OPINIONS FROM OTHERS.
Page 27
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The Editor invites correspondence on all subjects connected with the use of commercial motors. Letters snld be on one side of the paper only and typewritten by preference, The right of abbreviation is reserved, and no responsibility for views expressed is accepted.
Can the Air in Pneumatic Tyres be Cooled?
The Editor, THE COMMERCIAL MOTOR.
[1994] Sir,—Mr. Henry Sturmey has possibly had as wide a general experience of motoring matters as any man living, and it is gratifying to know that he still maintains his faith in the pneumatic tyre in the face of many attempts to belittle its achievements and stultify its future development by the introduction of substitutes.
That, the life of a pneumatic tyre depends very largely upon the maintenance of correct air pressure we quite agree, but, in our opinion, it is equally important that the tyre be kept cool. If a constant flow of cool air could be passed through the tyre whilst maintaining correct pressure, it appears to us that much would be achieved, and we should like to have your readers' and Mr. Sturmey's views on the feasibility of such a plan. Once a mechanical air compressor forms a part of a ear's standard equipment it does not require a very big stretch of the imagination to conceive of its use for such a purpose, bearing in mind that what may be impracticable and unnecessary for the tyres of light vehicles, may be both practicable and desirable for the heavy demands of buses, coaches, lorries, and other coinmercial types.—Yours faithfully,
ITARVEY FROST AND CO.; LTD.
A Criticism of the W.O. 30-cwt. Vehicle.
7h,e Editor, THE COMMERCIAL MOTOR.
[1995] Sir,--It is a truism that "one tale holds good until another is told," and one that is emphasized by this specification and the criticisms it has brought forth.
The War Office endeavour to embody in their specification those points which have proved themselves to be as near perfection as possible up to the time of drawing the specification, but it must not be taken for granted that, in detail, the W.O. have the last word.
It is appreciation of this line of reasoning that makes the views of the "well-known commercial vehicle firm who prefer to remain anonymous" so weighty. (See your issue August 15th, 1922.)
There is a small but important detail in the specification in which I have an individual interest, namely, the preference for a wick feed oiler for shackle bolts and steering joints. It has been stated in correspondence in your paper that the. wick feeds the bearing surfaces by capillary attraction, and, therefore, no excess oil is supplied over the demand at each particular lubrication bolt, but is this true ? One can understand that capillary attraction carries the oil-from the cup along the wick, but surely beyond this Point the wick will act as a syphon and deliver the oil as long as there is anoutlet for it. -There is also such a thing as surface attraction to be considered. Whereas siipe`rfluous grease would cause local disfiguration to a well-kept chassis, oil would creep over the surface of everything in the vicinity of the oiler. It was further stated that there was no risk of the introduction of grit or foreign matter because the direction of the oil was an outward one, tending to remove any such substance. This may be true enough, but it is rather beside the point. It is the introduction of grit and foreign matter (" muck " is a better term) into the cup (which can happen very easily in an oiler) which will cause trouble under normal road conditions. It requires very little imagination to picture a driver, -in a burst of enthusiasm, digging accumulated rubbish out of the oiler, includ
ing the very essential wick, the latter never to be replaced. I do not know who compiled the W.O. specification, but I should grant priority of experience to the designers of such cars as Armstrong-Siddeley, B.S.A., Charron. Humber, Karrier, Rolls-Royce, *Standard, Guy (surely not that of the great protagonist, of oil lubricators!), and other well-known makers-who, in these enlightened days, supply a patent grease lubricator as a standard accessory..
The theory of lubrication is really very simple. It consists of interposing a third pubstance between two metals to avoid the adhesion which will take place if they come into contact. This third substance may be solid, such as graphite, or talc ; liquid such as grease, or oil ; and even gas such as air. If a liquid, it must adhere strongly lest it squeezes out or, alternatively, it can be supplied copiously as in engine bearinglubrication, which consists mainly of running the bearing in a bath of oil: This method is commercially impossible for shackle pins and steering joints. It is the ahesion that is the main reason for the superiority of grease for this purpose.—Yours
faithfully, GILBERT C. BATE.
The Clearing-house and the Haulier.
The Editor, THE COMMERCIAL MOTOR.
[1996] Sir,—A few more observations on this subject please, and I have finished. I feel "The Skotch " haa given a comic turn to what should have proved an interesting discussion. His chagrin about,' long letters to the Editor " wee, quite`uncalled for, and I venture the suggestion that I traverse less ground than he in arriving at a point ; moreover, judging from the letters of congratulations I have received, ray readers are not left in doubt. I simply defended the honour and integrity of my company and other bona-fide clear ing-houses from the unwarranted attacks by him, just as ally other sensible man would protect his reputation. It occurred to rue that "The Skotch " being concerned in "helping hauliers," would be at least interested to learn that certain clearing-houses were act.lally doing useful work for hauliers, but, apparently, I was mistaken. Obviously, he was disagreeably surprised to find his position not so bad as he had alleged, although in some mysterious way he would appear to be engaged in briefing a case for clearing-houses. Regarding the insinuatiOn of "The Skotch " that the criticisms of " a typical clearing-house experience" apply to my company, this is nothing less than a hit below the belt! It being common knowledge that the criticisms do not apply to my company, I could have afforded to ignore the insinuation, but for the fact that silence might prejudice us with prospective customers. For the information of "The Skotch," there are no office boys or girls in our establishment who deal with drivers. Our office is opened at 8.45 a.m. either by our traffic m-anager, myself, or other adult 'staff, and closer 6 p.m., 7 p.m. or later to suit hauliers' requirements. Several loads.were arranged before 9 a.m. to-day. 'We wOuld open at 7 a.m: if our customers desired it, or if it served any other useful purpose. Incidentally, the office is never left unattended by at least One person in authority throughout the day. We do not have to ring to all the principal warehouses. In any ease, we only apply to our recognized pustorners, and this is seldom necessary, as they notify us of their requirements.—Yours faith fully, WALTER GAMMONS; Managing Director WALTER GAMMONS, LTD. [This correspondence has now closed.—En. C.M.]