A TRACTOR-TRAILER . FOR FRUIT TRANSPORT.
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A Combination of Well-known Names in a Tractor-trailer Outfit on Pneumatic Tyres for 4-ton Loads.
IN our issue dated April 17th our correspondent " S.T.R.," who specializes in haulage problems, went thoroughly into the question of the cost of operating lorries in the transport of fine agricultural produce, such as strawberries and peas, to Covent Garden Market. He therein discussed the various types of vehicle which could be used for the work, showed the difference in costs for the different kinds of produce, set out a scale of charges, and thus arrived at the profit that the haulier might expect from his -week's work.
• Our contributor devoted his attention in the main to the pneumatic-tyred tractor and trailer, holding that for delicate produce such as strawberries, and, in fact, any soft fruit, the pneumatic tyre -vas an essential part of the equipment. The publication of the article has brought to light the fact that a six-wheeler has been developed by Taskers, of Andover Ltd., for the forthcoming season's traffic in marketgarden and farm produce.
An interesting feature of the new product is that for the tractor portion there has been chosen the Thornycroft A2 chassis, with a special short wheelbase of 10 ft. This is regarded. by the makers as suitable for an imposed load of 2 tons, plus the allowance for the body, but the shortening of the wheelbase from 12 ft to 10 It. must result in a relative stiffening of the frame and enable the tractor to deal with a higher load, particularly when best part of it is super imposed over the rear axle. The engine of this chassis is 31 ins, in the bore of the cylinders and 5 ins, in the piston stroke, and develops 25 h.h.p. at normal speed. The engine, clutch and gearbox are combined in unit form, and the final drive is through worm and worm wheel.
The "central" (or nearly so) cross-member of the frame with its ample gusseting is, in the shortened chassis, now in line with the forward brackets of the rear springs, and another cross-member is introduced in line with the rear brackets for the springs. The height of the tractor chassis under full load is 2 ft. 4 ins., and the distance from the back of the driver's cab to the king pin is 3 ft. 9-e-, ins.
A special 20-degrees spherical mounting is bolted to the frame, and this has its " mate " on the forward end of the trailer and allows the vehicle to travel over rough ground without distortion of either the tractor chassis or the trailer chassis—a point which, of course, makes for the longevity of each component. The frame of the trailer js built of mild-steel channel 3i. ins. by 2 il3S. and 10 ft. long. It is strongly braced by means of cross-members of the same section, which are riveted to the side-members by means of gussets. The trailer is mounted on long flexible springs, the eyes being lined with phosphor-bronze bushes to take turned shackle bolts, grease-gun lubricators being fitted on all moving parts. Good design and the best material are employed throughout the axle, and the wheels of the trailer are interchangeable with those on the tractor chassis, the hubs being equipped with ball bearings and the wheels with 34-in. by 7-in, pneumatic tyres, these also being the same size as are used on the tractor portion.
The vehicle is capable of carrying a load of 4 tons, and where it is gen.erally to be employed for the conveyance of large and bulky goods the dimensions of the trailer can be increased. When strawberries are to form the load the type of body suggested is one having sides 5 ft. deep, and with one or two light removable floors additional to the main floor to carry the upper layers and to avoid the crushing of those beneath.
Such a vehicle has, of course, the advantage of speed over the small road tractor and four-wheeled trailer, whilst the large pneumatic tyres and the thorough springing would reduce the risk of damage to fruit to a vanishing point. The price of such a vehicle, including body and cab, a 12-volt five-lamp dynamo lighting set, speedometer and mileage recorder, petrol gauge, spare wheel and tyre, ranges from £670 to 1690.