The development of motors driven by one of the naphtha hydrocarbons (petrol, benzine, gasoline, etc.) is still in its infancy. Not until 1892 was it proved by experiments, carried out in France, that such automotor vehicles could be driven, not only on well-kept streets, but also on ordinary country roads, and at a pace which allowed of competition with the railway mail train service.
The development of motors driven by one of the naphtha hydrocarbons (petrol, benzine, gasoline, etc.) is still in its infancy. Not until 1892 was it proved by experiments, carried out in France, that such automotor vehicles could be driven, not only on well-kept streets, but also on ordinary country roads, and at a pace which allowed of competition with the railway mail train service.
This encouraged the attempt to utilise these motors in the construction of large automotor vehicles for the transport of heavy loads. And these attempts opened the way for competition among all kinds of engines adapted for mechanical traction. The builders of steam engines entered the lists with new models, which in England have so far won the day over the explosion motors, in that they alone have succeeded in fulfilling the stipulated conditions as regards power, endurance, and control. [For a full illustrated account of these ‘explosion' or 'detonating' motors, see Petroleum Motor Cars. By M. Louis Lockert. London: Sampson Low, Maraton & Company. M. Lockert has also published excellent little works in French on Steam Motor Cars and Motor Cars worked by Electricity, Compressed Air, etc.—Translator.]
The endeavour, so marked at the present time, to replace animal by mechanical traction on roads, is looked upon by many as a fad or folly of the day, whereas it is in reality a link in the chain of endeavour which connects the end of the century with its commencement.
In attempting to deal with the problem of selecting among different systems of mechanically driven vehicles such as may be suitable for military use, it is necessary to ascertain perfectly clearly the conditions under which the transport of heavy material is effected in war.
From this point of view an attempt will be made to describe the various methods of transport which are possible at the present time by means of mechanical traction (i.e. with engines of some kind in contradistinction to animal traction with horses, mules, oxen, etc.).
Oil-motors are a development of the gas-burning engines used in small industries,—they are also gas-motors, but on the explosion principle. The necessary quantity of gas is conducted into the carburettor and there mixed with atmospheric air; this explosive gas mixture is fired at the moment when the motor piston passes the dead point. In the so-called four-cycle explosion motors one stroke of the piston in the cylinder corresponds with two turns of the driving shaft.
In 1885 the German engineer Daimler substituted the incandescent tube lighter for the open flame ignition method used in stationary motors. It was now for the first time possible to construct fast road-motors of comparatively light weight (40 kg. (=80 lbs.) per horse-power). With small consumption of fuel (0.42 kg. benzine (not quite 1 lb.) per hour and horse-power) they could also now be used for vehicles (including boats). Complications with horse traffic arising out of the mechanism of motive power were unavoidable.
To overcome the resistances in the machine required the storage of power in a fly-wheel capable of from 1500 to as much in some cases as 2000 revolutions per minute. But with shaft and piston driven at such speed it was necessary to provide special arrangements for cooling the cylinder jacket, and running the axles in oil baths. The velocity of the fly-wheel and driving crank required some plan of reduced speed for transmission to the axles of the driving wheels. The great distance of the driving wheels from the motor necessitated an intermediate axle, on which are arranged driving drums graded for different speeds, and varying in form according as the transmission of rotation is effected by means of cog-wheels or chain.
The steering arrangements necessitate differential gearing, and of special importance are the arrangements for working the brakes, for running backwards, and for preventing the machine running backwards when stopped on a hillside:
After the incandescent tube the electric spark was also used for igniting the gas used for driving motor cars on the exploding or detonating method; ignition by means of magnetic induction was also tried. But the use of electricity necessitates batteries, accumulators, or a small motor-driven dynamo.
Successful working of the motor depends chiefly on the ignition of the gas mixture at the proper moment. Electric ignition is too complicated for use in war, and presupposes the possibility of recharging the batteries and accumulators. With gases derived from petroleum ignition by electric spark is not to be relied on. With electric ignition benzine gas could alone be employed, which, on account of its dangerously inflammable nature, can only be used to a limited extent for vehicles used in war. Escape of benzine through carelessness or leakage may give rise to explosions, since benzine evaporates at ordinary temperatures, and the gas mixed with atmospheric air is highly explosive.
Benzine motors can be used perfectly well in vehicles (Fahrzeuge)not intended for war purposes. In such cases the reservoirs can be filled up with the greatest care, and, whenever possible, only by daylight In war, when marching often occupies the whole of the day, there is no alternative but to replenish the store of benzine at night with a naked or at best badly protected light.
