FEATURES OF THE ENGINEERING EXHIBITION.
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Much of Interest to the Commercial Vehicle User and Manufacturer is to be Found. There are Electric Industrial Trucks, Several Novel Petrol Engines and a Gas Producer.
APART from the Commercial Vehicle Show at Olympia and the Roads and Tranvort Exhibition at the Royal Agricultural Hall, one of the most interesting displays in the course of the year to those concerned in transport, the promotion of efficiency in vehicle production or the general handling of goods is the Shipping, Engineering and Machinery Exhibition which is now being held at • Olympia, London, and which closes its doors on December 5th.
Actually transport, in the strict sense of the word, does not come under the auspices of the organizers of this exhibition, but, in spite of this, many of the stands display articles which come into the purview of this journal. For instance, there is quite a number of &ittery electric trucks, electric tiering devices, and at .least one mobile crane which has achieved quite a reputation and, incidentally, was much in demand during the preparation of the Show for lifting work in connection with the stands. This particular machine is the Orwell 15-cwt. mobile crane made by Ransomes, Sims and Jefferies, Ltd., who also show an interesting type of tiering truck which is eminently suitable for lifting goods from the ground level to platforms, or for works use in raising heavy castings, etc., up to a weight of 2 tons, on to the face plates of drilling and other machine tools.
The truck is not only mobile, but the platform is raised or lowered by electric power, and an automatic arrangement prevents overrunning. The one on the stand lifts at the rate of 5 ft. per minute, to a total height of 5 ft. 1 in.. from the floor level, involving a total
lift of 4 ft. 1 in. -•One of the important features of the
maChine is that the speed of descent is always the same whether the platform be loaded or unloaded, and regeneration to the extent of 12 amps. occurs when lowering with the load, thus providing an effectual electric brake.
Another most successful make of electric industrial truck is the Union, built by J. Booth and Brothers, Ltd., Union Iron Works, Rodley, Leeds. It will be remembered that it was the Union battery locomotive which gained the 4:1,000 prize in the Markham competition for coal-mine locomotives, meeting all the conditions of speed, safety, short radius turns, etc., one of the points being that the battery boxes, which normally rest on rollers, can be moved on to a platform in two minutes and replaced by newly charged batteries in the same time, thus reducing terminal delays.
The standard model, which is shown, is No. 3, to carry 2 tons. This is constructed of channel-section steel with stout cross-members, whilst the wheels are of cast-steel, equipped with rubber tyres. The platform is of the flush type, made of oak and bound with steel.
In the control gear the control is interlocked with the brake and so arranged that the truck immediately stops when the operator leaves the vehicle, even if the control be left in the " on " position.
All four wheels are steered by a tiller, Oita enabling short-radius turns to be made, whilst transmission is by electric motor to a live rear axle equipped with a differential gear, the final drive being through worm gearing. The company also build elevating trucks and side-control trucks for accommodating long bars, girders, etc.
Many improvements have beep embodied in the London • truck built by It. C. Seal, 18, Dartmouth Street, Queen Anne's Gate, London, S.W.1, since we saw examples at the previous Engineering Exhibition. At that time the truck was driven by a silent chain, but in the latest model worm drive is employed, the motor being mounted behind the axle, which is a Kirkstall pot type, the worm being overhead. In addition, the trucks are now mounted in wheel drums.
The London truck is by no means a new development; in fact, it is the result of 10 years' actual use. It is unusually accessible, the platform being arranged in two portions, hinged at the Centre, so that by lifting the forward portion all the battery connections, etc., are exposed, whilst lifting the rear portion gives access to the axle and driving motor. In addition the platform was formerly constructed of wood; it is now made Of chequered steel.
This truck is also equipped with what is known as a mechanical dead man's hand, and the sprung foot plate lifts directly the weight of the driver is removed from it and applies the brake. The G.E.C. controller is mounted at the front, so that the platform is not obstructed in any manner.
British Electric Vehicles, Ltd., Churehtown Works, Southport, show the Midget Whippet, a special truck for confined spaces; the Super Giant for loads of 5,000 lb.; and a steerable tractor with a haulage capacity of 5 tons.
The Whippet model carries loads up to 1,000 lb and it can turn out of a gangway 4 ft. wide and enter another 4-ft. gangway without manceuvring. The running cost of this little truck is about 3d. per day, and it can be equipped with hand-operated elevating mechanism when required.
The tractor can, if used on a road beside railway lines., haul on the railway track a load of some 40 tons.
The Super Giant can best be described as a motor lorry in miniature. It is well sprung on semi-elliptic and can be run on the mail:lest of roads or setts. If required, it can be equipped with a tipping body for handling coal, ashes, sand, etc., and then bears an even greater family resemblance to the fullsize vehicle.
R. C. Slingsby, SO, 95 and 97, Kingsway, London, W.C., stages quite a number of battery electric trucks and tractors. For general haulage work there is the Little Elephant tractor, which has a turning radius of 4 ft. 2 ins., three speeds in each direction ranging from 1 m.p.h. to 6 m.p.h., a normal drawbar pull of 600 lb., and an ultimate pull of 1,600 lb. The final drive is by a singlereduction worm gear. The motor is rated at 32r, h.p. and is spring-suspended to Isolate it from vibration. The metaldrum controller is directly operated by the control handle, thus avoiding loss of motion, and an interlocking device prevents the release of the brake and the applying of the power until the operator is in position on the seat of the tractor.
