In 1912, the company turned its attention to "rail-less traction" and set a bill before Parliament to authorise five trolleybus routes. These were to run from an interchange with the tramway near the Woodman Inn at Swinton north-westwards to Wath-upon-Dearne; westwards from Wath to West Melton; northwards from Wath to Goldthorpe; from the Denaby tram terminus eastwards to Conisbrough; and from Mexborough westwards to Manvers Main. At the time, local councils were considering constructing their own tramway or trolleybus system, and so opposed the scheme. When the Mexborough & Swinton Tramways Railless Electric Traction Act (1913) received the Royal assent, it only included authority to build the last two of the five routes. Construction began, and both routes opened on 31 August 1915, although they were physically isolated from each other. The three single-deck vehicles obtained for the opening and a few trams were stored in a new depot at Old Toll Bar, but there were only tram wires from the depot to the start of the Manvers Main route at Mexborough. The trolleybuses reached there with one trolley boom on the overhead wire and a skate running along the tram tracks to complete the circuit. They also used this method to reach the main depot at Rawmarsh, when they were in need of maintenance.