For these reasons military vehicles have to fall back on petroleum, although, apart from its unpleasant smell, it causes soot accumulations which choke the valves, necessitating constant cleaning, and the incandescent method of ignition which must be used with it is not unsusceptible to weather influences. [There is no smell or smoke from the ‘Motor-Car’ spirit sold by the Anglo-American Oil Company (specific gravity, 0.680). See account of the 1000 mile motor trial in the Appendix.—Translator]. Petroleum is subject to price fluctuations, and in this respect the competition between Russian and American supplies is advantageous to the consumer. [Handels-Revue, vi. No. 4, 31st January 1899]. In Germany in 1894 the price of benzine, duty free in barrels, was 16 marks 75 pfennings (16b. 9d.) per kilogram (=2 lbs.). At the present time, since the opening up of the Danube navigation (by blasting at the Iron Gates) up to Regensburg, the greater facilities for competition afforded to Russian petroleum will probably still further reduce the price of benzine.
The possibility of substituting home-made spirit for benzine and petroleum (in the interests of home industries) has been considered. But it appears certain that spirit cannot be produced cheaply enough. All the same, it is worth noting that we are not entirely dependent on foreign sources for the necessary gas-producing material.
Rubber tyres are necessary in the construction of light and rapid motor carriages. Even on the best roads a rapidly driven motor carriage is liable to jolts and shocks, and it is only by using rubber tyres that injury to delicate machinery can be avoided or greatly lessened. The cost of rubber is considerable, and its use necessitates larger and more expensive rims to the wheels, whether for ordinary or pneumatic tyres. Rubber tyre wheels are also expensive because the rubber loses its elasticity under the effects of great heat and cold; it perishes, and soon becomes useless.
Recently it appears to have been found possible to lessen the effects of wear and tear on rough roads. In Simms' patent there is a thick indiarubber tread which is so made as to be detachable when worn, when it can be replaced easily. Messrs. Simms have fitted a motor gun-carriage with their patent compound pneumatic tyre (see The Automobile for June 1899).
Very few substitutes for rubber exist at present, so that a reduction in price is not to be expected, especially as patents threatening their monopoly are bought up by the rubber manufacturers.
Even for motor carriages intended for carrying heavy weights, rubber tyres are necessary, as they permit a heavy weight to be carried with less waste of power than ordinary tyres. [All interested in heavy traffic should see the 'Roller Bearing’ Company’s exhibit at the Crystal Palace. —Translator]
Explosion motor carriages are constructed in various forms. Very light two- and three-wheelers, and light and heavy four-wheelers, 30 kg. (60 lbs.). Two-wheelers for one person have already been constructed, of from 1 to 4 horsepower; also two-wheelers for two persons (tandems). Motor three-wheelers, weighing from 70 to 80 kg. (140 to 160 lbs.), are used chiefly for sporting purposes. In France the good state of the roads has deluded the military authorities into the adaptation of three-wheelers for army purposes. But these machines, from the very nature of their construction, can never be serviceable for military purposes, as on bad streets and ordinary country roads with ruts they are useless. Light 240 lbs. four-wheel motors for two persons, and of from 4 to 6 horse-power, are to be had, and are considered in America to be suitable as Maxim gun carriages. For military purposes four-wheel carriages are best constructed with two independent motors, which can be worked together or singly; but this necessitates heavy machines. Carriages of this kind, with motors up to 15 horse-power, have been constructed to carry sixteen to eighteen persons (as omnibus), or a load up to five tons (as freight wagons).
Various suggestions have been made for the employment for army purposes in war time of the different kinds of automobiles not intended for drawing a train of wagons.
For instance, it is suggested to employ for courier service the light motor cars which are used in motor car races, and which with an average speed of 24 km. (14 to 15 miles) under favourable conditions on good level roads have done 30, 40, and even 50 km. in the hour (up to 27 or 28 miles). But it is questionable whether results such as these (attained in peace time under exceptional conditions) will be possible in war, when the roads are encumbered with troops and impedimenta of all kinds, and in thickly populated districts and in unknown countries. Moreover, there should be no illusion that map studying and taking one’s bearings be done without stopping, for the high speed makes it impossible to read a map or use a field-glass, even if one is not occupied in guiding the car. All the same the motor car will, in the long-run, get over more ground in the day than the horse-rider or cyclist can.
