THE LIGHTING OF COMMERCIAL VEHICLES.
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The Case for the Employment of Lamps so Mounted that They Turn with the Movement of the Steering Wheels.
By Henry Sturmey, WHILST there is often during the winter months an outcry in the Press with regard to the excessive illumination of some touring cars, I think it will be admitted that, more often than not, the commercial motor and the motor coach err in the opposite direction. Drivers are often provided only with oil lamps which, whilst giving a passable light when new and in proper trim, are very often so much out of adjustment of wick and in such a dilty condition, that the light given serves little better purpose than to disclose the darkness.
I have driven by these oil lamps many times and, on more than one occasion, have found myself heading off the road because of the poor illumination they give and although, of course, the commercial vehicle does not travel at the same speed as a touring car as a rule, there are certainly many which travel as fast when outside the town as do many of the more sober-minded drivers of touring cars. Hence a commercial vehicle should be as adequately—not necessarily as excessively—illuminated as the average moderate power touring car, and to this end the oil lamp is wholly unsuited.
Oil lamps serve their purpose when used to define the limits of the vehicle for the benefit of other users, and, whatever other lights are carried, one should be carried on each side in such a position as to indicate the maximum width of the track. This is a measure of precaution providing for the,safety of the vehicle and its driver in preventing it, by making its exact whereabouts':: known, being run down by other vehicles, but, as above said, an oil lamp really has very little other serious purpose.
The sources of illumination that are open to the users of touring cars are, of course, open to the users of heavy vehicles, but the electric light equipment has the disadvantage of high cost, which is an important factor in the consideration of the owner. If this system be adopted, however, the oil lamp can be done away with altogether and the low-powered side lights may also be electric. For commercial car uses, however, the acetylene headlight. appeals, because its cost is not excessive" and the light given is sufficiently powerful for all practical purposes—such headlights can, of course, be had, which are as excessively powerful as the best electric installations, but these are not necessary for commercial vehicle work. At night, any motor vehicle should carry a means to illuminate the road sufficiently far ahead to enable it to pull up, when travelling at its normal speed, well within the area of illumination, so that the necessary power of the light will vary with the average speed of the vehicle, and whether one lamp or two be used is immaterial, so long as sufficient light is available.
On another point, that of the value 'and power of the light provided, much can be said, and in this connection touring cars are as inefficiently lighted as are the heavier types of machines, but the cause of this is the misconstruction of the wording of the Motor Car Use and Construction Order, . which, whilst specifying that a motorcar shall carry efficient lights, specially prohibits them from carrying " searchlights," -with the result that motorists and others have rushed to the conclusion that any light which moves is a searchlight. In this connection they are only partially right. A searchlight, as such, is one with which the scenery around can be searched out In other words, it is a light which can be turned in all directions. The spot light which is so popular in Alnerica, and which is just beginning to catch on here and which is so very useful in cases of trouble, is really an illegal fitment, because its light can be turned in all directions.
But the Order also lays it down that cars shall carry lamps which will show a light in the "direction the vehicle is going or is intended to go," and this most certainly they ought to do, but it is equally certain that no vehicle on the road to-day does it. Just consider for a moment what the ordinary vehicle lamp does. It-is mounted rigidly upon some portion of the chassis-supported portion of the vehicle and, when the vehicle is running wlong a straight road, it throws its light beams in the direction in which it is going and, of course, in which it is intended to go. So far so good, but, directly we come to a turn in the road, the conditions are altered and no lamps used to-day comply with the Order under these conditions. What happens is this :—When the vehicle approachesra corner or is on a curve, it is intended to folloW" that curve or to go round that corner and the front wheels are actually doing so. But the line of the vehicle itself is tangential to the curve made -by the wheels, and the lights, being attached rigidly, throw their beams straight ahead, at a tangent to the. curve on which the vehicle is travelling: Now this results in illuminating the hedge or Wail on the of side of the road, which is certainly not the direction in which the vehicle is intended to go, whilst the actual path upon which it is travelling and is intended to travel (that is the road approaching the corner) is left in utter darkness, which, of course, is rendered the more dark by contrast with the illuminated hedge on the other side. Hence, it will be seen that, not only do the present lights on vehicles not give the driver that protection on a curve which_ it is desirable he should have, as well for his awn safety as for that of other road users, but it certainly does not comply with the wording of the Act, so that it is both legally and practically wrong.
.Objections Raised to Swivelling Lamps.
Several attempts have been made in the past, largely in America, to remedy this State of affairs by mounting the headlights on swivels and interconnecting.them after the manner of the Ackerman steering dhd connecting 'this system with the steering system of the vehicle, so that the lamps are turned synchronously with the wheels and, Otis, do throw their light around the corner and in the direction it is intended to go. But, in this country, the quidnunc& of the trade have at once turned this down as not being in accordanaa with the. Act.
In this I believe that all were wrong. These lamps are not searchlights in any shape or form, because they only move with the vehicle, and can be moved in no other direction. They cannot be used as a searchlight at the whim of the driver and, if the ease were fought out, I am sure that this view Would be upheld. The system, however, has gone out very largely hi
the States by reason, I am informed, of the fact that, owing to the numerous joints, rattle has resulted. so soon as wear has commenced to take place, but during the last few weeks a new method of applying the system has been introduced there which, whilst getting over this point, will, I feel sure, also get over the theoretical objections even of the Ministry of Transport. It is much more simple, too. Most motor vehicles have the wheels mounted on spindles to which the connecting arras are screwed, and the bosses into which the connecting arms are screwed from the back come through to the front, so what has been done has been to take advantage of this and to screw into these bosses coiled springs, upon the top of which the lamps are individually mounted.
A System of Swivelling that Should be Acceptable.
This -results in the lamps, of course, moving with their respective wheels, to the spindle of which they are rigidly attached. They, therefore, show the light around the curve upon which the steering wheels are travelling and thus obtain the desired result. Also, there being no steering connections and no moving parts, there can be no wear and no rattle, and I think that it is impossible for even the most cantankerous legal mind to object to the system, because these lamps do not turn at all !They cannot, therefore, in any sense of the term, be even theoretically spoken of as " searchlights." They move with the wheels, actually in exactly.the same way as the headlight of a bicycle or a motorcycle, whicti, attached directly to the steering head, moves with the wheel, &o that they act exactly as the headlight of a bicycle, which does and always has done exactly what the Aot and common sense require, i.e., it throws its light in the direction in which the machine is both going and intended to go. Therefore, if lights which are rigidly attached to the steering wheel mounting and move with it are legal on a bicycle, they must be and can only be similarly legal on a motor vehicle. I give an illustration of the system.