The first of a batch of 6 Garrett trolleybuses was delivered to Mexborough & Swinton in June 1927 and were given fleet number 34-39. A further 24 Garrett trolleybuses arrived between 1928 and 1930.
34 to 39 entered service in early 1928 when the section of tramway between Mexborough (Montague Arms) and Denaby was converted to trolleybus operation.
34 survived in service until the end of the second world war whereupon she was pensioned off and became a hay store on a farm. This single-decker was found back in 1974 by enthusiasts who bought it from the owner. 34 was towed the short distance to Sandtoft and is regarded as a major restoration project which will involve substantial rebuilding of the bodywork when funds and time permit.