Crosshead Engine

an internal-combustion engine, usually a diesel, in which the connecting rod and the piston are joined by a crosshead (slide block). During operation, the cross-head transmits a longitudinal force (with respect to the piston stroke) to the connecting rod and a transverse force to the guides, thereby relieving the piston from perpendicular loads, which in turn reduces cylinder wear.

Crosshead engines may be of the two-stroke or four-stroke, air-injection or airless-injection types, and they may have up to 12 cylinders. The rated power of a crosshead engine is about 2.2 MW (3,000 hp), the speed of rotation is 100–250 rpm, and the cylinder diameter is at least 600 mm. All crosshead engines are made with uniflow scavenging. Because of their considerable weight and several special features, crosshead engines are used in transportation only on ships.