HMS Hood & USS Arizona Magazine Explosions

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paul.mercer
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Re: HMS Hood & USS Arizona Magazine Explosions

Post by paul.mercer »

Steve Crandell wrote:
paul.mercer wrote:Gentlemen,
A couple of questions, on any warship, particulary large one like Battleships, when were the fuzes actually put in to the shell - was it only just before action was expected? Also what was the situation after action had finished were any shells that had been loaded into the breeches simply fired off or were they unloaded and the fuzes removed before returning to the shell room ?
It was difficult to unload a gun because the ramming process seated the shell pretty solidly. They were usually unloaded "through the muzzle" by firing the guns.

Fuses were usually installed in the shell when manufactured. They weren't activated until the shell was fired. The explosion of shells on board was due to heat build up from fires causing spontaneous detonation of the shell's explosive filler. That was not normally the cause of a magazine explosion, though. That was usually due to the explosion of propellant, not shells. Propellant was a lot more unstable than shells; especially Cordite, which I believe was only used on British ships.

Arizona was destroyed when the black powder charges for her catapults exploded and blew up the ship's forward magazine. It's use was soon discontinued for that reason.
Thanks for that Steve,
I read somewhere that Tirpitz was using her 15" fuzed to explode in the air, does that mean she would have had a mixture of AP, SAP and airburst shells
on board?
Steve Crandell
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Re: HMS Hood & USS Arizona Magazine Explosions

Post by Steve Crandell »

paul.mercer wrote: I read somewhere that Tirpitz was using her 15" fuzed to explode in the air, does that mean she would have had a mixture of AP, SAP and airburst shells
on board?
I don't know what here loadout was, but it does make sense that the timed fuse shells would only replace some other part of the load out she would normally carry. The Japanese did the same thing.
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Re: HMS Hood & USS Arizona Magazine Explosions

Post by alecsandros »

Steve Crandell wrote:
paul.mercer wrote: I read somewhere that Tirpitz was using her 15" fuzed to explode in the air, does that mean she would have had a mixture of AP, SAP and airburst shells
on board?
I don't know what here loadout was, but it does make sense that the timed fuse shells would only replace some other part of the load out she would normally carry. The Japanese did the same thing.
I don't know if they had special AA shells. I guess they had HE shells with some sort of pre-set fuze...
paul.mercer
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Re: HMS Hood & USS Arizona Magazine Explosions

Post by paul.mercer »

Gentlemen,
Once again thanks for your input. I understand that some of the earlier magazine explosions was due to either elderly or faulty cordite, if shells were fuzed when they left the armament factory they could also be in a ships magazine for years, did the fuzes or the explosive in the shell itself deteriorate and if so would they be capable of setting off a shell?
Steve Crandell
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Re: HMS Hood & USS Arizona Magazine Explosions

Post by Steve Crandell »

The USN had some problems early on with the fuses in the new "super heavy" 16" shells. They corroded and then would not function when they were supposed to. There was no problem with them going off when they weren't supposed to.
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Re: HMS Hood & USS Arizona Magazine Explosions

Post by tommy303 »

The usual practice in most navies was for empty shells to be sent from the factory to arsenals where they would then receive their explosive fillers. The shells would be put in store with inert travel plugs instead of fuzes in the cases of smaller projectiles and AP type based fuzed shells. Shells which had an nose fuze inside a ballistic cap were normally filled, fuzed and had the cap installed before leaving the arsenal. Base fuzed shells in many cases would not be fuzed until they reached the naval base where they would then be sent to a ship. An armourer would take the travel plug out and install the proper base fuse.

As far as the question of deterioration of fuzes or explosive fillers is concerned, most explosives are somewhat reactive to certain metals, so care has to be exercised in using a metal which will not react with the chosen explosive or to heavily varnish or lacquer the metal in question to prevent direct contact. The main problem is not so much a danger of spontaneous combustion, but the formation of sensitive compounds which might cause a shell to detonate when a gun was fired. Picric Acid and Explosive D were notorious for their reaction with most metals to form dangerously sensitive compounds which might cause a bore premature. Explosive D also caused problems with fuzes, as Steve mentions. In this case, Explosive D was used primarily in AP shells from 6" to 16" which, in time of peace are not normally stored fuzed and ready to go. In wartime, however, fuzes were installed in all war munitions so a ship would be ready to fight at a moment's notice. It had not been foreseen that a problem might arise, as the fuze and gaines had cardboard disks and tubes preventing direct contact with the granular Explosive D. Explosive D, however, gave off fumes which were corrosive to the zinc and alumnium parts in the fuzes, creating rapid oxidation of those parts and essentially preventing them from moving freely during the arming process. This in turn led to a high number of duds in combat. The problem was eventually recognized and dealt with by dipping the assembled gaines and fuze bases in bakelite resin, making them airtight.

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paul.mercer
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Re: HMS Hood & USS Arizona Magazine Explosions

Post by paul.mercer »

Gentlemen,
Once again, thank you vey much for your replies and information.
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