What an Operator Thinks of
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Alternative Fuels ACTUAL experiences of certain alternative fuels, and views on the possibilities of a number of others, were the main subjects of an interesting and highlrinformative paper read recently by Mr. W, C. Whalley, motor bus superintendent, Manchester Corporation, before members of the North-Western Section of the Institute of Fuel.
" Road Transport Fuels from the Operators' Point of View," was the actual title of the paper, which opened with a statement that, in Manchester, the costs of petrol and oil, respectively, represented 24.46 per cent. and 12.62 per cent, of the total running cost of the vehicle in each case. This and an experience of the author's nine years ago showed the importance of knowledge of fuel and had led him to make personal investigations.
Oil Dilution by Petrol.
On first going to Manchester he had found 22 buses out of a fleet of 110 in dock with bearing trouble, and had traced the cause to dilution of the lubricant, which was from 30-36 per cent. Further tests showed the petrol in use to have a final boiling point of 239 degrees C. (196 was a typical figure for No. 3). Since then he had regularly taken and tested sumpoil samples and had found them a good indication of the condition of the engine, and of the behaviour of the fuel.
Referring to the storage and distribution of fuel, Mr. Whalley said that this matter called for careful layout. At one of Manchester Corporation's garages, as many as 120 buses were run in during the half hour at midnight. Petrol was kept in 10,000-gallon underground tanks, whilst oil fuel was delivered into main tanks and thence pumped through a centrifugal filter to a service tank.
There were five runways through the fuelling bay, each having an electrically driven metering oil-fuel pump, and of these three also had similar petrol pumps. In the control room above were dials showing how much fuel eaCch pump was delivering, and a master switch. A clerk entered the quantities, and all the driver had to do was to fill his tank. No fuel could be drawn off in the clerk's absence.
Hardened Steel Jets.
Manchester practice, he said, once a standard jet setting for a type of vehicle had been obtained, was to fit nitralloy steel jets, which did not wear and could not be tampered with. Tuning operations included exhaustgas tests, so that the air-fuel ratio could be maintained at 14-15 to 1 by weight. All petrol engines were equipped with governor carburetters.
Early experiments with paraffin were discontinued because of rapid carbonization, objectional exhaust fumes and small cost advantage.
Following *them, a creosote distillate was "tried. With spark ignition and petrol starting, 6 to 1 compression was required, and total exhaust-jacketing of the induction manifold. Troubles included carbon deposit in the manifold through underheating, carbon deposit in the engine through overheating, and oil contamination. Therewas ' plenty of power and marked economy. The sum of the costs of fuel and oil for petrol and for creOsote were respeotively 3.726d. and 2,5954. per mile: Consumption rates were,_ petrol, 10.4 m.p.g.; creosote, 6.5 m.p.g. Prices per gallon were, petrol, Is. lid.; creo
sote, 7id.; lubricant, Is 8d.
On an annual mileage of 35,000 miles the saving was 2100 per bus. Nevertheless, the Cost Of Maintenance led to the abandonment of the experiment after -18 months.
In 1930, hecontintied, .the Crossley concern, in.,collaboration with the Gardner company, supplied three modified marine-type oil engines to .Leeds, Sheffield and Manchester respectively. They ran up to 1,800 r.p.m. (28 m.p.h.) and were immediately satisfactory."
At this point the author stressed the importance of using good-quality, uncontaminated oil fuel. Since his undertaking began centrifuging all oil before use, which cost only 0.1d. per gallon, troubles had been reduced.
An analysis quoted of a sample of sediment from a Hopkinson filter showed the following percentages:— Water, 38; mineral oil, 49.9; combustible material, 5.25; asphaltic material, 3.84; silica, 0.41; iron, S. 1-ce expressed the view that one of the most important points int grading or rating oil fuels was that the ignition delay angle should be as small as possible. Between this and the anti-knock value there was a definite relationship. zero knock equalling 3:5 degrees of ignition delay.
Mr. Whalley then touched on the subjects of alcohol .fuel, and compressed and producer gas. Of the first-named he admitted having had little experience. The weight of the cylinders, he suggested, was an almost insuperable objection to the second, although its other attractions were marked, For the third, he thought there was more hope. the plant being not unduly heavy, the power only 10 per cent. less than with petrol, the cost less than id. per mile. The engine could be started from cold in under 3 minutes.
Promise was shown by the Erren system of using hydrogen, alone With air, or to boost coal gas, water gas or liquid fuels. The fuel was injected at the end of the compression stroke, and a thermal efficiency of 42 per cent. was claimed. This compared with efficiency percentages of 32 for oil and 22 for petrol engines. With the system that had been developed of generating hydrogen by electrolysis at 160 atmospheres, the need for compressing stations was removed. It should be possible to produce hydrogen at 8d. per 1,006 cubic ft., equivalent .to petrol at 2d, liter gallon.
Steam the Finest Prime Mover.
Finally, he was glad to see that steam was not being neglected. For bus work it was the finest prime mover. Automatic flash boilers relieved the driver of much responsibilty and removed practically all risk. Steam engines were almost as thermally efficient as oil engines. There Were big incentives to find a cheaper fuel and to use a home-produced fuel. When the oil engine was in its early stages the fuel was tax free. On April 25, 1933, a tax of id. per gallon was imposed, and this was increased to 8d. on August 8, 1995. When one remembered the way the motor industry had been treated by the, Government there was no guarantee that even a homeproduced fuel would remain free from tax. On a route in Manchester, which, was converted from tian'is to buses, thp total taxation increased from 27,724 per annum to 220,620. Manchester Transport Department paid approximately 240,000 per annum in licence dues, 298,500 in fuel taxes, and 4420 in lubricant tax, totalling about 2138,920.
An increase or decrease of Id. per gallon in the cost of fuel represented 212,312 per annum to this department. Ile' gave the following figures relating to the cost of petrol and 'oil engines :—Price, including handling, etc., per gallon,. petrol, 13.171d.; oil, 12.125d.; consumption, petrol; 4.25 m.p.g.; oil, 8,5 m.p.g.; cost per mile, petrol, 3.099d.; oil, 1.426d. ,
On the basis of an annual bus mileage ,of _35,000, oil represented a saving of 2244 per bus per year In respect Of maintenance and length of life there was little difference. 55