OPINIONS and QUERIES Specific Gravity of Little Value as a Test for Oil Fuel.
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The Editor, TEE COMMERCIAL MOTOR.
[3713] Sir,—I notice in your useful book, "Compression Ignition Engines for Road Vehicles," that in a number of instances a value for the specific gravity of the fuel is specified.
It would seem that this information hes been supplied by the engine builder, but it is a great pity that any such specification should be given, as gravity alone has very little bearing on the suitability or otherwise
of fuels for high-speed oil engines. Practically the only influence which can be attributed to gravity itself is its effect upon the weight of the charge injected for• a given pump setting, and an appreciable increase in gravity might possibly change an exhaust at full throttle from a clear one to a smoky one.
In the early days of the automobile industry misunderstanding was created by the supposition that gravity was a test for the suitability or otherwise of petrol, and many thousands of tons of the very best petrol were deliberately destroyed as a result of this misapprehension. It would be a very great pity if anything similar should occur in connection with oil fuels.
At the present time it is by no means certain just what goes to make a first-class fuel for high-speed oil engines, and I therefore think that everything possible should be done to avoid creating any wrong impressions in the mind of the user, as once these impressions are given, they are extremely difficult to eradicate. It is with this object in mind that I am communicating with you. C. B. DICTUM, For The Associated Equipment Co., Ltd.
Southall.
How Some Hauliers Lose Business.
The Editor, THE COMMERCIAL MOTOR.
[3714] Sir,—As a regular reader of The Commercial Motor I feel that I must criticize the cabs on some of the modern light goods vehicles. Many designers would do well to copy some of the ideas used in the bodies of the heavY lorries, both old and new. I have driven a good many heavy old crocks in my time and they are Rolls-Royces compared with the discomfort and lack of space on some of the new 30-cwt. to 50-cwt. lorries.
One glance at a typical cab will assure any experienced person that he will need to be an acrobat to get in and out and will be contorted while driving.
If two men have the misfortune to be detailed for duty and they wish to take overcoats and food, owing to the limited space they must put their belongings outside on the load or sit on them.
Also the rear-view mirrors on most small lorries, owing to the narrowness of the cabs, give the driver an ideal view of the inside of the body and tailboard, but should the owner put on a tilt or a bolster then the reflectors will go out of action so far as their usefulness is concerned.
I am of opinion that when a modern light lorry with a small cab is bought the buyer does not give any thought for the comfort of his men, but concentrates his mind on the chassis and how much overload it will carry ; also on whether, if two men be put on it, it will do the work of a 6-tonner cheaper than a real 6-ton model. After the first year is ended he finds that he has made a dead loss of about 12s. per week, compared with the 6-tonner on the same job, and, finally, that the work has gone over to rival concerns. There is then not enough work to justify bringing out the heavies, and he is no longer a haulage contractor but
a jobbing carter—and so on to the end, DRWER. Guildford.
A Novel Way to Utilize Gas Fuel.
The Editor, THE COMMERCIAL MOTOR.
[3715] Sir,—Recently considerable progress has been made on the Continent in the use of compressed gas, stored in cylinders, as a fuel for motor vehicles.
May I venture to make the suggestion that it might be possible to develop this method into a dual-fuel system, by using the energy of the compressed gas, emerging from a specially arranged nozzle, to atomize crude or waste oil into a fog or vapour suitable for use in ordinary low-compression engines?
The engine could be started on gas only and the oil spray brought into use when the engine had become sufficiently warm.
This method would reduce the number of storage cylinders required and would facilitate the use of cheap low-grade oil in standard-pattern engines.
The views of your readers on this subject would be
of interest. W, ADAM WOODWARD. London, N.17.
Heavy Vehicles Unfairly Blamed for Accidents.'
The Editor, THE COMMERCIAL MOTOR.
[3716] Sir,—We enclose a cutting from The Yorkshire Post, which appeared in their "London Notes" of March 18th. You will notice that for some reason they are accusing the heavy road vehicle of being the principal cause of the large casualty list caused by road accidents.
We have no figures here analyzing road accidents, but we have the impression that the largest proportion is either met with by motorcycles or caused by them. After that it is probable that high-speed cars are responsible for as large a proportion of accidents as any other class of vehicle.
In any ease, we think that this attempt to put the blame on the heavy motor vehicle is definitely wrong and should be refuted as strongly as possible. It is all part of the propaganda which is being put forward by the railway companies just now in an attempt to persuade the public that the road-transport interests are being unduly favoured. The railway companies are pressing with all their power to get further restrictions put on the heavy vehicles, and if they can assist that claim by blaming the heavy vehicle for an excessive proportion of accidents they will not fail to take advantage of the opportunity.
In this ease, you will notice, it is stated that the opinion is growing amongst Members of Parliament. It seems to us that if Members are being fed with biased information of this kind it is high time that we took steps to correct it. If you have in your records particulars concerning the accident rates referred to we should be very pleased to forward them to local Members here and ask them to bear both aspects Of the matter in view.
We feel it is time that the road-transport interests made a more determined effort to put forward their views, because the propaganda issued by the railways is becoming stronger every week.
N. GELDARD, Director.
Leeds. For John Fowler and Co. (Leeds), Ltd.
