• OPINIO A IS and N QUERIES Is the Modern High-speed Oil Engine a Diesel? The Editor, THE COMMERCIAL MOTOR.
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[3675] Sir,—In spite of all that has been written and published on the point of what is and what is not a " Diesel " engine, I note that a great many people still insist that the high-speed solid-injection engine, which we are now using in ever-increasing numbers in this country, is not a Diesel engine because it does not employ blast air for the injection of the fuel. I am therefore asking you kindly to publish this letter, which I hope will put an end to this erroneous impression and convince those who now doubt it, that the solid-injection engine is a pure Diesel engine.
First of all—and this is perhaps the most important proof—is the fact that Dr. Diesel's first experimental engine constructed in 1893 had no air-supply pump and the fuel "was injected directly." These are Dr. Diesel's own words, and he showed a Picture of this engine at a lecture which he gave in London in 1912. [We were present at this lecture.—En.] Then we have Dr. Diesel's patent specification. This was No. 7241 of April 14th, 1892, in which absolutely no mention whatever is made of blast air or anything like it—on the contrary, the actual wording is "The fuel, gaseous, pulverized or liquid, is then gradually injected into the cylinder," etc., etc. The reference to " pulverized " fuel comes from the fact that before he experimented with oil he tried to use pulverized coal, and in this he failed owing to the difficult nature of this fuel. He did, however, for this purpose, use an air blast, and when, after finding some difficulty in injecting the oil efficiently, he turned to the air compressor to help him, it was purely accidental and because he had the ccimpressor handy, and long after his main and basic idea was formed, i.e., to fire the mixture or charge by the heat of compression.
This is the solid and fundamental invention of Dr. Diesel, to empress the initial charge, which is "pure . air or a mixture of air and a neutral gas" to such a pressure that the temperature resultant "far exceeds that of the ignition point of the fuel employed." These are Dr. Diesel's own words in his patent.
This high temperature could never be built up by compressing a fuel-air mixture, owing to pre-ignition, and this was one of Dr. Diesel's arguments—that to attain the hitherto unheard-of thermal efficiency which he secured, he had to keep the fuel out of the air until the last moment—i.e., at or about top dead centre, in this manner being able to raise the compression ratio to almost anything he wanted (within the limits imposed by mechanical stresses, of course). This he did, and, as all the world knows, the Diesel engine is the highest thermally efficient prime mover ever produced. Whether we blow the fuel oil in or whether we do not does not alter one iota the clear intention and idea of Dr. Diesel when he conceived this brilliant seheme, and an airless-injection engine is just as much a Diesel. as one in which blast air is employed for fuel injection.
To complete the subject, if any further proof he necessary, as late as 1931 a paper was read by Mr. D. R. Pye, M.A.; Deputy Director of Scientific Research at the Air Ministry, in which it was made abundantly clear that an airless-injection engine is as much a Diesel engine as one that uses blast air; in other words, that air injection of the fuel is not especially associated with the name of Dr. Diesel.
I have at various times noticed a tendency on the part of some engineers in this country to belittle this extraordinarily clever invention of Dr. Diesel, and it seems to me that this is an entirely wrong spirit and much to be regretted. Credit must be willingly given where credit is due, and in this case it is most certainly and undoubtedly due, therefore let us give it willingly. FAIRPLAY, Leeds.
Condensation On Sparking Plugs.
The Editor, THE COMMERCIAL MOTOR.
[3676] Sir,—With further reference to our letter No. 3621 published on January 12th and concerning a Dennis 30-cwt. lorry belonging to one of our customers, the matter has been taken up by the manufacturers and we are now glad to say that the trouble has been cured.
The alleged condensation on the sparking plugs was found to be not so much due to dampness as to oil, caused by habitual over-filling of the engine sump by the driver, and the refusal of the lorry to start was mainly due to the magneto being rather -weak. The magneto was not actually defective, as it showed a good spark at the plug points when a plug was removed from the cylinder, but apparently was not strong enough to produce a really " fat " spark under compression at slow speeds. At all events the fitting of another magneto has cured the trouble and the engine now starts without difficulty.
Thanking you for the trouble you have taken in the
matter. • USERS. Winchester.
Effects of the Road Traffic Act.
The Editor, THE COMMERCIAL MOTOR.
[3677] Sir,—The critics of the present licensing system write letters suspiciously like those received by every motorbus operator previous to the Road Traffic Act.
The new system is right in principle, and anyone having experience of the old system looks to the future with confidence.
Gone are the days when a hackney-carriage inspector In one town insisted on details that the official at the next town refused to allow; those meetings of the watch committee, made up of councils the interests of which were the municipal services, or the service of the next-door neighbour ; the disappointment of building up a service, only to see a newcomer taking the cream. when you should have received the benefits of your foresight.
We surely have not forgotten when certain operators cut fares and flooded the routes with vehicles to force off a man who would only sell at a price.
_The industry was in a state of chaos, and the Act has turned a searchlight upon it, to the annoyance of those
who prefer to work in the dark. 3. MORLEY. Lincoln.
The Editor, THE COMMERCIAL MOTOR.
[3678] Sir,—As a regular subscriber to your journal, I have read with very great interest the letter contributed by Mr. Hood-Barrs in a recent issue.
It is high time the public point of view on the licence question was ventilated, and the intolerable burdens of the operator exposed.
