OPINIONS and QUERIES
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The Need fcr Improved Facilities for Education in Connection With Road Transport
A Technical Discussion on Oil Engines. An Alliance for Ownerdriver Hauliers Transport Educational Facilities Neglected.
The Editor, THE COMMERCIAL MOTOR.
[4008] Sir,—Apropos your qeader. in The Commercial Motor of February 17, my own comments, as a student on the road side of the transport lectures arranged by the Manchester education authority, may be of interest.
The lack of knowledge of the broad principles of road-transport operation, finance and economics is more apparent in the transport industry, amongst the smaller firms, than in those of any other of our big industries. That is why, presumably, the small operator of public-service vehicles immediately flies to a member of the legal profession (who, only too often, does not know the difference between a theatre ticket and a motor-coach ticket) when he has to apply to the Traffic Commissioners for road-service licences.
The uncertainty of the future of road transport is a big hindrance to the young aspirant to a road-transport career. In almost every issue of your journal one finds that still another private concern has been taken over by the railways or a combine, and, within my own experience, the staff of the private concern are usually dispensed with and their duties allocated to the head office of the riewcoiner. The student employed by the railways or the large companies knows that he can confidently look forward to a transport career with great possibilities and can study to that end.
Whilst the Road Traffic Act has imposed obligations on the holder of licences, it has also given to such holder a quasi-public standing, and it is to be hoped that those smaller firms who are still determined to retain their independence will encourage their employees to better themselves and help the firms to fulfil their obligations to the public and the authorities by a study of the science of transport. The younger members of the staff could be encouraged to. attend transport lectures, secure in the know/edge that they are not wasting their time, but that at some future date they will he called upon to take up a more responsible position with the firm instead of working and studying in the fear that either Government legislation or a sale of the business will put "finish" to their aspirations of a transport career.
I must, of course, hasten to add that there is no reflection intended on the attitude of the railways or combine concerns to redundant employees of firms they take over. After all, they buy up the concerns to effect economies and, in any case, their own employees are entitled to have first consideration when any opportunity for advancement occurs.
I also agree with you when you say that the poor attendance is not due to the niggardliness of the educational authorities, but I would suggest that they inform the smaller transport concerns of the facilities they offer, as, at the present time, their intimations are forwarded only to the large companies, corporations and Government offices.
When the transport industry is more stabilized I do think that the education and welfare of its members will receive greater consideration and that the members will not be slow to take advantage of the -facilities
offered. N.T. Bolton.
The Editor, THE COMMERCIAL MOTOR.
[4009] Sir,—In connection with your remarks in a recent issue of The Commercial Motor regarding "Transport Facilities Neglected," may I, as an employee, state my opinion on this subject?
The failure of these classes was probably through no fault or lack of initiative on the part of potential pupils, but through the lack of advertisement. I suggest that 75 per cent. of the employees of road-transport undertakings were not aware that these classes were in existence. REGULAR READER. Enfield.
Oil-engine Efficiency.
The Editor, THE COMMERCIAL MOTOR.
[4010] Sir,—May I be allowed space to reply to your correspondent Mr. E. J. Fearn, whose interesting letter appeared in your issue of February 24? I confirm that Mr. Ricardo, in his lectures to the Royal Society of Arts in November and December, 1931, stated that "owing to the very large heat loss during the passage of the burning gases, etc., . . the loss being of the order of 15 per cent. to 20 per cent." Mr. Ricardo further stated that "the pre-combustion chamber would appear to be an easy but an inefficient, and therefore temporary, way" of avoiding, a big problem."
Why Mr. Ricardo now adopts a pre-chamber design in his engines is not for me to suggest or discuss.
I cannot possibly generalize on pre-chamber engines, owing to the great number of different designs now in use and to the fact that each type has quite distinct characteristics. I cannot agree that the pre-chamber engine has more flexibility over a large range of speeds than the direct-injection type. Take, as an example, the most popular pre-chamber engine in the world—i.e., the Mercedes-Benz engine. Its maximum torque and .h.m.e.p. are -developed at 800-900 r.p.m., whereas the most successful direct-injection engine— the Gardner—does the same at about 1,000-1,100 r.p.m.
