WWII shaped charge technical question

So, as you know, shaped charge (eg HEAT) warheads were used during WWII as tank killers, and I believe against some fortresses as well. This may be a stupid question, but why were they never used in bigger applications? For example, I could see a 1,000kg shaped-charge bomb, dropped from a dive bomber, peircing a carrier deck and wrecking havoc in the hanger. A bomb like that might also give you a better chance of knocking out an armored turret on a battleship.

Is there a good reason for not using these that I have missed? Is it more effective somehow to just use all the bomb's space for explosives (leaving no room for a cavity)? Is it too complicated or expensive? What do you think?
 

Hoist40

Banned
Shaped charges while being able to pierce thick armor don’t create a lot of destruction unless the stream happens to hit something important. Ships are big and there is a lot of space which is not particularly important. This is different then tanks for example where there is little space inside a tank and it is all either important or vital. A 1,000 lb shaped charge hitting an aircraft carrier deck could simply punch a hole through a couple of decks and not do major damage.
 
Also ships have room for more shaped charge counter measures than armored vehicles. Things like air-gaps, non-homogeneous armor and other baffling techniques could make a shaped charge hitting a Battleship mote.
 
In addition to the problems already mentioned, a shape charge weapon will only hurt the ship with a direct hit (as well as possibly a hit on an area of sufficient armour to set it off). In practice a lot of damage was done by near-misses and hits to unarmoured or very lightly armoured areas that now are undamaged.
 
The German "Mistel" project was a Ju-88 bomber with the cockpit replaced by a shaped-charge and controlled by a fighter mounted on top. They were supposed to be used against Soviet factories and were used against bridges.

The IJA fitted some "Peggy" bombers with a shaped charge in the bombbay firing forward and downwards at a 45-degree angle. If it struck a ship @ 45-degrees this fired the charge straight down. They were to be used against battleships but only a handful were built. If one hit the bridge and the charge went straight down into a turret I could easily see it hitting the magazine.
 
The German Reichenberg manned Fieseler-103 aircraft (which was never used) had shaped charge warheads for suicide attacks.

But now that you mention it, I don't understand why torpedoes weren't fitted with hollow-charge warheads.
 
Keep in mind that shaped charges were relatively immature at this period of time.

The German Reichenberg manned Fieseler-103 aircraft (which was never used) had shaped charge warheads for suicide attacks.

But now that you mention it, I don't understand why torpedoes weren't fitted with hollow-charge warheads.

You get the same effect, but with far more damage, by detonating underneath the keel, which every major power tried to do with its torpedoes both before and during the war (generally with quite a few fusing problems).
 
The German Reichenberg manned Fieseler-103 aircraft (which was never used) had shaped charge warheads for suicide attacks.

But now that you mention it, I don't understand why torpedoes weren't fitted with hollow-charge warheads.

Seems like it would have been very adaptable to a navalized V1 or Fritz X type bombs
 
There would be some technical problems to be overcome. If I understand rightly, a shaped charge has to detonate at a precise distance from the target in order for the jet to form properly and be effective - the later TOW and MILAN ATGMs, for example, had noticeable fuse extensions for that reason (and thats why slat armour and schirzen work, they detonate the projectile prematurely). In the case of a 1000kg bomb, the stand-off distance will be relatively large - perhaps impractically large, over 10 metres I'd imagine, requiring a considerable fuse extension and redesigned casing. This is going to change the ballistics of the bomb a lot.

None of this is insurmountable, of course, but you'd have to have a good reason to go to all that trouble. And given what others have said, I'm not sure that regular bombs aren't a better bet anyway.
 
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Shaped charge technology was just in its infancy; I can't remember exactly why, but adapting the technology to certain calibres (in the case of tank-launched HEAT shells, anyway) was very difficult. I think an EFP-bomb would be effective as an anti-ship weapon, but I'd doubt it an be made to work effectively with WWII-tech.
 
I seem to recall Japan developed about a 1000kg shaped-charge bomb. Don't think it was ever actually used, tho. As for the jet, don't forget, the diameter is variable; if you don't demand deep penetration (which small-diam shells tend to need), you can get quite a large hole.:eek:
 
EFP bombs are actually very simple, all that is needed is a pipe and a copper plate. However such a device on the scale needed for naval warfare would not likely be as effective as the super heavy shells or iron bombs already in use. The same goes for a hollow charge based explosive device.

Far more intriguing was the tests of a discarding sabot sub-munitions that the US Navy carried out near the end of WW2. After a series of successful test fires the project seems to have been abandoned.
 
The idea, as noted above, of a HEAT warhead is to drive a small hole through heavy armor with the high probability of hitting something vital with a small plasma jet (and the spall from the displaced armor) inside.

This works well with tanks; they're packed with ammunition, fuel, and crewmen. Hit any of those, you at least severely reduce the tank's effectiveness.

A ship is another story. Ships are full of water tanks, dry goods storage, pipes, and numerous other things that DON'T explode. Killing a few crewman on a ship with a HEAT round is unlikely to severely reduce its effectiveness. Magazines are small targets compared to the size of the ship, and proportionately more heavily armored than a tank.

Very few ships in WWII died from explosions (though being quite dramatic, those get a lot of attention) - most died from fire and/or flooding. A standard HE warhead has a better chance of causing a serious fire than an equal-sized HEAT warhead, and an HE warhead in, say, a torpedo will put a bigger hole in the hull than a HEAT one will, thus letting water in faster and being harder to plug. It is MUCH easier to fix a small hole than a big one (that is, a hole that is four times as big is more than four times as hard to fix).

Put another way, ships of the WWII era were designed to take a pounding and keep on fighting. There are numerous examples of this happening. Tanks, on the other hand, were designed to prevent damage. If they couldn't prevent it, they were generally expected to be put out of action at least for a while.
 
The idea, as noted above, of a HEAT warhead is to drive a small hole through heavy armor with the high probability of hitting something vital with a small plasma jet (and the spall from the displaced armor) inside.

This works well with tanks; they're packed with ammunition, fuel, and crewmen. Hit any of those, you at least severely reduce the tank's effectiveness.

A ship is another story. Ships are full of water tanks, dry goods storage, pipes, and numerous other things that DON'T explode. Killing a few crewman on a ship with a HEAT round is unlikely to severely reduce its effectiveness. Magazines are small targets compared to the size of the ship, and proportionately more heavily armored than a tank.

Very few ships in WWII died from explosions (though being quite dramatic, those get a lot of attention) - most died from fire and/or flooding. A standard HE warhead has a better chance of causing a serious fire than an equal-sized HEAT warhead, and an HE warhead in, say, a torpedo will put a bigger hole in the hull than a HEAT one will, thus letting water in faster and being harder to plug. It is MUCH easier to fix a small hole than a big one (that is, a hole that is four times as big is more than four times as hard to fix).

Put another way, ships of the WWII era were designed to take a pounding and keep on fighting. There are numerous examples of this happening. Tanks, on the other hand, were designed to prevent damage. If they couldn't prevent it, they were generally expected to be put out of action at least for a while.

On another board there was a discussion about the utility of naval shells with HEAT warheads for use against heavily armoured targets in WWII. (ie. if light crusier with say 6" guns is engaging a battle ship.) The consensus was they would not have been worth the hassle.
 
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