The Coaling Station. The operating expense for a steam locomotive is much greater then for diesel or electric locomotives. Taking on coal and water, sanding, firing up, lubricating, removing ashes and slag, turning in the direction of travel - the infrastructure for these tasks is concentrated in the railroad maintenance facility. Coal is delivered to the coaling station, unloaded, stored, and loaded into the locomotive tender. Depending on the number and size of the locomotives to be serviced, standard designs define the type and features of the coaling station. An ingenious coal management system is required at larger coaling stations. Depending on the locomotives being used, coal of different quality and in different sizes must be made available. The coaling procedure should take place as quickly as possible; the standard design tenders take up to 10 metric tons. Large coaling stations therefore have elevated bunkers or weighing bunkers. These are for fuel storage and are mounted over the tracks. They are loaded with the appropriate coal mixture and empty their fuel directly into the tender of the locomotive waiting underneath. The loading platform for a rotary crane with a clamshell bucket runs parallel to the tracks. It loads the coal from the freight cars into a large bunker, and it loads the weighing bunkers from this supply. The number of weighing bunkers and the capacity of the large bunker depends on the demand. In our prototype there are 4 weighing bunkers, each holding 20 metric tons of coal.