If there be any general "essential" difference betweeti the two types it is surely in the cylinder-head design and the.lost heat, as laid down by Mr. Ricardo. This, of course, brings in its train the need for higher compression ratios, heavier and more complicated construction, the need for heater plugs and heavy batteries for starting from cold, and in many cases a disadvantageous effect on lubricating oil. When we talk of "an efficient engine," apart from fuel consumption, all these points count seriously against the pre-ehamber engine, and they must entail an increase in-mainteianee costs.
The "life" of the engine, as with petrol units, is chiefly dependent on the speeds at which it runs—this is universally agreed by all infernal-combustion-engine experts. With the oil engine we have the great advantage of a powerful and sustained torque, which enables us to keep the engine speed down to a reasonable limit and thus lengthen the "life" of the engine, and to get all the road speed we want by means of suitable gears.
It is significant that the two most experienced oilengine makers in the world limit their maximum engine revolutions to, pre-chamber, 1,850 r.p.m. ; directinjection, 1,700 r.p.m. It is equally significant— perhaps Mr. Fearn has not noticed this—that recently, after many attempts at much higher speeds, some of the well-known British vehicle makers have found It necessary to reduce their speeds to approximately the same as the two makers above mentioned.
Mr. Fearn shows a graph of the results from a singlecylindered engine on the Oherhiinsli (Omo) chamber principle which has developed 23 b.h.p. per litre. Such an experimental bench result is no criterion, and most makers could produce a similar result on the bench by revving up to 3,000.
There was published recently an official report of a test run with a Tangye VM6 engine, on the road. This was a six-cylindered engine of 120 b.h.p. (capacity 9.2 litres), governed to 1,800 r.p.m. This large (for a light vehicle) engine was fitted to an old Lioness singledeck bus, weighing fully loaded less than 74 tons. The back-axle ratio was raised to 4.4-1. The engine started after the heater plugs had been switched on for 30 seconds. The consumption rate was 12.7 m.p.g., thus giving a total g.t.m.p.g. of 94. Mr. Fearn will, I feel sure, agree that this is not a very great performance— the Lioness as a petrol-engined bus will do almost as well, certainly over 80 g.t.m.p.g. A 120 b.h.p. engine put into such a light vehicle is not a fair and reasonable test—the engine is out of all proportion to the total load pulled.
I would have welcomed the report of such an engine fitted to something like a 15-ton Scammell, and given a good belting from Liverpool to London for a few weeks, pulling a total gross load of about 24 tons. That would be a real test, but it would have to do much better than 94 g.t.m.p.g. to hold its own with directinjection engines. There are 10 of the latter actually doing this work every day, showing 240-250 g.t.m.p.g., and sticking it bravely, although they are only of 8i litres capacity, and develop less than 100 b.h.p. at 1,550 rpm. Some of these vehicles are doing 1;500 miles per week, and have 'been doing for many months, without any maintenance expenses.
For the moment we are not concerned with cars, although we have recently shown what an oil-engined car can do, as compared with petrol-engined vehicles, in a severe test. Lorries and buses are the vehicles we oil enthusiasts are interested in, and although the weight of the chassis in both cases is very important, it has been found that 15 lb. per b.h.p. can be accepted without sacrificing anything. With this weight makers can produce an engine of sufficient strength and stability to stand up to hard road treatment. It is doubtful if this can be much reduced without having to sacrifice strength and stability. This has been amply borne out recently by several unfortunate happenings, which naturally one cannot write about.
A recently published report showed that a directinjection engine can run well over 100,000 miles without overhaul, with hardly any replacement cost worth mentioning, with a maximum cylinder wear of only .017 in., and without any appreciable loss of power. I think that I can say to Mr. Fearn that the clay of the "critical examination" has already come, and that the direct-injection engine has passed its tests with
flying colours. W. H. GODDARD. Leeds.
B38
The Editor, THE COMMERCIAL MOWS,.
[4011] Sir,—A most misleading letter on oil-engine efficiency appeared in your issue of February 24.
Your correspondent bases his arguments for the precombustion-chamber engine on the assumptions—first, that an engine running at 3,000 r.p.m. will last as long as one governed to a maximum of 1,700 r.p.m., and, secondly, that tax ratings have some connection with engine efficiency. The first proposition needs no comment, and the second is absolutely irrelevant, because piston diameter does not in any way affect commercialvehicle taxation.
