motorola Inc | why is it always broke? |
| du...@cadsun.corp.mot.com | |
--------------------------------------------------------------------

[Michael Holbrook]

From mh6...@cutter.ship.edu (Michael Holbrook)

David A Stephenson (da...@christa.unh.edu) wrote:

: The newest class of US Navy destroyer has steel armor (I think), I

: wounder if experiences such as the USS Stark and Royal Navy's HMS
: Sheffield (both used aluminum for armor) had anything to do with the
: Arleigh-Burke's design? Besides where is the eceonomy in buying weapons
: platforms that won't survive long enough to engage the enemy?

: David

: da...@christa.unh.edu

Is this true? If so, this is what I get for not buying a Jane's. I was
under the impression that the Burkes were the same as the Ticos (in the
armour category, that is). I'm not saying that I don't belive you,
David, but could you post the stats on the Burkes? I'd ike to see 'em.

Cheerio,
Mike Holbrook

[John Stoffel]

From jo...@avante.WPI.EDU (John Stoffel)

>>>>> "patterson,george" == patterson,george r <pat...@cc.bellcore.com> writes:
In article <CxGun...@ranger.daytonoh.ncr.com> pat...@cc.bellcore.com (patterson,george r) writes:

patterson,george> From pat...@cc.bellcore.com (patterson,george r)

patterson,george> In article <Cx7JF...@ranger.daytonoh.ncr.com>,

patterson,george> John Stoffel <jo...@avante.WPI.EDU> wrote:

>> One good example of this is the Japanese Kamakaze which hit a US
>> battleship around the end of WWII. Those planes had around 1000kg war
>> heads as I remember, and all it did when it hit the main belt was to
>> scratch the paint a bit. I'd have to look in Friedman's "US
>> Battleships" for more details.

george> Please do. The only kamikaze of which I'm aware that hit an
george> Iowa class ship was a Zero with a 250lb (est.) bomb
george> attached. The ship was the Missouri, and a photo exists of the
george> plane at the moment of contact. None were ever hit by a "Baka
george> bomb", which I assume is the aircraft to which you refer. The
george> "bakas" took out several destroyers and one cruiser - that's
george> all.

I haven't had anytime lately to even _think_ of looking in my
references, and I'm sure you have done a much better job. I must have
been thinking about the Zero and was upping it's load of explosives
too much.

george> Note in the above that a 250lb bomb does not carry 250lbs of
george> explosive.

But of course! :]

John

John F. Stoffel - jo...@wpi.edu - 508-831-5512 - FL 111F
Workstation Specialist - Worcester Polytechnic Institute College Computer Ctr.
Kill your television

[-D.WELLS]

From drw...@hogpg.ho.att.com (-D.WELLS)

In article <CxIo1...@ranger.daytonoh.ncr.com>,

David A Stephenson <da...@christa.unh.edu> wrote:
>
>The newest class of US Navy destroyer has steel armor (I think), I
>wounder if experiences such as the USS Stark and Royal Navy's HMS
>Sheffield (both used aluminum for armor) had anything to do with the
>Arleigh-Burke's design?

It probably has more to do with the Belknap fire in November, 1975.
The Belknap's aluminum superstructure melted. After that, the USN
decided that newly designed ships would be made of steel. The Spruances,
Perrys, and Ticonderogas were already designed at that point. The
Burkes are the first newly designed destroyers since then.

BTW: Neither the Stark or the Sheffield had aluminum armor, although
they did have aluminum supersturctures. This does save topweight,
which is important, (look how wide they had to make the Burkes to
keep them from rolling over) but it comes at a price.

>Besides where is the eceonomy in buying weapons
>platforms that won't survive long enough to engage the enemy?

A question I have often asked....

[Michael Holbrook]

From mh6...@cutter.ship.edu (Michael Holbrook)

-D.WELLS (drw...@hogpg.ho.att.com) wrote:

: From drw...@hogpg.ho.att.com (-D.WELLS)

: In article <Cx9Eq...@ranger.daytonoh.ncr.com>,
: Michael Holbrook <mh6...@cutter.ship.edu wrote:

: Also, CIWS could probably

: >hit a monster like the KITCHEN or SHIPWRECK easier then it could an exocet

: Actually, it's not that obvious. There's been some speculation that the
: CIWS might not be powerful enough to stop one of the big xSoviet ASMs or
: SSMs. The theory is that it is fairly unlikely that the CIWS will detonate
: the warhead, and even if some critical part of the missile is hit, the
: missile will still have enough inertia to get to hit the ship. Keep in
: mind that the range of the CIWS is pretty short. It's hard for those of
: us with no access to classified data to tell for sure, but the theory
: seems plausible enough to keep up the sales of Goalkeepers and Bredas.

Actually, there was an error on my part. When I said CIWS I should have
included Standard and our (the Good Guy's) other active defenses in the
statement. You are correct about the missile slamming on in after the
CIWS pumps it full of holes. But does Standard stand a better chance of
hitting the Big ASMs, or the Exocets and Harpoons? I think I know where
I'd place my $$$.

: >Even the deck armour of an Iowa would

: >probably fare well against something like a harpoon or exocet, and lets
: >face it, that is what most of the navies that the US will be facing will
: >be using.

: >PS actually, most of the navies that we'll be facing in the near future

: >will be using harsh language only. But we can't afford to bank on it.

: Would that this were true! I hear that our old friends the Iranians are
: buying Backfires and AS-16s. (no 1000 kg warheads on those, but you
: can fit more of them on a Backfire) As Mike says, we can't afford to
: bank on it.

Yah, you're right David. A guy (sorry, can't remember your name!) made a
good point a few posts back. How many of those Big ASMs are the Bad Guys
going to be able to throw at us (there is a big price tag on those
puppies, due to the fact that you need planes like Backfires to haul
just a handful of them)? I'd say not many. The active defenses handle
those. But the cloud of exocets that can be sent our way for the same
amount of $, now, I think the armour would be nice for that. I know that
you'd like it, too. :)

Cheerio,
Mike

[Paul F Austin]

From pau...@ic1d.harris.com (Paul F Austin)

drw...@hogpg.ho.att.com (-D.WELLS) writes:

>>
>>The issue isn't so much physical size as it issues of displacement,
>>desired speed, and engine size. Everything else being equal, engine
>>power needed to move a given at a given speed goes up much more than
>>linearly as the displacement goes up. So, to add more displacement
>>(eg for armor) to a ship requires also adding more power, or more or
>>larger engines.

