The Ruston patent 3-speed gearbox

The Ruston patent constant mesh gearbox was used in all chain drive narrow gauge designs until the hydraulically activated and hydrostatic gearboxes took over with the LB and LF designs respectively. This unit made the driving of Ruston locos very easy since the clutch and gear change were combined in one lever operation and enabled the driver to operate the loco whilst walking alongside. This was a great advantage over types such as Motor Rail locos when shunting and negotiating complicated trackwork where points have to be set along the route. CLICK HERE for notes explain how it works.

Below is an extract from the R&H parts book for early Ruston engined locos and shows the gearbox casing parts.

	Part No.	Description
	DL170	Gearbox top & bottom halves with nuts & studs
	DL171	Housing for sprocket shaft bearings
	DL172	Seat for driver
	DL173	Reversing gear casing - bottom half
	DL174	Bevel pinion shaft housing
	DL175	Seat support
	DL176	Reversing gear casing - top half
	DL177	Rear end cover
	DL178	Cover for end of layshaft
	DL179	Bolt & nut for seat
	DL180	Cover for top half of reversing gear casing
	DL181	Cover for clutch operating spring