The 50th anniversary of London Underground’s Bakerloo line trains

Sunday marks the 50th anniversary of the Bakerloo line trains on the London Underground. Introduced on 26th June 1972, they’re also now the oldest electric multiple units (EMU) in use anywhere in the UK.The trains have a bit of a complicated history — because this is the London Underground and nothing is ever simple. And the Bakerloo line trains owe their existence to, of all things, the extension of the Piccadilly line to Heathrow Airport in the 1970s.
In the early 1970s, both the N