These locomotives were built for the Ministry of Munitions by the Motor Rail and Tramcar Company of Bedford, England. Designed for the use of the War Department Light Railways just behind the front-line in France, they were built with varying degrees of protection for the driver, to protect him from bullets and shrapnel. This led to there being three types:

Open	Photo: Brian Budd	The open model carried armour plated ends, with open sides and a light canopy roof
Protected	Photo: Brian Budd	The protected model added side armour-plated doors, visors and a roof mounted on screw pillars that could be adjusted up or down as required
Armoured	Photo: Gareth Roberts	This model carried full armour plating giving it the appearance of a rail-based tank!

The power unit for all three variants was a Dorman 4JO petrol engine coupled to a Motor Rail patent two speed Dixon-Abbot gearbox.

A number of the later-build models did not make it to France, the furthest they reached was a Ministry supply depot in Purfleet. These locomotives were sold on, and some were re-constructed following the war.

Further technical and historical details can be found in the book A Guide to Simplex Narrow Gauge Locomotives (which has been out of print but is due to be re-issued around the beginning of April 2005) and its companion website.