 They were part of the second order received by Brush for trolleybuses, consisting of six for Phondda and three for Mexborough.Both were subsidiary companies of National Electric Construction Co, and both wanted to run the trolleybuses along sections of tramway, with a skate running along the tram tracks, which posed a problem for Brush, as the patent for under-running trolleys was held by RET Construction Co. Their first order had been for Stockport, which was the only British installation to use the Lloyd-Kohler method of current collection, consisting of two wires arranged vertically and suspended from ornate brackets, which Stockport's Tramway manager had seen in Bremen.A trolley ran along the top wire, and was connected to the vehicle by a flexible cable.