BBC News

The trains that saved soldiers in WW1

The mass casualties of World War One called for evacuation of the wounded on a scale never seen before. It could never have been managed without ambulance trains.

York's National Railway Museum is currently transforming a railway carriage of the time into an ambulance, ahead of an exhibition in summer 2016 marking the centenary of the busiest day of ambulance train traffic - during the Battle of the Somme.

Watch how moving these mobile hospitals - up to a third of a mile long - saved soldiers' lives.

Photofilm production by Paul Kerley. All images subject to copyright.

Images courtesy National Railway Museum and Getty Images.

Music by Kevin Coyne and EMI Production Music.