>This is clearly untrue. I can cite historical examples, if necessary.
>I don't have my reference books with me, but I recall a certain modern
>frigate needing about 70,000 SHP to move about 4000 tons at 27 knots.
>The Yamato needed 150,000 SHP to move 72,000 tons at 27 knots.

You are absolutely correct. I am not a naval architect but I recall that the
best hull speed is strictly a function of length to beam ratio. Historically
BBs were slow prior to the North Carolina class primarly because the hull form
was optimized as a stable gun platform (nice and wide).

In any case, modern propulsion plant is very power-dense compared with steam
plants of yesteryear. One problem with armoring a gas-turbine powered ship is
to provide sufficient uptake ducting through the deck armor without leaving
nice juicy targets for a high-diver with an IR seeker.

[John Schilling]

From John Schilling <schi...@spock.usc.edu>

drw...@hogpg.ho.att.com (-D.WELLS) writes:

>From drw...@hogpg.ho.att.com (-D.WELLS)

>In article <Cx9Er...@ranger.daytonoh.ncr.com>,
>John Schilling <schi...@spock.usc.edu> wrote:
>>
>>But, since these missiles were designed for use against CVs with armored
>>flight decks, it is unlikely that they are thin-skinned, point-detonating
>>types. Circumstantial evidence does suggest an SAP design.

>Does it? Why bother with a SAP for use against carriers? Flight decks are
>full of easily damaged/destroyed aircraft, some fully fueled, plus very
>often, armament for the aircraft. Hit some of that stuff, start a fire,
>and the carrier is mission killed. Remember the Forrestal?

Yes; also Akagi, Kaga, and Soryu; also Enterprise (CVN-65, not CV-6)

But the only time you find significant quantities of fuel and ordnance on
the flight deck (as opposed to hanger) of a carriier, is immediately prior
to launching a strike. 90+% of the time, the planes you see on the deck
of a carrier are empty and inert, barring a few ready fighters and helos.
And, given the warning time associated with large, high-trajectory missiles,
one expects the few fueled a/c to clear the deck prior to impact.

So, unless the Soviets were expecting perfect timing for their attacks, or
were willing to settle for fairly minor damage, their missile warheads can
reasonably be expected to have some degree or armor penetration capability.

[Paul F Austin]

From pau...@ic1d.harris.com (Paul F Austin)

la...@ifi.uio.no (Lars Henrik Bxler Olafsen) writes:
. The big Russion ASMs are HE
>>warheads, which means they have zero to low armour piercing ability.
>>And if you can't pentrate the armour, then you can't really do much
>>except ding it alittle and cause incidental damamge.

>What about pressure? Wouldn't the poor sods inside feel the effects of
>a 1 ton TNT charge detonating on the other side of a steel wall?
>I know that tanks can be taken out this way. Wouldn't it be possible
>to take out i.e the bridge or a gun turret in this manner?

I'm not really convinced that Russian ASMs have nil AP ability, but if true
then they would have only trivial effect on e.g a carrier deck. An example
exists to support this supposition.

In 1968, Enterprise suffered a catastrophic flight deck fire that cooked off a
deck-load of Mk8x bombs. The after action report described the effect as
equivalent to 17 major caliber bomb hits.

45 minutes after the fires were out, Enterprise was launching aircraft.

[Robert Wunderlick]

From wun...@oasys.dt.navy.mil (Robert Wunderlick)

In sci.military, pau...@ic1d.harris.com (Paul F Austin) writes:
>
>In any case, if the market were there, production capacity would emerge.

Unfortunately, this is becoming less true, particularly given the low
production rates of US combatants. The price may be unnecessarily high
for the steel to make it "worthwhile" (profitable ) for the industry
to begin production.

[Michael Holbrook]

From mh6...@cutter.ship.edu (Michael Holbrook)

Dan Schulz (schu...@gold.tc.umn.edu) wrote:

: From schu...@gold.tc.umn.edu (Dan Schulz)

: You almost put your finger on it. Reprogramming a missle is easy. The
: reason modern ships don't employ heavy armor is that it is easily defeated.
: Why spend lots of money of armor (which requires larger hulls, and will
: generally slow you down) when your enemy can develope a counter to it
: _for_a_lot_less_money_.

Ah, yes, but remember, this is a mission-kill only. It is comparatively
easy to put a new radar on an otherwise only damaged ship. It is much
harder and more expensive to replace the whole bloody thing.

: And I still think that a strike package compossed of A6's and F18's will put
: any BB to the bottom (it'll be a flaming wreck at least), assuming it is
: alone with no screening escort.

Eh? What? The British figured out in 1942 (or was it '41?) that ANY ship
without effective anti-air defense will go down, if subjected to a
concerted attack. This argument is pointless (it is worth noting that he
is right, that ship would be history). Armour only adds protection, it
most certainly does not confer invinciblilty. The question is: will
armour add to the survivability of a ship? And is this added survivability
worth the added displacement? The point is not "can an armoured ship steam
about with impunity?"

Cheerio,
Mike Holbrook

[Matt Melchert]

From ma...@waikato.ac.nz (Matt Melchert)

In article <CxGuM...@ranger.daytonoh.ncr.com>, drw...@hogpg.ho.att.com (-D.WELLS) writes:
>
[snip]

>
> I would say that from these real-world examples, the power needed to move a
> given displacement ship at a given speed increases much less than linearly
> as displacement goes up.
>
> This actually makes sense. Drag is proportional to the drag coefficient
> times the cross-sectional area. The cross sectional area is going to
> go up with the square of the spatial dimensions, whereas the displacement
> goes up with the cube of spatial dimensions. (this assumes that you're
> increasing all spatial dimensions at the same rate, a far worse assumption
> than reality) It seems then, that larger ships should actually have an
> advantage in top speed.
>

This was one reason battlecruisers were significantly larger than battleships
in WW I.

