Pat & Toad3,
This is for the Type IXC submarines that where at Portsmouth Naval Shipyar at the end of the war.

As originally armed, the vessels had one 105mm gun on the main deck forward of the conning tower with a spray shield.

Ready service ammunition was stowed in pressure proof tanks that consisted of 32 rounds.

218 additional rounds were stowed in the two magazine spaces below deck.

This gun was removed when the anti-aircraft armament was increased. Original anti-aircraft armament consisted of one 37mm gun on the main deck aft, and one 20mm gun at the after end of the cigarette deck. I naddition, one 8mm type c/34 machine gun was provided. Ready service tanks were provided topside only for the 37mm gun at that time.

As changed at the time of the general re-arament of the submarines, the vessels were provided with several different combinations of 20mm and 37mm guns, usually consisting of two twin 20s on the cigarette deck wings and a single 37 on the after extension of the cigarette deck. This was not uniform, however, for twin 37mm gun mounts have been observed on some vessels at the shipyard.

With the guns were provided the usual pressure proof stowage for spare barrels, ready service lockers and dip pots.

Pipe guards limit the depression angle at which the guns can be fired.

Scott