Turntables are used to turn railway locomotives around so that they do not need to run backwards for significant distances. This is especially important for mainline steam locomotives as these were not designed to run 'backwards' at speed or for long periods of time.
There are no intact turntables within the SCRCA. However, there are some surviving turntable pits and the latter have been classified as 'turntables' for the purposes of the SCRCA Project.