Rail (structure)

“ To secure perfect safety in ascending and descending such a tremendous grade, the track is composed of three rails bolted to a trestle of heavy timbers, the centre rail being an immense wrought-iron ladder, with rounds four inches apart, into which the cogs of the locomotive drive-wheel fit, and thus drag the train up the steep as well as control it, with aid of air-brakes, in making the descent. One and a half hours are consumed in making the round trip, and the fare is six dollars, but the view from the summit is so magnificent that it fully justifies the expense. ”

“ Rail manufacturers are now able to roll a section of rail combining the vertical stiffness of the ordinary flange, or flat-bottom, rail with the running-head and continuous wheel-flange groove, considered the most suitable for heavy tramway traffic. ”

“ The writer has had long mileages of each description of permanent way under his charge, both at home and abroad, for many years, and the result of his experience has shown that, although a fairly good road may be made with flange rails, still, for constant, heavy, fast traffic, the bull-head rail with cast-iron chairs makes a much stronger, more durable, and better permanent way than any flange railroad. ”

“ Wheels, axles, bridges, and rails have all been strengthened to carry their increased loads; but, strange to say, the splices which hold in place the ends of the rails, and which are really short-span bridges, are now the weakest part of a railway. The angle-bar splice has but one-third of the strength of the rail, and its strength cannot be increased, owing to its want of depth. Joints go down under every passing wheel, and the ends of the rails wear out long before the rest. ”

“ This is effected by a mechanique extremely simple in its action, moved by means of a lever, just as a pointsman moves his points at an everyday railway station. One movement of the lever depresses the centre rail, into a hollow made expressly to receive it, to the level of its confrères, and when it is necessary to elevate it again so as to place it in apposition with the centre rails at each side of the crossing, one movement of the lever raises it, and then it forms continuous centre rail just as completely as if there had not been any lever beside it to elevate or to depress it. ”

“ It is evident, therefore, that when the pivoted arms are set in the forward or backward position, and one of the wheels of a train or vehicle has passed on to the rail over the rocking-bar, the latter cannot be changed or raised and pulled over to the opposite extremity so long as any one of the wheels of the train or vehicles remain over the rocking-bar. ”

“ To accomplish this, two sets of railways will be laid so nearly level as not in any place to deviate more than two degrees from a horizontal line, made of wood or iron, on smooth paths of broken stone or gravel, with a rail to guide the carriages so that they may pass each other in different directions and travel by night as well as by day ”

“ In all cases substantial parapets, with a height of not less than 4 feet 6 inches above rail-level must be provided by an addition to the girders, unless the girders themselves are sufficiently high. On important viaducts where the superstructure is of iron, steel, or timber, substantial outside wheel-guards to be fixed above the level of, and as close to the outer rails as possible, but not so as to be liable to be struck by any part of an engine or train running on the rails. ”

“ Fig. 343 shows an arrangement of sleepering largely adopted for steel flange rails 26 feet long, and weighing 79 lbs. per yard. The length of a rail is more a question of convenience of handling, facility of transhipment, and general use, than of actual manufacture. There is no difficulty in rolling rails up to 50 feet in length, or more; but very long rails are extremely ungainly things to move about, and are more exposed to receive permanent bends or kinks in unloading, besides requiring greater spaces at the joints to allow for contraction and expansion. ”

“ In an ordinary railroad the functions of the iron or steel rails are twofold, first to carry the weight of the load, and second to guide the engine, carriage or truck in the right direction. Now the latter purpose—in the case of a rail-track never used for high speeds, especially in going round curves—might be served by the adoption of a very much lighter weight of rail, if only the carrying of the load could be otherwise provided for. ”

“ The earliest cast-iron railway was laid down before the middle of the eighteenth century, about one hundred years after the first wooden 'tram-ways.' Half a century later we find the first rail-and-wheel combination as we know it on modern tramways and railways, where the wheel carries an inner flange and runs upon the head of a narrow metal rail. This is the form which experience has proved to be best adapted for safety, speed, and economy in power. The improvements made since the beginning of the nineteenth century have been in matters of detail. ”

“ Wooden sleepers continued to be used, the rails being secured by spikes passing through the extremities, but about 1793 stone blocks also began to be employed—an innovation associated with the name of Benjamin Outram, who, however, apparently was not actually the first to make it. This type of rail (fig. 1) was known as the plate-rail, tramway-plate or barrow way-plate—names which are preserved in the modern term “plate layer” applied to the men who lay and maintain the permanent way of a railway. ”

“ Steel rails are not riveted to railroad ties but the spikes are driven close to each rail so that the heads hook over the edge and hold the rail down without absolutely preventing its movement forward and backward. ”

“ The cost for repairs, therefore, of express cars, would be somewhat greater than for any others.
431 COST AND MAINTENANCE OF WAY AND WORKS. As the speed is increased, the relative effect of grade and curves is lessened, but the absolute danger of passing curves is increased. Express trains require larger radius of curvature, or greater elevation of exterior rail than others, which extra elevation causes an unnecessary resistance to all other trains. The rails to resist large and heavy wheels must be heavier and more firmly fastened. ”

“ When chairs are used, the largest ties shall be selected for the joints. When the joint is made by fishing, there will be no tie directly under the joint.
RAILS. The rails will weigh about sixty pounds per lineal yard. No rail shall be laid on the tangents which is in any way twisted or bent. It shall be the duty of the first party to correct and make true any crooked rails received by him, also to bend to the proper curve, and in such a manner as not to affect the strength of the bar, all rails laid in curves. Punching of rails, and cutting, will also be done by the contractor. ”

