Petrol-Electric Trials in London.
Page 6
If you've noticed an error in this article please click here to report it so we can fix it.
The Wolseley-Siddeley omnibus, equipped with the Thomson-Houston system of petrol-electric transmission, which commenced an extended trial in London public service with the London General Omnibus Company, Limited, on the 18th of August last, was withdrawn from service, on the 24th of December last, in order that it might be opened up and examined after its four months' work on the London streets. Rumour has had it recently that, during its tests, no less than nine armatures had been burnt out and replaced. It is only due to the Thomson-Houston company that an emphatic denial should be given to that damaging report. This bus is the first petrol-electric vehicle to make a lengthy trial under public-service conditions in London, and its makers quite expected that many weaknesses in the installation would be revealed. The principal object in placing the bus in the London General Omnibus Company's hands was that its behaviour, under theusual bus conditions, might be observed, and that careful investigation of any weakness might be made. To this prompt investigation, and to the fact that no spare parts were kept in stock in London, much of the time which was lost during the four months must be attributed. The troubles which did arise were all caused by faults in the design of small details, and to the lack of care which had been exercised in assembling the motors, which were made at the French works. One instance which demonstrated this lack of care was the fact that the nearside, countershaft-brake drum was out of alignment with its motor shaft, and this resulted in the setting up of heavy strains in the latter shaft, and, consequently, in the armature windings. The actual cause of the trouble with this motor was not discovered for some time, but, after it was rectified, the vehicle gave no further trouble and it has since run a distance of 3,473 miles. The possible mileage which the bus could have run during the period of its test was 13,390, and the actual mileage run was 10,48o ; there was, therefore, a total loss of 2,910 miles and, of this total, 1,849 miles were due to failure of the electrical machinery, and 1,o61 miles to other mechanical troubles. The loss due to faults in the transmission gear thus amounts to about I3 per cent. This is a rather high figure, perhaps, but we must remember that this is the pioneer of petrql-electric transmission systems, and we should, therefore, make due allowance for it.
One interesting fact, which has been brought out by the trial, is that the company's system of control leaves nothing to be desired. At the foot of this page we reproduce photographs of the controller (in the centre) and (on the right) the control switch, by means of which a resistance is inserted in the generator field, in.order to reduce the yoltage to zero, before any make or break is made in the controller.
Another part of the equipment which needed no attention throughout, was the exciter, the armature of which is seen between those of the off-side motor and the generator, in our illustration. The mileages run by the latter twoarmatures since any adjustment was made to them are off-side motor, 7,600; and generator, 5,500.
We may expect to see another petrol-clectrie bus in London shortly. Thos. Tilling, Limited, has had such a vehicle built by J. and E. Hall, Limited, of Dartford, in which the Steevens system is incorporated. This bus is giving a demonstration run to-day, leaving the Motor Club, Coventry Street, at I r a.m, for the maker's works, at Dartford,