You state in your editorial comment that it remains to be seen whether the ultimate effects of the Road Traffic Act will be beneficial.
May I suggest that this attitude of wait and see by the industry as a whole has brought about the present stagnation which seems to have settled permanently upon all those engaged in the supply and operation of passenger-carrying vehicles?
I have been present at numbers of conferences during the term of office of the late Minister of Transport, Mr. Herbert Morrison.
On each occasion he made it clear that it was his intention ultimately to wreck the passenger-transport business for the independent type of operator, and for this he was constantly applauded by his hearers.
It is no use waiting to see what further damage can be inflicted by his lieutenants, as no doubt they have had their instructions.
The trade and the operators should, delay no longer, but approach the Minister of Transport and demand immediate withdrawal of this destructive legislation.
If this matter be not pressed forward there seems no doubt whatever that the majority of the manufacturers will be faced with ruin, and this at a time when every man thrown out of employment means a further drain on the nation's already overstrained Exchequer.
Bexleyheath. A. E. TYRRELL.
How to Keep Accurate Costs.
The Editor, THE COMMERCIAL MOTOR.
[3679] Sir,—As a regular reader of The Commercial Motor, which has on numerous occasions proved invaluable to me, will you kindly furnish me with the following information :—The details necessary to keep a good accurate log of upkeep charges, maintenance costs, etc., for two 2-ton lorries and three private cars, weekly, monthly and yearly summary ; also the approximate size of a suitable garage to house these vehicles, including room for a small office, benches, etc._, so that it can be used as a workshop.
If I remember rightly, you announced some time ago that you could supply a scale of charges (upkeep and running costs) suitable for fixing on the garage wall.
If you have a diary which you think would prove of value to me in my work please let me know its cost.
I wish your journal the success it deserves.
Swansea, H.H.M.
[I have sent to you a very rough outline sketch of the arrangement of a garage for the small fleet of vehicles you enumerate. You will appreciate that this is subject to modification in accordance with the space available.
The scale of charges, upkeep, running costs, etc., to which you refer is' I think, The Commercial Motor Tables of Operating Costs, of which a copy has also been sent.
To keep accurate costs you will find that "The Kwikand-Eexe " business account book, published by James McQueen, Ltd., Moat Road, Leicester, at the price of 4s. 6d., will meet your requirements.2S.T.R.] Forming a Transport Company.
The Editor, THE COMMERCIAL -MOTOR.
[3680] Sir,—I would appreciate your advice on the following matter :—At present I am a partner in a road express service for parcels and goods, and we have a depot which is very central. From this we run a twice-daily service to a Midland town.
Lately we have rented our depot to the operators of five independent services which also run to various parts of the Midlands.
Now I find it very difficult to open accounts with large firms, as they say it would be an impossible procedure to cater for each individual service, therefore I have proposed amalgamating under one title.
I have spoken to each of the five proprietors as well as to my partner, as to uniting, and I have suggested appointing a manager and canvasser. They have agreed that it is a valuable proposition.
I previously drafted a letter to each of these firms, putting before them the advantages gained by combining. They are all very anxious for me to go ahead and put the thing in operation at once. Each of these services is owned by a local man living in the town he serves, therefore I believe each holds a monopoly with his townsfolk, practically excluding outside opposition. This is also the case with my partner.
What would you suggest as regards forming a pri vate limited company, and what would be the pro cedure? UNITED. Accrington.
[Your idea of forming a limited company is an excellent one. Indeed, it seems to be the only practicable way of getting over the difficulty with which you are faced.
You should proceed, in the first instance, by getting together the managers of the various depots and discussing . with them the main points of the proposed agreement. These would include the proportions in which profits are to be shared, and I suggest that that proportion should be calculated according to the amount of business done froln each depot. Each of the existing proprietors would no doubt become a director and receive director's fees in addition to his share of the profits which, however, would be calculated after those fees had been paid. Each of them would agree to remain as manager of his own depot, thus retaining that goodwill to which you, quite rightly, attach so much importance.
Having agreed to these things and set them all down in writing, you should go to a solicitor and have the articles of association drawn up. In choosing your solicitor be careful to select one experienced in this class of work. You could find that out by reference to the information regarding existing companies, which information is obtainable at the hands of the Registrar of Public Companies.
When a Hawker's Licence is Required.
The Editor, THE COMMERCIAL MOTOR.
[3681] Sir,—" I wrote to you last June, asking for your advice regarding light hire work, and received a very courteous reply. However I eventually abandoned the idea in favour of drapery hawking, having obtained a light-delivery Chevrolet, fitted out and titled by myself."
This reader's letter appeared recently in the daily. press. I pay n a year for a hawker's licence and k5 10s. for a quarter's road tax on a vehicle weighing 21 cwt. Can you tell me if I am exempt or can claim
relief from either tax? HAWKER. London, N.W.10.
[There is no doubt but that if you act as a hawker of drapery, or of other goods which you do not make yourself, you require to have a hawker's licence, whether you carry the goods yourself or take them around in a motor, vehicle. We assume that the query to which you refer applies to eases where the traders take their goods to a point in a street where they use the vehicle -as a stand from which they sell the goods. In such a case a hawker's licence is not required, as such a licence applies only where the seller goes from house to house selling his goods. You must pay the vehicle tax.—En.]