The Bristol and Exeter Railway Fairfield was an experimental broad gauge self-propelled steam carriage.

The steam carriage was built to the design of William Bridges Adams at Fairfield Works in Bow, London.

It was tested on the West London Railway late in 1848, although it was early in 1850 before modifications had been made that allowed Adams to demonstrate that it was working to the agreed standards.

The design was not perpetuated by the Bristol and Exeter Railway, instead they purchased small 2-2-2T locomotives for working their branch lines.

It was revived around the turn of the century and the Great Western Railway built up a fleet of around 100 bogie rail motors.