Opinions from Others.
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Several Correspondents Further Discuss the Relative Merits of Assembling Methods. The Writer of the Original Article Design and Replies to Mr. Pentony.
Design or Assembly ? "Engineer
Designer" Replies. •
The Editor, THE COMMERCIAL MOTOR.
[1WI] Sir,—I shall be glad if you will allow me some little space in which to .reply to Mr. Pentony's criticism of my article on " D'2esign or Assembly?"
In the first place, I should like to make it clear that nothing that'I wrote was based on mere assumptions, but on first-hand knowledge and after careful and prolonged study of the subject. The assembled chassis, as known both here and in America, is more expensive to maintain and it depreciates at a more rapid rate than the other type. I still maintain most strongly that only those chassis which Mr. Pentony prefers to call " one-shop" chassis are really designed ; the other type is merely built of carefullyselected units, the difference in value between one and another depends on the factors governing the selection. In the same way, I must contradict the assertion that I compare the worst of assembled chassis*with the best of designed ones. I am not taking as examples cars thrown together merely for the purpose of selling during the war (I had almost written cars built tor the duration of the war ") nor commercial vehicles built from touring-car parts. From the nature of things, a properly comprehensive knowledge of assembled chassis is only to be derived from those of American manufacture. In this respect, I think I can quite fairly claim to have had better opportunities for investigation than are ordinarily available. I hope Mr. Pentony will forgive me if I remark that the citation of the Ford case seems once more to have got. well home.
Turning now to the third paragraph of the criticism, I have no intention whatever of trying to belittle the units of assembled chassis ; for these I have very considerable respect, The shortcomings of the completed machine are not due to weakness of their parts, but owing to the inevitable interference as between one and another, this failing being due to the fact that one brain does not supervise the design of them all, and that lacking this supervision, or, in its stead. some co-operation between designers of units and chassis.. it is inevitable that. some such trouble should ensue.
In the fourth and fifth paragraphs of his letter, Mr. Pentony proceeds to argue the efficiency of individually-constructed units as against those which form part of what I term a " designed" chassis. In this aspect I am in entire agreement with your correspondent and beg to quote from the article in which, referring to the selection of units, I say :—" As a general rule, it is true, owing to the variety of models marketed by each maker, he will have no difficulty in selecting parts admirably suited for the work in hand, and, considered from this point of view only, there would appear to be no reason why an " assembled " chassis should not be so good as a designed' one." As regards the one-shop man having to consider existing plant and tools—compare his case with that of the unit manufacturer who, after laying down expensive plant and tools for the manufacture of sonic; unit, discovers, when his product commences to be generally used, some unforeseen defect or shortcom ing of such a nature as to necessitate the scrapping or modification of very valuable machinery and jigs
before it can be remedied. And what happens? Mr. Pentony cites the case of the one-shop manufacturer fitting a six-ton chassis with a five-ton axle and trnsts ing to luck—this is argued as a "possibility." I
know of more than one case where the manufacturer of an assembled chassis has, for the sake of economy or perhaps because of the lack of facilities for acquirement of the right size of axle, sent out three, tour or live-ton chassis, as the case may be, with two, three or four-ton axles respectively ; these, however, are not examples which have been chosen for purposes of comparison ; they are merely mentioned as a reply to thecriticism offered.
I must reiterate my view that the various units of an assembled chassis are as good as, and in many cases perhaps better than, those produced by a oneshop firm, but repeat that complications ensue when these units meet on a common frame.
