© Railway Wonders of the World 2024  |  Contents  |  Site Map  |  Contact Us  | Cookie Policy

The Snow Plough and its Work

How the railways fight against the track-blocking snow with a variety of wedge and rotary snow ploughs

ROLLING STOCK - 12

FRONT END OF WEDGE SNOW-PLOUGH used upon the Canadian Pacific Railway.

IN countries which are liable to heavy snowfalls the railways are tied up under such visitations far more effectively than are those in temperate climes by the fog fiend. This enemy of the railway operator, despite the most valiant and herculean efforts, will oftentimes refuse to release its grip for days on end, bringing traffic to a standstill. The snow-shed offers an effective protection in mountainous districts where slides and avalanches are experienced, but upon open strctches of the steel highway the operator has only one course open to him — to fight his implacable enemy.

The scudding white fleece is no mean foe. It will fill a deep cutting to the contour of the country, and upon a level stretch will pile up huge hills which are not easily shifted. To force a passage by hand labour through such obstructions is a hopeless task; and in order to expedite the removal of the snow, so as to reduce the traffic interruption to the minimum, the engineer has devised wonderful mechanical appliances. Although they displace vast armies of men armed with shovels, the latter cannot be dispensed with entirely. In fact, often gangs have to be rushed up to extricate the plough after it has become stalled in a difficult position, and perhaps can neither advance nor retreat.

The oldest and most common form of mechanical snow-shifter is the wedge plough. As the name implies, it has the form of a big wedge or a double scoop turned edgewise with a sharp prow. Its lower edge is just clear of the rails, while in the largest types the top edge of the scoop is level with Or above the topmost point of the driving equipment. In some instances, as upon the Scottish railways, it is a somewhat improvised apparatus, attached to the front of the locomotive ; but such a system is applicable only in those districts where the obstruction is relatively insignificant, and is not packed tightly.

The method of operation is very simple. The pointed nose of the plough is driven into the drift or bank, when, merely by pushing it forward, the snow displaced by the prow is deflected along each side of the scoop, and thrown clear of the track. Sometimes the snow, which may have banked well after drifting, does not yield readily to the powerful sustained pressure of the locomotives behind. Then more drastic methods are adopted. The machine backs down the cleared track a short distance, and then drives headlong into the drift, this bucking being continued until either the bank is overcome or the plough is defeated. One great advantage of this form of snow-fighting machine is the speed with which the line can be cleared as compared with other methods, but its field of application is somewhat restricted. Deep drifts or banks in which layers of ice, arising from alternate thawing and freezing, and which always packs intensely hard, does not yield to such a method. The prow of the plough is apt to be forced upwards, and often the machine becomes derailed.

The wedge-plough is of very little use in mountainous districts where slides are prevalent, as the avalanches are apt to contain masses of rock, uprooted trees and other debris, which place this type of snow-fighter out of commission very readily. Shovel work would have to be practised under such circumstances but for the perfection of another wonderful appliance — the rotary snow-plough.

The rotary snow plough s the railway engineer’s finest weapon for combating the forces of winter, notwithstanding that at times the resistance is stern, the struggle for supremacy is bitterly contested, and progress is slow. Although in its present perfected form this tool is of comparatively recent date, the idea itself is by no means new, the first patent having been taken out 45 years ago. Perhaps it is not a strange circumstance, but the invention is of Canadian origin, and it was evolved, not by a railway engineer, but by a dentist! This was J. W. Elliott, a resident of Toronto, and he christened his conception a “compound revolving snow shovel”. Fundamentally, it resembled the machines of to-day, since it comprised a truck on which was mounted a boiler and an engine for driving the disk-wheel, the apparatus being pushed by an ordinary locomotive into the snow. The idea was to bore into the snow in the manner of an auger and, by catching the displaced material, to whirl it clear of the track by the revolving action of the fan-like wheel.

The invention appears to have been premature: at all events, it was not adopted, a result probably due to the lack of demand for such an equipment in those days.

FRONT END VIEW OF THE LATEST C.P.R. ROTARY SNOW-PLOUGH, SHOWING SCOOP WHEEL. The snow-plough measures over 80 feet in length, while the scoop wheel weighs 12 tons.

