Land Transport in Peace and War.
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By Col. R. E. B. Crompton, C.B., R.E., M.Inst.C.E.
The demand for transport increases as men become more civilized. Primeval man was very slightly differentiated from the brutes, and, as long as his chief source of food was obtained by bunting, he needed only to transport himself and his weapons. Later on, he had to carry with him a few cooking utensils, but jt was only when he became a cultivator of the soil that his transport needs substantially increased. He then found that the localities, which were generally the level alluvial plains, which be found easiest to cultivate and on which to grow his corn, were not necessarily the best places in which he could sleep, cook and eat, and fortify himself against the attacks of savage animals, or of enemies of his own race.
The Origin of Transport.
It is most probable, therefore, that the earliest forms of transport were developed on the tracks along which primeval man carried his food from his cultivated fields to his fortified villages. In certain cases, he found that he could do this most easily by water carriage, and his engineering ideas then first showed themselves. Rafts, and afterwards dug-outs. were probably the first means by which the food was floated down stream from one position to another, the food being landed at a point near the fortified village, carried on men's shoulders, and afterwards on pack animals, to the village storehouse, so that, probably, the first roads were those which led from the water to the village.
During the period that the loads were borne on men's shoulders, or on pack animals, these were pack roads, and all early road communications were by means of pack roads, which were chosen to follow routes as free as possible from natural interruptions. These pack roads led over the hills, or round their sides, a favourite position being a self-draining hillside where the road would best 'free itself from water, or from snow drifts. Hilaire Bello; in his very interesting hook, " Our Old Road," traces and gives the history of the development of the ancient East and West road of the South of England, part of which was eventually adopted by the pilgrims, who landed at the convenient harbour of Southampton and traversed it on their way to the Shrine of St. Thomas at Canterbury, giving to this old road the name of the Pilgrims' Way.
Antiquity of Wheeled Vehicles.
After a term of frictional sliding upon sledges, the next stage in land transport was the development of the
wheeled carriage. We know that wheeled carriages have existed throughout the historical period, probably for 4,000 years, but, in all probability, the pack road existed for enormous periods—possibly millions of years —before loads were hauled by men or animals, either by the use of the sledge, or at a later period by using the wheel. When the wheel u-as introduced, the real engineering of roads began, for its introduction necessitated grading, and greatly influenced the road itself : the hillside, suitable enough for pack animals, was no longer the most-suitable road for the wheeled vehicle. The two points to be connected by the road continued as before, coast or river at one end and inland fortified village or town at the other. The new route for the wheeled vehicle would naturally follow the line which combined the advantages of the shortest-possible route with easy gradients, and the one most free from any interruption by mountains, morasses or rivers, whilst, in the case of the rivers, the choice of the point at which they could be bridged had important influence on the route chosen. With the pack roads, rivers and water channels would be crossed at the points where they are broad and shallow, but, when the wheeled vehicle demanded that the
river should be crossed either by a boat bridge or by a permanent bridge, it was found, in most eases, that this was done most easily when the stream is deep and narrow, and when the road can be carried up to the two ends of the bridge on high banks. It is important to note that these principles of road engineering remain the same for our modern roads, whether they be metalled highways or railways, but, so long as transport depended on haulage by animal power, engineers devoted their attention chiefly to the road, and to a very small extent to improvement in vehicles. Once, however, man brought into use the forces of Nature to supplement his own muscles and the transport animals that he used, the improvement of the vehicles immediately took a leading position as a new branch of engineering. The limits of this article prevent my dealing with the question of transport by water, a matter on which we, in anghind, have always taken the lead, and of which we are justly proud.
Modern Internal Communication.
It is unnecessary to follow the development of railway transport from the days of Stephenson up to the present time, further than to point out how that civilized man's transport needs are vastly different, and must necessarily follow different routes, from the old roads connecting the cultivated land with the dwelling place. The complicated problems of modern civilization and the large population which has to be fed (in many cases from markets over-sea) demand that everything should be grown or manufactured at the points where it can be grown or manufactured most conveniently, and hence produced most cheaply, and should then be transported from that point to the point at which it can be worked up in the most-economical manner. Per contra, the goods that have to be bartered in payment for this food, or these manufactured goods, have to be carried back to the point where the food or raw material was obtained. In other words, the transport of raw material, partly finished, and finally of completed or finished material, whether it be food, clothing, footwear, or machinery, may now be said to form part of the cost of everything we use in our present mode of life.
The transport system of developed countries, such as our own, is at best a makeshift, this feature necessarily arising from its gradual development. Previous to the introduction of railways, we possessed a network of roads connecting our towns and villages, and giving us through routes, more or lass direct, between our seaports. When our railways came, they were at first laid near to these through roads, and thus, in many cases, ran parallel to existing lines of trunk road, which were then thrown partially out of use, so that it was only the cross roads which became really serviceable to feed the railways. This state of road communication exists up to the present time.
