TWO-DIMENSIONAL MOVEMENT
The above, I admit, is a very brief summary of an immense and complex subject, namely, the bridging of the gap which exists between the producer and the arterial railway, or the producer and his market, if it be a distant one. Ruling out pack and porter as being too uneconomical to be used on a large scale, we are left with the wagon, the lorry and the light railway. All these three means can cover great distances, but they do not solve the problem, because the solution does not only lie in power to traverse distance, but in ability to cover the largest area in the shortest time.
The difficulty so far has been that the wheel demands a road and destroys a road, and that, whilst it is easy, though frequently very costly, to make a road which will suit a wheel, it is most difficult to make a wheel which will not damage a road; for failing a cheap and simple form of Pedrail wheel, a system of multi-wheels has to be resorted to, and this system leads directly to the tracked machine, which not only can dispense with roads, but, what is equally important, can make its own track, just as the feet of a man form a path by frequently crossing the same piece of ground.
This is not the place to examine in detail the technicalities of roadless vehicles; but to-day there are two main types of these vehicles; an all-tracked machine of the tank type, and a half-tracked machine which has wheels in front and tracks in rear. The first is more suitable for heavy loads, and the second for light.
In the manufacture of these vehicles three main problems must be solved:
(1) The vehicle must be able to use roads without damaging them; nor must it damage the surface of the ground it travels over.
(2) It must be able to move across country without damaging itself.
(3) The cost per ton-mile must be equal or lower than that of existing vehicles.
It may seem a paradox to lay down that the first requirement of a roadless vehicle is that it can negotiate roads, but, in fact, it is not so; for it stands to reason that, when prepared tracks do exist, it is only wasting time and energy to travel across country. Further, if the tracks of the vehicle are so constructed that they do not damage roads, they will not damage the surface of the ground, and, consequently, by continually travelling over the same ground, they will compact and consolidate its surface and rapidly form a road of their own which will require no metalling. This advantage is one of the great secrets of its success.
As movement across country entails traversing rough ground, the tracks of a roadless vehicle must permit of the absorption of obstacles. This absorption is attained by springing the tracks. In an unsprung machine, obstacles are either crushed into the ground or the vehicle has to lift itself over them. In both cases the result is injury to the machine, and loss of power and discomfort.
It stands to reason that the vehicle must be durable, simple and easy to maintain; also that the ton-mile cost must be low. As regards this latter requirement, experimental machines have so far proved that this is a possibility. A one-ton roadless Guy Lorry recently travelled from London to Aldershot, and its ton mileage was fifty-two to the gallon. It has also been worked out that the cost per ton-mile of the Sentinel tractor, “including overhead charges, depreciation, interest on capital and all running charges, and allowing for a 20-tons net load for a reasonable number of working days in the year,” will be slightly under twopence per ton-mile.
SENTINEL TRACTOR
[Face p. [80]
In the future, the types of roadless vehicles are likely to be great as the surface of the ground differs in various countries; also fuels of all kinds are likely to be burnt, such as petrol, oil and coal, and in tropical countries, where these fuels are scarce or expensive, producer gas is almost certain to become the main motive power.
The most remarkable achievement as yet carried out by roadless vehicles is undoubtedly the crossing of the Sahara from Touggourt to Timbuctoo, during the winter of 1922–1923, by Citroën motorcars fitted with half tracks invented by Monsieur Kegresse. The distance travelled was three thousand six hundred kilometres, and the time taken was twenty days, that is on an average one hundred and twelve miles a day. All machines returned safely, and the total journey there and back was over seven thousand kilometres.
The nature of the country crossed was by no means uniform, for it was sandy, rocky, mountainous and, in the neighbourhood of the river Niger, covered with tropical vegetation. To build a railway from Touggourt to Timbuctoo would cost, at the lowest reckoning, a thousand millions of francs—possibly much more; this alone accentuates the importance of the achievement and its interest to us, for the Empire contains thousands of square miles of roadless country.
I fully realize that, though the roadless vehicle can replace the motor-car, it cannot replace the railway, if the railway is an efficient one. This is, however, not the problem. The problem is, first to bridge the gap between the producer and the railway, and secondly to create in undeveloped countries sufficient wealth to enable more railways to be built. Co-operation with existing railways, this is what must be aimed at.
CROSSLEY-KEGRESSE CAR
[Face p. [82]
For purposes of illustration, I will take British East Africa as an example. A railway runs from Mombasa via Nairobi to the Great Lakes. Forty miles on each side of this railway, generally speaking, is commercially remunerative. This is the first belt I mentioned above, the second two belts are productively a gamble for any but capitalist pioneers, and the remainder of the country is but the playground of rich colonists who can afford to speculate on likely railway extensions in the future, or else of simple fools.
I will now suppose that a reliable roadless vehicle exists which can transport across country five or ten tons of produce. What do we see? We see the first belt extending from forty miles on each side of the railway to a hundred miles, and the second two belts being pushed out, in vastly improved circumstances, fifty to a hundred miles on each side of the new central belt. In fact, we have more than doubled the central belt and trebled the belts adjoining it, and, in doing so, have more than doubled the commercial prosperity of the country.
What now is our next step in the evolution of economic movement? It is, out of the wealth resulting, to extend from our main Mombasa-Nairobi railway, metre gauge lines in herringbone fashion up to the confines of the new central belt, and at the termini of these to build receiving depôts. In place of metre gauge lines, huge roadless machines, carrying and hauling from a hundred tons upwards, will in the end, I think, prove more economical. Once these depôts have been established, the smaller machines belonging to the farms and stations can bring produce to them and dump it. Thus, by degrees, will the central railway be fed by a prosperous area some four to five hundred miles in width.
MORRIS ONE-TON LORRY
[Face p. [84]
To take another example. A transportation problem which faces every farmer is that of rapid door-to-door delivery. To-day, especially in such countries as Canada, what do we see? We see chain-tracked machines used for agricultural work, but we seldom see movement of the produce grown carried out save by horse-drawn vehicles, which can negotiate cultivated land if it be fairly dry.[[7]] Two horses cannot pull much more than a ton over a heavy field to the farm itself. At the farm, which may be fifty miles from a railway, the produce has either to be transported by cart to the station, which may take three days and two to return, or loaded into a lorry which, unless the roads are good, will take one day each way. The loss of time is considerable, and the roadless vehicle would appear to be the only practical solution. It can be loaded at the extremity of a field in any weather and condition of ground, and moved direct to the railway either by road or across country at a normal lorry speed, and carrying from three to ten tons according to size. Delivery is from door to door, and the only limitation as to load would appear to be the factor of safety of the bridges which may have to be crossed.
[7]. In Canada, snow offers a serious difficulty to movement by wagon or car during the winter months; there should be no great difficulty in producing a roadless vehicle which will cross snow almost as easily as grass land.
In waterless, as well as roadless areas, such as exist in Australia, wagons and lorries are frequently useless, and the roadless vehicle is again the solution, for it does not require a road to move along, or a well at which to seek refreshment. It carries its own roadway and its own water supply, and, if necessary, water for man and beast in districts where water is scarce.
In mining countries, such as Chili and South Africa, and in oil-producing countries, such as Mexico and Persia, the need for a weight-carrying, roadless vehicle is much felt, and in these countries, where again roads are few and bad, and water frequently scarcer, it would prove as useful as in agricultural lands.
VULCAN TWO-TON LORRY
[Face p. [86]