OPINIONS and QUERIES
Page 43
Page 44
If you've noticed an error in this article please click here to report it so we can fix it.
Oil-engine Efficiency.
The Editor, THE COMMERCIAL MOTOR.
[4020] Sir,—With reference to Mr. Goddard's letter published in your issue dated March 10.
It is not easy to find time to read all that Mr. Goddard writes, but is it not a fact that not very long ago he was appealing even more passionately in favour of the pre-chamber, as opposed to the open type?
Mr. Goddard states that Mr. Ricardo now adopts a pre-chamber design, but the Comet head, which is, of course, Mr. Ricardo's patent, is not a pre-combustion chamber in any sense of the word—it is the whole, or as nearly as possible the whole, of the combustion chamber. It depends foir its action on rotational swirl and on heating of the air after induction, but before admission of the fuel.
In the Comet head the passage between the combustion chamber and the cylinder proper is relatively very large, at all events as compared with that in a pre-combustion chamber, and the heat loss is nothing like so great.
The chief arguments in favour of the Comet type head are:— (a) The maximum pressure, is very low—about 700 lb. per sq. in., as compared with 1,000 lb., or over, In the open type.
(b) A single orifice of the self-cleaning pintle type can be used.
(e) The axhaust is not only smokeless; what is more important still, it is odourless—this latter is not possible with the open-type chamber, at all events in the present state of knowledge.
(d) Since the compression temperature varies with speed, the delay period can be kept constant in terms of crank-angle, and a fixed injection timing can be used at all speeds and loads, whilst the maximum pressure remains almost constant over 'the whole speed range.
It is a little unfortunate, I feel, for Mr. Goddard, that, in the same issue as his letter, a comparative test on a Scammell lorry fitted with an open-type engine, is recorded in considerable detail, and the consumption figures are nowhere near those he quotes as habitual.
I have no axe to grind. I am familiar with most types of compression-ignition engine, but I find a genuine interest nowadays in this type of power unit. My company produces both the open type, as now advocated by Mr. Goddard, and engines fitted with the Comet head. We are satisfied that the latter is the engine of the future, for reasons I have tried to give briefly and without overdoing them. I hope your readers will be interested in what I have tried to make a series of simple statements.
T. D. WISHART, Chief Designer, Manchester. For Crossley Motors, Ltd.
Transport Educational Facilities.
The Editor, THE COMMERCIAL MOTOR.
[4021] Sir,—With reference to your recent editorial regarding facilities for education in matters pertaining to road transport, as students at the Kennington Commercial Institute, London, S.E.11, where such subjects are taught, we would urge that a vigorous campaign be conducted in order to stimulate an interest in this vitally important matter amongst persons in the road transport and subsidiary industries. We agree, however, that some difficulty is experienced by persons engaged in the trade in attending lectures regularly, but, in our opinion, even this obstacle can be overcome by co-operation—a quality which appears to be sadly lacking in the road transport industry. We would ask you, therefore, to give publicity in The Commercial Motor to the classes held by educational authorities throughout the country. Your journal is the highest standard in the trade and read by those connected with all branches of the industry—both
employer and employee. GEOFFREY C. P. RIGGS.
J. Mtn EDWARDS.
London, S.E.6. P. MARSTON-CLARKE.
[We will be pleased to publish from time to time a list of institutions with the classes which they hold, and, with this in view, would like to receive both from them and other readers information as to where and when such classes are available.--En.]
Our Manual on Oil Engines.
The Editor, THE COMMERCIAL MOTOR.
[4022] Sir,—Many thanks for your quick dispatch of the two copies of your marvellous text book on compression-ignition engines. I gave one to the Kleiber Company's engineer, and he was delighted. Please send
me two more. ERNEST OHRT. San Francisco.
A Plea to the Horne Secretary.
The Editor, THE COMMERCIAL MOTOR.
• [4023] Sir,—If you think that the enclosed letter is of sufficient interest, I will be pleased if you will publish it, to attempt to attract the attention of the Home Secretary to certain matters regarding the attitude of the police towards road transport.
H London, E.3. H. C. SMITH.
The Secretary of State for Home Affairs.
Sir,—I venture to approach you through the medium of The Commercial Motor with a hope that I and others connected with road transport may be enlightened on certain points.
On March 7 I was travelling between RugeIey and Lichfield, when I came across a motorcycle combination with a police driver and passenger, riding dangerously close to the near-side rear of a lorry and trailer. I was, needless to say, aware of the probable consequences for the unfortunate lorry driver. I carried on behind for some considerable distance (it not being safe to oventake under the circumstances). At last the officers took advantage of the fact that the lorry was going down a gradient at an increased speed, there being at the moment, I assume, no need to wear out brake linings, which might prove more useful at some other time. This long-waited-for slip on the part of the lorry driver caused him to be stopped, and, to my surprise, I also was called upon to stop.
The police driver approached me and said, "You saw this trailer swinging over the line, didn't you?" I replied with truth, " No." The officer then said, "You were bound to have seen it." I maintained that I did not see such swinging, as all my interest was absorbed in watching water splashing up on to the sidecar passenger. I was allowed to depart, but I am sure the policeman doubted my word. In connection with the above, I ask, are these men trained to use such sly methods, or are they instructed to get cases, no matter how? Also, are police officers allowed to put questions in such a leading manner?