The road motor, to some extent, preceded the railway, and, if it had not been for the interested obstruction raised by horse owners to the use of the highways by mechanical transport in the first 30 years of the last century, it is probable that the whole transport system of the world would have been much more advanced than it is at present, that the system on which our railways were laid out would have been profoundly modified, so that, at a far-earlier period, the undoubtedly-correct system of Well-balanced trunk lines of railways, fed by wellchosen cross roads, would have been adopted years ago, instead of the full necessity for this only now forcing itself upon our attention. The Road Factor, It is only now that we are beginning to see that transport on wheels on the roads must generallyobey the same laws as transport on wheels on rails. The materials of which both the wheel and the road must be composed must in both instances be so chosen as to reduce the total cost of maintenance of both taken together to the lowest price. This was fully appreciated by our railway men long ago. Our rails have improved with our locomotives, and have always been considered part of the same machine, The case of the roads has been far different. The owners of horse-drawn carriages, and afterwards of the mechanically-propelled vehicle, have hitherto not :sufficiently considered the road maker; the road man, too, has not sufficiently considered the desigmir of the vehicle, En order to obtain good results, this state of affairs must come to an end, and there are already signs of this improvement. On all sides, there is a demand for roads to be constructed so as to reduce the rolling resistance of the vehicles running on them, and so as to give a. better surface both in the wet time of the year when mud is produced and at the dry time of the year when the same mud is blown away as dust. Dining the lest few years, great advances have been made. it is now found that the old ideas of road construetion are in all probability incorrect, that the variation of our climate from extreme net to extreme dryness has been the chief enemy with which our road engineers have had to contend, and that the system of 'Macadam, so long considered perfect, and which was undoubtedly a great step in advance of the roads which preceded it, is after all an expensive and unsatisfactory method for a moist climate such as ours.
Roads must be waterproof. The water which falls on them must run off, but must not penetrate the surface. The water which rises from the sub-soil below must not he drawn up so as to ascend into and soften the road metal. Many methods now exist by which the road material can be waterproofed. and at the some time consolidated, by using one or other of the compounds of a tarry or bituminous nature. It is already seen that waterproof roads can be made which are equally free from mud in winter and from dust in summer, and engineering knowledge has already advanced so ninch that the cost of those roads can he shown not to be in excess of roads made in the old way, and which are earrying the same amount of traffic.
I hare pointed out that, in the ease of the railways. the locomotive and the rail most be considered part of the same machine. Now that our roads have been improved, the designers of our vehicles and tractors must play their part, and must co-operate with the road eonstrnetor. Great concentration of weight, or of the tangential strains due to hauling the load, results in heavy and destructive pressures on the road surface, and must be avoided. Much experimental work remains to be done, in order to determine -the extent of the stresses to which road materials can be subjected, and in order to get the most-economical results in the maintenance of roads .suitable for all kinds of motor traffic.
Smaller Units and Axle-weights.
fE..w years age, the lowest enKt of transport on roads was that obtained by' heavy traction engines dragging trains of heavy wagons. On the driving wheels of these engines, and on the front wheels of the wagons, the weights were so great that the stresses were greaten' than the 'metalling would carry without fracture, so that they broke down the surface of many of our roads. especially of those which had weak foundations. 'We now know that these excessive stresses can he kept down by .sub-division of the loads. 'We must either can our loads in lighter wagons, and make up for the smaller loads carried by increased speed, or, when we desire to economize Weser, we most run trains of light wagons, and diminish the driving stresses by applying the driving power to an increased number of driving wheels. These are the lines on which advances are now being made, and it is certain that they will reduce the cub of maintaining the roads, without de:Tensing the efficiency or speed of transport.
Military Considerations.
Turning, now, to transport in war time, in what does it differ from peace transport ' Chiefly in this. That, in war time, the defenders of a country are compelled tis hamper the enemy's advance by destroying all means of transport. When the defenders of a country retreat, they temporarily disable their own railways, as far as possible, by blowing up bridges and by removing rails. The bridges on the metalled roads are also destroyed, but, on account of the time required for destroying the metalled surfaces of the roads, thia is rarely done between the bridges. The work of the transport engineers of the advancing army is to deal with " islands " of railways and roadways, which are disconnected by blown-up bridges or rail removals. The railway men are required to restore the railway C0111munication ; their work resembles the work in a new country. As the Army advances, " railhead " is advanced as. fast as may be, " railhead " being the technical term foe the most-advanced point to which railway locomotives can advance drawing trains of -railway materials for further constructional work, as well as the food, ammunition and baggage of the advancing army. The modern Military Engineer has learnt much in tire' work of railway reconstruction. Nothing that has been written on the late war in South Africa has, in my opinion, done justice to the magnificent work of our railway engineers on the rapid reconstruction of the 1,300 miles of railway which lay between Capetown and Pretoria, the disabling and part destruction of which by the Boers commenced at a. point about 600 miles from Capetown, and was practically continued right up to the Vaal river. It was interesting, in this reconstructive work, to notice how that, in re-bridging water-courses, it was necessary to, choose new points of crossing. which followed much more nearly the ancient roadways leading to the fords than those leading to the high banks where the river is permanently bridged in the easiest manner. In most cases. at river crossings, deviations were constructed leading from the line of railway to the ancient fords, and the laying-out of these deviation works is one of the interesting problems which present themselves to the Military Engineer.
