Used for the playback of long playing records, this unit rotates records at a constant speed so that an attached phono cartridge can extract a musical signal. Must be used with a tonearm and cartridge to comprise a complete playback system.
A section of track, typically 40 - 60ft long, mounted on girders with a central pivot, which could be rotated to enable a locomotive to be turned end-for-end. Until BR days most turntables were pushed around by man-power. They were provided at engine sheds and also at major terminals. Smaller turntables about 12ft diameter were often used to turn goods wagons in goods depots, or to move them through 90 degrees to another track. The existence of these turntables (and other archaic fixed installations) prevented the development of larger and more efficient goods wagons.
In rail terminology, a turntable is a device used to turn railroad rolling stock. When steam locomotives were still in wide use, the railroads needed a way to turn the locomotives around for return trips as their controls were not configured for extended periods of running in reverse and in many locomotives the top speed was lower in reverse motion. Turntables were also used to turn observation cars so that their windowed lounge ends could be oriented toward the rear of the train.
An INFO file containing the turn impedances between pairs of network links. There can be sixteen possible turn impedances between four network links meeting at a node (i.e., left, right, straight, and U-turn for each of the four network links).