Bunk Racks
The sleeping quarters on a submarine are often referred to as bunk racks.
Submariners typically sleep in narrow bunks that are arranged in rows, with each bunk having a small space for personal belongings. The bunks are designed to be space-efficient, so they are usually stacked on top of each other in multiple tiers, with a ladder or stairs providing access to the upper bunks. Because of the limited space, submariners often have to sleep in shifts, with some crew members resting while others are on duty.