Abstract: An extendable safety rail for locomotives wherein a set of parallel bars is secured horizontally by the ends to vertical posts adaptable for vertical movement inside suitably sized sleeves mounted on the locomotive sides so as to safeguard men working on a locomotive top when the safety rail is in an upward position. When no work is being done the safety rail is lowered onto rubber cushions by the posts sliding into the mating sleeves to insure sufficient underpass clearing when the locomotive is enroute in regular service. The safety rail includes a centrally spaced support rod hinged to a lower horizontal bar for temporarily holding the guard upwards until the ends thereof are secured by appropriate pins at each vertical post, such that one man can extend the guard.