The removal of Locking on a function, for example, the removal of RouteThe path along a section of track between one Signal and the next, along which an authorised movement is to be made. More
Locking or the unlocking of a function such as a Ground FrameA control point containing levers or switches to permit the local operation of Points in Running Lines, Sidings and, where provided, the associated Signals. Thi... More.