WHAT All ICAN MAKERS ARE DOING
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A Trend Towards A Vehicles, Improvement: Design and Shorter \A Lengths are Features () Practice in the Unitec
THE word " truck," as used by the American commercial-vehicle industry, is a generic term embracing goods vehicles of all types and capacities Because of the great diversity of haulage and delivery requirements of industry and commerce, there can be no such uniformity in vehicle design and size as obtains in the private-car and taxicab fields, where the models produced by any manufacturer are limited in number, are redesigned each year, and all look much alike.
By contrast, truck makers build many types. One, for example, now produces 120 models, ranging from an open-body pick-up vehicle of just under 9 cwt capacity, to a tractor-trailer outfit rated at 29 tons.
Commercial-vehicle makers do not, therefore, usually redesign their whole line annually and designate the models by years. They add, perhaps, a new type of vehicle, from time to time, make various improvements in others as they are developed. Thus, the leading makers who build for the mass market, have improved their range throughout in the past five years. Smaller companies manufacture specialized types for specific purposes, such as small vans for house-to-house service. and huge straddle trucks designed for hauling logs slung under the chassis, or models that carry and operate cranes for heavy lifting.
For these reasons, the design of individual models cannot be described in detail within the limits of a short article. It must be confined to a general survey of the design trend represented by the latest models of several principal manufacturers.
The G.M.C. Truck and Coach Division of the General Motors Corporation lists, in addition to 54 lightand medium-duty models, 61 heavy-duty vehicles, of which 16 are powered by oil engines. The list is as follows:-
Among 87 basic model chassis produced by the Intel national Harvester Company are two West Coast highway, and four off-highway trucks, ranging from 13 tons 8 cwt. to 40 tons gross laden weight, a new group of six-wheeled chassis with gross weights of from 9 tons 16 cwt. to 22 tons, another new group comprised of forward-control chassis ranging from 6 tons 5 cwt. gross laden weight, and a line of Metro-body multi-stop vehicles of from 2 tons 7 cwt. to 4 tons 9 cwt. gross laden weight; the last mentioned including three body sizes, one adapted for use as a bus. There have been notable increases in the number of models of cab-over-engine design, making for shorter Wheelbase lengths and greater manoeuvrability. The use of tractor-trailer combinations for long-distance haulage has increased tremendously during and since the war. Many semi-trailers have a payload capacity of about 26 tons, equal to half that of a railway goods van. The Ford Motor Co. recently added to its range a parcels delivery chassis with wheelbase lengths of 8 ft. 8 ins. and 10 ft: 2 ins. They are of cab-overengine type, and the maker will supply bodies to purchasers' specifications.
With few exceptions, manufacturers follow•convention in chassis design. Frames are of channel-section steel, the engine is mounted over the front axle,,and rear-wheel .drive and leaf-spring suspension are adopted Innumerable improvements are, however, to be found in engines, and in the design of cabs, bonnets, wings, grilles and bumpers.
Such improvements result in a general increase in
strength and ruggedness, more engine povver and operating economy. shorter wheelbase lengths, reduced turning radius, roomier cabs, and better visibility. The lines of the cab, bonnet and front wings are such as to suggest power and massiveness, a feature which applies more particularly to the heavy-duty models.
The Ford line of commercial vehicles for 1950 consists of eight types, including conventional, cab-over-engine, parcels delivery and school-bus models. Wheelbase • lengths range from 8 ft. 8 ins. to 16 ft. 3 ins., and with gross laden weights of from 2 tons 2 cwt. to 9 tons 1 cwt. Double channel-type frames in the two extra-heavy-duty series models provide about 50 per cent, more strength than the normal type of frame.
Models with wheelbase lengths of 12 ft. 4 ins. and 14 ft. 10 ins, have been added to the series; and the F-7 series trucks are now equipped with 15-in. by 5-in brakes of dual-cylinder type. Single-speed rear 'axles or Iwo-speed axles are available in the series F-6 and F-8 :nodels.
The 145 b.h.p. Ford engine now has -.exhaust valves that are free to rotate in their guides. This ensures that the valves seat properly, whilst at the same. time, the formation of deposits on the stems and in the guides is prevented. A new engine, which develops 110 b.h.p. and provides a torque of 212 lb.-ft., is optional equipment on F-6 trucks. A four-speed synchromesh gearbox also represents optional equipment on these models.
The line of Chevrolet commercial vehicles introduced last December embraces 20 models, there being a choice of nine wheelbase lengths. The gross laden weights of the range are from 1 ton II cwt. to 7 tons. Improvements in the company's valve-in-head engines raise the power of the Thrift-Master unit, as used in light and medium-duty trucks, to 92 b.h.p., and that of the Load-Master for heavy-duty units to 105 b.h.p.
Heavier front springs, optional auxiliary rear springs, plus improved shock absorbers give the vehicles better riding properties. The width of the seat cushions in all Chevrolet cabs has been increased to 4 ft. 8 ins., and the panel and canopy truck models have one-piece, five-ply wood floors in the cabs.
The Studebaker Range Roomy, comfortable cabs with good visibility, alligator-type bonnets and four-speed gearboxes with overdrive gears characterize the Studebaker range. It includes 10-cwt., 15-cwt., 1-ton, 11-ton and 2-ton vehicles with wheelbase lengths of from 9 ft. 4 ins to 16 ft. 3 ins., and gross laden weights from 2 tons 1 cwt. to 7 tons.
The cabs have wide, adjustable seats fitted with coilspring air cushions. A ventilating and heating system can be introduced at extra cost. A large, sloping V-shaped windscreen makes for good visibility.
