Submarine deck guns

[marcelo_malara]

Anyone can tell if the steel employed in submarine guns is the same as in surface ships guns?, I mean it is exposed to the highly corrosive sea water, may be some form of stainless stell is used.
Moreover, when the sub goes down, the bore remains open or it is made watertight?, and if so, the breech is made watertight too? how?

[Hartmann10]

Hello MArcello, I am not very aware of the materials which was made the gun, but in the part of the barrel, there was a kind of plug, which sealed the inside part of the barrel and the breech. Hope this help. Bye

[Captain Morgan]

From navweaps.com
about the US 5"25 cal gun used on submarines in WWII

The Mark 17 was a "wet mount" version for submarines and was unusual in that it did not require breech or muzzle plugs. This was because it used a special liner resistant to corrosion from sea water and could thus be submerged and flooded without harm to the gun. The Mark 17 Mod 0 used a tube of higher strength steel than that used for earlier Marks with a shrunk forged copper-nickel alloy liner. The Mark 17 Mod 1 was a bored out Mark 13 Mod 0 fitted with a tapered copper-nickel alloy liner and used semi-fixed ammunition in order to ease handling on submarines. Both Mark 17 mods had chrome-plated bores and neither had the pneumatic rammers used on other Marks. This was acceptable as the Mark 40 mounting used on submarines was an SP type with a maximum elevation of 40 degrees.

[marcelo_malara]

Thanks!!!

[Gary]

Hi Marcelo.

I once read a case of a U-boat (sorry the number eludes my memory) where the crew fired the deck cannon with the plug still in.

[marcelo_malara]

Hi Gary.

Now you mention it, do you know how this plug worked? Were there plugs for bore and breech? What were they made of?

[RF]

The gun was primed with the plug still in, and the discharge caused an explosion that wounded the gun crew.

I have been trying for some time to find out the properties of the plug, I gather it was some form of reinforced rubber but as I am not a technical expert I don't know whether this is correct or not. Perhaps since this thread was last active some one can now come up with the info.....

[lwd]

I seem to recall reading of at least one US submarine captain scavanging a bigger gun from somewhere. I think his sub was based at PH and the gun came off a surface ship. Submariners were not above jury rigging stuf and the loss rate was such that they probably weren't worried about the long term effects on the gun.

[Bgile]

I seem to recall reading of at least one US submarine captain scavanging a bigger gun from somewhere. I think his sub was based at PH and the gun came off a surface ship. Submariners were not above jury rigging stuf and the loss rate was such that they probably weren't worried about the long term effects on the gun.

Other than Nautilus and Narwal, which were designed with them?

Bigger than 5"? If so, I don't think it's listed in Friedman's "US submarines". Do you have a source?

[lwd]

I seem to recall reading of at least one US submarine captain scavanging a bigger gun from somewhere. I think his sub was based at PH and the gun came off a surface ship. Submariners were not above jury rigging stuf and the loss rate was such that they probably weren't worried about the long term effects on the gun.

Other than Nautilus and Narwal, which were designed with them?

Bigger than 5"? If so, I don't think it's listed in Friedman's "US submarines". Do you have a source?

I think it was an up gun to a 5" but don't remember all the details. I think it was mentioned in the old show The Silent Service but I read about it later somewhere as well. It may also have been an upgrade from one gun to another of the same caliber. Apparently the skipper thought they used to many rounds to too little effect with the existing gun.