The impression of the engine room can almost not be conveyed by words. The machinery (and virtually every inch is taken up by machinery, piping, etc.) is a combination of strict functionalism and artistry. There are two engine rooms, each containing one engine. Each engine is a triple expansion engine, about 29 feet in length and close to 20 feet tall. In addition, the space includes a condenser, major steam lines, and smaller auxiliary equipment. On the main engines, the piston heads are surrounded on the sides by a layer of tongue and groove stained wood as are the major steam lines.The largest of the engine's three pistons is 92 inches in diameter! One of the triple expansion engines was capable of generating nearly 9,000 horsepower. The British had claimed that the OLYMPIA was over-engined, but this never seemed to be the case.
The connecting rods leading from the pistons to the propeller shaft, which runs through the space, are open, and of mammoth size, as can be seen in the image at left. The photo shows the piston rod as it attaches to the shaft. The size can be judged by the sailor's hand in the photo. The rods and other moving parts had to be oiled and maintained as much as possible while they were moving!
Working in the engine room, when it was in operation, must have been a challenge...and a real safety hazard! Live steam would leak into the space, and boiling water would drop from the pipelines overhead onto the men. Smoke from lubricating oil would also fill the air (depending on how much oil was used on any given watch). The noise of the engines was tremendous when the ship was moving at battle speed of 21 knots, and making close to 140 revolutions per minute. In action, the men could only make themselves heard to one another by yelling. Of course, the men serving in areas such as the engine room had little knowledge of what was going on topside during a battle. They had to hope, pray, and rely on the sparse information that was given to them.
The shaft itself passes through the space. Near the aft end of the
engine room, the propeller passes through the thrust bearing. The thrust
bearing is what transfers the thrust of the propellers on the hull of
the ship.