OPINIONS FROM OTHERS.
Page 20
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The Editor invites correspondence on all subjects connected with the use of commercial motors. Leiters should be on one side of the paper only and typewritten by Preference. The right of abbreviation is reserved; and no responsibility for Mews expressed is accepted.
Experience with Gas-driven Motorbuses.
The Editor, THE COMAIERCIAL MOTOR.
[16021 Sir,—My company has been using coal-gas for motive power now for 12 months on motorbuses in ragulais service, and, I have reason to believe, has hitherto been one of the largest users of gas in the country for these purposes. I welcome the report of the Gas Traction Committee because it is an eminently practical document, and coincides in every important particular but one with our experience, the most essential points of which are the necessity for using only the best container material, otherwise leakage is abnormal, the desirability of covering the bag to protect it from light and wet, the use of a continuous valance all round the bag, and the necessity for fitting an automatic cut-off valve for filling. The one point where I feel we are directly at issue with the report is in regard to paragraph 6, which reads as follows
• " Economy. It is reasonable from a commercial point of view, to adopt a mean consumption of 250 cubic ft. of ordina,ry town gas (with, say, a gross calorific Value of 490-500 British thermal units per cubic foot) as the equivalent of one gallon of motor spirit, and on this consumption ratio gas at 4s. per 1000 cubic It: shows the same fuel cost as motor spirit at Is. per gallon, apart from interest on cost of installation and the maintenance of flexible containers and filling arrangements."
The idea gained by the superficial reader is that the cost of gas for motive power is very considerably less than petrol. I submit that this statement may ea,sily mislead. Our experience, using gas for daily business purposes,
is quite different. Our experience coincides with the report that 250 cubic ft. of gas will take a, vehicle as far as one gallon of petrol, but that, I submit, is only a very" superficial comparison, and omits from consideration many matters which in practical use make all the difference. Nothing is said of leakage, but this is a most vital and determining factor at present.
The report entirely omits to mention most important factors which must be taken into consideration in any comparison. One is the greatly increased liability of the tray surrounding tile gas bag to accident. We find the tray is continually getting cramaged, and the cost of repairs is a serious item. My second point is that one is continually obliged to undertake repairs to bags or covers or trays. The delay to the vehicle, keeping it out of service, to say nothing of the cost of repair, tell very heavily against gas. Then there is the serious amount of time wasted in filling, which would otherwise be utilized for useful running.
We find from actual costs incurred that, with average price of gas at 3s. per 1000 cubic ft., the cost of motive power is only slightly less than with petrol at 2s. 7d. per gallon. In making up these figures we allow a life of six months per bag and charge £10 ner annum for cover a-nd fittings and £10 -per annum
for increased liability to mishap. • The man who is obliged to run his vehicle on gas, so far as our experience goes with the knowledge and materials available hitherto, cannot expect to save money, and he will most certainly find himself in for a lot of trouble. We run our vehicles on gas because we are obliged to do so or cease running, but we shall welcome the day when petrol is no longer rationed and we can discard the was appara,tus.—Yours,faith
fully, E. B. HUTCHINSON, Manager, United Automobile Services, Ltd. Bishop Auckland.
Gas Bags and Metal Cylinders.
The Editor, THE COMMERCIAL MOTOR.
[1603] Sir,—In THE COMMERCIAL MOTOR you have given particulars of the Gas Traction Committee's interim report, wherein the Committee give it as their unanimous opinion that the substitution of coal-gas for petrol for the propulsion •of motorcars can be effectively, safely, economically and promptly carried out. Your sundina•ry, however, did not include that part of their report dealing solely with gas bags, wherein they report that gas bags merle of inferior fabrics may leak after being in use only one month to the extent of losing as much gas as they use.
. This seems to me absolutely to_condemn the gas bag as a commercial proposition, as even when employing the best possible fabric for making the bag, the capital outlay has to be repeated at the end of eight months, while the waste of gas when using the cheaper bag is already 100 per cent. of the ,amount consumed in the engine before it has been in use five weeks. Such a waste of gas is unpardonable in war time, and it is quite probable that this is the reason for the sudden cessation of the issue of fresh gas permits.
I understood that this interim report was originally
intended only to review the employment of gas in•flexible containers, but, no doubt owing to this res ported waste of gas, the committee have already`investigated the question of compressed gas, and their report in that respect is most satisfactory, for they say in paragraph (17) Metal Cylinders : "It is desirable to encourage forthwith a limited number of experiments on a commercial scale with compressed gas 111 rigid metal cylinders at pressures of 1800 lb. per square inch (120 atmospheres)."
The 3-ton Wolseley lorry fitted up on the Flugel compressed system for the M.T., A.S.C., was fully tested by the Senior InsPector of Army Transport, and inspected at work by the Gas Traction Committee, and gave entire satisfaction ; but it is evidently now desired that this high-compressed system should be taken up oss: a commercial scale so that its marked superiority to the flexible container can be fully demonstrated.
I understand that, if necessary, a special licence will he granted for this purpose by the Board of Trade, but that gas permits already granted to users
of gas in flexible, containers can be used for it. ,
I shall, therefore, be glad to get in touch with any firm considering the question of using compressed gas for essential transport purposes. The cost of driving on gas is only about one-third of the cost of driving on petrol, so it is quite certain that, after the war, commercial firms will all use gas. One large municipal authority, whose petrol motors have been convested to the compressed gas system, tells me that they save 25s. per day per vehicle by substituting gas for petrol.—Yours faithfully, B. FLUGEL.