Below the deck in the Control Room is the Pump Room. This space contains the pumps and motors for shifting water in the submarine or pumping it overboard. This "trim system" provides a means for adjusting Cod's overall buoyancy and her fore and aft balance. Also located here are pumps for moving oil and two air compressors which provide the high-pressure air needed for surfacing and running the boat. These are quite large and provide air at a pressure of 3000 psi (pounds per square inch) to banks of large air bottles (or flasks) located outside the pressure hull within the ballast tanks.
High-volume, low-pressure blowers located in this space are used to force the last of the water from the ballast tanks when surfacing so as to conserve high-pressure air.
Also located here are the refrigeration compressors that are a part of the food storage and humidity control systems aboard the submarine. Also located in this space is the hydraulic IMO pump and accumulator that provides high-capacity hydraulic power for raising and lowering the periscopes and radar mast, moving the ship's rudder and bow and stern planes, and operating a number of valves and other hydraulic systems.