Introduction to Marine Engineering

An engine flywheel is a heavy, rotating disc attached to one end of the engine’s crankshaft. It serves three purposes. First, its inertia stores rotational energy, which smooths out the engine’s power delivery and reduces vibration as each cylinder fires. Second, it is the mounting surface used to bolt the engine up to its load. Third, on some diesels, the flywheel has gear teeth around its perimeter that allows the starting motor to engage and crank the diesel.