The basic construction of a submarine consists of the pressure hull, the tanks that are built around the pressure hull, and the superstructure. The pressure hull, which includes the conning tower, is the principle part. This hull must be watertight and airtight and able to resist the water pressure when submerged. The hull is circular for maximum strength and is reinforced by steel frames over its entire length.
Watertight bulkheads with watertight doors subdivide the hull into separate compartments.
These compartments contain all the machinery, equipment and furnishings necessary to operate the submarine. Let’s see what each compartment is used for.