INSPECTING PUBLIC-SERVICE VEHICLES.
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An Expert's Views on the Need for the Careful and Regular Examination of Vehicles Used for Carrying Passengers.
THE inspection of public-service vehicles is a highly important problem and one which is deserving of the most earnest attention of all concerned, especially now that road traffic has assumed such remarkable
proportions. The number of buses, coaches and cars now using the roads day in and day out is so large that any vehicle of any type which is not in a mechanical condition which enables it to be under ready control, particularly in regard to its braking equipment, may well be considered a potential source of danger by all road users. Some licensing authorities are fully aware of these factors and strive to prevent the use of unfit and unsuitable Vehicles (more especially hackney carriages), _ but others display little concern in such Matters. The need for the periodic examination of such vehicles by competent officials is clearly surveyed in a paper by Major R. Vernon C. Brook, 0.B.E., A.M.I.E.E.. M.I.A.E., which he recently read before a meeting of the Institution of Engineering Inspection, and, as it deals with the subject in an exhaustive manner, we refer to it at some length.
It is the author's opinion that the inspection of public-service vehicles has, until recently, been sadly neglected, except in the case of the Metropolis and certain cities and towns. He stresses the fact that even to-day there are many vehicles licensed for the conveyance of passengers which are subject to no official examination whatever, and even in those instances where official inspections are carried out the work is frequently done in a haphazard manner and sometimes by men who have no engineering training. He supports this contention by citing two recent examples which came to his notice. In one case the local authorities considered the appointment of a qualified engineer, but ultimately decided to give the job to a local policeman who was "a very experienced motorcyclist."
Public-service vehicles which have to be inspected can be divided into two classes, one dealing with motorbuses and motor coaches and the other with taxicabs. In each case, says Major Vernon Brook, three essential features are necessary, these in their order being safety, reliability and comfort. Safety, he points out, means safety for the general public using the roads, as well as for the passengers in the vehicle, and under this heading can be included a number of items. First and foremost is the question of braking power and the general efficiency of the brakes, after which the steering, wheels and tyres, frame and other chassis parts must be considered, whilst, finally, the safety of the body of the vehicle itself.
Dealing with these items separately, the author then stresses the general requirements in connection with motorbuses and coaches, first, as to constructional details and, secondly, asta methods of testing on the road.
He has much to say in his paper on constructional requirements from a safety point of view. In -dealing with the power unit, he says that the inspection should be carried out in daylight, preferably in the open air. No vehicle submitted in a dirty condition can be properly inspected. He believes that an accumulation of oily dirt may readily hide a weak point and even obscure a serious and dangerous fracture.
Reference is then made in the paper to parts of the engine which should receive special attention, and in this connection oil and petrol-pipe connections are dealt with. It is mentioned that there must be no " pockets " in which any overflow of petrol may linger, and in the author's opinion there should be a clear opening of at least 6 ins. around the underside of the centre of the carburetter, or 2 ins, from a line dropped vertically from any part of the carburetter, so that any escape of fuel will fall quite clear of the chassis and engine parts.
Major Vernon Brook does not relate some of the artifices that are adopted by sonic owner-drivers in an endeavour to get their vehicles through a test, but says that the methods employed often defeat their object by showing up some weakness other than that which it is endeavoured to disguise.
The question of the examination of the transmission is next dealt with, and reference is made to the awkward position in which this often has to be carried out. The author points to a certain weakness in design when he says that constructional requirements may well be laid down ixt respect of bodywork which will enable the transmission readily to be inspected from above.
Tinder the heading of transmission, references are made to the clutch, gearbox and back axle. In connection with the last-named component the author wishes that better provision were often made for inspection, and says that, although there are one or two makes of vehicle on which it is possible to remove an inspection cover to reveal the final drive and differential gear, this is generally the exception rather than the rule.
. The steering gear then comes under notice, and in Major Vernon Brook's view it is really extraordinary in what a bad state this part of the vehicle is often allowed to get. He gives it as his opinion that the worst offenders in this respect are vehicles which are not called upon to be officially inspected, those owner-driven lorries—the tramp steamers of the road—which toil about the country day in and day out (usually at unreaumerative rates, the author adds) in the hands of their hard-working yet impecunious owner()Hyena, who have DO time and less inclination to pay proper attention to this vital but usually unseen part of the vehicle's mechanism.
We note that the author has, with considerable wisdom, given much space in his paper to the subject of brakes. The importance of the braking system is now generally appreciated by designers who nowadays do not merely supply equipment which will work efficiently -when a vehicle is first delivered, but which will give satisfactory service over long periods, and, moreover, which is capable of easy adjustment when necessary.
He deals with different forms of braking arrangement, and has something to say anent the type of brake often used on the propeller shafta methed which he does not favour, for he considers that it throws severe stresses on the whole of the.transmission gear, including the universal joints; differential gear and axle shafts. He touches, a vital point when he says that failure of some part of the transmission system between the propeller-shaft .brake and the rear road wheels usually renders the brake completely inoperative, and then if the wheel brakes are not effective the speed of the vehicle cannot be checked. The author obviously does not disguise his dislike for this, type of brake when he says that when inspecting them he is always merciless in his decisions.
The paper next contains a brief reference to wheels and suspension, and to features which should come under the eye of the iuspecting engineer.
In the final section of the paper, Major Vernon Brook dilates upon bodywork in general. We are inclined to think that lie is right when he says that it would appear that the prime consideration in the inspection of many public-service vehicles is the condition of the body, and Particularly of the paintwork, and that, providing the exterior is presentable and the inside well cushioned, the vehicle is passed for service as O.K.
The author pays some attention to single-fleck buses fitted with an emergency rear door, and stresses the need for the close examination of door catches and handles, as well as steps, hand rails and window lifts and catches.
In his final paragraph, Major Vernon Brook says that it is important that all public passenger-carrying vehicles should be subject to at least an annual examination and an occasional " snap " examination during the intervening period by a competent engineer who has had practical training.