Rack steam railcar Bhm No 9 Pilatus Railway PB 1889 The Pilatus railway is the steepest rack railway in the world. In addition to a special rack system, it required other technical innovations. It was for example the first railway in Switzerland to only use steam railcars and saturated steam. This made it possible to save a lot of coal and thus weight. The boiler, which was fitted sideways to the running direction avoided dangerous, gradient dependant variations of the water level. Number 9 was in regular operation until 1937. SLM system Locher gradient 480 %o 77 kW 4,5 km/h narrow-gauge 800 mm restoration by PB