Good Enough for the Continent?
Page 50
Page 51
If you've noticed an error in this article please click here to report it so we can fix it.
THE use of auxiliary braking systems on coaches engaged on Continental tours is a subject about which Mr. Eric A. Pillon, of Imperial Motorways (Birmingham) Ltd., Bromsgrove, feels very strongly. The danger of brake fade represents a constant hazard when descending the many steep passes on the Continent, and this can normally be avoided only if constant use is made of the lower gear ratios. Although safety can be ensured by extreme care on the part of the driver, the mental and physical effort required is very tiring and mechanical wear and tear of the vehicle increased
In Mr. Pillon's view, power-assisted steering is another feature which would be of value on both Continental and home tours, particularly when applied to underfloor-engined coaches. In winter, greatly increased steering effort is required to overcome joint stiffness.
Imperial Motorways is associated with a French concern, Paris Autocars. and Mr. Pillon has a first-hand knowledge of the capabilities of the Chausson vehicles operated by them. Telma electric braking systems of the type used on Paris buses are fitted to some of the coaches, and although the equipment is costly and adds appreciably to the weight of the vehicle, it is invaluable on mountain routes and reduces the amount of maintenance called for with drum brakes, He regards the use of an exhaust obturator brake as a half-way measure which would ease, but not solve, the braking problem under severe operating conditions.
About 80 per cent, of the total mileage covered by Imperial Motorways' vehicles is on Continental tours, which include visits to countries as far afield as North Africa. The greater difference between the cost of petrol and oil fuel on the Continent, as compared with this country, adds to the advantage of operating oil-engined vehicles. Based on a seasonal mileage of 32,000, the estimated annual saving on fuel is over £500. Moreover, this comparison is between the cost of operating a 4I-seat oiler and a 37-seat petrol-engined coach
Change-over to Oil Engines
In the interests of standardization and because of the high reputation of the make, six Bedford vehicles, powered by Perkins R6 engines, have been purchased for the 1954 season, and eventually all the 12 oil-engined coaches in the fleet will be replaced by the same type. The vehicles are fitted with Plaxton 38-seat bodies and it is expected that the fuel consumption will average 18 m.p.g.
A Commer Karrier with a Reading 14-seat body has been in use for some time, and a second coach of this type is a recent addition. Although an oil engine would be preferred, the chromium bores of the Commer petrol engines promise a long wearing life, and Mr. Pillon is satisfied with the performance of the vehicles and their freedom from maintenance troubles.
The coaches are used for small private-party work, and satisfy a type of demand which appears to be increasing. The average fuel consumption is about 18 m.p.g.
The record of the fleet is a credit to the high wearing qualities of British vehicles. Of three Tilling-Stevens coaches fitted with Plaxton bodies and powered by Gardner 6LW engines, one covered over 400,000 miles without a major overhaul, and there was no expenditure on repairs apart from routine maintenance work.
A Duple-bodied Maudslay fitted with an A.E.C. 7.7-litre engine averaged nearly 18 m.p.g. throughout its life, and on many occasions returned 20 m.p.g. with a full load. Another outstanding virtue of the main engine was its quietness of operation.
TwoA.E.C. Mk. IV chassis with Plaxton 4I-seat bodies arc still in operation. They also give excellent service. Initially, the front tyres had to be replaced after a low mileage, but after Michelin Metallics were fitted the
tvhicles covered -upwards. of 20,000, miles on Continental tours and in this ountry averaged 35,000 miles-between
yres changes. .
Many of the vehicles and drivers do tot return from the Continent during he entire season, and although the :oaches are serviced under contract at he port of disembarkation at Boulogne, his increases the responsibility of the lrivers with regard to the mechanical ondition of the vehicles and the early liagnosis of faults.
All the drivers are fully qualified tiechanics and no separate workshop taff is employed at the base in 1romsgrove. Mr. Pillon claims that the eet's reliability index is more favourble than the average for vehicles mployed on similar work, and this is ttributed, in part, to the mechanical nowledge of the Myers.
One of the few breakdowns in recent ears on the Continent resulted from iston failure The coach was many tiles from the nearest centre where tpair facilities and accommodation for te passengers might be found, but in ss than two hours the vehicle was inning satisfactorily on five cylinders ith the faulty piston and connecting id removed. Mr. Pillon points out at this could not have been done if e engine had been petrol driven. The oach was running on all its cylinders e following day. The knowledge of oil engines possessed by garage mechanics throughout the Continent compares favourably with that shown by the average British mechanic, particularly in areas remote from large centres of population. A willingness to work on an emergency repair at any time of the day or night is credited to the Continental mechanics.
British concerns, generally, are found wanting in this respect, but A.C.V. Sales, Ltd., are quoted as an exception, their 24-hr. service being highly praised.
The engines are lubricated by B.?. semi-detergent oil, similar grades of which are now obtainable both at home and on the Continent. The oil is changed at 3,000-mile intervals and the engines are normally decarbonized after the vehicles have covered 40,000 miles.
Mechanics Work in Pairs
Vehicles which are returned to the base are serviced two at a time so that both drivers can work together. This policy is regarded favourably by the driver-mechanics as it gives them the opportunity of pooling their knowledge and experience in a way which would be impossible during casual meetings.
Regarding other desirable coach features, Mr. Pillon criticizes the average standard of dustproofing on British vehicles, and says that, in particular, there is room for an improvement in glazing technique. He considers that flashing-light indicators are greatiy ELreferable to the semaphore type. On the Continent, indicators are used when travelling at high speed and are often held in the operating position by the pressure of the wind. Flashing indicators require far less maintenance.
Suspension systems, says Mr. Pillon, could be greatly improved by the use of double coil springs in conjunction with high-capacity shock absorbers, Integral construction of the Chausson all-steel or Harrington light-alloy type isconsidered to have an important future for coach applications, given that the cost is not excessive, and that the reduced weight enables single rear wheels to be used.
When travelling at high speed the airflow round twinned tyres is reduced by their close proximity, and this can result in overheating. Carrying an equal load, single tyres would, it is considered, operate satisfactorily for a greater mileage.
The acute hair-pin bends which are often found on Continental journeys cannot, in some instances, be negotiated by British vehicles without particular attention being given to the ground clearance, and Mr. Pillon would prefer an additional clearance of at least 4 in. Apart from this fault, the underfloorengined coach has the advantage with regard to manceuvrability,