[With reference to the points put forward by Mr. Geldard, the following are the accident figures in Great Britain for the year 1930. In each case the first figure denotes the number killed and the second the number injured:— buses and coaches 938, 11,332; trams and trolley-buses 107, 6,171; motorcycles 2,054,49,064; private cars 1,882, 55,458; cabs 78, 2,671; motor vans and lorries 1,402, 21,547; horse-drawn vehicles 158, 3,773; cycles 574, 27,576. The vehicles mentioned are those to which the accidents were attributed.—En.] Pedestrians who Must Walk in the Road.
The Editor, THE COMMERCIAL MOTOR.
[3717] Sir,--I have read with interest "Justice's" letter in The Commercial Motor Of March 22nd. "Justice" says he will be interested in reading the views of other readers. As a reader of your journal, I would suggest that he looks at the question from the point of view of what he would have said if, instead of encountering a woman pushing a perambulator on the road, he had overtaken a man wheeling a wheelbarrow or pushing a handcart. In these cases the "pedestrians " could not have used the pavement.
"Justice" says in his letter : "By a tremendous effort I pulled up and just managed to miss this woman." It seems to me that he is condemned out of his own mouth as driving to the danger of the public, and is, therefore, subject to a fine for this offence under the Act of 1930. No one, of course, is going to take proceedings against him, but I suggest that he gives the amount he deserves to be fined to some local charity.
T. C. FOLEY, Hon. Secretary, The Pedestrians' Association.
The Ridging or Grooving of Brake Drums.
The Editor, THE COMMERCIAL MOTOR.
[3718] Sir,—Whilst agreeing generally with Mr. Bailey in his remarks, contained, in your issue of March 22nd, as to the cause of ridging in brake drums, we feel certain that the present-day speed and load factors must also be taken into account.
Speeds and weights, including overloads, have increased out of all proportion to "braking surfaces.
As manufacturers of the " Resista " steel brake-drum liner, we are in agreement with Mr. Bailey when he recommends a sorbitic steel.
Our experience of cast-iron liners in brake drums is that, owing to the excessive heating and chilling effect, surface cracking is set up which gradually extends. In some cases we have had drums sent us already fitted with cast-iron liners to be replaced by steel, and from these liners pieces had broken away, due to the above causes.
Another point to be considered is heat dissipation. e30 Drums that are designed on the outside with circular fins so as to get rid of some of the heat set up by the braking friction also save a certain amount of distortion. H. G. TURNER, .A.M.I.A.E., Managing Director, Dartford Automobile Engineering Works, Ltd. Dartford.
Municipal Bus Stations.
The Editor, THE COMMERCIAL MOTOR.
[3719] Sir,—As readers of The Commercial Motor and bus operators, we are interested in the report in your issue dated March 29th, entitled "Stands at Newcastle Bus Station."
Objection has been lodged by the local council against our licences, now up for renewal, to force us to use a new bus park constructed quite close to our premises as a terminal station for picking up and setting down passengers. The Commissioners, after a long hearing, have referred it back for the council to confer with bus operators and submit a scheme. We would he greatly assisted if you, sir, or your readers through your journal, could give us information as to conditions under similar circumstances where bus operators are being compelled to use stations, pay tolls and submit to regulations imposed. The main points in which we would be interested are layout, loading platforms, destination indicators, charges and shelter for waiting passengers.
rough plan and regulations of the Newcastle or similar station would be of great help.
ERNEST C. HICKS, Braintree. or Hicks Bros.
[It is a pity that discussion between the local authority and operators such as yourselves should have been delayed so long, and the Traffic Commissioners recognize this. It will be difficult for the municipality to obtain a licence condition compelling you to use its bus park without consideration being given to the length of lease held on your present premises, provided they be suitable.
Schemes for municipal stations elsewhere in the country provide for covered or uncovered platforms dividing parallel vehicle ways, also a covered shelter and other conveniences. Charges should not exceed, in annual total, the cost to you of your existing premises.—En.]
Transporting Fruit and Vegetables: The Editor, THE COMMERCIAL MOTOR.
[3720] Sir,—I was interested in the article on fruit and vegetable haulage in a recent issue of your journal, particularly as I have been intending to do this class of work, but not knowing the Evesham district at all well, one hesitates to go just on the off chance. I was wondering if you could suggest a likely district, or perhaps you could put me in touch with somebody in a position to give sound advice? Do you think it possible to make it pay, using only a 1-ton vehicle?
I should like to say how helpful I always find The Commercial Motor in these hard times and I thank you for advice given in the past. AR,NOLD KAY. Chelmsford.
[The best place to make a start with working up a carrying connection between fruit and vegetable growers and their salesmen in the markets of the consuming areas is the district one knows best. Evesham is a good district, but it would be well to know something about it before starting. The crops look like being very heavy this year, but many local people area awakening to the possibilities of this branch of carrying.
There are many areas similar to Evesham and none of them has as yet been adequately "worked." Does Chelmsford not offer any opening?
A 1-ton lorry is suitable for the beginning, but to make a living out of the business one of at least 30-40-cwt. carrying capacity is needed.
An undertaking of this kind should pay in any growing area not already covered, provided, of course, that it is carried on upon strictly business lines.—En.]