I am confident—and for the sake of the industry as a whole—happy in asserting that your correspondent is very wide of the mark indeed when he says that the tendency is to assemble cars more and more. In America, the user in search of a sound chassis is stipulating to a greater extent as time goes on that It shall not be an " assembled " machine. Certain American manufacturers are already advertising " not an assembled proposition" as an inducement. If Mr. Pentony is referring only to British products, then his statement needs qualifying. The presens state of things in this country istemporary only. In any case, to be fair, he should distinguish between chassis built up from units built to order, and chassis made from standard parts. There is striking differ once. This also has a bearing on your correspondent's next paragraph. If the " designer " of an " assembled' chassis does not select his parts from the catalogue or the equivalent he must have them built specially, and in this case, as I pointed out in the article under discussion, his machine comes uncles the class " designed." If his parts are merely selected, then I maintain that as things are, the features of inaccessibility dealt with (although I agree with Mr. Pentony that they are not peculiar to the asaembled machine) are, as a matter of fact, inherent in that type. . Let us suppose an assembler selects engine from A, gearboxes from B, and axles from C, and—and here we venture further into the realms of supposition— let us believe that these units when in place are such that they do not interfere one with another, nor is their accessibility diminished owing to their position in the chassis, or with respect to the remaining parts not mentioned. Another manufacturef may agree as to the suitability of A's engines and C's axles, but prefers the design of D's gearboxes—note that the question of buying on price, a not inconsiderable factor, is left out of the question—is it to be expected that the combination of A. D, and C will also be free from the defect of interference to the same degree as that of A, B, and 0? If your correspondent will bark back to his schooldays when he toyed with such things as permutations and combinations, and will
apply his knowledge then gained to working out the odds against the right set of tumts appearing togethersupposing that they are in existence—I think he will see my point. Before discussing the relative merits of British "assembled" and 13ritish " designed " chassis, I would like to be directed to an all-British chassis, which is also an " assembled" one in the strict sense of the word as laid down in the article, and which has been sold in any number. In passing, and referring to the closing sentence of paragraph ten, I hope that a request for your correspondent not to take the worst of " designed " chassis to compare with the best of the other sort, will not be deemed a " reprisal."
In quoting two eases of inaccessibility, I distinctly stated that these were selected from many, and have very good grounds for my statement. With the conclusion your correspondent has expressed in the penultimate paragraph of his letter, the suggestion that assembly from units has progressed in the States as far in heavy vehicles as it has in touring cars, I cannot agree. In neither has the stage been reached which I suggested as a means of improving the quality of the finished product.
My own concern is principally with heavy vehicles, and ray knowledge of touring cars, although not negligible, is of secondary value only. With regard to the former, results show that; assembly is improving neither the quality nor strength, and, furthermore, the assembled chassis is heavier for what seem to me to be obvious reasons. The advantage of increasing interchangeability is nullified by the inaccessibility, and as to the question of price, one of Lancashire's biggest users in conversation with a friend of mine the other day, speaking from experience, stated that the majority of cheap assembled machines would not last long enough to pay him, he preferred to be without, and it is within the writer's knowledge that this particular man is badly handicapped owing to lack of suitable vehicles for transport.--Yours faithfully, THE WRITER OF THE ARTICLE.
Dzsign or Assembly ? A Letter from Wrigley's Designer.
The Editor, THE COMMERCIAL MOTOR.
[1592] Sir,--I read, with interest, the article entitled "Design or Assembly " in your issue of the 3rd inst. The author lays particular stress on the supposed inaccessibility of vital parts of the assembled chassis. He speaks as though the majority of assembled chassis are made up from a heterogeneous collection of parts having no central idea or guiding motive.
This lack of homogeneity is not essentially a fault of the assembled proposition. As a matter of fact, at the works with which the writer has the honour to be associated, a. -new chassis is always "designed " with the standardized " motor units" which' we supply drawn into place, and the " design " is carefully checked over . not only for accessibility but to ensure that the various components are " functioning " as a whole. When this method of dealing with the assembled proposition becomes more general we shall hear less of the advantages of indivic:ual design.
FRANK G. Wooetaan, Designer, For E. G. WRIGLEY AND CO., LTE.
Design or Assembly ? Unit Assembly All of One Make.
The Editor, THE COMMERCIAL MOTOR.
[1503] Sir,—I believe I am correct in assuming that Mr. R. Pentony, one of your correspondents in your issue of 17th February, and from whom you reproduce a letter on pages 503-4, is the designer of the line of commercial-vehicle engines manufactured so successfully by Dormans of Stafford.