Matt

[Michael Holbrook]

From mh6...@cutter.ship.edu (Michael Holbrook)

Rob S. Rice (rr...@netnews.upenn.edu) wrote:

: From rr...@netnews.upenn.edu (Rob S. Rice)

: True enough--in fact the tactic evolved of using the Limey carriers

: as Kamikaze bait, BUT...there's always a trade off. 1)His
: majesty's aircraft carriers could carry nought but HALF the plane load
: of the American ships, hence the incredible size of the Midway
: and later classes--jets and armor, 2)If the British carriers got
: hulled, they took an immediate and severe list. I can still
: remember the picture of the _Ark Royal_ going down off Gibraltar with
: her aircraft unable to get off her tilting deck.

: Rob S. Rice
: rr...@ccat.sas.upenn.edu

Too true, too true. Especially the bit about the lists. That was a
design flaw of the Ark Royal (and she paid for it). The later I-class
made up for some of that by trading aircraft capacity for range (hence
larger fuel bunkers, hence balast down low). But, like you said, they
carried a small amount of aircraft. Also remember, they WERE small
carriers compared to the Essex class...

Cheerio,
Mike Holbrook

[James Dusek]

From du...@cadsun.corp.mot.com (James Dusek)

In article <CxGuM...@ranger.daytonoh.ncr.com>, drw...@hogpg.ho.att.com

(-D.WELLS) wrote:
> I would say that from these real-world examples, the power needed to move a
> given displacement ship at a given speed increases much less than linearly
> as displacement goes up.

This is untrue. They found out you can get better speeds with longer
narrower ships than shorter "fatter" ones of the same tonnage. So adding
weight and width would require more power than adding wight and making the
ship longer.

James Dusek

[Stephen Harker]

From phs...@vaxc.cc.monash.edu.au (Stephen Harker)

In article <CxGuI...@ranger.daytonoh.ncr.com>, rr...@netnews.upenn.edu (Rob S. Rice) writes:
>
> From rr...@netnews.upenn.edu (Rob S. Rice)
>

> [deletions for brevity]
> : If so, then they were foolish to base the move on this information. Take
> : the experiences of the US Navy's carriers late in the pacific campaign
> : and contrast them to the Royal Navy's carrier experiences at that same
> : period. The limies had a saying: "If a US carrier is hit by a kamikaze,
> : six months in port with fire damage. If a Brit carrier gets hit, time to
> : fetch the brooms". This was ENTIRELY because of the armour that the
> : British afforded their carriers, armour that the American carriers
> : lacked. And the deck armour of an I-class carrier was not really that
> : thick. Indeed, the US navy learned from the British and placed deck
> : armour on the Midway class.
>

> True enough--in fact the tactic evolved of using the Limey carriers
> as Kamikaze bait, BUT...there's always a trade off. 1)His
> majesty's aircraft carriers could carry nought but HALF the plane load
> of the American ships, hence the incredible size of the Midway
> and later classes--jets and armor, 2)If the British carriers got
> hulled, they took an immediate and severe list. I can still
> remember the picture of the _Ark Royal_ going down off Gibraltar with
> her aircraft unable to get off her tilting deck.

A couple of minor points. The Ark Royal was _not_ an armoured
carrier, she was designed with two hangars and had a designed
complement of 72 aircraft compared to the Illustrious classes 36 on
roughly the same displacement. I believe that in practice the maximum
carried was 60, though with the same late war practices used to boost
the Illustrious class capacities (deck parks etc.) it should have been
possible to increase this to around 80. I don't think Ark Royal even
had an armoured flight deck. In theory she appears well suited to the
Pacific war, though the problem of her small lifts and their llfting
capacity may have necessitated an extensive refit. The first of the
armoured carriers was the Illustrious.

The sinking of the Ark Royal was one of the factors in a
fairly heated debate in the Royal Navy during and after the war.
Apparently the Royal Navy had a policy that preferred to not counter
flood the ship to reduce a list `Don't let water into the ship: that's
what the enemy wants'. This was blamed by many as a major factor in
the ship sinking, I don't know whether this has been resolved. A
further factor (according to the `Profile' publication on Illustrious)
was a design defect that was discovered when one of the Illustrious
class carriers was torpedoed in _very_ smooth waters in the Indian
Ocean. Apparently the ventilation(?) ducts were too low and could
lead to disastrous interflooding of the boiler rooms. The carrier in
question was only saved by the smoothness of the seas. This fault was
only gradually corrected in the carriers. In combination with the
policy against counter flooding it could explain many problems.

--
Stephen Harker was phs...@vaxc.cc.monash.edu.au
ex Monash University now s...@phadfa.ph.adfa.edu.au
now ADFA (Canberra) Baloney baffles brains: Eric Frank Russell

[Michael Holbrook]

From mh6...@cutter.ship.edu (Michael Holbrook)

Stephen Harker (phs...@vaxc.cc.monash.edu.au) wrote:

: possible to increase this to around 80. I don't think Ark Royal even

: had an armoured flight deck. In theory she appears well suited to the

Yes, I believe she did. If I recall, it was 3 inches of steel plate.
Quite enough to stop most small bombs.

: --

: Stephen Harker was phs...@vaxc.cc.monash.edu.au
: ex Monash University now s...@phadfa.ph.adfa.edu.au
: now ADFA (Canberra) Baloney baffles brains: Eric Frank Russell

Cheerio,
Mike Holbrook

[Timothy Allen]

From tja...@mbunix.mitre.org (Timothy Allen)

In article <Cxo9s...@ranger.daytonoh.ncr.com>,

phs...@vaxc.cc.monash.edu.au (Stephen Harker) wrote:
> In article <CxGuI...@ranger.daytonoh.ncr.com>, rr...@netnews.upenn.edu
(Rob S. Rice) writes:

> > [deletions for brevity]

> The sinking of the Ark Royal was one of the factors in a
> fairly heated debate in the Royal Navy during and after the war.