May I be permitted to express my opinion that this persistent trailing of motor drivers earning their living (we are not criminals) is a source of danger to all road users as well as to the police. I would also like to comment on the fact that it is my opinion that the percentage of good drivers is higher on the commercial side than in any other, not excluding the mobile police. I have, in various parts of the country, seen some very fine specimens of bad driving performed by uniformed men. I think that in the case St driving, experience is the best tutor.
The training of point-duty men is another matter which has baffled me, and, I am sure, must be of interest to all road users. When application for a driver's licence is made, one is presented with a booklet, in which is depicted a range of traffic signals as performed by the police, and these should be recognized by all. In London, I agree that these signals are used, but in many other districts such is not the case. Instead, we witness quite fanciful flourishes of the hands, together with displays of body twisting which often result in misunderstood signals, followed by a bullying by the per
former. Why cannot the whole of the country's police forces train their men to the standard of the Metropolitan police?
In conclusion, I beg to ask, can we motorists look to you for the assistance that is needed in the case of the easyvictim commercial driver—some modification of methods at present in use, which do not make driving as safe as it might otherwise be? I realize that the mobile police must show some results of their work, and that there are not sufficient bandits to keep them all occupied, but, on the other band, a driver cannot keep his head quite clear if he has to look ahead, watch his speedometer, and peep into his driving mirror in case there may be a man in blue behind when the vehicle of which you are in control gains a little momentum
down a hill. H. C. Siarru, The Alliance of Owner-drivers.
The Editor, THE COMMERCIAL MOTOR.
[40241 Sir,—May I ibelpermitted to comment on the editorial note appended to my letter as published in your issue dated March 10.
The object of this organization is to give to the owner-driver, as a class, some practical assistance and to safeguard his future by overcoming the disadvantages under which he at present labours. In that, there is room for us.
Is there any reason, therefore, why we should not march with the and the R.H.A. towards a mutual objective, i.e., the well-being of the industry?
Ts there any reason, also, why we should not be admitted to affiliation, in clue course, to the British Road Federation, which, it would appear, may now be considered as the combined representation of road transport? The haulage industry should welcome our advent as a means for strengthening one of its weaker limbs.
A draft of the mutual-benefit section of our programme has been submitted to a well-known insurance n30 corporation and its practical value has been remarked. This section will embody :—(1) A thrift fund for those desiring to provide against renewal of vehicle tax and insurance premiums. (2) A depreciation fund whereby a member will be able to replace his vehicle at the end of a period. (3) A superannuation fund. (4) A loan fund.
As has already been stated, the first general meeting will be held in London so soon as applications for attending it warrant. It will be arranged for a Sunday to suit the convenience of the majority.
London, S.W.11. E. H. El, PALMER.
An Unsatisfactory Scheme of Taxation.
The Editor, THE COMMERCIAL MOTOR.
[4025] Sir,—Perhaps you will allow me space in your valuable paper to raise the question as to whether the deputation that, under the leadership of Mr. Frank Peck, waited upon the Chancellor of the Exchequer, was justified or wise in expressing as its opinion that a ease had been made out for the imposing of a higher tax on vehicles using fuel or power other than petrol.
First, it presupposes that the petrol tax is necessarily a permanent form of taxation and that it will always be at the same rate per gallon. Secondly, it would introduce an entirely new and, to my mind, a very objectionable, principle into taxation generally, i.e., that because a person does not pay one form of tax then he should be assessed at a higher scale on a tax which he does pay. It is surely equiva lent to his being called upon to pay a higher rate of income tax because, as he does not visit places of amusement, he escapes payment of entertainment tax.
To follow the recommendations of the Salter Conference to their logical conclusion, each improvement in design of a petrol lorry which results in a more economic use of petrol would, or should, require a careful readjustment of licences. How great this adjustment might be is evidenced by the fact that even to-day there are petrol vehicles on the road made by the same manufacturers having the same unladen weight, same wheel-bearing surface, same weightcarrying capacity, yet so great has been the improvement in engine design that the ratio of petrol consumption is 4 to 6.
The result is that the difference paid in petrol tax by two vehicles doing the same mileage per year, and presumably doing the same damage to the roads, is as much as £100 per year, and the designers of petrol engines have by no means said their last word in the improvement of petrol consumption.
It is equally certain that designers of engines and vehicles using fuels or power other than petrol are also making and continually seeking improvements in the fuel consumption.
Then, again, the possibility, and now high probability, of the production of petrol, oil or fuel (not forgetting gas) from our own home resources (coal) on a commercially economic basis, should not he overlooked. It can surely be assumed with safety that Such fuel will not be subject to duty.
I am sure that the majority of your readers and owners of vehicles will agree, that, having conceded the claim that the damage to highways that can justly be attributed to motor vehicles should be paid for by vehicle owners, then the only equitable scale is one based on those factors that have any direct relationship to that wear, tear and damage, such as weight of vehicle, weight of load, wheel-bearing surface, tyres, construction and design of chassis, etc.—based, in turn, on the assumption that all vehicles of the same size, etc., run the same number of miles per annum. Finally, it surely must be only justice that advantages that may accrue to an owner by the use of amore economic fuel or engine should remain his as a reward for his foresight and business acumen.
Richmond. J. A. M. BRIGHT.