Rudyard Lady is a Bo-Bo type diesel engined locomotive. It has a Perkins 3 cylinder diesel engine linked by a four speed gearbox to the wheels. The clutch uses standard car parts and drive to the rear bogie wheels is by chain.

The engine is probably the largest diesel locomotive on this gauge of track with seats for two and space for 3 in the cab. Built by a local engineer Mr. L.A.Smith from Leek in 1989. It has a generator providing 3KW power at both 110 & 220 volts. Its on board air compressor can power air tool as well. Its therefore ideal for track work. Now used mainly for works trains it was originally often used on passenger trains. It was overhauled and repainted in 2007 and emerged in the yellow livery in 2008.

Originally fitted with a single pipe skid type air brake it now has the standard two pipe system with a brake cylinder applying the brakes to the front bogie. Rudyard Lady is a frequent sight at both the steam and diesel galas. It was repainted in a version of its original livery in 2019 and has undergone various maintenance since then.