Shaped charges against battleships

Just recalled some material that I found a few month ago. It was an article from "Guided missiles and techniques". Summary technical reports of Division 5, NDRC (Vol.1), published in 1946. Quite a good source about old USA guided weapons, but it is not the point here.

The point is, that in April, 1945, the Dahlgren Naval Ordnance Station tested the effect of shaped-charge aerial bomb against the model of battleship's hull. They used a standard 1000-pdr GP bomb casting, equipped with shaped charge of about 18 inches diameter. It was placed on the test rig, composed of several metal plates, separated from each other with 8-ft spaces.

The plates were, from up to down:

* 11-inch (28 cm) hardened cemented plate or armor steel.

* 4-inch (10 cm) hardened cemented plate or armor steel.

* 0,75-inch mild steel plate

* 0,75-inch mild steel plate

* 0,75-inch mild steel plate

Between fourth and fifth plates, several 100-pdr bombs (without fuses) were placed. The whole test rig imitated the horizontal protection of battleship's main turret magazines. Navy wanted to knew: would shaped charge be able to penetrate into ship's magazines & would it have enough power to detonate ammunition in case of such hit?

As it happens, it would.

When the charge was detonated, the metal jet penetrated the whole test rig, from the first to the last plate, and caused detonation of 100-pdr bombs inside.

This was one of the reasons, why armored fleets disappeared shortly after World War 2 and never returned.

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So basically, as soon as somebody would invent a Munroe effect on Safehold (and, considering that they already have high explosives, it would hardly took too long), the era of battleships would be over fast.

And only Charis has high explosives so no one else can make HEAT or HESH weapons until they have such themselves.
Though if they do...
if an enemy Archangel AI or whatever supplied the Emperor of remains of Harchong with info on weaponry...

Long thought smaller shape charge aerial bombs with pre-for med fragments (nipped steel wire) and just very thin, rolled metal cases, in sizes according to anti tank or naval, would be extremely useful and effective.
Drogue would ensure relatively vertical impact and give aircraft more time to escape the area.

Dilandu wrote:Just recalled some material that I found a few month ago. It was an article from "Guided missiles and techniques". Summary technical reports of Division 5, NDRC (Vol.1), published in 1946. Quite a good source about old USA guided weapons, but it is not the point here.

The point is, that in April, 1945, the Dahlgren Naval Ordnance Station tested the effect of shaped-charge aerial bomb against the model of battleship's hull. They used a standard 1000-pdr GP bomb casting, equipped with shaped charge of about 18 inches diameter. It was placed on the test rig, composed of several metal plates, separated from each other with 8-ft spaces.

The plates were, from up to down:

* 11-inch (28 cm) hardened cemented plate or armor steel.

* 4-inch (10 cm) hardened cemented plate or armor steel.

* 0,75-inch mild steel plate

* 0,75-inch mild steel plate

* 0,75-inch mild steel plate

Between fourth and fifth plates, several 100-pdr bombs (without fuses) were placed. The whole test rig imitated the horizontal protection of battleship's main turret magazines. Navy wanted to knew: would shaped charge be able to penetrate into ship's magazines & would it have enough power to detonate ammunition in case of such hit?

As it happens, it would.

When the charge was detonated, the metal jet penetrated the whole test rig, from the first to the last plate, and caused detonation of 100-pdr bombs inside.

This was one of the reasons, why armored fleets disappeared shortly after World War 2 and never returned.

-----------------------

So basically, as soon as somebody would invent a Munroe effect on Safehold (and, considering that they already have high explosives, it would hardly took too long), the era of battleships would be over fast.

Can you find the study you mentioned? I ask because shaped charge warheads generally loose effectiveness once they have penetrated one or two individual layers of armor and/or have their jet disrupted. This is why German armor used side skirts on their tanks and SPGs in 1944-45. This is also why ATGMs have started to use dual warheads.

doug941 wrote:
Can you find the study you mentioned?

Of course. It's in the Internet Archives:

https://archive.org/details/guidedmissileste01spen

A very good study about early US guided bombs.

doug941 wrote:I ask because shaped charge warheads generally loose effectiveness once they have penetrated one or two individual layers of armor and/or have their jet disrupted. This is why German armor used side skirts on their tanks and SPGs in 1944-45. This is also why ATGMs have started to use dual warheads.

The thing is, that size did matter. The anti-tank warheads are tiny, their jet is relatively low mass, and could be easily disrupted.

Now, anti-SHIP warheads are huge. They are much larger in diameter, their metal liners are much more massive. Jet from shaped-charge anti-ship warhead - a P-15 "Termit" ("Styx"), for example - is a spear of hypersonic metal with enough mass to NOT be easily dissipated or splashed.

So, it is not correct to use anti-tank warheads as an example of anti-ship ones.

Dilandu wrote:

doug941 wrote:
Can you find the study you mentioned?

Of course. It's in the Internet Archives:

https://archive.org/details/guidedmissileste01spen

A very good study about early US guided bombs.

doug941 wrote:I ask because shaped charge warheads generally loose effectiveness once they have penetrated one or two individual layers of armor and/or have their jet disrupted. This is why German armor used side skirts on their tanks and SPGs in 1944-45. This is also why ATGMs have started to use dual warheads.

The thing is, that size did matter. The anti-tank warheads are tiny, their jet is relatively low mass, and could be easily disrupted.

Now, anti-SHIP warheads are huge. They are much larger in diameter, their metal liners are much more massive. Jet from shaped-charge anti-ship warhead - a P-15 "Termit" ("Styx"), for example - is a spear of hypersonic metal with enough mass to NOT be easily dissipated or splashed.

So, it is not correct to use anti-tank warheads as an example of anti-ship ones.

Size DOES NOT matter as much as you think. A Munroe Effect (shaped charge)warhead begins to lose effect as soon as it makes contact with a surface strong enough to detonate it. A warhead's size will have some effect on the amount of matter it will penetrate ON THE FIRST CONTACT. But going thru deck after deck after deck? Not gonna happen. Also, the jet hitting practically any hull fitting and/or piece of equipment under the weather deck will stop the weapon's effect butt cold. Remember the jet MUST maintain cohesion to work. Once it has eddies or other structural errors, it is all over.
To go thru multiple decks like that takes extreme kinetic energy such as the Fritz-X that went out of HMS Warspite's bottom before exploding.
One other thing to remember. Iowa class vessels had multiple layers of armor and decking, and the only exterior armor likely to matter was on the turrets. Belt and deck armor was all interior.

doug941 wrote:
Size DOES NOT matter as much as you think. A Munroe Effect (shaped charge)warhead begins to lose effect as soon as it makes contact with a surface strong enough to detonate it. A warhead's size will have some effect on the amount of matter it will penetrate ON THE FIRST CONTACT. But going thru deck after deck after deck? Not gonna happen.

Since I have proof of the actual experiment performed in 1945 - and knowledge about anti-ship missile warhead design - I'm afraid I should dismiss all your rhetoric as unsubstantial. Yes, it gonna happen. The mass of jet is sufficient to go through deck after deck.

Dilandu wrote:
Since I have proof of the actual experiment performed in 1945 - and knowledge about anti-ship missile warhead design - I'm afraid I should dismiss all your rhetoric as unsubstantial. Yes, it gonna happen. The mass of jet is sufficient to go through deck after deck.

Are you sure that was not an explosively formed projectile? The penetration seems extreme for what is in effect a Whipple shield. I would expect lens effects to significantly diminish the penetrating power of the metal jet with each deck penetrated.