It was soon appreciated by the enemy that these deviations were vulnerable points of attack, and, hence, at these points, the talents of our engineers were shown, not only in laying out the deviations, but in their military knowledge of laying out the defences which were absolutely necessary to maintain intact the lines of communication. Many of the severest fights and losses of skilled officers and men took place at these deviations, and, as one who was present and personally engaged on this work, I was profoundly impressed by its interesting nature.
Loss of Animal Lire.
Up to the time of the Cape war, it was believed in military circles that an army advancing far from its base must chiefly depend for its supplies on railways, and that the secondary distribution from the points on the railway must take place by animal haulage of the ordinary kind, hy wagon, or by loading direct from the railway on to pack animals ; but, for a long time, I personally had formed an opinion, which is now increasingly held by military officers, that we must look to mechanical haulage as the main source of military transport to impplement our railway work.
It is almost impossible, for those who have not seen it for themselves, to realise the immense destruction of animal life that goes on during a war. After the mutinyin India, and again following on the various frontier wars in ,Afghanistan and elsewhere, the destruction of animal life, horses, mules, camels, bullocks—all taken away from their agricultural or commercial employment for war purposes-was so enormous as to seriously cripple the resourees of the cmintry in the period immediately after the war, and so to hinder its recuperation.
Let us consider the transport work of an arms' in the field. We have to feed the men, the horses of the fighting 71r1118, i.e., of the cavalrymen and artillerymen. the horses, mules or other baggage animals of the Army
Service Corps, and, eventually, we have also to feed the enormous mass of animal haulage impressed from the country which is the theatre of war; we have also to convey, to limits as near the fighting line as possible, the enormous weights of ammunition required by modern quickfiring guns. In most cases, the animals get insufficient food and die off rapidly, and the means of transport are thus gradually reduced, so that the extent to which an army can advance can be measured often by the available hauling power of its diminished transport. When an animal falls sick or dies, it generally remains unburied ; its decaying earcase fouls the watercourses, and enteric fever follows thereon. Again, the weight and bulk of the forage, which must be transported for all classes of animal transport, is enormous. Compare all these disadvantages with modern mechanical transport work. The weight and bulk of the fuel is many times lees than the food of the animal haulage. The broken or damaged mechanical vehicle can be repaired, or the parts replaced from other vehicles, and losses can be minimized in that way. The length of roadway occupied by mechanical transport, and the flank exposed to the enemy's attack, is so greatly reduced, that escort duties are thereby greatly diminished.
Slowness of Substitution.
It may be asked, then : why has, up to the present, the use of mechanical transport by the Army been so limited ? The answer is, chiefly, that the choice of design of mechanical-haulage apparatus for war purposes differs widely from that for use on the well-constructed roads for peace time. The deviations in war time, to which I have already referred, nearly always become terrible depressions, suggestive of the Slough of Despond of "
Progress." At every such deviation, in South Africa, we found vast numbers of the bodies of dead animal, poisoning the air and communicating enteric germs to the water. The vehicles which had been hauled by these animals, when alive, were generally abandoned and frequently were broken up and burned for fuel. it is probable that, with our present improved knowledge of waterproofing roadways, part of the road deviations can be made to carry wheeled vehicles without the fear of their becoming such terrible quagmiree as they were at the Cape, but, whether the conditions of the temporary crossings themselves can be bettered or not, the design of the vehicles must be such that they can satisfactorily traverse these deviations. The diameter and width of the wheels, the nature of the springing, and the means of hauling the uagons by rope from a distant point, must be all considered, with a special view to getting the loads across these deviations as rapidly as possible. From the foregoing it will be seen that, after all, transport in war time greatly resembles the transport to which our forefathers were accustomed when our country was unprovided with roads, or transport in existing countries where roads have not yet come into existence. Vehicles fur war uses, or for the development of new countries, other than in and around cities, towns, and levelled camps, necessitate special designs. They must be able rapidly to transport their loads across roadless plains and mountain passes, and to do this they must be provided with wheels of such diameter that they can pass through river crossings, morasses, or the deviations I have described, getting their hauling power direct where sufficient adhesion is obtainable, or, wherever this is not the case, by the aid of a handy means of rope hauling their loads from distant Points on the firm banks.