Armor and Nimitz class survivability.

[pghcc2006]

Hello, I was wondering why heavy armor like the kind that was used on ww2 ships especially the Iowa's is spoken of as though it's a lost art or medieval potion that cannot be done today. Is this true and if so why is it? also, i read in the book Warships by David miller that the nimitz class was designed to absorb three times the punishment that the essex class did. Is a modified kamikaze val or zero comparable to a modern anti ship missile or does the increased speed of ASM’s make them much deadlier because of increased penetrating power?

[IDonT]

Hello, I was wondering why heavy armor like the kind that was used on ww2 ships especially the Iowa's is spoken of as though it's a lost art or medieval potion that cannot be done today. Is this true and if so why is it? also, i read in the book Warships by David miller that the nimitz class was designed to absorb three times the punishment that the essex class did. Is a modified kamikaze val or zero comparable to a modern anti ship missile or does the increased speed of ASM’s make them much deadlier because of increased penetrating power?

Same reason why the Knights stop using plate armor when the musket was introduced. It was not worth it. The time, money, and effort needed to put a modern heavy armor on a warship is a losing proposition because creating an anti-ship missile that can penetrate layers of armor requires a fraction of that cost. Such assets are better spent on preventing the ship from being hit in the first place.

[Stitch]

Hello, I was wondering why heavy armor like the kind that was used on ww2 ships especially the Iowa's is spoken of as though it's a lost art or medieval potion that cannot be done today. Is this true and if so why is it? also, i read in the book Warships by David miller that the nimitz class was designed to absorb three times the punishment that the essex class did. Is a modified kamikaze val or zero comparable to a modern anti ship missile or does the increased speed of ASM’s make them much deadlier because of increased penetrating power?

Several reasons, although I'm sure RB can say this better than I can . . . . .

For starters, a modern warship's first line of defense is prevention: "know thy enemy". The idea is to stop an attack before it starts (i.e.: destroy the launch platform before it has a chance to launch). Secondly, between the carrier's escort ships (in particular the Aegis-equipped cruisers & destroyers), it's CVW, and it's own CIWS (especially the Phalanx), the carrier should be able to destroy any incoming missles (or aircraft) before they hit the ship (hopefully). Lastly, as Dreadnought (I believe) mentioned in another thread (forget which one), nobody is better at DC than the US Navy, particularly a carrier crew. I think what he meant by "three times the punishment" is that the magnitude of an attack that a Nimitz-class carrier can survive would be three times that of an older Essex-class.

As for your second question, a kamikaze was not specifically designed to sink ships, an ASM is. A kamikaze is just a 5,000 lbs. guided missle without much of a warhead (or none at all); an ASM is specifically designed to sink a warship. Between an ASM's greater speed (up to Mach 4), and it's specific design, it is probably at least 10 times better at damaging a ship than a WWII-era kamikaze. I don't know the flight profile of an Exocet or a Silkworm, but I know that a modern AGM-84 Harpoon's profile attacks the ship from above, attempting to penetrate the decking of a ship, which is usually thinner than the hull. After that, it usually penetrates three or four decks before exploding, attempting to do as much internal damage to the ship as possible.

[TopHatter]

Hello, I was wondering why heavy armor like the kind that was used on ww2 ships especially the Iowa's is spoken of as though it's a lost art or medieval potion that cannot be done today. Is this true and if so why is it?

Good questions!

Yes, that is true, if only because there are no facilities left existing to manufacture heavy armor.

A couple of terms are useful here: "Perishable job skills" and "vanished industrial base". Basically summed up as "use it or lose it".

It's the reason why what we did "yesterday" cannot be done "today".

Sending a man to the moon for example. All of the Project Apollo hardware used is essentially gone (museum pieces not withstanding) and most/all of the manufacturing equipment to make the hardware is equally gone.

Of course, they are gearing up to return to the moon with the Project Constellation/Orion initiative, but they're basically starting from scratch, at least from an equipment perspective.

[RustyBattleship]

I am not familiar with warhead protective systems on a Nimitz but they are most likely similar (if not identical) to those on a Forrestal.

In WW II Carriers had a relatively thin belt armor to trigger torpedo hits or mine hits and allow the inner compartments (void spaces, fuel tanks, etc.) take up the concussion damage. However, by the time those ships were built, torpedos had evolved into extremely damaging weapons with mines only being a nuisance (to large ships). For a mine to float, it needs an air pocket above which wastes a lot of the explosive power of a mine. But a torpedo is something else.

