High Quality Content by WIKIPEDIA articles! The NRE 1GS7B is a low-emissions diesel switcher locomotive built by National Railway Equipment. It is powered by a single Cummins QSK19C I6 engine which develops a total power output of 700 horsepower (522 kW). There have been seven 1GS7B locomotives produced to date, all manufactured at NREC`s Mount Vernon shops in Southern Illinois. It`s also the only current single-engine switcher marketed in NRE`s N-ViroMotive catalog.