FRENCH AFTER-THE-WAR PROBLEMS.
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Import Duties : the Returned Lorry : Standardization.
AT THE CONGRESS of Civil Engineers, held in Paris last week, some important announcements were made on the future policy of French motor manufacturers. According to a report made by M. Lumet, an effort is being put forward_ by the leading association of motor manufacturers to obtain. an import duty of 70 per cent, on the value of all motor vehicles brought into France during the 12 months following the declaration of peace. For the second year this would be reduced to 40 per cent. and for the third and following years to 25 per cent. The French manufacturers are also alarmed at the prospect of army vehicles being put on the market. It was voted that the Government should be requested to retain after the war all foreign-built motor vehicles, so that these would not come into conipetition with French makes of machines. The French attstude appears to be that, if adequate provision had been made in time of pea-ce' there would have been no necessity to purchase motor , lorries abroad, and, therefore, the home manufacturers should not be penalized by having to compete against these foreignmade lorries. In the motor section of the Congress, the question of the standardization of metals was not discussed in detail, for this whole matter is in the hands of the general engineering section devoted to standardization. M. Lumet in his report mentioned that the Paris General Omnibus Co. had sought to reduce the number of special steels used in motor construction and had drawn up six or seven specifications, showing their quality, tensile strength, elongation, heat treatment, etc. It was believed that these specifications were sufficient to cover the whole of the require
ments for motor lorry construction. The necessity was also pointed out of standardized specifications of castings of all kinds, this matter being even easier to negotiate than that of special steels. M. Lumet believed that there should be standardization of most of the accessories used on motor vehicles, but expressed the opinion that this standardization should not be so stringent as to arrest progress. The parts on which it should be possible to get unity of action are water connections, petrol pipes and unions, radiator filler caps and petrol caps, and the plugs in base chambers, gearboxes and differential housings. The automobile service of the French army has paid a considerable amount of attention to this matter and has succeeded in getting uniform magneto bases and couplings, also a few standardized types of driving chains. The Congress was of the opinion that this could be extended to ban bearings, springs, and lubricators.
The number of sizes of tyres is still too high, but a, step has already been made towards improvement by the establishment, since April, 1917, of standardized diameters and circumferences, with recognized tolesslices of both rims and the steel bases on which solid tyres sire mounted. The war department has found this absolutely. necessary, not only in their own interests, but m those of tyre manufacturers, lorry makers and general users. As an example of what has been done, it has been decided that a rim with a. diameter of 1000.5 mm. shall have an external circumference of 3144 mm. while the base to fit this rim shall be 999.8 mm. diameter and 317 mm. internal circumference. The tolerances are + 1 ram., a 0 for the rims, and ram. + 0 for the bases. The circumferential measurements are taken with a ribbon of 3-10th mm. in thickness, thus the measurement is not exactly 3.1416 times the diameter.
The question of the limitation of axle loads was brought up, M. Lumet stating that the restrictions formerly imposed by the military and civil authorities no longer met modern conditions. This question had been discassed at various road congresses, and the French Department of Roads and Bridges had declared, at the second Brussels Congress, that the road would be protected against abnormal wear by the limitation of speed and a suitable unit of load per centimetre of the linear section of the tyre in contact with the ground. For motorbuses and industrial lorries this unit was 330 lb. per centimetre for a maximum speed of 15.5 miles an hour, and a load limit on any one axle of 4 tons. When the inaximum speed was 12.4 miles an hour the axle load should not exceed 4i tons, and should not be more than 7 tons for vehicles having a maximum speed of 7.4 miles an hour. It was understood that this limitation of 330 lb. per centimetre was for wheels of I metre (39 ins, diameter), and that for bigger diameters the load should be calculated according to the formula, C = 150 OS, in which D is the diameter in metres ani. C the load in kilogrammes. The Section passed a resolution requesting the Government to continue experiments, in conjunction with the manufacturers' associations, to determine more accurately the local limits which should be imposed on vehicles, and also the influence of the dia.meter of the wheel on these limits.