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