1972 There are about 11,444 miles of railway routes in Britain.
1973 ASLEF members join a one-day General Strike on 1 May to protest against pay and conditions. Almost all of Britain's rail services are disrupted.
1975 The first commercial Intercity 125 high speed train route runs between London and Bristol.
The 125 is the fastest diesel engine in the world and is introduced to compete with motorways. The average speed of diesel trains is increased from 60mph to 125mph.
One Intercity 125 reaches a top speed of 143mph in testing in 1972, which is bettered by a record speed of 148mph in 1987.
In February a tube train fails to stop and crashes through buffers and into the wall of the dead-end tunnel on the Northern Line at Moorgate Station, killing 43 people and injuring 74.
The driver dies in the crash and the cause is never determined, but investigators find that the brakes were never applied.