The Track Structure of American Railways

Technical Descripton of the RAILWAYS IN THE UNITED STATES

(from the report of Colonel Melnikov's trip to America)

While not getting involved in a detailed description of each of the existing railways in the United States, we shall attempt to present here, in a shortened form, a description of various systems for constructing the roads, which have been employed until now and which are in use now, with an indication of their relative merit, according to data obtained until the present.


Shape of rails.

The main difference between the railways of the United States in their construction lies in the type of rails used on them, and in this regard they may be divided into two main categories, to wit: 1) roads with light strap-rail; 2) roads with heavy bar rail. These latter include two more sub-categories, depending on whether they use bar rails with a T shape (so-called T rails), or rails in the shape of a sideways H (so-called H rail). We shall examine each of these three types of rail in turn.

Strap rails consist of an iron strip as little as inch thick, 2 to 2 inches wide, and from 12 to 18 feet in length, which is affixed flat to a wooden beam (called the wooden rail) which has a cross section from 5 by 6 inches to 9 by 10 inches. For affixing the iron strap to a wooden rail, use is made of iron nails or spikes about by inches in cross section and from 4 to 7 inches in length.

I offer as an example a table of the dimensions of such rails on several roads in the United States and Canada.

[insert table]

Iron rails are joined at their ends, cut either perpendicular to their length, or at a 45 angle, or (as is better) cut with a square mortise about or inch on a side into the end of one rail, and in the end of the other rail, a corresponding tenon cut in.

The apertures in iron rails to admit nails typically have the following shape in cross section along the length of rail.

[insert small diagram]

Parts a and b each occupy half the width of the rail, and the bases of the truncated cone a have the usual form of ellipsoids, in which the larger axis, directed along the length of the rail, is twice as great as the small axis. This is done so that the rail can slide on the nails when its length changes due to changes in temperature. Sometimes the aperture of the middle nail is made so that it tightly embraces the nail, and consequently, when changes take place in the length of the rail, its middle remains stationary.

To prevent loading or indentation of the ends of the iron straps into the wooden rail, sometimes an iron plate is placed under the ends of adjoining rails, its thickness being about inch, its width up to 3 inches, and its length about 6 inches. Instead of iron bolsters, the New Orleans & Mexican Gulf Rail Road employs cast iron chairs weighing one pound and having the following shape and dimensions:

[insert small diagram]

The strap-rail system is employed on the entire line along the Atlantic coast from Fredericksburg to Greensboro, in all the Southern and Western states and on many roads in the states of Pennsylvania and New York.

It is entirely natural that the cheap strap-rail system was employed when railways were first introduced in the United States, primarily in the states of the Southeast and West, where due to the population being new, capital was still scarce. There, the main centers of industry and trade are separated by large, scarcely populated spaces, and high-quality timber is entirely abundant Finally, due to the flat, even terrain and moderate climate, the earth-moving work needed to prepare the roadbed is generally not significant. Thus, the expenditure to purchase rails obtained from England constitutes one of the main items of expense; and therefore the founders of the roads in those states could not fail to use a system of construction in which the weight of the iron of the rails on a known length of road, constitutes no more than or of the weight that is required, with the same length, for T- or H-shaped bar rails.

Incidentally, about eight years of experience in the existence of such roads in the United States have shown that this system is not beneficial, and that it may be permitted only in extreme instances where, due to a total lack of capital, bar rails cannot be had, or where the road is intended only for slow transport of light freight without the use of locomotives.

Here are the main deficiencies of the system of railways described:

1) Rain water that penetrates beneath the road bed, within a short time produces rot in the corresponding part of the wooden rail; this part loses its resistivity, and when a locomotive passes over it, the iron strap is palpably depressed into the wooden rail; then, by the action of its elasticity and the pressure of the locomotive on further parts, it separates somewhat from the wood, and is thus subject to vibrational motion, alternately up and down. This causes the spikes to gradually weaken, and within a short time virtually stop functioning altogether*).There have been instances in which the connection of the iron strap with the wooden rail became so weak that merely by the adhesion of the locomotive's wheel with the strap, the latter was torn out of its place, and following the motion of the wheel, it was thrown forward a great distance, with danger to the men in the engine. But in particular it often happens that the when the leading wheels of the locomotive press on the separated end of the strap, it pulls away from the wooden rail, or the locomotive pulls out or breaks the spikes, which in a convulsive motion of the rails come out of their places. Even the most attentive observation of whether a road of this type, that has been somewhat long in service, is in proper order, is powerless to prevent all such instances, for the spikes by which the straps are attached are always in one and the same wooden rail. Therefore, after some time in service, when the wood in the vicinity of the spike has been somewhat expanded, the spikes do not hold at all, and then but one remedy remains, to replace the wooden rail.

