Training team 45-mm naval universal artillery gun 21-K on the Soviet M-172 submarine of the Northern Navy of the USSR.
In the photo, from left to right, you can see: a projectile carrier, a loader, a crew commander and a gunner.
The photo is supposedly taken at the training ground.
Source of submarine M-172 photo information:
- museum-polar.narod.ru
Location: USSR
Date: 1942