Later, however, another inventor, Orange Jull, revived it. The main feature in this instance was a knife-wheel, which, cutting up the snow, passed it through to a fan-wheel mounted behind, which ejected it through an opening in the casing. This device was taken up by Leslie Brothers, of Orangeville, Ontario, who constructed a full-sized machine. During the winter of 1883-4 it was tested by the Canadian Pacific Railway. The trial was scarcely fair, because the winter had broken before it was completed; but in order to ascertain what it could do, snow and ice were dumped into a cutting to give an approximate representation of a drift. The artificial snow-bank was not very deep, but sufficed to establish the invention, the snow being caught up and hurled through the air for some 200 feet.

This experiment served to suggest certain improvements, such as the ability to throw the snow to one side or the other as required. Another machine was built upon the improved lines by the Cook Locomotive Company, now amalgamated with the American Locomotive Company, and was put into operation upon the Union Pacific in the winter of 1887. By the aid of this first practical rotary blockades which had defied the railway’s ordinary snow-fighting methods for weeks were raised in a few days. The very first run served to satisfy the railway that at last a reliable mechanical snow-fighter had been designed.

Through the enterprise of the American Locomotive Company, assisted by suggestions for improvements which have been extended by the men who have had to use the machines, and who thus are in the best position to discover weak points, the rotary has been brought to a high pitch of perfection. In its present form the scoop wheel, which is the vital feature, comprises ten hollow, cone-shaped scoops, set radially like the spokes of a wheel. The surfaces of these conical scoops are quite smooth, so that the snow cannot possibly stick in any way. On the front side each scoop is open throughout its entire length, to enable the snow as it is cut up to be taken in. On each side of the opening, knives are hinged, and in such a way as to adjust themselves automatically to the cutting position and according to the direction in which the wheel is revolving, the knives which point in the reverse direction lying flat out of the way. The wheel is encased in a huge drum having a square hood fitted with a shoot at the top, through which the snow caught in the conical scoops is discharged into the air in such a way as to fall far from the line. This shoot is fitted with an adjustable cover which can be turned to suit the direction in which the snow is being thrown by the wheel.

FRONT VIEW OF THE CHICAGO, MILWAUKEE AND PUGET SOUND RAILWAY'S HUGE ROTARY

SNOW-PLOUGH. Built by the American Locomotive Company. The wheel is 11 feet in diameter.

The operation of the machine is very simple. The machine, its boiler and driving mechanism, are mounted upon a heavy truck, which is completely enclosed in a cab for the accommodation of the crew. By means of windows in the front end above the drum the pilot has a clear view of the snow ahead. All the controls are within immediate reach, including the steam whistle, by means of which, according to a pre-arranged code, instructions can be communicated to the locomotives which are pushing the plough, as the latter is not self-travelling: its machinery is purely and, simply for rotating the wheel.

The plough is pushed into the snow bank, the wheel being set in motion — about 150 revolutions a minute — before it touches the snow. The knife edges cut the snow, which, dislodged, is forced down the scoop until it reaches the periphery of the wheel. Further travel is prevented by the drum, and the snow can only escape when the end of the scoop comes opposite the shoot in the hood. The centrifugal force set up is sufficient to enable the snow to be thrown in a continuous fountain high into the air, and some 60 or more feet from the track.

Now and again obstructions will be encountered, and unless the fates are kind trouble follows. Sometimes the machine is derailed; but more often than not it is the knives which suffer. There is a heavy sudden jolt, and if the obstruction be a boulder or a good-sized tree-trunk, then the knives are torn off, or so damaged as to be useless. But the demands that the line shall be opened with all speed renders such accidents unavoidable, and unless the damage is extensive, no notice

is taken at the moment. Repairs can be effected later at leisure. With the big drifts and banks where ice and snow have packed hard, forming a substance almost as dense as rock, bucking is practised. The plough with the engines backs down the track, and then the obstruction is. charged. The pressure is maintained until the obstruction obtains the upper hand, causing the wheel to slow down, when the signal to back out is given hurriedly before there is an opportunity for the machine to become stalled. Bucking is continued until the machine drives its way through the packed mass, or is compelled to acknowledge defeat. In the latter event there is no alternative but to turn to manual labour—to blast and shovel out the obstruction as if it were rock. On the steep mountain grades the battle between the railway-men and the forces of Nature often is terrific. Four or five big locomotives, the rims of their smokestacks only just visible above the level of the drift, belching steam and smoke for all they are worth, and with the plough itself absolutely out of sight, though betrayed by the fountain of snow which it is spouting, are often required in order to achieve success; and the fruits of this herculean labour is revealed in the deep square-cut trench through the white wall, disclosing the tracks, and of just sufficient width to permit the waiting trains to pass.