*) The elliptical form of the apertures in the strap, through which the spikes pass, plays no small role in the weakening of the connection of the straps with the wooden rails. This is because when long trains pass, the straps are more or less drawn by their motion, and they are subject to slippage in one direction or the other if the line is single-track, and trains move in both directions over the same strap. By use of a round aperture for the middle spike, this inconvenience is reduced. That is what is done on the St. John & La Prairie road.

To prevent the danger in such instances where the strap pulls away from the wood rail, which we have just spoken of, on some roads constructed very recently, the ends of each strap are attached not by ordinary spikes, but by bolts, which pass through the thickness of the wooden rail, coming to an end below. Their heads are trapezoidal in cross section, and are recessed into the thick dimension of the strap. This, for example, is what is done on the New Orleans & Mexican Gulf Rail Road. These bolts each weigh 1 pounds, while the spikes on that same road have a weight of only of a pound.

2) Due to the transverse action of the locomotive's two cylinders, its motion is never totally parallel to the axis of the line. On the contrary, it constantly deviates to one side or the other, its flanges each time coming to rest on the internal ribs of the rails. Trials have shown that strap rails have not the strength to long resist this action, and that they expand in both directions, thus causing even more damage, both to the track structure and the engine. To reduce this inconvenience, on some roads a second row of straps have been placed in proximity to the first, situating their seams in a groove. This causes the expenditure for iron to be doubled, but nonetheless the difficulty is not totally overcome. On the Charleston & Hamburg road, the former flat rails are replaced when worn out by new rails which, in cross section, have the form of a rectangular corner, whose one side, namely the perpendicular one, lies on the outer edge of the wooden rail. This is somewhat better, but with all this, the other disadvantages of the wooden rail are not removed, while the weight of the iron is considerably increased. The new rails on the Charleston road weigh 27 pounds to the yard, i.e. half of iron bar rails.

3) The wooden rail has not the strength to resist energetic motion of heavy locomotives. The wood disintegrates under the weight of the latter.

4) Roads possessing wooden rails do not allow profitable use of the motive power for carriage of freight, because 1) due to the lack of strength in the track structure, engines cannot have sufficient weight on their driving wheels to attain the most favorable limit of wheel-to-rail adhesion, and 2) resistance to motion on these roads is considerably greater than on roads with bar rails.

5) Repair of them costs more (see the section on expenses for maintenance of railways), because these roads require very close monitoring, and consequently a larger number of workers who are constantly on the line. In addition, they need more material for repair. If such a road is somewhat carelessly maintained, then in a short time it will become totally impassable. In the United States there are many examples of roads coming into such a condition.

6) In the winter, the iron straps separate from wooden rails by action of water at times freezing and accumulating beneath the straps.

I could present still more deficiencies of strap-rail roads, but I imagine that this suffices to admit them to be disadvantageous in all instances when the desire is to have a railway that would satisfy the conditions of safe, error-free and rapid travel, favorable for the usage of mechanical motive power for carriage of freight, and with expenditures for the road's maintenance kept to a minimum.

The reasons for strap-rail roads being disadvantageous presented here are the results of numerous trials which could not escape the observations of American engineers, and could not fail to cool them from being disposed in favor of this deceptively cheap system. In the opinion of the best of these men, such roads must be limited to temporary use, or, where major construction work is carried out, or on lines of communication where locomotives are not employed as motive power. As I mentioned above, only an extreme shortage of capital could cause the engineer to decide to use the strap-rail system for a freight route, where steam is used as the motive force, but having in view to replace the strap iron with bar rail, when the traffic initiated on the road will draw funds for making the expenditure necessary for the replacement.*

* Incidentally, the lack of profitability alone of roads with wooden rails, for freight transport, compels doubt that this last supposition could be valid, other than in very exceptional circumstances.