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.