LOADING FOR ROAD TESTING.
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A Few Suggestions on an Essential Factor in Testing for Repairers who Have Not Yet Had Much Experience of Repairing the Heavier Types of Commercial Vehicles.
By "Vim."
IN a recent issue of this journal (February 8th) there was a very informative article dealing with testing a chassis after overhauling. I would like here to deal with the question of the loading . of the vehicle under test.. A commercial vehicle cannot be properly tested, save on the read and. under full load. Light delivery vans and lorries for small loads should really he included under this rule, but, in practice, it is not absolutely necessary that they should be weighted, because a good tester, who is -thoroughly accustomed to timing up private cars on the road, can generally make fairly correct allow ances for the absence of burden, since private vehicles are commonly tested "light." ----But all commercial vehicles of a capacity of one ton and over ought always to be fully loaded before any attempt is made to try their capabilities after they have been overhauled, or to apply the finishing touches known to the profession as "tuning up."
Important to Choose Suitable Load Material.
_ Any repairer who means to make a special feature Of repairing goods vehicles should, therefore, pro'vide himself with dummy loads for testing purposes. IA number of units of pre-determined weight are preferable to a mass of junk, consisti,ng of lumps of old iron and other garage refuse, for many reasons. Scrap metal is both diffieult and dangerous to handle; it not only wastes tims in loading and unloading, but also presents a good. many nasty corners and edges, laden with germs, with which the men may curt themselves when handling the stuff, and so contract blood-poisoning. Junk, carried loose, is. hound to damage bodywork ; and, if put into sacks, ..Inickly cute its way through. el Some material a little softer and a little less jagged than old metal should be chosen. Sand or ballast 1. tput up in sacks containing 2 cwt each strikes me as 'being the handier form of dummy load. Sufficient to make up 4 tons will cost it few pounds, it is true, But if the sacks are of good quality and are treated with respect, the expense is a first one only, and 'one that it is well worth while incurring. ,
Sand in 2-cwt. Units.
• Naturally the sacks, once filled, will be kept filled ; in fact, they will be regarded as so many 2 cwt. weights, which must never be tampered with, even if a little sand happens to be wanted to soak up a pool of oil at any time. They should each have the weight painted on them in large characters to draw attention to their mission in life. Incidentally, they will constitute a good "talking point" when a prospective customer is being shown over the premises, for they will help to prove that repairs to commercial cars are actually a speciality a the firm and not merely a side line. In a recent article I referred to the great value of impressing on users of motor transport that private vehicles are not the sole arm and object of a garage's existence, and this is one way of doing it.
An alternative plan to the seeks scheme for ma.king up a dummy load has been. described to me by a friend who is making a bold bid for the motor transport business in his town, and who says that he is adopting it himself. Ilia objection to weighting vehicles on test with solid materials is that, if anythins: should go wrong on the road and a tow-in he necessary, the load would be a serious inconvenience, as he lives in a hilly district. Accordingly, he is negotiating for the purchase of several stoutly built water tanks-ecx-Goverument property, I believe— of the kind that are entirely closed in, except for a "hand hole" at the top. He calculates that each tank, when nearly filled, will weigh just 5 cwt., so that he will be able to make up a full load for , any vehicle by using as many full tanks as required.. Permanent lifting rings are to be fitted to these vessels, which will be put on or taken off a car with the assistance of the overhead run-way and tackle with which his repair shop is equipped. My friend's idea is that if •a breakdown should occur while a vehicle was out on the road, the plugs could he removed from the bottoms of the tanks and their contents allowed to escape, so getting rid of -a large portion of the load and rendering towing-in a simpler job. I am not prepared to say that he has not been struck by a genuine brain-wave, but it seems to me that if he should suddenly let loose on the road a few tons of water, there would be a sporting chance of the landscapes .being altered from that time on, and that the rescue could only be effected by a marine salvage company arinedewith the latest. boatraising appliances
All Testing Should be Under Load.
Whatever form of load may be selected, I agree that it is imperative that no vehicle should be passed as fit for service after repair untilit has been thoroughly tried out on the read under conditions equivalent to those which govern its ordinary use. When travelling light, it is difficult to detect whether the engine is misfiring on one cylinder; let alone to make adjustments to carburetter, ignition, and so on, so as to get the last ounce of efficiency out of the power unit. Overheating weaknesses will not reveal themselves unless the engine is given something more to do than pull just the weight of its own chassis along. Steering that may he unbearably stiff or extremely erratic under load will sometimes appear to be quite passably good when the vehicle is travelling empty. Weight shows up vring weaknesses which otherwise might go undetected. If these reasons for going to the trouble of loading commercial vehicles before testing them are not enough (and surely they aresmore than enough I), one may add the argument that brakes cannot possibly be guaranteed in satisfactory working order until they have been proved on a steep hill with full load up. Apart from failures due to worn-out, fabric, accidents have been known to happen through brakes having been adjusted to hold a vehicle whilst unladen and turning out to be entirely ineffective when called upon to stop the laden vehicle. And here is .another tip : never send a lorry out on test without a couple of hefty scotches on hoard; they may came in very useful indeed in an emergency: