Twins v Warspite & Valiant

[Dave Saxton]

The various books i have read re the loss of the Scharnhorst state that there was a massive explosion underwater just after she sank, presumably this was one or both of the forward magazines which blew the bow off,

I think the same.

If one studies the pictures of Barham one can see that she was right over on her side and about to capsize before she blew up, so presumably the water entering her was not sufficient to stop the magazine from exploding.

You can add Yamato to that list. Yamato had a tremendous explosion just after it sank as well. In some cases when battleships roll over, or just after, they suffer explosions. One notes that the Tirpitz had an explosion that blew C turret off its barbet while rolling over. It did not, however, blow the hull apart, nor was it as violent as the Barham explosion.

[Dave Saxton]

What was the 14" dud rate?

This is a question better answered by Tommy 303. Everybody had duds but I don't know the rate of the British 14".

[Rick Rather]

One notes that the Tirpitz had an explosion that blew C turret off its barbette while rolling over. It did not, however, blow the hull apart, nor was it as violent as the Barham explosion.

I wonder if this was an explosion in the shell storage, rather than in the propellant magazine? The shells only had a bursting charge of 19 - 64 kg (depending on type) but each required more than 200 kg of propellant to fire. In American battleships the projectiles were stored in the barbette, whereas the powder magazines were lower-down (see the first three minutes of this training film for the layout). Did German warships also use this scheme?

Following that thought, perhaps the alleged magazine damage on Scharnhorst was actually in a projectile room. This would make sense in the context of the "magazine-was-flooded-then-pumped-out" story - more-so than the wet silk powder-bags that would have resulted from a sprinkled propellant mag (I do not know how (or if) the silk fore-charges were segregated from the brass-cased main cartridges in German magazines).

[alecsandros]

I wonder if this was an explosion in the shell storage, rather than in the propellant magazine? The shells only had a bursting charge of 19 - 64 kg (depending on type) but each required more than 200 kg of propellant to fire. In American battleships the projectiles were stored in the barbette, whereas the powder magazines were lower-down (see the first three minutes of this training film for the layout). Did German warships also use this scheme?

Yes, the powder charges were beneath the shell rooms in GErman battleships also...

[tommy303]

shell rooms were beneath the powder magazines in German ships.

[tommy303]

This would make sense in the context of the "magazine-was-flooded-then-pumped-out" story - more-so than the wet silk powder-bags that would have resulted from a sprinkled propellant mag (I do not know how (or if) the silk fore-charges were segregated from the brass-cased main cartridges in German magazines).

The fore charges were stored within the magazines in flash and waterproof containers as shown in the foto in the link below:

http://www.flickr.com/photos/yetdark/5931415988/

The cases for the brass main charge cartridges are near the wall, while the more slender cases for the forecharges are closest to the camera.

[tommy303]

What was the 14" dud rate?

This is a question better answered by Tommy 303. Everybody had duds but I don't know the rate of the British 14".

I am not certain of the dud rate for the British 14-inch, or even if anyone ever really got that figured out, but it seems to have been less than say the USN dud rate up to 1943 when the problems with the base fuzes were finally figured out and corrected. British and American base fuzes were not graze action, per se, while the German base fuzes were. The latter worked better at higher oblique impacts than either the British and USN fuzes, but were more susceptible to damage at higher velocities and the closer the angle of impact approached normal (which oddly enough seems to be at odds with the addage that German naval guns were intended for close range battles). USN and British fuzes were more prone to malfunction at higher angles of impact, and operated better at low angles of impact and higher velocities than the German equivalents.

[Thorsten Wahl]

USN and British fuzes were more prone to malfunction at higher angles of impact, and operated better at low angles of impact and higher velocities than the German equivalents.

tommy303 do you have a reference for this information. As the reliablity of fuzes is not subject of criticism in german documents on naval gunnery.
I could find only an Krupp ballistican(interogation of Gercke in ADM 213-951 steel_ap_and_theory_of_penetration_1946 that mention such problems, but specifically for army projectiles. And in that regard it seems whining at a high level. Thank you

[alecsandros]

shell rooms were beneath the powder magazines in German ships.

I may be misleaded by the language..

But aren't the shell rooms right near the shell magazines ?

...

Because... I have the plans of Tirpitz with "powder magazines" located exactly beneath the shell magazines...

[Dave Saxton]

My large scale copy of the Official Kriegsmarine Tirpitz drawings show the 38cm granat (shell)kammer below the 38cm pulver (powder)kammer. The powder cases are shown stacked horizontally in several seperate armoured lockers. The shells are shown stowed also horizontally.

[tommy303]

tommy303 do you have a reference for this information. As the reliablity of fuzes is not subject of criticism in german documents on naval gunnery.

Hi Thorsten,

I was not actually criticizing German fuzes, with which I am actually quite impressed, simply comparing them with British and USN base-detonating (BD) fuzes. For the most part, from what I have read, German naval fuzes tended to work properly at relatively greater oblique impacts than either RN or USN BD fuzes. The difference between the two was the German fuzes were of a simple graze action type--i.e., the German BZ fuzes, when armed were relatively sensitive to changes in velocity and the close proximity of the inertial slug carrying the primer and the firing pin meant that even at very oblique angles of impact the fuze would normally function. If a spring was incorporated at all between the firing pin and the inertial slug, it was to decrease this sensitivity somewhat to prevent premature initiation when striking non-armour structures. At high velocities and very low to normal angles of impact, there was a tendency for the fuzes to be damaged, but at such low ranges as would permit those circumstances, the structural limit of the shell itself would probably be exceeded anyways. I presume that it was these circumstances that prompted designers for anti-tank projectiles to incorporate fuzes such as the BZ 5127 which worked better at high velocity, low angle impacts as would predominate in tank vs tank combat.

USN and RN base detonating fuzes were rather more complex and had fairly strong anti-creep springs as part of their safety mechanism, as well as multiple safety interlocks to give an adequate margin of bore safety. They, particularly the USN types, were quite complex and made to very tight tolerances. As a rule, they would not operate unless very suddenly checked in flight, and oblique impacts could jam one or more of the moving parts. USN fuzes, in fact, did not complete arming until actual impact occurred and fired only when impact forces have diminished sufficiently to allow a spring loaded plunger with the firing cap to be propelled onto the firing pin.