Railway Construction

by William Hemingway Mills

On important through lines high-speed running has become a leading feature, and compels a very efficient standard of perfection in works and rolling-stock to effect its attainment. There is no indication of remaining contented with what has been already accomplished; on the contrary, the spirit of restlessness is always urging to do something more. The travelling public speak as calmly now of a speed of seventy miles an hour as they did of thirty-five a few years ago; they thoroughly recognize the value of railways, and they merely desire to travel still faster. The incentives of emulation and competition are ever present to encourage further and further reduction of the running time, and the railway that offers a special fast through service for some of its passenger and mail trains, reasonably expects its popularity and patronage to be in the ascendant. Much has been done in permanent way and equipment to make the present high speeds possible, but more will be required if the speeds are to go on increasing. The passenger carriages for such work must be very substantial, and naturally heavy. The locomotives to haul a long train must have increased power and weight, and will necessitate stronger rails to carry the greater rolling loads. With the present system of motive-power, the heaviest item is the locomotive, and its weight must always determine and regulate the character of the works and permanent way. Rails weighing 90 pounds per yard are becoming common, and there is clear indication that before very long sections weighing from 100 to 120 pounds, or more, per yard will be brought into use on many lines. There will be no difficulty in making a permanent way strong enough for rolling loads very far in excess of anything in the present practice; but it will be costly, and the extra expense per mile, extended over a few hundred miles, will represent a sum so large as to raise the question in many cases whether the probable advantages and additional remuneration to be obtained will warrant the outlay.

To some extent the increased speed may be attained by dividing the present long trains into two shorter trains, with a fair interval of time between them. There are many splendid locomotives now running, which on a fairly level line can reach a speed of considerably over seventy miles an hour with a short train, but would be quite incapable of doing so with a long train. At the same time it is possible that if passengers increase in the same proportion as the inducements provided, the short train might not be sufficient for the numbers presented, and there would be no other alternative but to resort to still greater rolling loads and stronger hauling power.

Perhaps electricity, which has already achieved so many marvels, is destined to take a still more prominent part as a motive-power in the working of ordinary railways, and may help out of the difficulty by inaugurating still higher speeds without the necessity of incurring stronger works or heavier permanent way. In addition to its success in the telegraph, in the telephone, and in its brilliant light, electricity is every day coming more and more to the front as a motive-power. At present many tramways and short lines, some of them in tunnel, some above ground, and many of them with very steep gradients, are successfully worked by electricity; but these, being of modern construction, were specially designed and equipped for that method of working, and none of them as yet resort to high speeds. Such rapid strides have, however, been already made in the progress of this system of haulage, as to promise that both increased power and speed will be forthcoming when the demand for them is made manifest. Various modes of application are being tried: overhead wires, underground wires, conductors on the level with the rails, storage batteries or accumulators, and self-contained electric motors, each and all of them being carefully tested to ascertain the comparative cost and efficiency. Much will depend upon the localities and advantages to be obtained for the respective generating stations. In places where a large, constant, and unutilized water supply is available, a great saving may be effected in the most expensive item of electric working, but in the greater number of cases steam-power will have to be adopted for driving the generating machinery. The main question will be whether electricity in its most approved form of application can haul a ton of paying load for one mile at a less average cost, and at as great or greater speed

than the ordinary locomotive. Until there is very clear evidence that electricity is cheaper, there will not be any great inducement for its general use as a motive-power on ordinary railways.

Experiments have been made on some existing railways to ascertain how far this new motive-power can be made serviceable under special circumstances. In one case, a powerful electric motor-car has been introduced for working frequent and heavy trains through a long tunnel, where the atmosphere with ordinary steam locomotives became foul almost to suffocation, and the result has shown that the traffic can be hauled efficiently by electricity, and the air in the tunnel maintained pure and clear. In this instance, the question of cost was of secondary importance, the primary object being to avoid the asphyxiating gases emitted from the ordinary locomotives.

In other cases, specially designed electric motor-cars have been constructed with a view to obtain a higher speed for passenger trains than is at present attained with the locomotives, and the trials made have proved that these cars could reach a high speed, but so far only with limited loads. Experiments are still going on with larger and improved machines, from which it is expected to obtain both high speed and much increased hauling power.

It is more than probable that amongst the earliest practical applications of electric motive-power on existing railways will be its introduction as an auxiliary on the steep gradients of some of the mountain railways abroad. In many of these regions there are millions of gallons of water running to waste down the ravines, a portion of which could be utilized in working powerful generating plant, to drive strong electric motor-cars for assisting the ordinary locomotives up the steep inclines. In such localities, with free water-power, the cost of the electricity would be at a minimum, while the cost of the ordinary locomotive would be at a maximum.

In whatever form the electric motor-car may be designed, we are brought face to face with the old axiom, that there must be a certain amount of weight to obtain a certain amount of adhesion; but there will be one important point in favour of the motor-car, that whereas in the ordinary locomotive the weight for traction can only be distributed over a few working wheels, the electric arrangement may distribute it over a much greater number, and so diminish the insistent weight of each wheel upon

the rails. There would also be the saving of the dead weight of the tender, the fuel, water, and other minor accessories, as well as the advantage that the active power would be applied in a rotary form instead of reciprocating.

There are important interests at stake in the perfecting of this new system of haulage, and day by day new developments are being made to add to its efficiency and reduce its cost. Existing railways will, however, naturally require some very convincing proof of the all-round superiority of electricity before adopting that power generally in place of their present locomotives. The latter, with their corresponding workshops and appliances, represent so large an amount of invested capital, as to demand most thorough trials and investigation of the new power before they are superseded; nevertheless, if further experience proves that electrical power is better and cheaper than the ordinary steam locomotives, then the change will undoubtedly be made.