Bus Driver Dislikes Pre-selection
Page 44
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ALTHOUGH 1 am only a bus driver, I cannot share with Mr. A. A. M. Durrant his enthusiasm for the hydraulic coupling and pre-selective transmission, which he expressed at the recent Congress of the International Union of Public Transport at Edinburgh. .
The system calls for more skill and patience in operation than does the conventional crash-type gear change, unless the passengers are to be subjected to the neck-breaking jerks which are so familiar to riders in some of London's buses. This is particularly so in the case of vehicles in which the engine loses its revs. slowly when the accelerator is released and the operating pedal for the gear change is heavy in action.
No benefit can be obtained from the braking power of the engine, and should there be a failure of the airpressure system it would be impossible;
to select a lower gear, which, in certain circumstances, could be most dangerous. This, of course, applies only to the later types.
Furthermore, there is often a tendency for the bus to creep, even when the hand brake is applied, unless the engine be set to idle extremely slowly, which is apparently impracticable, as it would then be apt to stall when cold.
I think it is true to say that most drivers would prefer the more positive feel of the solid " drive of a modern constant-mesh gearbox, whilst a servo for the clutch would make the physical effort required even less than is needed to work a modern pre-selective type.
The travelling public would not then have to be submitted to the frequent convulsions of the vehicles resulting from drivers trying to hurry the process of gear changing.
London, W.I3.
OPERATING NATIONALIZED BUSES IN BOMBAY
nUR corporation has been operating bus services for the past three years, and is interested in collecting statistical data to help in obtaining the most economical operation.
We have at present a fleet of some 1,400 vehicles, the road surface being mainly asphalt and stone, only a small part being asphalted. There are about 60 per cent. of petrol vehicles and 40 per cent, oil-engined, the average unladen and laden weights being some 10,000 lb. and 16.000 lb., respectively. Bodies are of the composite and all-metal types, and the average mileage is about 120 to 130 per day. There are daily, weekly, monthly and quarterly inspections, and major dockings at about 90,000 miles. The average load factor varies from 75 to 85 per cent., and the rate of breakdown is 2-3 per cent. per day.
Assuming the life of a petrol vehicle at 120,000 miles and that of an oiler at 240,000, we would like to know the maximum vehicle utilization per day under our conditions which would not involve additional cost for repairs and maintenance during the entire life.
What would be the standard cost of repairs, consumable stores and spare parts at different stages of the life of petrol and oil vehicles?
Details are also required of the tyre and battery c8 mileages for standard types, and to what extent they vary with different classes of road surface.
What would be the general trend of fuel consumption at different stages of the life of these vehicles?
To what extent are oilers cheaper to operate than petrol models, taking into consideration depreciation and interest on the one hand and cost of fuel, repairs, spare parts, etc., on the other?
MOTOR TRANSPORT CONTROLLER,
Bombay. State Transport Central Office.
[The limit of daily mileage covered by a vehicle is governed by the time off the road for maintenance and repair. It
is customary for passenger vehicles to run double the mile age mentioned in your letter, and I would not like to
venture an opinion as to the maximum limit of utilization for economic operation. The cost of repairs, etc., will vary within wide limits, being governed, first, by the way in which the vehicles are used; secondly, according to the prices of labour and materials in the area covered. The following figures are, therefore, tentative: (a) For the petrol vehicles, first year, £250; second year, £500; third year (when they are nearing the end of their useful
life), £200. (b) For the oilers : first year, £150; second year, £400; third year, £200; fourth year, £500; fifth year when as little as possible should be spent upon them), £100. Tyre mileage depends upon a variety of conditions—type of road, care taken, and particularly the maintenance of specific pressures by constant checks, wheel alignment, loading, daily attention to the removal of flints, etc. I would say that the life could be anything from 20.000 to 40,000 miles per set. The life of batteries does not depend upon mileage at all. It is reasonable to assume replacements at about two-year intervals. Provided that vehicles be reasonably well maintained in accordance with the schedule laid down, there should not be d:fferences of more than, say, 5 per cent, for the figures for fuel consumption. As regards your last question, the answer depends upon the comparative prices of the two fuels. In Britain, where the difference is only 2d. to 3d. per gallon, it is usual to expect a saving of not less than lid. per mile in favour of the oil engine. That figure takes into account the factors mentioned in your inquiry.—S.T.R.]
WOMEN DRIVE LUTON DOUBLE-DECKERS WITH regard to the interest shown in recent issues " of your journal about women drivers of doubledecker buses, the following incident may help to prove that this practice is more general than it is usually thought to be.
On being dropped at Luton station by the Vauxhall Works bus after the regent visit of the Institute of Road Transport Engineers, I boarded a Luton Corporation double-decker going in the direction of the Dunstable road, and was much surprised to note that the driver was a woman. London, E.3.
W. A. BRAY, A.I.R.T.E. (For Permanite, Ltd.) [Much interest has been shown in the question of women driving double-decked public service vehicles. This appears" to be more common than had been thought at first. To our knowledge, there are women drivers on the staffs of the transport departments of Portsmouth and Rotherham, as well as at Luton and in South Wales. During the war, many concerns employed women drivers, Oxford being one of the cities where women drivers were often seen on. city-service double-deckers.—ED.]