OPINIONS and QUERIES
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[4547] Your leader, entitled " The Voice of the Mechanic," is most timely, and our experience is that the voice very often has to say, with much additional emphasis, "The man who designed this evidently doesn't have to work it I" Our particular bugbear is nuts, bolts and screws, especially those which are of no known standard and which no standard wrench will fit. Why the maker of a much used truck has to design its own comic threads when there are Whitworth, B.S.F., B.A. or metric threads to choose from is more than we can understand a.nd we should very much like to be enlightened by those responsible. This may be all right in London or in any big centre where adequate stocks are available at a moment's notice, but what happens in places where these trucks are used on the outposts of civilization, or even in a comparatively isolated English village? It means that any odd nut, bolt or screw that is an approximate fit is used, regardless of its suitability to take strains or stresses, to the great detriment of the efficiency of the vehicle. Wrenches which are supplied in the tool kit of the vehicle are soon lost and are generally replaced with standard Whitworth-sized wrenches. These, as a rule, do not fit the heads of the bolts which are on the truck, and are a fruitful cause of skinned knuckles, blasphemy and lost time, in addition to making the bolts or nuts round-shouldered and impossible of either removal or tightening.
Another 3-ton truck has one point which needs attention. The brake adjustment of the back-axle is undoubtedly good, but why do not the makers include in the tool kit wrenches with which one can adjust it? This vehicle also has lubricator connections made from round-section brass, which are most difficult to manipulate when a nipple has to be changed. These would be just as cheap to manufacture from hexagon section to fit, say, a i-in, wrench, and would then be 10 times more serviceable.
One other grouse we have against the latter Stormer is the method of attaching the wheels. Here, the other scores handsomely. With the type of wheel studs used on this model, we have to remove the wheels with a 7-lb. sledge hammer—the method shown us by the maker's main dealers from whom we bought the vehicle. This unfortunately reduces the pay-load somewhat, owing to the weight of the tool kit carried.
Until recently pipe unions were made from hexagon brass that no standard wrench would fit. True, as a rule, one had an adjustable wrench in the tool kit, but
our views on this are that the man who invented adjustable wrenches ought". to be made to use them, and, in any event, the unions were usually in such a position that it was impossible to get at them with a wrench of that type. The unions were therefore usually manipulated with pliers, which rapidly rendered them unserviceable.
The Ford instruction book has sadly deterioriated from the old days of the Model T. In those days, the Ford Company gave the purchasers of its vehicles the credit for a little ability, and anyone with an average amount of common sense could almost completely strip and reassemble the vehicle with the aid of the instruction book. The explanations were clear and the diagrams were admirable and showed every part. The spare part book was a model that might have been followed by every maker with advantage; but now the present instruction book is very nearly useless. In respect of anything the least bit out of the ordinary the book says, "Take it to the dealer." What happens if the dealer be 700 miles away, as was the writer's experience in West Africa? Besides the average fleet owner wishes to carry out his own repairs, usually at a time when all good dealers are in bed, and it is only fair to him that the instruction book should explain every operation in detail and sequence in order that it may be done efficiently and expeditiously.
We lookforward to reading of other people's snags— no doubt you will have plenty of correspondence on the subject. . G.. W. IRwris, Linton. For Linton Haulage Company.
[We are sure that the makers of the vehicles to which Mr. Irwin refers will welcome such helpful and constructive criticism. It is not often that practical men can voice their opinions so adequately, but it is they who have to suffer inconveniences which might well be obviated —En.] WEIGHT TRANSFERENCE ON VEHICLES.
[4548] It has been very gratifying for me to note the interest taken by Mr. H. King in my article under the above title, published in your valuable paper on April .19.
I cannot quite agree with Mr. King on the question of overloading the capacity for mathematics of your readers. It has been my experience that, for the past few years, more and more capable technical people are put in charge of the running of fleets of commercial vehicles, and I am of the opinion to-day that a very large proportion of the readers of The Commercial Motor are capable of digesting such matter. n29 Furthermore, it would have been quite easy to publish only the curves, but to prove my conclusion, the formulai on which these curves were composed became more or less essential, and perhaps, what is more important, with the help of these formulw readers can produce similar curves which apply to their own particular requirements.
Mr. King's contribution is no doubt a very helpful one, but in my article I preferred to " spice " with facts and figures the various factors relative to weight transference, and to furnish evidence on a subject of which little information was hitherto available.
It is, of course, quite correct that manufacturers have to design the vehicle to withstand all reasonable weight transference, but a combination of factors, such as described in my article, can—depending also on the condition of the vehicle—have a severe effect on it. Furthermore, it should be evident from the article that any overloading beyond the rated load Capacity of the vehicle will cause the stresses due to weight transference to be immensely increased.
The illustration of all these factiirs should therefore be a helpful warning even to the non-technical man, since the information is given in a picture of curves which most people are able to read. In conclusion, I would say that I am grateful to Mr. King for having raised these points, for he has thus given me an opportunity for further elaborating on this subject. A. LAMPERT, Chief Engineer, for Armstrong-Saurer Commercial Vehicles, Ltd. Newcastle-upon-Tyne.
A PREPARATION TO SOLIDIFY ORDINARY SOIL.
[4549] Some considerable time ago, possibly two years, I seem to remember reading in your journal something about a liquid preparation for dressing ordinary soil, setting it hard like concrete. I believe it had been used by the W.D. with good results.
If possible I should like to find out more about this preparation, in connection with a stand which I shall shortly be making for lorries. I have in all a considerable area of ordinary pasture land to prepare for carrying traffic, and wish to do it as cheaply as possible.
Duddington. H. C. THOMAS.
[The emulsion for hardening the surface of unmade roads is called Terolas, and is made by Colas Products, Ltd., Colas House, Buckingham Gate, London, SAVA.. It was demonstrated at the W.D. trials held in May last. Colas Products, Ltd., will no doubt be pleased to give you full details regarding the use of Terolas.—En.)