Taxi Fleet Runs 4,000,000 Miles a Year
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By P. G. TUCKER
A Rigid System of Servicing and Maintenance Pays Dividends in Trouble-free Running of 150 Vehicles
HOW do the new types of taxicab compare with pre-war vehicles in respect of general reliability, wearing qualities, mileage returns, and so on? These were some of the questions I had in mind when I visited York Way Motors, Ltd., York Way, King's Cross, London, N.1, a concern operating 150 cabs in the London area.
The mileage covered by these vehicles is over 4,000,000 annually, and each averages about 32,000. The mileage of the pre-war cab is less than that of the post-war vehicle, which does about 40,000 a year.
Whilst the company still runs a number of pre-war cabs, these are being replaced by the latest Austin and Oxford models. Of these, the managing director, Mr. L. Levy, said that, in the first place, they possessed excellent advertising value, and, secondly, the increased comfort that they provided was fully appreciated by the public.
Brake-facing Wear
The fact that they could make point-to-point journeys quicker than the old types was, from the operator's point of view, a mixed blessing. Whilst this might increase the number of hirings per day, it also meant that the vehicles were worked harder. , One direct result was the greater wear on brake facings, which the new cabs were using up at twice the rate of the old vehicles.
Wear on rear tyres had shown no increase. Their average mileage had worked out to 40,000, but those fitted to the near-side front wheels gave only 75 per cent. of this figure.
B6 Dunlop taxi tyres arc used, and Mr. Levy told me that he could not recall an occasion when a tyre had given out prematurely as the result of a structural fault.
I think it can be said that a taxicab operating in London has a life of mixed experiences. It runs on good roads, and the engine is rarely called on to do any real collar work; but it is operating in heavy traffic conditions during its whole career, with many sl-arts and stops., In addi tion, the " ranking." and station work that falls to its lot means that the engine has to be started many times during the day, often from cold, a factor that must increase cylinder wear. This applies particularly at night, when the engine gets cold quickly, and the procedure of warming up has to be gone through.
Incidentally, the number of hirings depends on whether the cab is driven by one or two drivers per day. In the latter case the number of hirings may be as many as 50 per day.
Some of the records which were shown to me by York Way Motors, Ltd., were of an exceptional character. For instance, there was the history of an Austin which had run for 300,000 miles without removal of the crankshaft. which meant, of course, that the main bearings were as fitted by the maker. Then there was the case of the first Oxford to be put into service by the company. This has now run for 80,000 miles with one change of pistons, because cylinder wear at 40,000 miles, when the new pistons were fitted, was not sufficient to call for a rebore.
Study of Bore Wear
The matter of cylinder-bore wear, however, is being studied at the moment. Whilst the removal of a block for reboring is not an extensive operation, the removal of the complete engine, as becomes necessary with a one-piece cylinder and crankcase, is another matter. The extra man-hours called for to do this may easily affect vehicle availability, and this is one of the reasons why the company is investigating claims made for Laystall Cromard cylinder liners.
These liners, which are made from drawn steel tube, have a 0.0025-in. layer of chromium deposited on the full.length of the bore. In February, 1946, Mr. Levy decided to try a set of these liners, which were fitted into the engine of an Austin taxi chassis. Since that date the vehicle has run for 88,907 miles, and I was invited to the York Way depot to witness the stripping of the engine for bore inspection and measurement.
It should be mentioned that the average useful life of a cast-iron bore was given to me as 50,000 miles, this being the stage at which something had to be done to counteract the heavy consumption of oil.
After 90,000 Road Miles After the block had been removed and the bores were wiped clean, I noticed slight scuffing marks, some of which were in the form of small patches at ffie top ends of the bores, and others were longitudinally marked as though scoring had taken place. In no case, .however, was there any feeling of roughness, which was an indication that the original chromium surface had not been penetrated;
The accompanying chart was prepared from the readings taken from each bore. It shows that the maximum degree of wear occurred at the top end of No. 4 cylinder, whilst the minimum overall wear was in No. I bore.
I think it will be agreed that the condition of these liners after nearly. 90,000 road miles can be considered highly satisfactory. During this period, the engine has had two sets of pistons, the second set being fitted at 51,879 miles. With such a small amount of wear, the liners would, of course, he good enough to retain in service, as an appreciable layer of chromium still remains on the wall, as the chart below shows.
These liners were of the original smooth-bore type, and were not given the matt finish which is the standard practice to-day. The matt finish, of course, promotes " wetability " and assists in maintaining an oil film on the surface, and thus such liners should show even better wearing properties than those not so treated.
The liners are pre-finished and require a little more care in fitting than with liners supplied with an allowance for subsequent honing. The block has, therefore, to be bored and honed accurately to the sizes given for the particular liners to be fitted. These sizes are specified with the set of liners.
The Laystall concern is at present supplying them in 65 different sizes, ranging from 2.230-in. to 4i-in. bore. As an example of cost, those of 72 mm. bore for an Austin taxi cylinder block, work out at 36s. 6d. more per engine than normal castiron liners. The cost per liner of 72 mm. bore is Ll I6s., a complete set, fitted to a four-cylindered engine, corning out at £13 5s. 4d. There is a 10 per cent, surcharge on liners only.
Another instance of the longevity of specially hardened components is concerned with Laystall-hardened steel brake liners which York Way Motors, Ltd., fitted to a number of cabs during the war. The problem of the frequent reconditioning of east-iron drums, when adequate facilities for doing this work were unobtainable, assumed serious proportions. Hardened liners provided the solution. I was informed that they stood up for nine years without showing serious signs of wear.
Fueland oil-consumption figures of this fleet of cabs work out in a remarkably consistent manner as between the various machines, which is indicative of the similarity of the work which they perform. The average figure for fuel consumption was 18 m.p.g., which, as a taxi operates practically the whole of the time in traffic, is good. On the average, oil consumption is at the rate of 3 pints per week, based on 700 miles' running, a little over 1,800 m.p.g.
Economizing in Fuel
The foreman fitter has his own ideas concerning carburation, and every engine is fitted with an automatic choke device and a hot-air muffle which takes the warm air from round the exhaust pipe to the air inlet of the carburetter.
Maintenance is carried out on a rigid basis, the oil sumps being drained and replenished once a month. Chassis parts are then greased, brakes inspected and tested, and ignition features examined; in fact, what amounts to a complete top overhaul is carried out. Every two months engines are decarbonized and valves ground in, and every year each vehicle is given a major overhaul.
This annual overhaul is most thorough, as after 12 months a taxicab licence has, to be surrendered, and it is not again granted until the cab has been reinspected and passed by Scotland Yard.
Old Vehicles are Replaced Rather than operate 'out-of-date vehicles, Mr. Levy takes them off the road, when they are completely reconditioned and sold. Just as much care is taken in rebuilding these prewar machines as if they were going back into the company's service and, whilst they may not have the same advertising value as the modern type of machine, they should lack nothing in reliability.
The successful operation of a fleet of 150 taxis in London, on day and night service, calls for considerable administrative work, in addition to a comprehensive records system covering vehicle maintenance. Having been shown the working of the recording systems employed in the offices and works of York Way Motors, Ltd., I should say that this company has little to learn regarding taxicab operation.