"Titfield thunderbolt" was filmed on the disused GWR Branch line between Limpley stoke and Camerton, near Bath. Titfield station itself was actually Monkton coombe, whilst "Mallingford" was Bristol Temple meads.
Many of the filming locations can still be seen today, the landscape in the area having changed very little over the years. The track bed and the Bridges/viaducts in the film are still there.
It is the Eton Boating Song, also known as "Blade on the Feather."