Four-inch I-beams are employed for the frame, which is supported on the rear axle by two heavy coil springs. Stiiht bumper plates at the front and rear protect both the machine and the operator.
• Normally the wheels are 16 ins, in diameter, but 20-in, driving wheels can be substituted.
Next comes a lifting-tiering truck, in which the platform is raised by means of a single large screw revolving in a stout bronze nut carried in a trunnion and well lubricated. Loads of 4,000 lb. can be lifted 1 ft. in 12 seconds, and there is an automatic cut-out in the extreme posIVons. It can be supplied in three heights, with lifts of 3 ft. 4 ins., 5 ft. and 6 ft. 3 ins. The smallest truck is of the standard platformtype, equipped with overhead worm drive, and having a carrying capacity of 2,000 lb. The axle is of the full floating type and has a differential gear. The pedal operates contracting shoes on a drum mounted on the worm shaft.
Many of the trucks are equipped with Exide Ironclad batteries, and as these batteries are used to a -tremendous extent for all kinds of transport work and for lighting sets on buses and other heavy vehicles, the visitor to the exhibition should certainly call at the stand of the makers, the Chloride Electrical Storage Co., Ltd.
These batteries stand very heavy vibration and have a special type positive grid consisting of what are termed pencils having fine cross-slits, which allow the entry ofacid but prevent the paste from falling out, whilst buckling is altogether obviated. The negative plates are also thicker than the ordinary type. Ample sediment space is provided in the plates, and there are feet on both the positive and negative type, the plates bein& separated by wood diaphragms. The cells are free from leakage and have flexible connections. For lighting purposes they are usually supplied in units of 12 and 6 volts.
Amongst the exhibits staged by C. A. Vandervell and Co., Ltd., are dynamos of all types and the special C.A.V. batteries provided -with patent threadedrubber insulators. It may be mentioned that for marine work the electrolyte is jellied.
Another interesting type of accumulator is the Nife made by Edison Accumulators, Ltd. This is, of course, of the nickel-iron alkali type, which, although more expensive in first cost than the ordinary pattern, has an extremely long life, whilst the cages, being of steel, are not subject to damage through vibration.
An interesting and simple type of gas producer is to be found on the stand of the Compound Gas Power Co., Ltd., of Reading. This producer consumes approximately 2i lb. of wood per bh.p.hour. It is of the down-draught type, and no water it required for the formation of the gas, that contained in the wood fuel being sufficient. The downdraught principle has an advantage, because it obviates the employment of a large number of joints, for the upper part of the producer need not be gastight.
The examples shown are of course. for stationary plant, but other types for commercial vehicles are being developed. The fuel employed can be waste wood, peat, coconut shells, corncobs, cotton seeds and other waste vegetable products. It is interesting to note that no complicated gas-washing or scrubbing process is necessary, and that the gas generated is stated to be perfectly clean and free from dust, tar and other impurities. It goes straight to the engine after being mixed with the necessary amount of air in an automatic valve.
On the stand of the British Petroleum Co., Ltd., are two pleasing models of commercial vehicles. One is a 1.000 gallon Karrier for delivering motor spirit in bulk and the other a Dennis combination tank and can lorry for the transport of lamp oil in bulk and motor spirit in tins.
The Anglo-American Oil Co., Ltd., show two of their Gilbert and Barker self-measuring pumps, one delivering five gallons at one stroke of the pump and the other one gallon.
Much Interest is being displayed in the exhibits of Alexander Duckham and Co., Ltd., who give practical demonstrations of the properties of their New Process Adcol motor oils. These oils whilst being comparatively thin at normal temperatures, neither thicken when cold nor thin so much as some oils, apparently more heavy-bodied, when hot, thus starting is facilitated in cold weather and there is no excessive loss of oil through it passing the piston rings or leaking past joints when the engine is warmed up.
The Shell stand is very effectively arranged. Strikingly displayed above the stand is a remarkable model of a shell finished, to resemble mother of pearl and illuminated by concealed lights. Below this is a series of glass panels, down which flow the various grades of their lubricants and cutting oils.
For those who did not have an opportunity of examining in detail the remarkable type of gearbox with oiloperated clutches which is used on the S.L.M. vehicle, this gearbox can be seen opened on the stand of Bernard Rolland said Co.
There are two engines which deserve particular mention, as they possess extremely novel features. One is the Michell swash-plate type exhibited by Crankless Engines, Ltd., the other is the Redrup, Made by Redrup Motors, Ltd. This is a20 h.p. power unit embodying what is• known as the axial system of
engine construction. '
This engine must not be confused with the awash-plate type; certainly it has a rocking device, but this does not revolve. It is carried on a crankpin set at a comparatively small angle from the centre line of the crankshaft, and around the crankshaft are arranged the cylinders, of which there are five in the example-staged, although they actually represent double this number, for they are double acting, each piston being long and provided with rings at each end. In one type ordinary poppet valves are utilized, and this type we illustrate, whilst the other model is a two-stroke. In this case the Combustion chambers are all at the forward ends, the other ends forming compression chambers.
The rocking device is carried on ball and roller bearings, and the valves, when these are employed, are operated by cam rings.