SIDE VIEW OF THE HUGE ROTARY SNOW-PLOUGH built by the Canadian Pacific Railway for service among the rocky mountains.

To-day the snow-plough is practically standardised. The scoop wheel has been enlarged to 11 feet, the boiler pressure has been increased, and the machinery is of very great power. Knives fashioned from steel plate have been superseded by knives of cast steel, and are of greater strength and weight. The drum, too, has been improved and strengthened so as to be able to stand up well to the heavier duties imposed. Taken all round, the modern rotary is a formidable unit in the railway’s fighting equipment.

Although all the railways of North America which traverse the great mountain ranges are compelled to maintain a battery of rotaries, and are engaged in grim struggles during the winter, probably the Canadian Pacific, owing to its more northern situation, and the heavy varied character of its mountain section, experiences the toughest task to keep its line open. In fact, the struggle became so fierce that those responsible for the maintenance of communication called for larger and more powerful machines in order to enable them to do their work more efficiently. “Give us a plough that will not break down, and strong and powerful enough to drive through any snowbank, and we will keep the lines open”.

GENERAL VIEW OF THE CANADIAN PACIFIC WEDGE SNOW-PLOUGH.

The request did not go unheeded; its significance was appreciated. The railway company’s engineers set to work, and they produced a snow-plough which probably ranks as the heaviest and most powerful rotary which has been contrived yet, and wherein one or two novel departures from existing practice have been introduced by Messrs. H. H. Vaughan and John Player, who were responsible for its creation. Some idea of its immense size may be gathered from the fact that the main frame measures 48 feet 4 inches over all, and is carried upon two six-wheeled bogie trucks, while its total weight in running order is 130 (American) tons. The frame is built upon bridge girder lines, and to the front end the drum is attached. Upon this frame is mounted the boiler, which is similar to that used in the Pacific Class M-4 Consolidation locomotives of the system, working at 200 pounds pressure, having 2,108 square feet of heating surface and 44 square feet of grate area. The conventional system of driving the scoop wheel through bevel gearing has been abandoned in favour of a direct drive upon the marine principle, the designers maintaining that this is a superior method. The vertical engine has cylinders 20 inches in diameter, with a stroke of 24 inches, and although of light design is of strong construction. The scoop wheel, which is driven at 400 revolutions per minute, weighs over 12 tons. The cab is of steel, with all bracing and so forth on the exterior, so that a smooth surface is presented within. This practice was adopted to mitigate the risk of injury to the crew in cases of derailment, which is one of the worst dangers to be feared in snow-fighting.

THE ROTARY SNOW PLOUGH UNHOUSED, showing boiler and engine for driving the scoop wheel.

Attached to the plough is a tender of the locomotive type. It has been made especially long, measuring 32 feet over the frames, and carries 16 tons of coal and 7,000 gallons of water, so that the total length over frames of this machine is over 80 feet.

Two of these powerful ploughs were built as a first instalment and were dispatched to the mountains immediately upon completion in January, 1911. Although the winter was not so severe as those experienced in previous years, and consequently an opportunity did not arise to submit the machine to a most exacting test to ascertain its capabilities, yet the work which was carried out therewith served to indicate this railway had secured a plough such as they desired. With the aid of only one locomotive instead of two, drifts of packed snow and ice 250 yards in length were forced with ease, speed being maintained from one end of the cut to the other. Ability to tackle the avalanche with its concealed trees was demonstrated also, because trunks 4 inches in diameter were cut up by the knives as if they were straws.

FRONT VIEW OF UNHOUSED ROTARY SNOW PLOUGH, showing scoop wheel and its driving gear.

You can read more on “The Canadian Pacific Railway - 1”, “Clearing the Line” and

“Snow Sheds - 1” on this website.