Motor Rail was a British locomotive-building company, based in Bedford. Formed in 1911 as The Motor Rail & Tramcar Co Ltd, they built petrol- and diesel-engined locomotives, mainly narrow gauge. During World War I over 900 locos were supplied for use on temporary military supply railways. The trade name Simplex was used from the early days; in 1972 the company was renamed Simplex Mechanical Handling Ltd.
In 1987 loco manufacture ceased, business being transferred to Alan Keef Ltd of Ross-on-Wye, who continue to provide spares and have built several locos to Motor Rail designs.
Many Motor Rail products survive in preservation, and they are probably the most common make of narrow gauge locomotive still in existence in the United Kingdom.
Heritage railways with Motor Rail locomotives include:
- Amberley Museum Railway
- East Lancashire Railway
- The Battlefield Line Railway
- Corris Railway
- Ffestiniog Railway
- Golden Valley Light Railway
- Leighton Buzzard Railway
- Moseley Railway Trust
- Nottingham Transport Heritage Centre
- Welsh Highland Railway
- West Lancashire Light Railway
- Almond Valley Light Railway
- Leadhills and Wanlockhead Railway
- Volk's Electric Railway
- Wicksteed Park, Kettering, Northamptonshire
- Hall, D.R. and Rowlands J.A.S. (2001). A Guide to Simplex Narrow Gauge Locomotives. Moseley Railway Trust. ISBN 0-9540878-0-1.