In Napoleon’s time the courier service with relays of horses, a franc etrier, was the chief means of transmitting diplomatic dispatches and army orders, and that, too, over such distances for instance as from Paris to Moscow or Madrid, [Memoires du General Baron de Marbot: Paris, 1891.] and there is no reason why a similar means of communication should not be of the greatest service at the present day at some decisive moment, when the ordinary railway communications are interrupted or do not exist But under ordinary conditions the field telegraph does away with the services of couriers, so that it is not likely there will ever be any extended use of motor cars for such purposes.
The use of light motor carriages for the transport of ammunition and the wounded may be possible in the future. At present they are not suited for this purpose, as they are not constructed for work other than on roads.
Motor freight wagons as already used by breweries, furniture removal businesses, etc., in towns, can be used for military purposes. It is simply a question in this case of cost of mechanical as compared with horse power. If it is cheaper, it will find such extended employment that the army can rely on it for the establishment of supply columns. They must be taken as they are, and used to the best advantage possible.
But if it is a question of creating types of motor freight cars, specially adapted for use in train formation for ammunition, commissariat, and baggage transport for an army in the field, the possibility that animal draught may be necessary must always be kept in view. For this reason the wagons must not be too heavy, though this may necessitate less carrying capacity than is the case with motor freight cars not specially constructed for army use. In non-military motor freight cars the utmost advantage must be taken of the fact that with a powerful motor, heavier loads can be carried than by means of an ordinary two-horse wagon. In this case the object in view is greater money-earning power, and whereas an ordinary motor freight car may be constructed to carry five tons, that specially intended for military use must not be built to carry more than a ton or a ton and a half.
The employment of motor kitchen cars, which has also been suggested, is not worth consideration. It would be of more consequence to so construct the tool cars (werkzeug-wagen) of the pioneer detachments of cavalry divisions, that they could be either driven by a motor or drawn by horses.
The only really felt want for the automotor is as light baggage carriers to accompany the cycle corps, whose employment for independent service is only possible in conjunction with them. Supplies of ammunition, surgical bandages, maps, etc., can be carried by their means as quickly as the average pace of the cycle corps requires.
It is of the greatest importance that officers of the general staff sent to some distant point under protection of a cyclist detachment should be able to cover the ground without too much fatigue, so that when their work of reconnoitring and sending written dispatches begins they may come fresh to it.
Experiences with automobile vehicles as such (i.e. not used for drawing carriages) are too few to give much clue to their value for military purposes. Competitions between such vehicles were encouraged in the French press in 1892, and a race which took place on the 6th and 7th of March 1898, between Marseilles and Nice, [France Militaire, 28th January 1898 and 15th April 1898.] is noteworthy from the fact that on one of the days the weather was fine and the roads in good order, and on the other wet and the roads bad. The average pace established, even for bad weather, was 25 to 30 kilometres (about 15 to 20 miles) per hour for light four-wheel automobiles, for motocycles (three- and two-wheelers) only 20 kilometres (12 to 13 miles). As one is inclined to consider light two- and three-wheelers as faster than four-wheelers, this result is striking. But the explanation is a perfectly natural one, viz., that driving a two- or three-wheeler over slippery roads requires great care, whereas the four-wheeler can be driven at the higher speeds even under such conditions.
The two-wheeler has probably a wider field of utility before it, although at present scarcely answering all requirements. The three-wheeler alone is unsuited for military use; it takes up as much width on the road as the four-wheeler, but with its three-wheel track is unable to avoid the bad places so well
Races have also taken place between heavier automobiles, which have proved that they can be run at a very considerable pace on good roads. But experiments under military conditions, i.e. such as exist in war time, are wanting, these consist specially in the necessity for a long train of vehicles following close one after another. Collisions may arise in consequence of differences in the pace of the column, caused for example by the head of the column being retarded at the commencement of a steep incline, whilst the rest of it still on level ground keeps up its pace. In consequence of the long duration of the march, especially when it takes place at night, the nerves of the drivers get overtaxed. It remains to be seen whether the acetylene light, which is recommended for other military purposes, such as searching the battlefield for wounded, will be so improved for lighting vehicles as to be perfectly reliable. Without some such system of lighting the wagons or other vehicles must be kept far apart and the pace greatly moderated.
This question, and that of keeping the roads clear at night, and many others, must be answered by actual experiment under such conditions as obtain in war time, before any decision can be arrived at as to the value of automobile vehicles for transport of heavy loads in war.
See Harmsworth's Magazine, April 1900, for interesting illustrated articles on 'The 1000 Mile Motor Race' and 'The
Cycle as Ambulance.'
I have given some account of the great race at the end of this work The value of 'Petrol' has been thoroughly established in its best forms it is smokeless, odourless, and cheap. The ignition question appears not likely to present any grave difficulties in future. —Translator.