Hydraulic catpult cables
The cables behind the red posts were connected on end to the large horizontal brass cylinder containing a piston, and to an aircraft up on the flight deck on the other end. When the pressure was released in the brass cylinder, it pulled the cables with tremendous force, flinging the aircraft along the flight deck and into the air at a high initial speed. Aircraft carrier USS Hornet Museum.
Hydraulic fluid containers
The hydraulic fluid was pressurized in these steel domed cylinders before being sequentially released into the horizontal brass cylinder. Note the labeling of the domed cylinders as containing various alcoholic beverages (Rum, Vodka, etc), one of the few sanctioned cases of humor on board ship. Aircraft carrier USS Hornet Museum.