AT THE HEART OF THE ROAD TRANSPORT INDUSTRY.

Call our Sales Team on 0208 912 2120

A New Oil-engined

2nd June 1931, Page 55
2nd June 1931
Page 55
Page 55, 2nd June 1931 — A New Oil-engined
Close
Noticed an error?
If you've noticed an error in this article please click here to report it so we can fix it.

Which of the following most accurately describes the problem?

Industrial Tractor

A Single-cylinder Machine of 30 b.h.p. Cold Starting and Simple Control

IN our issue dated June 3rd, 1939, we described the Marshall oil-engined agricultural tractor. The maker, Marshall, Sous and Co., Ltd., Britannia Iron Works, Gainsborough, has recently brought out a modified version for industrial haulage duties. On a 15 per cent, gradient it will haul 4-i tons, on a 7-i per cent. gradient 9 tons and on a 3 per cent, gradient 15 tons. Its own weight is 3 tons 10 cwt.

The single-cylindered engine is placed horizontally and has few working parts owing to the adoption of the two-stroke cycle ; it starts from cold, no heater plugs, starting lamp or hot bulb being employed. The cylinder has a bore of 8 ins. and a stroke of 10i ins. The running speed is . 550 r.p.m. and the maximum power at the belt is 30 b.h.p., 27 b.h.p. being the normal output ; an adjustable governor regulates the various speeds.

Points in the engine construction are a detachable cylinder barrel, automatic forced-feed lubrication, air and fuel filters, and there are a fan and pump to aid the radiator. The fuel-consumption rate is said to be about .48 lb. per b.h.p.-hour.

Three castings house the transmission details: the cone clutch is carried in

the engine bed, whilst the change-speed gears and their operating mechanism occupy the centre one. The third casing contains the differential and final drive to semi-floating shafts. The three forward ratios give road speeds of 3 m.p.h., 5.25 m.p.h. and 8.75 m.p.h., whilst reverse gives 3.75 m.p.h.

Driving effort is taken through the twin-tyred (solid) rear wheels, which have a diameter of 3 ft. -6 ins, and a width of m ins. The front wheels are of 2 ft. 4 ins, diameter and 5+ ins. wide. The front axle is of I-section steel and is equipped with a transverse semi-elliptic spring which insulates the front end of the machine. Worm-andsector steering is employed; to the right of the steering wheel are brake and gear levers.

Both brakes take effect upon the rear wheels of the tractor, one being foot controlled and the other by hand. Above the engine is a 12-gallon fuel tank, whilst the fan, belt pulley and other moving parts are fully shielded. At the rear is a platform on which two men can stand ; to safeguard them there are substantial shields over the two driving wheels. The driver occupies a sprung seat.

In order to prevent "snatch" between the tractor and trailer a spring drawbar is provided ; stationary plant can be driven by belt from a 26i-in. by 7-in, pulley, which runs at 550 r.p.m. and delivers the full engine power, there being no gearing interposed. At, extra cost electric lighting can be supplied, also a canopy for the driver and cleats for the driving wheels. The wheelbase of this model is 6 ft. 1 in., the overall length is 10 ft. and the overall width 5 ft. 9 ins. It will turn in a circle of 26 ft. diameter and has a ground clearance of 9 ins.

As this tractor is intended for use Upon the highway a silencer has been installed ; this is slung below the frame so that the exhaust system does not cause any obstruction to the driver's vision. The principal points of difference between the new machine and its agricultural prototype lie in the wheel equipment, final-drive ratio, exhaust layout, front springing, driving seat, etc.

The Marshall tractor is, of course, the product of a famous British concern which has a very wide experience in engineering. This new model should meet the needs of many ; it is capable of hauling trailers at maximum, legal speeds.

Tags


comments powered by Disqus