The London North Western Railway works at Crewe built 132 or more of these odd vehicles for use by the Allied armies during the First World War. Based on the ubiquitous Ford Model T car they could be driven on road and then converted to run on narrow gauge railways. The idea is credited to Miss Cooke, daughter of Mr Bowen-Cooke, the Chief Mechanical Engineer of the London North Western Railway. Miss Cooke met a British Officer in Paris who told her of the difficulties in getting men and supplies to and from the trenches on the Western Front. Her idea was for a vehicle that could speed over made roads to where it was needed and then be put on railway wheels to run on the 2ft gauge tracks that ran over rough ground to the trenches. The LNWR developed the idea, using the Ford Model T bolted to a pressed steel railway chassis and driving four railway wheels through chains and sprockets. In road going form the Ford could carry its own dismantled railway chassis and wheels. These tractors were used mostly on trench tramways which linked the trench systems to light railway railheads. On test at Crewe railway works they could pull 5 tons up a 1 in 20 gradient though on the rough track of trench tramways the haulage capacity could be much less.