The portable pump set comprises a 2 speed 3 phase motor driving the pump wia a helical reducer from Bockwoldt. This is an interesting application of what is termed a shaft mount transmission. In this case the "shaft mount" achieves a compact design and renders the pump part readily accessible, by raising its height. Shaft mount geared motors and speed reducers from Bockwoldt range from 120watt to 55kw. Output speed as low as .5rpm are available and overload protection and backstop control can be incorporated.