—THE COMMERCIAL MOTOR— 26th March, 19Tcl.. BOOSTING THE BATTERY VEHICLE.
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Discussion following Mr, Ayton's Opening Paper, with which we Deal on the Two Preceding Pages.
Mr. Ayton, referring to some experiences with electrical vehicles at Blackburn, said that the Borough Electrical Engineer there had written to say that, in obtaining competitive prices for electric and petrol vehicles, he found it very difficult to get guaranteed figures ef miles per gallon, whereas the cost per mile of running electrical vehicles was easily obtainable from all the makers. Electric vehicles had now been working therefore nine months with complete success.
West Ham has Exactly Six.
Mr. J. 1V. Beauchamp (Borough Electric Engineer, West Haim) said there were six electric vehicles running in his &stria, and the average, revenue to the electricity department was £20 per annum, charging for current at id. per unit. He did not advocate the price being reduced much below this figure. What the industry wanted at the-present time, more than anything else, was an unlimited supply of money in order prnperly to push electric vehicles. There was an absolute necessity for some arrangement by which electric vehicles could be put upon the streets for haulage or traction work in the Mara manner as steam and petrol wagons were let Cut 00 hire, and he believed that, if some comprehensive scheme could be undertaken figures could be quoted much lower them the present charges for steam traction. Another difficulty at present was that purchasers of electric vehicles had to wait months before they could obtain delivery.
Current Should be id per Unit.
Mr. R. J. Mitchell said he had heard it stated that leld. should be the charge for current, but ha regarded this as a grave mistake. The ideal to be aimed at should be id. per unit. He regarded the electric vehicle as snore likely to be a. competitor with horses than with petrol or steam-driven vans. There was great need for careful research luta the whole problem of mechanical traction on roads, and particularly with regard to the cosi, of operation, upon which a very small amount of information indeed was at present available. ft would be a useful addition to our knowledge on transport if the -University of London followed the example of the Massaehasetts Institute of Technology and instituted a vehicle transport research committee to obtain reliable information upon all forme of transport. Some years ago a. research upon road resistance with petrol ears was started by Mr. ShrapnellSmith arid Professor Hele-Shaw, but. this did not eventually cover the field it was originally intended to, but only a few thousand hours work would cover all the principal types of roads and districts in the United Kingdom from the point of view of road pesistance. He thought it would pay centralstation engineers to begin at once to have facilities available for charging electric vehicles even if they had to wait months before the first caw came along, because such a policy would give e distinct stimulus to the development of the use of these vehicles.
L.C.C. Batteries Last 6000 Miles.
Lieutenant Sladen (Chief Engineer to the London Fire Brigade) said that for the last four years the London County Council had had a number of electric vehicles in use, and perhaps A, few particulars would be interesting. At the present time they were using lead batteries of 84 cells with a capacity of 200-ampere hours at the six-hour discharge. rate. The current was controlled by a series parallel controller and was led direct to motors in the wheels without the intervention of any gearing. The total weight of the vehicles was about 51, tons when fully equipped with men, and this was about 5 cwt. or 6 cwt. heavier than a similar petrol vehicle. The contract speed on the road was about 25 miles an hour, but that had been exceeded and the speed on a gradient of one in nine was about 15 milks an hour. The circuit breaker went at 250 amperes, so that there was a considerable amount of current used in breasting the MIL The results of tht.%e vehicles had been so satisfactory that the London County Council had decided to adopt them, in a measure, as standard for lifesaving appliances in localities where the gradients were moderate. This indicated that they had considerable confidence in the reliability of the electric vehicle. Of course there were limitation-s to the use of thee-s vehicles for firebrigade purposes. There was the limited mileage arid the question of want of uniformity, because it was difficult, if not impoesible, to have a complete elettrically-equipped vehicle., the difficulty being that a prime mover ether than electricity was required for the pumping engine, at any rate for a fire-pumping engine which might have to work at full speed for 12 hours or so. in Germany, Holland, and other places the type of vehicle had been adopted with a battery in the front for propelling the vehicle and a steam pump on the back. With regard to the cost of maintenance he was afraid he could not give any figures which would be of great value to commercial users. It, would perhaps be a shock to those who thought they could run electric vehicles rhea-ply, when he told them that the vehicles in use by the London County Council rust about is. per mile to maintain, and that did not include the driver's wages, first cost or depreciation. But perhaps the feelings of those gentlemen who expected to hear something more favourablewould be changed when he said that for similar petrol vehieles the cost was a-bout is. 3d. per mile, Taking ieto excel-ant the first, east, depreciation and maintenance, an electric fire-escape and a petrol fire-escape came out to practically the same, namely £150 per annum. The annual cost of repairs for an electric escape which ran 800 miles in the year was .E40, which included renewals of battsries. No particular troubles had been experienced with lead batteries, They -ran for 6000 miles before the whole battery required renewal. It might be thought that trouble would arise through sulphating, but this difficulty scented to have been got over by arranging to discharge batteries down to about 1.9 per cell for two months and then filling them up and giving them intermittent over-charges. A difficulty had been experienced in getting current at a suitable vdtage. They may required about 30 amperes for the batteries, and the maximum voltage was 240, but very few electric supply authorities in London would give current under 400 volts, and therefore they either had to waste a good deal in charging or else put in a generator, which was a considerable expellee. On the other hand, he quite recognized the difficulties of central-station engineers in London, because the bill for charging the vehicles was only about 22 a quarter, so that they did not get very much out of it. The vehicles very seldom required repairs, and the rapidity of turn-out was absolutely unequalled by any other form of traction. It was no uncommon thing with an electric escape to turn out ie eeven or eight seconds, whereas with other forms of motors, it would take fifteen. Another important point in favour of the electric vehicle was the electric braking as an addition to the ordinary mechanical brake.
