Neil-117 is quite correct, the film makers were given permission by the Southern Railway to smash an old locomotive and carriages into a lorry on a disused branch line, hence the spectacular train crash.
I think his other comments are a little unfair. The film is taken from a play called 'The Wrecker' by Arnold Ridley (who also wrote 'The Ghost Train' and later became Private Godfrey in 'Dad's Army'). The whole point of the plot is that a serial murderer is staging train crashes to disguise his crimes.
Of course the film is dated but it's good, well-paced entertainment. If you enjoy Hitchcock's British thrillers (especially 'The Lady Vanishes', also a Launder and Gilliatt screenplay) you'll like this one.
I think his other comments are a little unfair. The film is taken from a play called 'The Wrecker' by Arnold Ridley (who also wrote 'The Ghost Train' and later became Private Godfrey in 'Dad's Army'). The whole point of the plot is that a serial murderer is staging train crashes to disguise his crimes.
Of course the film is dated but it's good, well-paced entertainment. If you enjoy Hitchcock's British thrillers (especially 'The Lady Vanishes', also a Launder and Gilliatt screenplay) you'll like this one.