“ The keys which hold the rail in the chairs are usually of oak and are placed outside the rails; the inside position has also been employed, but has the disadvantage of detracting from the elasticity of the road since the weight of a passing train presses the rails up against a rigid mass of metal instead of against a slightly yielding block of wood. The rails, which for heavy main line traffic may weigh as much as 100 ℔ per yard, or even more, are rolled in lengths of from 30 to 60 ft., and sleepers are placed under them at intervals of between 2 and 3 ft. ”

“ The comparative narrow flange places the spikes at great disadvantage in point of leverage for holding down, and this weakness is soon made manifest, particularly on curves, where additional crab bolts or other devices are rendered necessary to counteract the tendency of the rail to rock and tilt over sideways. When the head of the rail cannot be kept in its proper position, the gauge becomes widened, and an irregular sinuous motion takes place in the running of the train. ”

“ Even were we to use a smaller wheel to decrease the centrifugal force, we would have to increase the number of revolutions, so there would be no gain in so doing. Our trains run upon two peculiarly constructed rails, and the runners are flanged to exactly fit the rail. There is, in addition, on either side of the tunnel, another rail of similar shape, while upon the upper part are two more. ”

“ The flange rail, Fig. 265, was designed to give a broad, direct bearing on the sleepers, and thus avoid the necessity of using chairs. Rails of this section have been laid down on many of our lines at home, and are very largely used on the Continent, in the United States of America, and in our colonies generally. This section is, also, nearly always adopted for narrow-gauge railways. Having fewer parts, it makes a cheaper road than the bull-head rail, but is not considered so strong or suitable for heavy and fast traffic. ”

“ The Reporter is therefore to recommend an edge rail warranted to work with two tons, including the wagon, of the weight of 140 lb. per lineal yard of finished double railway. Lighter dimensions might indeed be found to answer; but for a public railway, the rails should be made of a greater strength than is barely sufficient for a given weight, as this cannot always be kept within bounds, or regulated to a nicety. ”

“ Valuable and interesting statistics have from time to time been recorded, with a view to ascertain the average life of a steel rail, by obtaining the number of million tons of train load which it would sustain before it became worn down to such an extent as to be no longer of service on the line. It will be readily understood that the rate of wear of a steel rail will depend not only on the weight and section of the rail itself, but on the class of rolling-stock, and the description of traffic it has to carry. ”

“ The railroad in its modern form would be impossible if Bessemer and others had not taught the world to make steel cheaply. Iron rails, even under comparatively light loads, wore out and had to be replaced constantly. Steel rails, introduced gradually after 1860, could bear double the load on each wheel, and still outlive many iron rails. The modern rail, simple as it appears, is both in material and in proportions a great feat of engineering, “a beam whose every dimension and curve and angle are exactly suited to the tremendous work it has to do.” ”

“ The introduction of electricity facilitated the construction of monorail systems of roads, which had long been the dream of railroad constructors, since this power192 could be applied with so much more flexibility. The defects of the parallel rail system are apparent both in construction of the roadbed and the operating of trains. It is almost impossible to lay and maintain the rails in exact parallels, and even more difficult to keep each rail at the proper height at all points. ”

“ We now have a kind of rail which conforms to the condition already mentioned, namely, that of being capable of being laid down in front of the wheel of the truck or vehicle, and of being picked up again when the weight has passed over any particular part. The hoop, in fact, constitutes a rolling railway, and the larger it can with convenience be made, the nearer is the approach which it presents to a straight railway track as regards the absence of resistance to the passing of a loaded truck-wheel over it. ”

“ With a deep rail it is preferable to place the nuts inside, so that the platelayer inspecting his length can see both rows of nuts as he walks along between the rails. With shallow rails the nuts must be placed outside and the cup-heads inside, to give ample clearance to the wheel-flanges. ”

“ When we build a bridge we wish its roadway to remain as level as possible while a load passes, so that no hills and hollows may waste tractive power: levelness is secured by a design which is rigid as well as strong. If a railroad has weak, yielding rails, a great deal of energy is uselessly exerted in bending the metal as the wheels pass by. A stiff rail, [7] giving way but little, avoids this waste. To create forms which in use will firmly keep their shape is accordingly one of the chief tasks of the engineer and the architect.
Rubber strip suspended plank-wise, and joist-wise. ”

“ It is evident that the rail which would last for very many years under the small traffic, would have a very short life under the frequent traffic. Hence the reason why it is found expedient to give a large increase of material in the heads of rails carrying the heavy, constant train service of many of our main lines. ”

“ The railroad track must be true; there is not room for even the variation of a fraction of an inch in the gauge of the two rails.
In fastening the two long lines of rails, the profession of track-laying rises to almost supreme heights. The men who fasten the rail with angle iron and a single roughly-adjusted bolt in each rail-end are head-strappers and past masters in their art. After them in due season come the back-strappers, finishing that fine work of solidly bolting the rail against the vast strain of a thousand-ton train being shot over it at lightning speed. ”

“ The wheels will, undoubtedly, be as safely guided in the shallow as in the deeper channels, and the rails will be equally durable with those of greater weight. When rails of this description are sunk into a channel in a rail of stone or wood, the base being wider than their upper sides, the pressure of sand into the seams on each side of the iron, caused by the running of common carriage wheels over them, will effectually confine the iron plates between the jambs of the stone or wood. ”