Mr. P. A. Mossay referred to the less wear of tires oceasiened by electric vehicles, and referred to a case in which the tires on electric cabs gave 80 per cent, more mileaee than did similar tires on petrol cabs.
The Noisy Electric Tram.
The Porter (Medical Officer of Health, Metropolitan Borough of Marylebone) welcomed the electric vehicle from the point of view of eliminating noise, which he said had a bigger influence on the health of the people than was generally imagined. Children in London suffered grievously from electric-tramcar noises.
Mr. Barber's Belief as to Costs— Mr. C. Barber refereed to the absence of figures relating to working costs in this country, although there are a good many to be obtained from experiences in America and from the Continent. He believed, too, it would be found that fur short distance work up to 40 or 50 miles eleetris vehicles could be used for commercial purposes at 20 per cent. lees cost than petrol-driven vehicles. The cost of repairs was also less than with steam or petrol, and he believed the whole question would depend upon this matter. Another important point was to induce central-sta. tion engineers, amid particularly menieipal electrical engineers to push departmental use of these electric vehicles.
—and Mr. Peseatore's Belief.
Mr. A. B. Peecatere painted out that, the wear on the chassis of an electric vehicle was only half that. talon a petrol vehicle, and that in consequence the chassis could he looked epon as lasting twice as tong. This would result in much lower working costs than with petrol vehicles. He believed it would he found that the cost of maintenance, including renewals, materials, repairs and the handling and charging et' batteries would vary between id. per mile arid 2Lti. per
Boosting the Battery Vehicle. -con.
mile for vehicles carrying loads between 2 and 5 tons, whilst the total expenses would vary between 10. and 3A. .Figures of this description had been obtained upon the electric buses in Brighton. As regards the current consumption the figures he had been able to obtain showed a Consumption of betweeu 110 and 140 watt-hours per ton-mile few the types of vehicle mentioned.
Mr. A. Fox did not think there should be any difficulty in designing a commercial battery capable of 100 miles per charge. One reason why the cost of maintenance was much less with an electric vehicle than with other forms was that an increase in the current consumption was at once apparent to the driver, so that a hot bearing or a rubbing brake shoe
could be immediately discovered and put right. He commented upon the fact that many electrical Lee:ewers seemed to be poorly informed as to the capabilities of the electric vehicle, and recommended that the study of eleetrie-vehicle practice should now become part of the regular curriculum in the technical schools as was the case in America.
Mr. H. Brazil said he had recently driven what he believed to be the largest electric lorry in this country which had a .260 ampere-hour battery, the lorry itself weighing q tons in • addition to carrying a load of five tons. The maximum speed on the level was 9 m.p.h., and the consumptien of current was about one unit per mile loaded, and, takine the efficiency of the battery at 75 per cent., this gave 1.3 unit per mile. The method of control was rather new to him, as it aimed at keeping the load factor on the battery as high as possible. The vehicle was equipped with two motors on the hack axle both directly coupled. They were in series, and the battery divided into two parts and put into parallel. The first notch gave 40 cells on each half of the battery which were pu1 in parallel, with the motors in series and the resistance in circuit. That gave the slowest speed. The next notch left the motors still in series and the battery still in parallel, but the reeist anee was cut out.. The third notch left. the batteries in series and the motors in series and resistance out. At the fourth notch the motors were pot in parallel, but the fields were left in series, so 'that there was a elower speed due to the whole of the cur root having to go through the field where it was split ep between two armatures. Finally, at the highest speed the batteries were in series and the motors and tho fields in parallel ; that. gave 9.1 m.p.h. Beyond the zero point, one obtained the electric brake. Finally, Mr. Brazil referred to an instrument which lw had designed in conjunction with Mr. F. Lydell for indicating at a glance the amount of current left in the battery.
Berlin Cabs at Id. Per Mile Cost.
Mr. A. J. Makower (Secretary of. the Board of Studies in Electrical Engineering at the London University) said he welcomed the idea of carrying out. tests such as had been suggested. As an interesting contribution to the discussion, he
The weight of the cab fully loaded was 2.4 tons. nu: average mileage 90 per day, and the average peiformance 350 days per annum. The figure for current pointed the moral to station engineers, because this service of cabs ran 3,000,000 miles, and took current fnvolving an annual bill of £11,500.
Mr. A. E. Burgess recommended closer co-operation between the battery maker and supply authorities, and also that, the charging apparatus should be in the bands of the latter, Mr. W. E. Burnand referred to satisfactory experiences with electric vehicles of the regenerative principle.
The Field of the Battery-van.
Mr. Shrapnell-Smith said it seemed to him that the electric vehicle would very probably in the next few years go through some of the early stages of trouble, or, at any rate, lack of commercial appreciation through which the petrol and steam vehicles went in the early days. He believed that the electric vehicle would mark out its own place, and it seemed to him that it was in cities that those who were seeking to popularize the electric vehicle would have the very best field of action. With reference to the noise of petrol vehicles, he did not think it was entirely appreciated that any silence in these was only so long as the top gear was in use. He suffered as well as others in London from the noise occasioned whilst, for instance, a taxi-driver was changing from low to top gear, and also from the noise of the engine whilst the driver was waiting for the fare to pay, and he could not but agree that, generally speaking, the electric vehicle was silent at all times and at all speeds. He did not think the electric vehicle was likely to come into much use for long-distance work, because it, would he found that the current consumption in country work would go up to something like 100 per cent. owing to the difference in the character of the roads. He warned manufacturers and supply authorities against being too optimistic, end believing that they would begin to make money from the very connueueement of the new form of traction. They would have to be prepared to fight. very considerable odds fur the first few years.