Excavator [Ruston R-4]

Ruston-Hornsby Limited, Manufacturer

See full details


Maker and Role
Ruston-Hornsby Limited, Manufacturer
Production Date
Ruston R-4 Navvy Excavator, green cab with white, curved overhead roof. The Excavator is powered by a 4-cylinder, petrol driven Dorman engine, generating 32 HP @ 1,000 RPM. The 24" bucket at the end of the boom is controlled by a 20 mm diameter cable operated system. A long beam protrudes out the front with a shovel that acts as a digger as well as an excavator. The whole unit runs on caterpillar tracks and is capable of swivelling 360º to perform its various tasks. No.1 painted on the side of the cab. The navvy bucket is of heavy all mild steel construction, made up of steel plates, channels and angles. 3 mild steel teeth with double shear steel digging points are fitted on the outside. The bucket hinges and doors are of very strong construction.
The bottom frame is of steel construction with British section beams securely cleated together at the ends and braced by heavy corner gusset plates on the top flanges.
The tracks are of all steel construction and consist of a number of steel castings each of which forms a combined link and track pad. These castings, known as track links, are each of sufficient strength to carry the maximum wheel load. The links are connected together by 3% nickel steel pins thus forming 2 endless bands, each driven at one end by a heavy steel sprocket wheel, the intermediate links being supported on each side by 2 large diameter cast steel idler wheels carried on 2 "H" section cast steel axles, running under, and bolted to the bottom frame. Both tracks can be driven in either a forward or backward direction; and for steering, either track can be locked stationary by means of jaw clutches. The large bearing surface of the track links enables roads to be traversed without damage to the road surface.
The travelling power is transmitted from the engine through reversing dry plate clutches, friction fibre lined, and by machine-cut cast steel spur gears to the centre post shaft; thence from the bottom of the centre post shaft by machine-cut cast steel bevel wheels to a transverse shaft directly over the back axle. This transverse shaft is fitted at either end with double-ended jaw clutches which can either lock the caterpillar stationary or engage it at travelling speed. The final drive to the back axle is by machine-cut cast steel spur wheels.
The whole of the gearing on the bottom frame is totally enclosed. The machine is fitted with 2-speed travelling gear, giving slow speed for working conditions and high speed for road travelling.
Other Name
Shovel - Mechanical
Processed Material/Metal/Alloy/Steel
Processed Material/Metal
Signature/Marks and Type
W. Stevenson & Sons Ltd. Contractors No.1 Painted
Accession No
Credit Line
Ruston-Hornsby Limited. 1927. Excavator [Ruston R-4], 1964.221. The Museum of Transport and Technology (MOTAT).

The development of MOTAT's online platform is a continual process. Records are updated regularly, with new information and images. There may be mistakes or omissions in the information provided and we welcome input from the public.

Related Objects

 Do you know something about this object? Contact us or comment below.

Be the first to comment.