Light Trailers for Goods Haulage.
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By Henry Sturmey.
It is no uncommon sight to see a goods engine pulling 70 or 80 loaded trucks or some seven or eight
• hundred tons of dead load in addition to the weight of the trucks. It is needless to say no one would think of trying to pile all the load Oil the engine even if the platform could be made large enough tee.hold it. This everyday practice of the railways proves,
almost to the reductio ad abeurdam, the ifact that . any form of prime mover can haul a greater weight than it can carry, just as with a man or a horse.
Of course, the flattening out and smoothing of the road in the ease of the railway enable this to be done to the greatest advantage, and loads of such magni
tude could not be hauled so easily en the road. But it has been shown to be possible with a. hydraulic
geared tractor to draw loads as high as 45 tons and
. to take 15 or 20 tons over quite respectable gradients. . Of course. at a slow speed. Instances such as these demonstrating the correctness of the traction' prin ciple-it seeint.to me that we have not hitherto made as much use of it in automobile work as we might have done,-for it heart to have been almost tacitly left to the -steam wagon and traction engine to exploit the principle. In A.mei.ica, however,, where people are less-wedded to the' conventional thanwe are, quite a development in this direction is taking place, and trailers of all kinds are being used not only as attachments to trucks but also for bitching
on behind touring cart. •
The Troy trailer, -which was described in TEE CoatHEILOIAL MOTOR recently, is one oiltcome of this move' ment, but that provides the carrier for really heavy loads, and is intendexi more Particularly for nse with large cars in direct competition with the steam wagons and tractors. 'The new development to which I refer is taking place at the other end of the scale, light trailers being provided suitable for the conveyance of loads as small as 71 cwt., and I learn that quite a large and rapidly-growing trade is being dons in them. These trailers are of two types, viz., two and four-wheeled; the two-wheeled outfits being rather the more popular. The Jackson'trailers exemplify the first class, and are built in three ty-pes for 1000 lb., 1200 lb. and 1500 lb. loads respectively. They follow the lines of a large hand-truck, being mounted on two rubber-shod wheels running on a through axle and carrying on a spring-supported platform bodies of the various types which are used on motor wagons. They are drawn by a central single draw-bar furnished with a t descope -arrangement which enables them to be hitened on to cars with different amounts of overhang behind the frame, and are attached to the centre of the chassis frame by double joints allowing both fo,' side swing as they follow the tractor round corners and also adjustment for different heights of frame in the ears to which they will be attached. When not in use a vertical strut drops down and supports the front 'of the frame so that they can be loaded up on a level keel, and the car which will draw them can be backed up to them and connected up. The other type is best exemplified by the " Simplex Short-Twin trailer," which carries its load on four Ivheels and is built for SOO lb. and 1000 lb. loads and furnished with a very ingenious steering system which enables the trailer wheels to track with the tractor. This is shown in the annexed illustration. Both axles are centrally pivoted and are connected by a system of levers which have the effect of causing them to synchronize in movement but in opposite directions, so that if the front axle swings the near side in and the off side out, the rear axle does the reverse, thus causing the wheels towards the centre of the curve upon which the outfit is running to run
automatically on a smaller radius than the others, thus following the tracks of the tractor ear, however sinuous its course may be. The primary movement of the front axle is secured by the. expedient. of attaching it to the car by two connecting rods which are crossed, which has the effect of swinging the front axle of the trailer oppositely tothe movement of the axle of the tractor.
This Simplex trailer has connecting rods coupling directly on to the axle of the car, or, if this is prevented by obstructions, fittings are supplied by means of which a draw-bar to which the rods may be attached' is secured to the bottom spring plates. I cannot say I admire either the attachment to the axle or the direct attachment to the springs, as it seems to me that it must be a much more correct principle to take the, pull through the springs and hence that the attachment should he made to the chassis frame. The interconnected axle arrangement is, however, a very pretty device if there are not too many unprotected joints in it. The two-wheeled outfits are naturally somewhat the cheaper of the two, and can be bought for from to 230. An. idea of what can be done with them may be gleaned from the experienee -of one user of a Ford who is in the milk trade. He puts 16 five-gallon -cans on the -Ford platform and loads 24 similar cans on the trailer, making 800 lb. on the car and 1000 lb. on the trailer. He takes this load Over a .50-mile -route in one -afternoon, whereas with horse traction the journey took two days, and as regards
fuel consumption gallonS are used on the trip.
Such work as this amply demonstrates practicality and usefulness, and -it seems to me, that such trailers as these must be very useful for extra or emergency work in a business which has its busy days and hardly enough work to justify the maintenance of another ear.. They can be hitched on to an already fullyloaded van or connected up with the firm's business car if it has one, whilst for use in the service of a country h-ease or an agricultural estate they should prove very Useful.