WWI 16 Coach Ambulance Train 

Pulled by a Midland Compound then a ROD 2-8-0
WD Specification:
French Grey top panels. Khaki on lower panels and fascias, latter being picked out with yellow and fine-lined with red. Two Geneva crosses on each side of each coach with the Royal Arms emblazoned on one of the French Grey panels. "War Department Ambulance Coach" was painted on the lower portion of the coach side.
The first ambulance trains were made up of French stock. However ATs started to be produced in the UK and were initially 10-12 coaches before the full 16. The US ordered all of their trains on the British specification and were also build in the UK. The public paid for most of them through donations.
AT40 was built in Derby.