Check out this film, detailing how the BedPan line was modernised in the late 1970's-early 1980's. This is the line that serves Mill Hill, Hendon, Cricklewood and West Hampstead. It is fascinating to see the attitude to health and safety. Navvies working in bare chests, no protective helmets, balancing ladders precariously on wires etc, as trains thunder by. There is some nice footage of Cricklewood, Hendon and West Hampstead. A great piece of local industrial history.
Hat tip to https://twitter.com/BSACCRP and https://twitter.com/13milepost for the tip