This is just one of four power plants that helped give the ship its' speed. Two sets of turbines sit at the bottom of each engine room hatch (there are two) about 120 ft below the base of each funnel. We have cold air being drawn or forced (I don't know yet) into the engine room through ducts that line the hatch. This ocean air is in the 50s so things are kept fairly reasonable in the engine room. The exhaust air travels up the open space in the center of the shaft. I made this sketch from lots of different pieces to see how it all fits together.