tipple
An apparatus for unloading railroad freight cars by tipping them; the place where this is done.
tipple: where gravity empties a railroad car
A tipple is a fixed installation that tips an entire railroad car on its side to discharge bulk cargo, most commonly coal but also ore, grain, or other free-flowing materials. The car sits on a pivoting frame or rides on specially designed rails that allow it to rotate around a longitudinal axis. As the car tips, gravity does the work: the contents slide out through the open side or bottom into a hopper, conveyor, or receiving bin below.
The mechanism itself is usually powered by a hydraulic cylinder or, in older installations, a steam or electric winch. A typical coal tipple might handle cars in the 70 to 130-ton range, rotating them 45 to 90 degrees depending on the cargo density and flow characteristics. The car tips, the load discharges in minutes, and the empty car is returned upright and sent back up the line. This is far faster and less labor-intensive than manual unloading or using grab cranes.
A stationary tipple occupies a fixed position in the rail yard and the loaded car is pulled into it. A portable or mobile tipple can be moved along a siding to different discharge points. The receiving hopper beneath the tipple may feed directly to a conveyor system, a bunker, or a processing plant. Some installations include a rotary car dumper, which uses a rotating drum rather than a simple tip frame, and allows for finer control over discharge rate.
The biggest wear points are the hinge pins and bearings that support the rotating frame, and the guide rails if misalignment is allowed to develop. Abrasive loads like coal dust work into joints and accelerate friction. Hydraulic seals fail if the pressure swings too wide or if dirt gets into the fluid. Weather matters too: ice or wet coal can stick to the car interior, so some tipples include impact hammers or vibrators to break the load free.
The term tipple comes directly from the verb to tip, meaning to tilt or turn over. The word has been in use for railroad coal discharge since at least the late 1800s. In modern mining and rail transport, tipple is the standard term across English-speaking industries, though the technology varies widely in scale and sophistication from small rural grain tipples to massive high-capacity coal tipples serving power stations or export terminals.