====================

A long time ago, I saw a study of bomb and torpedo damage inflicted on
warships during WWII. The Ark Royal received a single torpedo hit
amidships, which admitted seawater into a single large internal
compartment, and sank quickly. Later in the war, the Japanese built an
aircraft carrier that, after it was launched but before it was
operational, received five torpedo hits, developed a severe list, and
eventually sank. In the author's opinion, the Japanese carrier, if it had
been operational and had a trained damage control crew, would not have
sank because of its extensive compartmentalization.

Armor generally provides protection against shells while
compartmentalization is needed for protection against torpedos. The
value of armor with respect to any particular missile would then depend
upon whether the damage-inflicting action of the missile is more
"shell-like" or "torpedo-like."

[Bleyle]

From ble...@infi.net (Bleyle)

Michael Holbrook (mh6...@cutter.ship.edu) wrote:

: David A Stephenson (da...@christa.unh.edu) wrote:
: : The newest class of US Navy destroyer has steel armor (I think), I
: : wounder if experiences such as the USS Stark and Royal Navy's HMS
: : Sheffield (both used aluminum for armor) had anything to do with the
: : Arleigh-Burke's design? Besides where is the eceonomy in buying weapons
: : platforms that won't survive long enough to engage the enemy?

: Is this true? If so, this is what I get for not buying a Jane's. I was

: under the impression that the Burkes were the same as the Ticos (in the
: armour category, that is). I'm not saying that I don't belive you,
: David, but could you post the stats on the Burkes? I'd ike to see 'em.

The DDG-51s have all-steel superstructures and several hundred tons of
Kevlar armor.

Mike.

--

*********************
* Bleyle *
* ble...@infi.net *
*********************

[Charles K. Scott]

From Charles...@dartmouth.edu (Charles K. Scott)

In article <Cxo9s...@ranger.daytonoh.ncr.com>
phs...@vaxc.cc.monash.edu.au (Stephen Harker) writes:

> A
> further factor (according to the `Profile' publication on Illustrious)
> was a design defect that was discovered when one of the Illustrious
> class carriers was torpedoed in _very_ smooth waters in the Indian
> Ocean

When did this happen? I recall reading of only one British carrier
being attacked in the Indian Ocean, the Hermes, and it sank.

Corky Scott

[n...@babel.cb.att.com]

From n...@babel.cb.att.com ()

In article <CxGuI...@ranger.daytonoh.ncr.com>,
Bob Lyle <madr...@metronet.com> wrote:
>
>From madr...@metronet.com (Bob Lyle)
>
>Michael Holbrook (mh6...@cutter.ship.edu) wrote:
>
>: well, lets not forget that we're talking about DESTROYERS here, not BBs!
>: And I was responding to a guy that said that the US stell industry
>: "couldn't handle it".

>
>Actually, there is a real lack of steelworks capable of large castings.
>If my informants are correct, there are onlt two in the USA that can cast
>even tank turrets. Rolled plates od armor quality are nearly as hard to get.
>

>Bob Lyle

There is a lot of truth to this. THe equipment to make M1 tanks had to go
from PA, where it was built, to Lima, OH. THe equipment masses enough that
the delivery was slated to go only on back roads. THey used two of the
largest tracrtors the Kennworth company made. THe extra one was for pushing
up grades. THey stopped near the village of Lodi, OH, since it started to
rain. THe folks in Lodi happen to own a portable scales, and when the
truck moved, they nabbed it.

It was so overloaded that it was not legal on ANY Ohio road *period*.
Heavy enough to threaten freeway overpasses. So heavy that they needed two
more tow trucks to get the assembly up the four inch hill onto the portable
scales. It took presidential pressure to finaaly get the equipment moved
through the village to a rail siding. THis after an extensive pipe-finder
survey so that every pipe under the road could be checked for integrity.

In short, the stuff is heavy, custom made, and of low demand.

Source: THe Ohio Magazine.

Neil Kirby DoD# 0783 n...@babel.cb.att.com
AT&T Bell Labs Columbus OH USA (614) 860-5304
President Internet BMW Riders
It's very red. It's very fast. And it's mine: 1994 R1100RSL

[Scott Norton]

From nor...@ACM.ORG (Scott Norton)

In article <CxGuM...@ranger.daytonoh.ncr.com> drw...@hogpg.ho.att.com
(-D.WELLS) writes:
> In article <Cx7JF...@ranger.daytonoh.ncr.com>,

> Frank Kastenholz <kas...@lard.ftp.com> wrote:
> >
> >The issue isn't so much physical size as it issues of displacement,
> >desired speed, and engine size. Everything else being equal, engine
> >power needed to move a given at a given speed goes up much more than
> >linearly as the displacement goes up. So, to add more displacement
> >(eg for armor) to a ship requires also adding more power, or more or
> >larger engines.
>
> This is clearly untrue. I can cite historical examples, if necessary.
> I don't have my reference books with me, but I recall a certain modern
> frigate needing about 70,000 SHP to move about 4000 tons at 27 knots.
> The Yamato needed 150,000 SHP to move 72,000 tons at 27 knots.

[ Another good example delete for brevity ]

> I would say that from these real-world examples, the power needed to move a
> given displacement ship at a given speed increases much less than linearly
> as displacement goes up.
>

> This actually makes sense. Drag is proportional to the drag coefficient
> times the cross-sectional area. The cross sectional area is going to
> go up with the square of the spatial dimensions, whereas the displacement
> goes up with the cube of spatial dimensions. (this assumes that you're
> increasing all spatial dimensions at the same rate, a far worse assumption
> than reality) It seems then, that larger ships should actually have an
> advantage in top speed.

The maximum speed of a ship is determined mostly by its length. The
wave-making drag goes up at the quite quickly with velocity, more than
the v-squared of subsonic drag, since wave-making is really a
supersonic type of phenominon--the ship is travelling faster than the
wave's speed, and trying to "outrun" the wave just piles more water
up. So you can add armor to a ship and not reduce its maximum speed
too much.

But at lower speeds, the viscous drag and the underwater hull drag are
important. Add armor, and you must add beam, both to carry the extra
weight and to maintain stability since the armor moves the CG up. And
that means a larger low-speed drag. You'll pay a price in fuel
through the life of the ship.

