BBs have glass chins?

[mciann]

I noticed that whenever the big battleships got hit by an airstrike, they would take an inordinate amount of damage. I'd seen Yamato and Iowa class battleships go down with a single torpedo hit rather frequently, while destroyers in the same task group take 4-5 torpedo or 10-15 bomb hits to sink.

I poked around with the editor to try to figure out what metric was causing the battleships to go down so easily. I played around with vulnerability, armor, etc. but eventually discovered that the game tends to assign more damage for a bomb or torpedo hit if the ship has a large displacement. If I drop the displacement on the big battleships down to 1000 tons, they start taking hits like destroyers do.

What's going on here? While it isn't inconceivable that a ship like the Yamato or the Iowa could sustain a torpedo hit that would eventually prove to be fatal, the idea of being destroyed instantly by one such hit (think destroyer blown in half) seems completely inconsistent with history. Musashi took 17 bomb hits and 20 torpedoes before going down at Leyte gulf. Yamato took 12 bomb hits and 7 torpedoes.

[Sarconix]

There is a similar question here:

tm.asp?m=1885997

... but no solid answer yet. Anyone else know?

[elcidce]

I think it might have to do with the displacement of the ships. Damage caused from topredos is not primarily caused from the charges in the warhead. The real damage is caused from the weight if the ship not being supported by the water in the void caused by the torpedo blast. Basically there is a hole in the water where the ship is not supported. Its own weight causes it to pull itself apart or be crushed. The superior armor and structure of the larger ships plays against it because of its weight.

There are two terms that would also apply in general. Hog and sag. Ships are hogging if they are supported in the middle and not the ends. This is dangerous because the weight of its ends can tear the ship in two from the top down. The decks are in tension. Sag occurs in just the opposite case. The ends are supported and the keel is in tension. The weight unsupported in the middle would break the ship's keel apart.

Getting back to the reason why smaller ships are not effected as much, I would suspect that smaller ships would be pushed through the water by the blast and have more of their hulls exposed ie they are not in compression and tension at the same time.

I dont know if that is what was intended to be modeled but there is some physics behind this.

[elcidce]

dup

[elcidce]

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[random_rail]

ORIGINAL: elcidce

I think it might have to do with the displacement of the ships. Damage caused from topredos is not primarily caused from the charges in the warhead. The real damage is caused from the weight if the ship not being supported by the water in the void caused by the torpedo blast. Basically there is a hole in the water where the ship is not supported. Its own weight causes it to pull itself apart or be crushed. The superior armor and structure of the larger ships plays against it because of its weight.

There are two terms that would also apply in general. Hog and sag. Ships are hogging if they are supported in the middle and not the ends. This is dangerous because the weight of its ends can tear the ship in two from the top down. The decks are in tension. Sag occurs in just the opposite case. The ends are supported and the keel is in tension. The weight unsupported in the middle would break the ship's keel apart.

Getting back to the reason why smaller ships are not effected as much, I would suspect that smaller ships would be pushed through the water by the blast and have more of their hulls exposed ie they are not in compression and tension at the same time.

I dont know if that is what was intended to be modeled but there is some physics behind this.

However, those would be more along the lines of an underwater nuclear blast rather than what can be done with WW2 aerial torpedoes. Especially since they used contact rather than magnetic detonators, requiring a hit on the side rather than exploding directly under the keel.

[elcidce]

It doesnt matter where it exploded. A contact mine still uses the ships own weight to damage the ship not the charge.