a common unit of power, the rate at which work is done. The power of cars and other motors of engine-driven vehicles, including container ships, is often measured in brake horsepower.

When referring to the power of an engine, brake horsepower is the power output of the engine.

A measurement of the actual usable power (not calculated power) measured at the output shaft (usually the crankshaft) rather than at the driveshaft or the wheels. Thus none of the auxiliaries (gearbox [..]

The horsepower required at the top or end of a pump shaft (input to a pump). The energy provided by a motor or other power source.

See Horsepower, Brake

The horsepower needed at a compressor’s input shaft for proper performance.

the power available at the shaft of an engine after minusing the frictional losses in the running component of the engine but before passing through reduction gears or other transmission devices; for direct-connected diesel engine this power is same as shaft horsepower; this is measured using a brake which gives the name; bhp for short