--
Scott Norton
Nor...@ACM.org
Defense Technology, Inc.
2361 Jefferson Davis Hwy, Suite 500
Arlington VA 22202-3876
(703) 415-0200, fax: (703) 415-0206
--
Scott Norton
Nor...@ACM.org
Defense Technology, Inc.
2361 Jefferson Davis Hwy, Suite 500
Arlington VA 22202-3876
(703) 415-0200, fax: (703) 415-0206

[Bri Kaszycki]

From no...@cybernet.cse.fau.edu (Bri Kaszycki)

> nice juicy targets for a high-diver with an IR seeker.

Why dosen't someone just put the vents for the gas turbines underwater?
i know it would be very bad if you were in sub infested waters but it
wold be a very effective temporary way to damper the ir signature of a
boat(they would be seconday vents say 30ft underwater or however deep the
bottom of the boat is wich would use a micro perforated hose like in
reverse osmosis fish tank filters all th way around the ship, it would
dissipiate heat quite nicley, and if the prarie masking system talked
about in red stor rising actualley exists it would be used in that wth a
few modifications), it would only be a emergincie measure once a missle
was detected.
nord

[Bleyle]

From ble...@infi.net (Bleyle)

: Would that this were true! I hear that our old friends the Iranians are

: buying Backfires and AS-16s. (no 1000 kg warheads on those, but you
: can fit more of them on a Backfire) As Mike says, we can't afford to
: bank on it.

side note: Norman Polmar dispelled the Iran/Backfire rumor in a recent
edition of USNI Proceedings. Not that we can bank on it...

[Scott Norton]

From nor...@ACM.ORG (Scott Norton)

In article <CxIo1...@ranger.daytonoh.ncr.com> da...@christa.unh.edu (David

A Stephenson) writes:

> The newest class of US Navy destroyer has steel armor (I think), I
> wounder if experiences such as the USS Stark and Royal Navy's HMS
> Sheffield (both used aluminum for armor) had anything to do with the
> Arleigh-Burke's design? Besides where is the eceonomy in buying weapons
> platforms that won't survive long enough to engage the enemy?

Both Sheffield and Stark were hit in the hull, which is steel.
Aluminum made no difference to these ships. The only ship I can
recall that suffered extra damage because of aluminum was Tattinall.
They had a small fire in their movie locker, in the after
superstructure. The aluminum warped badly enough to ruin the
alignment of her missile directors.

Arleigh Burkes use all-steel because they don't need aluminum. They
have a beamy hull, and so don't need to reduce topside weight as
desperately as the narrower hulls.

Aluminum costs more, both for the material, for fabrication (the
bimetalic joints are very manpower intensive), and in life-cycle
maintenance. As a former division officer on a aluminum-
superstructured CG, I remember what a pain it was just to have a
liferail fixed. MIG welding requires lugging argon bottles up
ladders, and shelter from the wind topside, but steel can be stick
welded with just an electrode. And you have to have an HT who can MIG
weld.

Don't assume steel equals armor. The superstructure is designed to
have a certain strength, and that means either 1/8-inch steel or
1/4-inch aluminum. Neither one would stop a rifle bullet. Armor can
be steel or aluminum, added beyond what is needed for structural
strength. The CGs had 1-inch aluminum armor, enough to stop
fragments. And it was proven effective when the Worden was hit by a
Shrike fired by a confused Air Force pilot. The SPS-48 was shredded,
and bosun's mates sleeping on deck were killed. But no one and nothing
in CIC was touched, despite CIC's location on the top deck of the
superstructure, below the SPS-48.

Now, someone help me out. I recall reading that the Sheffield didn't
have an aluminum superstructure, but was all steel. But I can't find
the reference, and what I do have doesn't say. The photos I have make
me believe its steel--I don't see a riveted bimetalic joint, and the
superstructure itself is quite low. And the ship itself is fairly
beamy, meant for operating in the North Atlantic. Can someone cite a
good reference, one way or the other?

--
Scott Norton
Nor...@ACM.org
Defense Technology, Inc.
2361 Jefferson Davis Hwy, Suite 500
Arlington VA 22202-3876
(703) 415-0200, fax: (703) 415-0206

--Boundary (ID a0x71wWfNmLO0krxkJY6Qw)--

|------------------------- end of forwarded message ------------------------|

[Scott Norton]

From nor...@ACM.ORG (Scott Norton)

In article <Cx6It...@ranger.daytonoh.ncr.com> pau...@ic1d.harris.com
(Paul F Austin) writes:

> [...] I
> think this logic is flawed since armor is cheap and gives the defense systems
> more margin but I think that this is the logic.

The naval architects don't see armor as cheap. You have to drag that
weight around for the entire life of the ship. It may be cheap to
install the mass of steel, but you pay in fuel cost every day the ship
is underway. You also pay for an engineering plant that's twice the
size, if you want your ship to go the same speed as its unarmored
equivalent. That's a fixed cost, to buy the boilers and engines, plus
upkeep, manning, etc., over the lifecycle.

When the analysts compare two ship options, the lifecycle costs swamp
almost everything else.

[-D.WELLS]

From drw...@hogpg.ho.att.com (-D.WELLS)

In article <Cxo9s...@ranger.daytonoh.ncr.com>,

James Dusek <du...@cadsun.corp.mot.com> wrote:
>
>In article <CxGuM...@ranger.daytonoh.ncr.com>, drw...@hogpg.ho.att.com
>(-D.WELLS) wrote:
>> I would say that from these real-world examples, the power needed to move a
>> given displacement ship at a given speed increases much less than linearly
>> as displacement goes up.
>
> This is untrue. They found out you can get better speeds with longer
>narrower ships than shorter "fatter" ones of the same tonnage. So adding
>weight and width would require more power than adding wight and making the
>ship longer.

Consider the following example:

Yamato:
SHP: 150000
Speed 27 knots
Length to beam ration: 256/36.9 = 6.93 : 1
Displacement: 72,809 fully loaded

Knox:
SHP: 35,000
Speed: 27 knots
Length to beam ratio: 438/46.8 = 9.35 : 1
Displacement: 4260 fully loaded

The Yamato displaced about 17 times as much as the Knox, used only
4.3 times the power to get the same speed, and was relatively fatter.
Care to explain?

