Standardisation.
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By Douglas Mackenzie.
The suggestions that are now before the Council of the Institution of Automobile Engineers with reference to the standardisation of parts, if adopted by that body, should prove to be of immense value to the industry. In the near future, the growth in number of the already ubiquitous motor vehicle will render it more and more -essential that standardisation should be obtained at once in the minor details, such as bolts, nuts and spanners, and, ultimately, in many parts of the vehicles themselves. The list of standardised parts must not be made too comprehensive if one heeds the arguments against the adoption of such a system. The limit of its operation might well be stated to be that at -which standardisation begins to interfere with efficiency or improvement. Supporting the plea for standardisation, are interchangeability, simplification of design and construction, and even reliability. Most automobile engineers will have experienced, at some time or other, the annoyance of finding that no stock nut will fit a particular bolt or Spindle end, and, when the experiments with those at hand have been tried, they may have found the spindle end has been ruined by nuts which appeared to have the same thread but—were slightly different. With every thread made to standard, a few spare bolts and nuts may be carried, with the certainty that they will meet every case. The engineer may query " Have you never heard of Whitworth?" "Do you know that the Engineering Standardisation Committee has prepared lists of standard bolts, nuts, and spanners that meet all requirements?" The latter statement is correct, if we except the last word but one. The special necessities of the automobile engineer have not all been fully met. The essential need for lightness, and the greatly improved tenacity of the steels used in motor-vehicle construction call for lighter nuts, and spanners, than has been the case in previous engineering practice. The suggestion, made during the discussion on Mr. Martineau's paper, was that the size of nuts should be that fixed by the Engineering Standards Committee for the next smaller size of bolt. Possibly, in some cases, this might be carried further, so that two neighbouring sizes of nuts might have the same dimensions over the fiats, and fit the same spanner. It must not be forgotten that a great deal of work has been done in this direction, because, in addition to that of the Engineering Standards Committee, some excellent work was done by the pioneer of the Institution of Automobile Engineers, viz., The Cycle Engineers' Institute, whose standards have he.pn generally adopted for cycle work ; and the British Association has also standardised certain sizes of small screws and nuts. It is probable that the Council of the Institution of Automobile Engineers, which contains so many engineers of great repute, will work in conjunction with the existing Engineering Standards Committee, and will only supplement the work of this committee by suggesting additional standards for the special needs of motorcar manufacturers. It has, however, no easy task because of the large number of foreign cars in this country, and also because of the adoption of metric dimensions by many English motorcar engineers. It will prove very difficult to decide between the claims of the two systems of measurement, and to secure the adoption of either to the exclusion of the other. A modus vivendi may be found in the adoption of a plan that has long been the practice of Milnes-Daimler, Limited ; this company makes the bolts and shafts to millimetre figures, but cuts an English standard thread with a nut made to inch figures. A determined effort must be made to get the Continental manufacturers to adhere to whatever standard may be adopted ultimately, and this should not be very difficult, in view of the international character of the Engineering Standards Committee. Collaboration should be able to secure standards that will be acceptable to the manufacturers of all countries alike, and interchangeability would then reach a high degree of useful. ness.
In addition to this call for work with regard to nuts, bolts, and spanners, there is another field in which the need for standardisation is even more crying. This concerns certain special constructional details, of which the following may be enumerated :—The position of the clutch and brake pedals relative to the steering pillar; the position of the various speeds in a gate change-speed gear ; the relative position of the speed lever for straight-threugh gears ; the direction of motion of the hand-brake lever; the standardisation of radiator sizes. It would be obviously unfair to lay down rules for details that are often good talking points, if not valuable features in the design of particular cars. The details enumerated are of no importance from that point of view, but are often of great consequence to the driver. They are of importance more especially to the owners of commercial motors, because of the particular class of driver that has to be employed. A man who is always driving the same car may get accustomed to the clutch pedal on the right side, and the brake pedal on the left side, but, where there is a chance that a strange driver may have to take charge of the vehicle in an emergency, such a reversal of the usual construction is pregnant with the possibility of accidents. The strangest pedal arrangement, that has come within the writer's experience, was that originally fitted to the omnibuses constructed at the Stratford Works of the Great Eastern Railway Company, where the clutch and foot-brake pedals were both on the left of the steering pdlar, and the space between the driver's legs was occupied by an emergency brake wheel. The driver had to twist his right leg round this brake standard, and apply the pedal brake with the side of his boot. It is not often that one comes across such extraordinary design (which was evidently intended for a driver with three legs) but the reversal of the pedals is unnecessary and inexcusable, and the Institution should use, therefore, the full weight of its influence to ensure that the left pedal always operates the clutch, and the right pedal applies the brake.
