Titanic's Prime Mover and very much essential Power

Titanic’s plant was to extract stored energy from coal and convert that energy into useful work used to move the ship, power equipment, heat and light living spaces. For propelling the ship, the heat energy released from the burning of coal in the ship’s boilers was transferred into steam which was then sent to the ship’s engines where it was converted into mechanical work turning the ship’s propellers. High pressure saturated steam (red) from the boilers at 215 pounds-per-square-inch gauge pressure (psig) at 394° F is fed to the high-pressure (HP) cylinder on each reciprocating engine.

Turbine the steam is further expanded down to 1 psia at 102° . During maneuvering operations or when going astern and would be redirected by the changeover valves to exhaust directly into the two main condensers. Meanwhile, exhaust steam at 5 psia from the four steam engines that ran the ship’s electric dynamos was passed through the shell and around the tubes of this surface heater where it was condensed by the cooler feedwater flowing inside the tubes.