[Low Kok Keong]

From ab...@cfn.cs.dal.ca (Low Kok Keong)

patterson,george r (pat...@cc.bellcore.com) wrote:

: From pat...@cc.bellcore.com (patterson,george r)

: In article <Cx7JF...@ranger.daytonoh.ncr.com>,
: John Stoffel <jo...@avante.WPI.EDU> wrote:

: >One good example of this is the Japanese Kamakaze which hit a US
: >battleship around the end of WWII. Those planes had around 1000kg war
: >heads as I remember, and all it did when it hit the main belt was to
: >scratch the paint a bit. I'd have to look in Friedman's "US
: >Battleships" for more details.

: Please do. The only kamikaze of which I'm aware that hit an Iowa class
: ship was a Zero with a 250lb (est.) bomb attached. The ship was the
: Missouri, and a photo exists of the plane at the moment of contact. None
: were ever hit by a "Baka bomb", which I assume is the aircraft to which
: you refer. The "bakas" took out several destroyers and one cruiser -
: that's all.
--
I have read somewhere ( I think it was Carrier War in The Pacific ) that
the USS Indiana was also hit by a Japanese plane loaded with a
conventional bomb at the main armour belt. The armour was only dented.

[Ed Rudnicki]

From Ed Rudnicki <erud...@pica.army.mil>

In article <CxvMu...@ranger.daytonoh.ncr.com> mh6...@cutter.ship.edu (Michael Holbrook) writes:
>James Dusek (du...@cadsun.corp.mot.com) wrote:
>: Which leads to another point, even if the ship is missle proof, torps
>: will still ruin its day, esp. the Russian torps. We all know the soviets
>: had plenty of submarines.
>
>this is very true, but torps have a much shorter range than missiles, and
>require big, expensive submarines to get them close enough to do
>anything. Very good point, though.

When the SOVREMENNY-class DDG BEZUDERZHNY was in NYC last year, I
noted she carried 2x2 torpedo tubes for very large anti-surface
torpedoes. A couple of the officers aboard a CG-47 class ship, also
in the city, mentioned that such long-range torpedos, fired from
surface units, are considered a substantial threat under certain
circumstances. FWIW.

Ed Rudnicki erud...@pica.army.mil All disclaimers apply

[David A Stephenson]

From da...@christa.unh.edu (David A Stephenson)

In article <CxME6...@ranger.daytonoh.ncr.com> mh6...@cutter.ship.edu (Michael Holbrook) writes:
>From mh6...@cutter.ship.edu (Michael Holbrook)

>David A Stephenson (da...@christa.unh.edu) wrote:

>: The newest class of US Navy destroyer has steel armor (I think), I

>: wounder if experiences such as the USS Stark and Royal Navy's HMS
>: Sheffield (both used aluminum for armor) had anything to do with the
>: Arleigh-Burke's design? Besides where is the eceonomy in buying weapons
>: platforms that won't survive long enough to engage the enemy?

>: David
>: da...@christa.unh.edu

>Is this true? If so, this is what I get for not buying a Jane's. I was
>under the impression that the Burkes were the same as the Ticos (in the
>armour category, that is). I'm not saying that I don't belive you,
>David, but could you post the stats on the Burkes? I'd ike to see 'em.

>Cheerio,
>Mike Holbrook

Hmmmm, how do I get out of this gracefully? Ah well I guess I just get
scortched. The original post was the result of not enough sleep and too
little coffee. I had been told ( probably desreputable source) that the
USS Stark and HMS Sheffield had aluminum armor and that the Burkes had
steel and I wanted to find out if this was true. I recently got an
E-mail response and was told that the Burkes have all steel construction
as opposed to using in places.

Hanging my head in shame

david

[John F Carr]

From j...@mit.edu (John F Carr)

In article <CxMED...@ranger.daytonoh.ncr.com>,
James Dusek <du...@cadsun.corp.mot.com> wrote:

> Which leads to another point, even if the ship is missle proof, torps
>will still ruin its day, esp. the Russian torps.

Yes, especially the Russian torps. Even the Iowa class doesn't have enough
armor to survive a nuclear warhead exploding against the hull.

--
John Carr (j...@mit.edu)

[Michael Holbrook]

From mh6...@cutter.ship.edu (Michael Holbrook)

James Dusek (du...@cadsun.corp.mot.com) wrote:
: Which leads to another point, even if the ship is missle proof, torps

: will still ruin its day, esp. the Russian torps. We all know the soviets
: had plenty of submarines.

this is very true, but torps have a much shorter range than missiles, and
require big, expensive submarines to get them close enough to do
anything. Very good point, though.

Mike Holbrook

[Paul F Austin]

From pau...@ic1d.harris.com (Paul F Austin)

mh6...@cutter.ship.edu (Michael Holbrook) writes:

>Is this true? If so, this is what I get for not buying a Jane's. I was
>under the impression that the Burkes were the same as the Ticos (in the
>armour category, that is). I'm not saying that I don't belive you,
>David, but could you post the stats on the Burkes? I'd ike to see 'em.

The Burkes use a completely different hull design that the Spruance/Kidd/Ticos
with less lenght and more beam for better sea keeping. At the same time, the
Navy switch to steel superstructure from aluminum. I wouldn't call any of this
"armor" since to the best of my knowledge no additional plating was
installed over and above structural requirements.

The reason most often give for the switch to steel was to get some better
ballistic protection around the combat spaces and to avoid the high
temperature structural problems that aluminum is reputed to have in a fire.

I wonder about the first reason since a simpler solution would be to place the
CIC between engine rooms in the hull. Does anyone have info about the general
arrangement of the Burkes?

