Effect of bombs

[RF]

Gentlemen,

....what effect would the average bomb dropped either from a carrier or land based aircraft have on a heavily armoured battleship - besides making a bit of a mess of her upperworks? I have always thought that the sinking of Yamoto & Mushashi was the direct effect of multiple torpedo hits, so would the bombs just bounced off them and other modern ships?

I am minded of the bomb that blew up the USS Arizona during the PH attack which so far hasn't been mentioned here. Apart from the fact that the ship was stationary in harbour, was there any particular factor in one bomb causing a magazine explosion?

[lwd]

It was a custom built AP bomb dropped from an altitude calculated to allow it to penetrate the deck of a US battleship.
I believe it's the Type 99 No.80 Mk 5 in the list at:
http://en.wikipedia.org/wiki/List_of_Ja ... navy_bombs

[Bgile]

It had to be dropped from 10,000 feet to achieve the necessary velocity. Arizona was destroyed because it set off a black powder magazine used to store catapault launching charges. The other battleships targeted by the same type of bombs ... basically all of the inboard ships ... received light to moderate damage from the same type of bomb.

At sea, dropping an unguided bomb of that type from 10,000 feet isn't likely to hit a maneuvering target.

[Byron Angel]

This was the USN's best guess, circa July 1944, as to the effects of aerial bomb hits upon a modern (in WW2 terms) battleship, assuming that weapons were properly fuzed for optimal penetration performance -

Weapon_____Assumed Chg Wt TNT_____1 hit___2 hits___3 hits___4 hits___5 hits___6 hits
1000lb AP_________150lbs____________0.23____0.41____0.55____0.66____0.73____0.79 to sink
1600lb AP_________240lbs____________0.23____0.41____0.55____0.66____0.73____0.79 to sink
1000lb GP_________500lbs____________0.01____0.05____0.10____0.18____0.40____0.70 to disable
2000lb GP________1000lbs____________0.02____0.10____0.20____0.40____0.55____0.90 to disable

By my understanding of the explanatory text, the apparently high lethality values for 1 or 2 AP bomb hits is basically related to the podssibility of them striking a magazine space.

For what it's worth .....

B

[Bgile]

The problem with that of course is that it was virtually impossible to hit a magazine space on a modern battleship with an AP bomb. In fact, I'm unable to recall that ever happening against a maneuvering battleship.

[Byron Angel]

The problem with that of course is that it was virtually impossible to hit a magazine space on a modern battleship with an AP bomb. In fact, I'm unable to recall that ever happening against a maneuvering battleship.

..... There is little question that the likelihood of scoring a hit upon a maneuvering warship by means of horizontal bombing at 10,000 feet is extremely low. However, once the hit itself is conceded, the likelihood of it occurring in the way of a magazine space is approximately as given by the USN analysis. A modern battleship stowed approximately 300-400 tons of main battery propellant alone.

B

[Bgile]

The problem with that of course is that it was virtually impossible to hit a magazine space on a modern battleship with an AP bomb. In fact, I'm unable to recall that ever happening against a maneuvering battleship.

..... There is little question that the likelihood of scoring a hit upon a maneuvering warship by means of horizontal bombing at 10,000 feet is extremely low. However, once the hit itself is conceded, the likelihood of it occurring in the way of a magazine space is approximately as given by the USN analysis. A modern battleship stowed approximately 300-400 tons of main battery propellant alone.

B

My apologies if I misinterpreted your original statement, but I didn't see any reference in it to an altitude of 10,000 feet or horizontal bombing.

[Byron Angel]

My apologies if I misinterpreted your original statement, but I didn't see any reference in it to an altitude of 10,000 feet or horizontal bombing.

..... No worries. I probably was insufficiently clear in my introductory remarks. The data was represented to give a best estimate of the likely result of X number of effective hits on a given target by weapons "properly fuzed for optimal penetration" - a phrase which I interpret to mean penetrating hits. For AP bombs versus an average of 6 inches horizontal protection common to first-class BBs of the WW2 period, that pretty much dictates weapon delivery from +/- 10,000 ft or more.

I by no means disagree with your comment that the likelihood of scoring hits from such an altitude on a menuvering target was definitely low. My point was only that the USN data did not discuss the chances of hitting, only the predicted effect of hits achieved.

B