Now comes missiles. They can hit at the waterline, above the waterline or straight down through the main deck. Only an Iowa class Battleship has enough LAYERS of thick steel and/or armor to take multiple hits. A Carrier is extremely vulnerable should the warhead punch through to the Hangar deck and start a chain reaction of blowing up planes stowed down there.

Even with extremely accurate anti-missile weapons, the fragments alone could cause serious damage to ANY ship.

Therefore the Navy had a change of heart back in the 80's realizing that many classes of ships could not withstand a direct hit of a modern missile. HOWEVER, via an accident on board a ship with a Shrike missile, we found that the fragments did just as much damage as a direct hit would by penetrating the aluminum bulkheads and knocking out critical electronics. The development of anti-missile missiles and the CIWS gave us a good chance of knocking out an incoming. But if that incoming was very close by the time it blew up, fragment damage would be almost disasterous.

So, on the Spruance Class Destroyers we designed "Fragment Protection" which was basically Applique Armor over the existing bulkheqds to protect against "Near Misses". The idea was to combine all bulkhead thicknesses between the equipment on to the outboard bhd and add thick enough plating to be equal to 1 3/4" inch thick Type 5086 Aluminum "Armor".

Similarly the 5-inch and CIWS magazines on the Tarawa class were rebuilt of HY-80 "Fragment Protection" armor (3/4" thick HY-80).

Even the Iowa class reactivations only called for addition of "Fragment Protection" armor from 1/2" thick, through 3/4" thick, through 1" thick and finally 1 1/2" thick depending upon how critical the spaces were (or how far inboard they were).

I don't think you will find those details on any website as the plans that developed them had to have my signature on them. So I know what thicknesses were used and where they were placed but would probably be arrested if I told you exactly where (even though many of those ships are now fishing reefs).

Therefore, anti-missile weapons have a very high priority in development and we have even gone so far as to build a powerful Laser that actually melts the nose of an incoming 8" shell (TopHatter has a You Tube on this somewhere - I think).

But finding a contractor with the lowest bid but the highest quality with the most Congressmen in favor of them in order to issue a sufficient quantity of these weapons is our greatest weakness.

[avon1944]

I know that a modern AGM-84 Harpoon's profile attacks the ship from above, attempting to penetrate the decking of a ship, which is usually thinner than the hull.

The Harpoon is a couple years older than the Exocet Missile but, the Exocet was the first anti-ship missile to possess the "pop-up" mode of attack! The USA's and USSR's navies thought about the idea but, at that time this tactic complicated the defense against the incoming missiles, so they stayed away from that option. The French Navy decided to implement this mode to make the Exocet Missile more effective.

Adrian

[Tin Man]

AVON, I wasn`t aware that Exocet had an original pop-up mode? Both missiles were developed along similar time lines, the in service and production dates are roughly around 1972-1975, for both weapons, depending on where you look and which version!!!!

Harpoon had pop-up mode, but in later versions it was selectable, either pop-up or sea skimming to target. I always thought Exocet was purely a sea skimmer, I would not be surprised if later versions were selectable though.

Do you have any linkies showing that the first Exocet versions utilized pop-up attack modes, thanks in advance, Otomat had both modes, which was also a part French design, evolved around the same time.

[Master Chief]

Its the Harpoon that started the pop-up Not exocet.

[avon1944]

Its the Harpoon that started the pop-up Not exocet.

NOOoooo... the first Harpoons remained in the sea skimmer mode. This was back when the USSR and USN did not want to have deal with the problems caused from defending a ship from an anti-ship missile going into a ballistic climb and then diving onto the target. The French Navy is rather proud of this fact that they were first on this.
The pop-up maneuver was not the first time the USA and USSR did not develop a weapon system because of the problems caused by the new type of system. I remember back in the 1980's when some people got the bright idea of placing a whole bunch of air launched cruise missiles on rotary launchers, within a B-747 cargo plane. The launch aircraft could stay back more than five hundred miles or more and launch cruise missiles at early warning radars and then move a little closer and go after interceptor bases. Neither NORAD nor the PVO wanted anything to do with systems like this.

Adrian