[Scott Norton]

From nor...@ACM.ORG (Scott Norton)

In article <CxME6...@ranger.daytonoh.ncr.com> drw...@hogpg.ho.att.com

(-D.WELLS) writes:
>
> From drw...@hogpg.ho.att.com (-D.WELLS)
>

> In article <CxIo1...@ranger.daytonoh.ncr.com>,

> David A Stephenson <da...@christa.unh.edu> wrote:
> >
> >The newest class of US Navy destroyer has steel armor (I think), I
> >wounder if experiences such as the USS Stark and Royal Navy's HMS
> >Sheffield (both used aluminum for armor) had anything to do with the
> >Arleigh-Burke's design?
>

> It probably has more to do with the Belknap fire in November, 1975.
> The Belknap's aluminum superstructure melted. After that, the USN
> decided that newly designed ships would be made of steel. The Spruances,
> Perrys, and Ticonderogas were already designed at that point. The
> Burkes are the first newly designed destroyers since then.
>

Belknap looked pretty bad, yes, but that's because they got stepped-on
by the Kennedy's flight deck overhang, and then got sprayed by JP-5
from the fuel riser. I doubt a steel ship would have survived either.
But that damage mode is not a creditable threat.

Or are you suggesting we return to the ram as a weapon of war? :)

[Matthew L. Ward]

From war...@picard.cig.mot.com (Matthew L. Ward)

>From: da...@christa.unh.edu (David A Stephenson) in Article 10632 of sci.military

[old article deleted]

>The newest class of US Navy destroyer has steel armor (I think), I
>wounder if experiences such as the USS Stark and Royal Navy's HMS
>Sheffield (both used aluminum for armor) had anything to do with the

>Arleigh-Burke's design? Besides where is the eceonomy in buying weapons
>platforms that won't survive long enough to engage the enemy?

Actually the Navy decided that Aluminium belongs only on airplanes during
the Vietnam war when a mifired US Sidewinder (AIM-9) hit the aluminium
superstructure of an USN vessel (don't recall which).

Aluminum is a very ductile metal and tends to have a very high modulus of
elasticity, which means it bends alot before breaking. Coupled with high
temperatures of an explosion this means shrapnel, and lots of it.

Of course, with *really* high temperatures, Aluminum burns quite well
and putting out a metal fire is almost impossible even if anyone in the
general area of the hit is still alive to do it (see point one above).

During the bad old years, a number of stupid things were tried, aluminum
was one, polyester uniforms was another one.

------------------------------------------------------------------------------
Matthew Ward, Motorola Advanced Products Division - Japan Digital Cellular
Arlington Heights, IL. USA - My words are not Motorola's
_______________________________________________________________________________
For a good time call: The Capitol Hill Switchboard: 1-800-768-2221
and ask for the office of your Senator or Representative
(don't think of it a toll-free call, you already paid dearly for it)
-------------------------------------------------------------------------------

[Ed Rudnicki]

From Ed Rudnicki <erud...@pica.army.mil>

In article <CxzI0...@ranger.daytonoh.ncr.com> mh6...@cutter.ship.edu (Michael Holbrook) writes:
>Ed Rudnicki (erud...@pica.army.mil) wrote:
>
>: When the SOVREMENNY-class DDG BEZUDERZHNY was in NYC last year, I

>: noted she carried 2x2 torpedo tubes for very large anti-surface
>: torpedoes. A couple of the officers aboard a CG-47 class ship, also
>: in the city, mentioned that such long-range torpedos, fired from
>: surface units, are considered a substantial threat under certain
>: circumstances. FWIW.
>

>At what ranges, though? Are we talking hundreds of miles, here. I don't
>THINK so.

Of course not. I did say "certain circumstances", and I didn't see
any need to mention the obvious. Next time I will, for your
benefit.

[Michael Holbrook]

From mh6...@cutter.ship.edu (Michael Holbrook)

Ed Rudnicki (erud...@pica.army.mil) wrote:

: When the SOVREMENNY-class DDG BEZUDERZHNY was in NYC last year, I

: noted she carried 2x2 torpedo tubes for very large anti-surface
: torpedoes. A couple of the officers aboard a CG-47 class ship, also
: in the city, mentioned that such long-range torpedos, fired from
: surface units, are considered a substantial threat under certain
: circumstances. FWIW.

At what ranges, though? Are we talking hundreds of miles, here. I don't
THINK so.

: Ed Rudnicki erud...@pica.army.mil All disclaimers apply

Cheerio,
Mike Holbrook

[JUSSI MIKAEL SAARI]

From JUSSI MIKAEL SAARI <jms...@phoenix.oulu.fi>

On Tue, 18 Oct 1994, Michael Holbrook wrote:

> this is very true, but torps have a much shorter range than missiles, and
> require big, expensive submarines to get them close enough to do
> anything. Very good point, though.

The russian Type 65 torpedo has a range of 100 km, which is more than
Exocet's maximum range. It does take a big submarine to launch this
monster though.

[David M.V. Utidjian]

From utid...@remarque.berkeley.edu (David M.V. Utidjian)

I don't think this question is off topic but it does deviate
from the current thread a little.

My father and I were discussing warship armor and the structure
of modern ships and ASM effects on them. There was an incident in the
80's with a US ship, (I forget what class it was but I think the name was
the Stark), that was purportedly struck by an Exocet(tm) ASM and the light
alloy superstructure burned/melted causing great loss of life and equipment.

My father claims that because of this incident that all or most
US ships-o-the-line have been retrofitted with steel superstructures, is
this so?

Thanks for your time and attention.
-David Utidjian-

[James Dusek]

From du...@cadsun.corp.mot.com (James Dusek)

In article <CxvMu...@ranger.daytonoh.ncr.com>, mh6...@cutter.ship.edu

Not really, a good DE sub can do the job just like a nuke, and are alot
less expensive and are in the hands on many third world navies.

[Andrew Clark Toppan]

From el...@wpi.edu (Andrew Clark Toppan)

David M.V. Utidjian (utid...@remarque.berkeley.edu) wrote:

: My father and I were discussing warship armor and the structure

: of modern ships and ASM effects on them. There was an incident in the
: 80's with a US ship, (I forget what class it was but I think the name was
: the Stark), that was purportedly struck by an Exocet(tm) ASM and the light
: alloy superstructure burned/melted causing great loss of life and equipment.
: My father claims that because of this incident that all or most
: US ships-o-the-line have been retrofitted with steel superstructures, is
: this so?

