You are standing between the two boilers that generate steam to move the vessel and run auxiliary machinery. As you tun around the compartment the blower gauge board both boilers and the steam powered fuel oil pumps can be seen.
The water in the boiler steam tubes is super-heated to 700 degrees, and is fed to the high-speed turbine. As the steam expands and loses energy, it is fed to a low-speed turbine, for greater efficiency. The steam is then condensed and sent back through the system to be re-used.
The combustion chamber uses a heavy (bunker) oil as fuel, which is so thick that it cannot flow at room temperature. It is therefore kept at 100 degrees in the storage tanks, built into the hull. It must be heated again to 180 degrees to burn efficiently. While underway, steam from the boilers is run through piping in the fuel tanks to keep the bunker oil fluid. When firing a dead cold engine, an auxiliary diesel unit must be used to "prime" the system.