The position of the speed gears is of next importance to that of the pedals. There must always be the essential difference between the two types, Panhard or sliding-type, and Mercedes-type or gate-change, but the speeds should always be in the same position in gears a the same type. Commercial motors must always be kept in full work if they are to prove remunerative investments, and strange drivers have frequently to take cars at short notice, in the absence of the regular driver through illness, or through having to answer a summons for having his rear tight extinguished, or 'even owing to his dismissal from any cause. It is very disconcerting, not to say dangerous, to find that the position of the lever for the various gears is the reverse of that on the car• which the man has previously driven, and, even though he has noted it before starting, he is very likely to forget it in an emergency. When he wants to step down on a hill, he will step up to a higher gear by mistake and pull the engine up. The writer witnessed a case, last summer, in which the driver changed from one car to another both of which were fitted with Panhard-type gears in which the positions of the lever were exactly reversed. Of course, the lever was left-in the neutral position, whilst the car was standing, and he moved it one notch forward thinking that he had put in his reverse ; instead of this he had put in his first speed. He then looked over his shoulder to steer backwards out of the garage, and let the clutch in, with the result that he ran into a wall in front of the car before he had time to realise what had happened. In this instance, the driver had been on this particular car for ten days, but the effect of previous habit was so strong that it affected him even after such an interval. It is equally important that the positions for each speed should be fixed in the case of the gate-change. A driver will find it very disconcerting when on a strange car, if that position of the change-speed lever which he has always associated with the top speed is now the third' and, further, if the position that he has always associated with the first speed should prove to be the second or third, there is a considerable risk of his pulling up the engine every time that he lets in the clutch.
The third point calling for attention is the direction of motion of the hand-brake lever—that is to say, whether it pushes on or pulls on. This is of great importance, be-. cause the hand-brake is generally used for an emergency stop, and, if the driver has to wait to consider which way to move the lever, an accident may be the result.
The next point mentioned, that of radiator sizes and shapes, does not stand in the same category with the control, as there is no question of danger involved, but it would be a great convenience to the commercial-motor user to have radiators and bonnets all of one standard outline, varying, naturally, with the size and power of the car, so far as dimensions alone were concerned. Standardisation might result in eight or ten regular sizes that would be stocked by all radiator makers, and by many large repairers, so that a damaged radiator could be readily replaced, and much delay and inconvenience avoided. The Associated Omnibus Company has had much trouble with the radiators fitted to a particular.make of omnibus, the shape of which rendered it very difficult to replace them. A new type of radiator is now being fitted to these omnibuses ; the attempt to conform to the original outline has been boldly abandoned, the new radiator being of rectangular shape with a special ledge secured to it, to take the original bonnet. The radiator may become the curse of the driver's existence, and a heavy drain on the owner's pocket, but standardisation would make it so easy to obtain another radiator to fit the vehicle, that ir would be a simple matter to remedy the evil. Radiators could be made of any design of honeycomb pattern, or of flat or round gilled tubes, horizontal or vertical, so long as
they conformed to the standard outside dimensions, were attached to the frame in the same manner, and were drilled for the same bolt-holes. There should be two or three tabulated areas of cooling surfaces for each size of engine, so that the owner could effect an improvement in [his direction if he wished to do so.
The Institution of Automobile Engineers should be the authority on all such points of design, and it is to be hoped that it will use its undoubted influence to secure standardisation in these extremely important details of motorcar manufacture. Very possibly, the Institution may find later that there are still further matters in which it can usefully influence design, but until the general design settles down upon regular lines this would he undesirable and unwise. Standardisation is an excellent thing if not pushed too far, and, whilst it may be of immense help to the industry, it would be harmful if it fettered design in these early stages. Many engineers can remember that, for the first six years of the safety bicycle, the frame was continually altered in shape but that, for the last 12 years, the diamond frame with 'the parallel top tube has reigned supreme, and no bicycle would sell that departed from it to any appreciable extent. It is probable that similar uniformity will ultimately prevail in motor-vehicle design, but, in the meantime, the designer should be allowed absolute freedom so that the Lest results may be obtained on the Darwinian principle of the " survival t>f the fittest."