A 'Butterley Patent' wagon body, which is unusually mounted on a wooden underframe. Production wagons had steel underframes. This may be a temporary pairing for the photograph, or a short trial of the steel body on an underframe that would later have a wooden body fitted. The body appears to be black, whereas the wooden parts of the underframe are grey or red, which indicates that the body and underframe are not intended to run as 'one' - wooden underframes almost invariably were the same colour as the body.