double-ended and 4 single-ended Scotch boilers at 215  psi . Two four-cylinder triple-expansion reciprocating engines each producing 15,000  hp (12 MW) at a speed of 75 rpm for two outboard wing propellers. One low-pressure (about 7 psi absolute) steam turbine producing 16,000 hp (13.5 MW) for the centre propeller at 165 rpm. Total 46,000 hp at