The ISOTTA FRASCHINI Sulzer S20U is a new generation of four-stroke mediumspeed diesel engines specifically designed for reliable, continuous operation in heavy-duty marine propulsion and auxiliary applications. Available with six to nine cylinders in line, they cover a power range of 960 - 1575 kW ( 1308 - 2142 bhp ) at speeds of 900 and 1000 rev/min.