Before GOODS and conversion
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EXTENDING the frameless van body of a semi-trailer and equipping it with new running gear to exploit a change in the regulations at minimum cost, might be regarded as an unrepeatable expedient. But the manner in which this has been done by the York Trailer Co Ltd and the conversion of tanker shells to give therb a new lease of life and increased usefulriess are forms of development that could aid productivity on a long-term basis whether or not there are further changes in the regulations.
Taking advantage of the increases in permitted overall length of artics (from 35ft to 13m and later to 15m) Golden Wonder Ltd has had 20 of its single-axled York Freightmaster trailer vans lengthened to raise their carrying capacity by up to 50 per cent. Using standard 26ft Freightmasters purchased when the 35ft overall length limit applied, about 1000 standard cases of potato crisps can be carried in the vans. Some of the vans are seven years old and continue in service delivering mainly to supermarkets and other outlets where manoeuvring space at the dropping point is restricted.
When the maximum allowable length was raised to 15m (49ft 2in.), Golden Wonder looked into the potentialities of longer trailer vans, hauled by the original Ford D600 tractive units. And 14 new Freightmasters were put on the road, built to derive the maximum benefit from the length concession. They are 40ft 6in. long vans in which 1900 cases of crisps can be carried.
In the longer vans the cases are handled on 4ft pallets, a practice adopted following tests with shorter trailer vans including two 35ft drop-frame models. The trials of the 40ft 6in. vans were particularly successful in terms of boosting productivity on the basis of cubic load capacity rather than the weight of the potato Orisps carried. So the company decided to switch to maximum-length Freightmasters for all applications for which they were suitable.
Rather than replace the 26-footers with new longer vans, it was decided to exploit the older Freightmasters' frameless modular construction. One of the main advantages of spreading beam strength through the side walls is that repairs and alterations to the structure can be made without difficulty. York's truck equipment division, at Corby, undertook to extend 20 of Golden Wonder's older 26ft Freightmasters by over 50 per cent to the new maximum-allowable length.
Stretched vans
A Freightmaster box-section with single rivet-line post attachments and having a length of 14ft 6in., a height of 91t and a width of 8ft 24in., is joined to the 26ft structure behind the existing front bulkhead. Because of the side walls' beam strength no additional reinforcement is needed at the raves or cant rails, so that the stretched vans arc no heavier than standard units of the same length weighing just on 34 tons unladen. No problems were experienced in mating the Mk 1 panelling with its double rivet-line side posts to the new structure. And jointing the floor, with its 12in.-pitched cross-members, was a simple exercise.
Because the amount of daylight that can penetrate to the forward end of a 40ft van from the rear opening is strictly limited, a one-piece translucent glass-fibre sheet was used as the roof panel for the 14ft 6in. extension.
Although absolute load capacity in tons is not crucial on the Golden Wonder vehicles, (plated gross combination weight is within the 16 tons limit originally proposed for quantity licensing) the correct apportioning of laden weight on the trailer axle and the fifth-wheel coupling is maintained on the extended Freightmasters. The rear axle overhang is increased from 4ft to 6ft while the kingpin is 15in. further back, 3ft 9in. behind the front end of the trailer.
Golden Wonder peanuts can account for up to 10 per cent of the payload in the long Freightmasters. This much denser load is positioned strategically to avoid any imbalance in axle weight distribution. A further useful life of at least three years is planned for the stretched seven-year-old vans. After allowing for the growth in Golden Wonder's business and the corresponding increase in annual "routecubic-foot-mileage", the switch to longer vans yields a reserve in fleet capacity of 33 per cent without adding extra vehicles.
Stainless steel is an expensive material. When used in vehicle construction its working life must be long enough to justify the outlay. The principle of transferring old but serviceable tanks onto new chassis assumes an even greater importance when the shell is constructed of a material as costly as stainless steel sheet.
T. Heard and Sons Ltd, one of the transport and engineering companies of the Unigate Group, based at Westbury, Wilts, has undertaken a programme of modernizing its fleet of articulated milk tankers. Advantage is being taken of the concession allowing 24-ton combination weights on artics with only three axles. The company's Scammell Highwayman tractive units hauling tandem-axled 3000gal chassisless tanks on large single-tyred axles with Scammell rubber suspension, are being phased out of service. And the 23ft-long, 5ft 6in.-diameter cylindrical stainless steel tank shells are being equipped with a standard York RG3 single-axle 10-ton running gear by the truck equipment division of the
company at the Llantrisant branch near Cardiff. The tanks can carry a payload of 16 tons when coupled to an AEC Mercury tractive unit. The gross trailer weight is 19.75 tons.
Use of the original automatic coupling gear would have inhibited flexibility by eliminating interchangeability between the tractive units and semi-trailers in the fleet, and the gear has been replaced by an orthodox fifth-wheel kingpin and rubbing plate. A fabricated pedestal is used by York to bring the front bottom edge of the tank 10in, above rubbing-plate level. It is of mild steel, welded to the stainless tank by the specialist welders employed at Llantrisant. With a standard tractive-unit coupling height this gives an unladen height above ground of 5ft 2in.-4in. higher than with the old coupling.
After the Scammell bogie has been removed, the box-section ring around the circumference of the shell on which the rocking beam pivots are attached is cut away locally. The R03 running gear is then bolted to a special cradle, designed by York engineers, which provides three ribs under the belly of the tank and is welded to the shell. Two additional ribs run longitudinally to brace the sub-frame to the otherwise redundant circumferential ring. The rear end of the tank is raised by 10in. to 311 6in., so that the slope, front to rear, is decreased from 26in. to 20in. to adjust axle weight distribution in accordance with 24 tons gew attic operation on three axles. York landing gear is also added to the tanks which in standard form had to be propped on stands when uncoupled. And other details inialude three-line air braking.
Rigid tankers
Extensive modifications to a number of sixand eight-wheeled rigid tankers operated by the Wolverhampton branch of Wincanton Transport have enabled the company to modernize part of its fleet without great capital expenditure. At the Cannock branch of York's truck equipment division the old vehicles have been transformed into up-to-date 24-ton goy three-axle artic tankers by removing the tanks from the chassis and remounting on new York running gear and speciallydesigned sub-frame. The addition of York two-speed landing legs, fifth-wheel kingpin and ancillary equipment such as an access ladder bring the tankers into line with modern standards and give the tanks a new lease of life.
As artic units, the tankers can operate at the Same gew as one of the old eight-wheelers but at a much reduced unladen weight with consequent savings in running costs and a considerable improvement in manoeuvrability. They are now mainly used for carrying industrial and domestic heating fuels, although the higher specific gravity of the load means that the 4000gal eight-wheelers are running under capacity. Wincanton considers that the low capital investment involved makes this acceptable.