The ship was the Stark, FFG 13. It was struck by 2 Excocets, one of
which detonated. US ships have *not* been retrofitted with steel
structures. This would require literal removal of the entire
superstructure- rather expensive. And the added weight (all up high)
would make the ships unacceptably top heavy. Some CV/CVN and some
CGNs (I think) have been fitted with limited armor around/over vital
spaces. The new DDG 51 class ships have a steel superstructure,
however. There have not been retrofittings on a massive scale.

Andrew
******************************************************************************
Andrew Toppan Smile, for tomorrow will be worse!!-
el...@wpi.edu a student at WPI
Railroads, Aircraft, Ships, Boats
Questions and answers are welcome, flames will be ignored.
******************************************************************************

[George Herbert]

From gher...@crl.com (George Herbert)

In article <CxttA...@ranger.daytonoh.ncr.com>,

drw...@hogpg.ho.att.com (-D.WELLS) writes:
>In article <Cxo9s...@ranger.daytonoh.ncr.com>,
>James Dusek <du...@cadsun.corp.mot.com> wrote:
>> This is untrue. They found out you can get better speeds with longer
>>narrower ships than shorter "fatter" ones of the same tonnage. So adding
>>weight and width would require more power than adding wight and making the
>>ship longer.
>
>Consider the following example:
>
>Yamato:
>SHP: 150000
>Speed 27 knots
>Length to beam ration: 256/36.9 = 6.93 : 1

^^^^^^^^ meters

>Displacement: 72,809 fully loaded
>
>Knox:
>SHP: 35,000
>Speed: 27 knots
>Length to beam ratio: 438/46.8 = 9.35 : 1

^^^^^^^^ feet

>Displacement: 4260 fully loaded
>
>The Yamato displaced about 17 times as much as the Knox, used only
>4.3 times the power to get the same speed, and was relatively fatter.
>Care to explain?

The short story: James is right. Max practical displacement hull speed
is 1.3*sqrt(Lpp in ft) [Lpp = length between perpendiculars, the forward
waterline entry to rudder post, nearly exactly for most ships the waterline
length]

Thus "hull speed" for a 256 meter ~= 820 foot BB is around 37 knots.
Hull speed for a 440 foot FF is 27 knots exactly. So the Knox is at
max practical hull speed, with the BB at only 73% of that speed.
As a rough approxomation, resistance is porportional to
(speed / hull speed) ^ 2.5
...though that's an _amazingly_ rough approxomation.
Anyone who shows that to my Propulsion and Power professors
and gets them on my case will be torpedoed (or tied to a barge
and then torpedoed if they aren't already at sea).

The long story: I'd need ugly things like the block coeficient,
actual detailed hull form and measurements, propellor effeciencies,
etc., to explain in detail exactly where all the differences
come from. _Principles of Naval Architecture_ vol 2 (SNAME) will have
all you ever wanted to know and more about the details.

| george william herbert | UNIX/Internet Consultant Usenet Old-Fogie |
| KD6WUQ gher...@crl.com | Part-time Aerospace Engineer & Moderator of |
===== ftp://ftp.crl.com/users/ro/gwh/home.html ===== sci.space.{tech,science}

[-D.WELLS]

From drw...@hogpg.ho.att.com (-D.WELLS)

In article <CyAsB...@ranger.daytonoh.ncr.com>,

David M.V. Utidjian <utid...@remarque.berkeley.edu> wrote:
>
>From utid...@remarque.berkeley.edu (David M.V. Utidjian)
>
> I don't think this question is off topic but it does deviate
>from the current thread a little.
>
> My father and I were discussing warship armor and the structure
>of modern ships and ASM effects on them. There was an incident in the
>80's with a US ship, (I forget what class it was but I think the name was
>the Stark), that was purportedly struck by an Exocet(tm) ASM and the light
>alloy superstructure burned/melted causing great loss of life and equipment.

Actually, the Stark was hit in the hull, just forward of the bridge.
I've heard from some that she was actually hit by TWO missiles. Can't
confirm this though.

> My father claims that because of this incident that all or most
>US ships-o-the-line have been retrofitted with steel superstructures, is
>this so?

Ships of the line? I don't think we've had any of those in over a century.
(unless you count battleships!) Anyway, I don't think that any of our
destroyers and frigates have had their superstructures replaced. The
extra topweight would make the ship quite unstable, unless the beam was
increased at the same time. (note the broad beam of the new, all-steel
Burke class DDGs)

[Michael Holbrook]

From mh6...@cutter.ship.edu (Michael Holbrook)

James Dusek (du...@cadsun.corp.mot.com) wrote:

: Not really, a good DE sub can do the job just like a nuke, and are alot

: less expensive and are in the hands on many third world navies.

Hmmm, well... No. A DE is a good sub still, to be sure. But lets look at
the sustainiable speeds they have, the range of the batteries, and so
forth. They are quiet as all hell running on batteries (the Kilos and
Upholders, for example, ar quiter than most nukes), but they lack the
mobility and flexibility of a nuke boat. If you're the skipper of a Kilo
(I'm not sure that those have been sold in large numbers to third world
nations, but lets give you all the advantages), and you are charged with
sinking a US Tico cruiser (with or without armour), you had better pray
that one of the following is true:

1. She is steaming at less than fifteen knots

2. She blunders right into your path.

3. She has no escorts, and her own passive sonar operator is inept, so
you can run on snorkel.

Unless one or more of these is true, you will not get off a shot with a
DE boat. DE's cannot maintain high speeds on batteries (in order to keep
up with/catch/get into postion to fire on high speed enemy ships).
Perhaps more importantly, you have almost a zero chance of escaping
afterwards if you are subjected to intense counterattacks. This is why DE
boats are mainly ASW units, and not anti-surface. Ships usually don't
wander into your range, although it will happen. DEs are a lot more
flexible than, say WWII subs where fast liners like Queen Mary were able
to run the Atlantic at 30+ knots with impunity. There still are
limitations, however, that make a DE's lack of mobility a severe
liability. Also, don't even try to run with snorkel. That just won't work.

It is a good point that DE boats can deliver torps to target, and they are
cheap and plentiful. They are not, however, nearly as good as nuke boats.

Cheerio,
Mike