Kinnerley and Glaslyn both worked at Blockleys Ltd, Hadley, Telford, before coming to the WHR. Both are type 40DL, although Kinnerley retains a Ruston 3VRH engine rather than the Perkins 6.354 which Glaslyn has.
Kinnerley's transmission is still the standard Ruston gearbox, without any fluid flywheel or other additions. One of the selling points of the Ruston was that it has clutches inside the gearbox, and all gears constantly in mesh. Gear change is accomplished by means of a lever which engages one of the clutches, thus causing a particular combination of gears to be placed in the drive train. In industrial use this meant that the locomotive could be driven by a person standing or walking alongside the vehicle.
For use on the WHR it has been fitted with air brakes (powered by a compressor added at the side of the engine) and a cab. Some years after entering service a starter motor was fitted. Because there is no drive facility, however, there is no means of charging the battery other than through an external socket from a charger when the locomotive is in use.
Kinnerley is now used as a mobile air compressor for visiting steam locos.