The International Harvester Co.'s L-line of trucks, announced in December, reveals new design features from front bumper to tail lamp. The models are notable for their unique front-end styling, a bonnet top that lifts from the front end, shorter overall length for better weight distribution and manceuvrability, and improved valve-in-head engines including a new sixcylinderecl unit in two sizes—one of 220-cubic-in, piston displaeement, rated at 100 b.h.p., and another of 240-cubic-in. displacement, rated at 108 b.h.p. The cabs have been designed for maximum driver comfort.
32 Different Four-wheelers
.In addition, the International range includes four types of conventional four-wheeled trucks comprising 32 different models. There are five bus chassis and 11 tractor-trucks of gross laden weights ranging from 121 tons to 26 tons, a group of multi-stop delivery vans having three different sizes of body, a new group of 14 six-wheeled chassis, a second new group of six forward-control chassis, 14 six-wheeled units and two highway and four off-highway West Coast models.
Much attention has been given to cab design, cab width has been increased to 4 ft. 101 iris., height to 4 ft. 3 ins, and length to 4 ft. 10 ins. Various types of seat are offered as optional fittings; full-width and individual seats have a 4-in. adjustment range and maintain correct angle between seat and squab at all positions. A cowl ventilator, working in conjunction with ventilating windows, affords fresh-air circulation under all weather conditions Available as optional equipment, is an air-heating, defrosting and ventilating system. The large, curved ene-piece windscreen gives unobstructed forward visibility. Corner pillars have been moved back and the cab farther forward, so that the driver is afforded a better view of the -road close up to the front of his vehicle.
Wheelbase lengths of the new I.H.C. trucks have been shortened, in some models as much as 7 ins., and wheel tracks widened. These changes, together with the new cab position, result in.better weight distribution between front and rear axles. increased payload capacity. .and a front-wheel turning angle of 37 degrees..
Super Blue Diamond and .Super. Red Diamond engines embodying many improvements now give more power, are more efficient and show greater economy. Both have a compression ratio of 6.3 to .1. Piston displacement of the former is 269 cubic ins., and the rated horsepower is 11.5. The Super Red Diamond is produced in three sizes rated at 144, 154 and 162 b.h.p. respectively.
The most important developments for 1950 by the G.M.C. truck division are 12 new medium-duty models and the new heavy-duty petrol or oil-engined machines as previously set out. However, changes have been made in nearly all components of the light, mediumduty and heavy-duty series to increase strength, power, driver comfort, safety and appearance.
Special attention has been devoted to cab design in all types, with, the result that they are roomier, have 'larger windscreens, doorand rear-window glasses, and improvements •have been incorporated in the cab mounting to reduce twisting and the transference of road shacks from chassis frame to cab. Two styles of sleeper cab, with a berth for the use of drivers in roundthe-clock operation, are offered on models-in the three series of conventional or cab-over-engine chassis.
Cabs for Sleeping
The all-steel cabs are welded and have a transverse berth behind the driving seat, whilst large storage compartments are arranged on each side of the cab. The berth is 6 ft. 3 ins long, 2 ft. wide and is fitted with a comfortable mattress. The cab roof has a ventilator above the berth and a dome light at the rear. There are also two small side windows and two rear windows at berth level.
. Deadweight savings of up to 12 cwt. on the conventional four-wheeled tractors and over a ton on the sixwheelers, are possible by optional design features. These include aluminium components in oil-engined models, aluminium rear-axle housings and brake shoes and drum, aluminum auxiliary gearcase, aluminium wheels, and lightweight frame, front axle, rear springs and front bumper and the omission of front brakes on the standard axle.
Truck arid tractor models in the heavy-duty. series are powered with petrol engines of five sizes ranging from 136 to 225 b.h.p., or with the G.M.C, fouror six-cylindered two-stroke oil engines of 133 or 203 b.h.p. respectively Compression ratios in the petrol engines have been increased to 6.5 to 1, and in the oilers to 17 to 1.
Large Variety of Trailers
Trailers are produced in a great variety of types and capacities. They range from 9-cwt. payload to mammoth trailers for moving complete fiveor six-room dwellings. The majority are two-wheelers, including 'van-type semi-trailers, and dollies for hauling long objects such as telephone poles, long pipes and huge boilers: The van-type semi-trailer predominates for the haulage of miscellaneous loads over long distances— household goods to any point in the United States, fruit and vegetables from Florida and California to northern • and inland cities—and in the distribution of supplies to chainand independent retail-stores in Metropolitan areas.
The construction of standard-type trailers is so simple that little chance is afforded for design changes. The most recent alterations were in body features and in the provision of means in the running gear for reducing body sway and for absorbing road shocks." Aluminium construction of bodies to decrease the deadweight has made much progress, and front ends, roofs and corners are now rounded.
A novel development in the industry is the making of aluminium-alloy van-body sub-assemblies by the Reynolds Metals Co. one of the three or four producers of aluminium in the country. These major parts are sold to trailer makers, who assemble them as complete bodies with floors and lights and mount them on their own running gear.
Sub-assemblies supplied by Reynolds comprise body under-frames, body sides, roofs, curved front-ends and doors, all being assembled from fabricated standardsize units. They are built to the purchaser's specification for body lengths of from -20 ft. to 36 ft. in increments Of 2 ft. All bodies are 8 ft. wide and 7 ft. high.
Bodies built of this light alloy reduce the deadweight of singleor dual-axle trailers by as much as I to 2 tons compared with trailers of conventional construction and corresponding size. What this means in operating economy is evident. Moreover, the bodies need no painting, do not rust or corrode, and maintenance is reduced almost to zero.