on the rail system, to shuttle them out of containment. In wind turbine generators, trunnions are used as two of three or more mounting points for the gearbox (transferring power from the rotor to the generator) which allows for limited movement due to torque variations and an accessible way to remote and service the drive-train . Trunnion bearings In mechanical engineering, it is one part of a rotating joint where a shaft (the trunnion) is inserted into (and turns inside) a full or partial cylinder. Often used in opposing pairs, this joint allows tight tolerances and strength from a large surface contact area between the trunnion and the cylinder. In airframe engineering, these are self-contained concentric bearings that are designed to offer fluid movement in a critical area of the steering. The term is also used to describe the wheel that a rotating cylinder runs on. For example, a lapidary (stone-polishing) cylinder runs on a pair of rollers, similar to trunnions. The sugar industry uses rotating cylinders up to in diameter, long, and weighing around 1,000 tons. These rotate at around 30 revolutions per hour. They are supported on a pathring, which runs on trunnions. Similar devices called rotary kilns are used in cement manufacturing. In mining, some refining plants utilise drum scrubbers in the process that are supported by a large trunnion and associated trunnion bearings at each end. See also Gimbal References Hardware (mechanical) Mechanisms (engineering) Bridge components Artillery components