Assuming that Dormans made not only engines, hut gearboxes, back axles and other units, then if all these were purchased by an assembler and built up by him, the latter, with moderate skill, will reproduce what was in the mind of the original designers as a whole. But if Mi. Pentony's engine be linked with, shall we say, a David Brown back axle and a Wrigley gearbox, there could not exist that uniformity of design which would accrue had all these otherwise excellent units been sunervise.d by one man and one brain. Would . Mr. Pentony be prepared to take n58 responsibility for such a chassis in respect of firstclass design throughout—not only for the units themselves?
I fully appreciate the point, raised by your contributor, "Engineer Designer," that the assembly of individually-contrived units from various specialists' factories is, failing any co-ordination of effort between such rival concerns, more than likely to Tall short of the chassis of which the design has been supervised by one brain, particularly in respect of the all-important features of accessibility, ease of assembly and dismantling.
He would certainly want a say in the whole design if he were to be held responsible for the symmetry of the final production. And small blame to him :— Yours faithfully, MiexaEGATE."
Petrol Prices and Supplies.
The Editor, THE COMMERCIAL MOTOR.
[1594] Sir,—Being constant readers of your most valuable and instructive paper, we should be greatly indebted to you if you could find time to give us your opinion on the following matter. We are at present engaged on carrying munitions for the Government, with a war-type four-ton Maudslay, our other wagons having been taken at the commencement of the war. We have been unable to get a contract for petrol, and in consequence we are experiencing great difficulty in delivering our goods, owing to the petrol people refusing to supply the spirit, and having to run about the town for it where it costs 2s. 611. per gallon. Why all this inconvenience to owners of commercial vehicles, especially to those on munitions? If you can advise us what to do to obtain spirit, we should be much obliged.—Yours faithfully,
Burnley. GREENWOOD BROS.
[If you hr.ve no contract for petrol, you will have to suffer, under the present shortage of spirit. in the same way that other people suffer when they have no contract, for any other commodity of which the price is advanced. The fact that you are engaged on munitions transport should give you a preferential claim. We agree that the matter is a hardship, and we took steps last week to bring it before the Commercial Motor Users Association, in order to press, not only for a renudy, but for some safeguards for the future. Bee also, our further article on this subject (page 2). We trust that your difficulties may soon be alleviated. We are already in close touch with the inauguration of immediate steps by the Ministry of Munitions and other Government Departments to take a considered and sound worse to the end that petrol supplies and distribution shall he supervised.E.,a The Editor, THE COMMERCIAL MOTOR.
[1595] Sir,—Could you give us any information concerning the present shortage of petrol? We have two chassis on order, and if things go on as they are at present it will be a serious matter for us. There are about 100 business cars hung up for petrol about this district.—Yours faithfully,
THE BARNSLEY MOTOR CO., LTD.
[See article on Lage 2, Steps are being taken to press such facts home to the petrol companies. They clarne the railways in part. We are hopeful of results from Government control—Fn.] Tire Editor, THE COMMERCIAL MOTOR.
[1596] Sir,—We note in your remarks re petrol a portion reads—" Only those commercial users who are enjoying the benefit of contracts placed some months ago are free from the uncertainty of the situation." We are fortunate enough to be covered by contracts for our requirements up to the end of 016, but we have had to purchase retail (at considerable trouble) 130 gallons during the past eight days, while we have only been able to get 24 gallons under our contracts.
Is there any special reason for this shortage of contractual deliveries ?—Yours faithfully, .
CHEETHAM BROS. Ilathershaw, Oldham.
[The railway companies, as you know, only accepted petrol on certain days in the week, before the war. They are now not preserving their pre.war practice, and local shortages are unfortunately sometimes unavoidable, so fares we CSI,71 judge, having regard also to restricted supplies of petrol.. .Private-car users will soon only get suptilies if they are