Glenfinnan lost its semaphore signals on 13 April 1986, in preparation for Radio Electronic Token Block (RETB) signalling. RETB was commissioned between Mallaig Junction (now Fort William Junction) and Mallaig on 6 December 1987.
Glenfinnan's semaphore signals were replaced by RETB signaling on April 13, 1986, to facilitate the implementation of a new signaling system between Mallaig Junction and Mallaig.