The only practical method of comparison between the two types is a consideration of their relative performances at the speed at which they will normally run to give reasonable economy to the owner of the vehicle in question. The ability of the pre-chamber engine to run up to 3,000 r.p.m. is in practice worthless, because of the disproportionately greater wear and tear and the increased fuel consumption at that speed.
Considering the published curves and assuming a reasonable average rate of revolutions to be 2,000 r.p.m., the Tangye engine at this speed develops 12.3 b.h.p. per litre and the Gardner engine 13.1 b.h.p. This is not all the story, for we find that the fuel consumption of the Tangye engine at this speed is 0.445 pint per b.h.p.-hour, whilst the Gardner gives 0.428. So that in addition to a 7 per cent. increase in specific power output the direct-injection engine shows a 4 per cent. improvement in fuel consumption. At 1,300 r.p.m. the consumption of the Gardner engine drops to %. per cent. lower than that of the Tangye.
When it is considered that in addition to the superior performance and economy indicated above, the smoother-running DJ, engine eliminates heater plugs and sometimes even electric starters, the practical man cannot hesitate to make it his choice.
Incidentally, it is amusing to note that, in spite of the wonderful claims anent the performance of these pre-chamber engines at high speeds, every one of them is governed to 2,000 r.p.m. or lower.
Penn (Staffs). H. MAYNARD THOMPSON.
The Alliance of Owner-drivers of Commercial Vehicles.
The Editor, THE COMMERCIAL MOTOR.
[4012] Sir,—In order that this movement may have the consideration of your readers, the following is a summary of its intentions :-
The primary object will be to provide the responsible owner-driver with a decent livelihood and to secure his future.
Every endeavour will be employed to convert him, collectively, into an efficient and indispensable unit of the haulage industry, with ability to compete for work on a fair and reasonable basis.
It will encourage and foster in every way the raising of rates to a practical level, and it hopes to play a not unimportant part in lopping off the dead wood from this branch of the industry.
These objects will be attained by direct methods. A service will be established, first in London and then elsewhere, as becomes necessary, to find every class of haulage and hire work suitable for its members and their vehicles. The undertaking of long-distance haulage with vehicles unsuitable on account of condition or limited capacity will be discouraged.
The next consideration will be the reduction of individual operating costs. A method has already been devised by which a member, wherever he may be, will enjoy the advantage of purchasing fuel and lubricants on a bulk basis. Then there will be a system for the co-operative use, in certain cases, of garages and garage accommodation. Finally, members desiring to be covered for repairs and maintenance will be offered a service at minimum cost.
Should a member be unable to complete, a job on account of illness or other unavoidable mishap, means
will be furnished to finish it for him, and So keep faith with the customer. Thus, every . member will confidently be able to guarantee service.
A fund will be open to voluntary contributions from those -desiring to provide against the renewal of tax and vehicle depreciation. This will either be registered under the Friendly Societies Act or otherwise secured in the interests of contributors.
Another fund, probably in the form of a Trust, will make provision for sick benefits and pensions or endowments, according to circumstances.
Some of the negotiations in connection with the foregoing are pending; others, to all intents and purposes, have been satisfactorily concluded.
'.Realizing that the resources of the average ownerdriver are somewhat limited, care has been observed in planning the most reasonabieterms for membership.
It is proposed to invite all'bona-fide owner-drivers within reach of London to apply for admission to a general meeting which will be held so soon as the number of such applications warrants this move.
* Your readers are requested not to draw me into correspondence when applying for admission to the proposed general meeting, as I feel sure that discussion on the merits and demerits of the Alliance and its programme would be better left until then.
E. H. B. PALMER.
6, 'Norfolk Mansions, London, S.W.11.
[We have every sympathy-towards any move that will tend to improve; the state of the haulage industry in respect of rates, employment and social conditions, but we question the advisability, at this juncture, of starting another association. The tendency during recent months ha:been to reduce the number by combining them into more fully representative organizations, such as the Road Mintage Association and the Commercial Motor Users Association, which are working on national lines. It is not possible to express 'a decided opinion as to the probable success or otherwise of an alliance founded purely for the purpose of trading. The scheme presents cattail
• attractive features of an idealistic nature, but their practical development will undoubtedly present some difficult problems. Organizations of this pattern have been tried out in the past without any great measure of success, but,. much must depend upon the energy and enthusiasm of the leaders.--ED.1