This is a Hornby locomotive using a modern Meccano 6 volt motor driving a worm gear that drives a 60 tooth gear that in turn drives a 25 tooth (fixed at an angle) pinion driving no. 20 flanged wheels. The toothed portion of the pinion has been cut in half so that it will fit into the flanged wheels for O gauge. The body is that of Hornby locomotive whose clockwork motor has been removed. I could not use the original hornby wheels. The battery is placed in the tender. I had cut the front portion of the modern 6 volt meccano motor so that it would fit the engine.