Handbook of Railroad Construction; For the use of American engineers. / Containing the necessary rules, tables, and formulæ for the location, construction, equipment, and management of railroads, as built in the United States.

by George L. Vose

CHAIRS AND JOINTS.

287. The chairs most common at present are made of a wrought iron plate, with two lips, either cut and punched up, or forged up, to hold the lower web of the rail. Such chairs weigh from six to ten pounds each, and are less liable to break than the common form of cast-iron chairs. It is probable that a cast-iron chair may be made, however, with properly shaped lips, and so hollowed out as to be at once strong and light. (See Clarke’s R. R. Machinery, “Permanent Way.”)

Of late the chair of Mr. David L. Davis, of Dedham, Mass., has attracted considerable attention, and bids fair to be the means of obtaining a better rail surface than has heretofore been possible. This gentleman has been for twenty years Road-master of the Boston and Providence Railroad, and has had ample opportunity for considering the subject of track laying in every respect. The rail bears upon a cap of wrought iron, which rests upon a piece of rubber, lying in the chair. The testimony of the leading managers of the New England Railroads bears witness of the excellence of the arrangement.

The practice of notching each end of the rail causes the expansion to be exerted directly against the fastenings, which should not be the case. Some point should be fixed longitudinally, to resist the end shocks from the wheel. This point should be either the centre or one end of the rail. End chairs may hold the rail laterally, and vertically, but not longitudinally.

The weakest part of the track is that, where, to resist the concussions of the wheels it should be strongest, namely, at the joint: here we lose the strength of the rail and depend entirely upon the tie. The flattened ends of rails which have been laid for a few years show the bad effect of the common joint. The complete remedy for this is, so splicing the rail that it is as strong at the joint as elsewhere. The method termed “fishing,” is not much more expensive than the ordinary method of jointing, it is perfectly effectual, and has had the test of long and successful use. It consists in bolting a plate two and one half feet long, two and one half or three inches wide, and from one third to one half inch thick, to the ends of both rails making the joint; one plate being placed on each side. The plates are convexed a little from the rail as in fig. 138, so that being sprung by screwing on the nuts, the latter shall not work loose by the vibration of the rail.

Fig. 138.

In the above arrangement there is no tie below the joint, but the latter lies midway between two sleepers.

Another method of “fishing” is, to place a piece of ᕼ or ⊤ iron beneath the rail, bolting it firmly to the lower flanges.

In bolting rails together at the ends, the bolt holes must be cut a little larger than the bolt, to allow for the expansion of the iron.

The effect of the joint upon the passing carriage, is the jumping motion; the middle of each rail being a summit, and the end a depression, (the strength at the joint being taken away); and if the joints are not opposite to each other, there is generated a very injurious and dangerous side rocking. Figs. 138, 138 A, and 138 B, show the methods of fishing.

Fig. 138 A.

Fig. 138 B.

Fig. 139.

To avoid the wear caused by frequent joints, various forms of compound rails have been proposed; consisting of two or more parts breaking joint. One form has been contrived in which the section is vertically halved; another of three parts, a head placed on top of a double vertical web. Fig. 139 shows what would seem to answer any purpose (if compound rails are at all allowable). The joint is here divided into four parts, so that the strength of the bar at any point is reduced only one fourth. In bolting the parts together the joints should be left open enough (see in advance) to allow for contraction; and the bolt-holes, as before noticed, should be longer than the bolts. (This enlargement, extending only in the direction of contraction, and not in the line of the force.) The upper part of such a rail should be hardened to resist the rolling of the wheels, while the webs must possess the strength to act as a girder.

It is questionable whether, by dividing the rail, particularly when it is done horizontally, we do not prevent the mutual extensile and compressive actions which ought to have place in the top and bottom; for we cannot make the bolts perfectly tight because of expansion.

Some of the compound rails which have been laid in America have given good results, others have not.

Mr. W. B. Adams observes, that a compressed rail to be as strong as a sixty pound whole rail, must weigh ninety lbs. per yard.

Some engineers have proposed such a rail that when one side becomes worn it may be turned over so that the lower may become the upper table. This is quite wrong in principle; as when the lower fibres have been subjected for some time to extension, they are entirely unfitted to oppose compression.

OF THE LIFE OF RAILS.

288. The time which a rail will last, depends upon the form and weight, and on the quality of the iron; and upon the number, weight, and speed of engines and cars passing over it.

Note.—The effect of quality is altogether too little regarded in America. How worthy of attention it is may be seen by the following.

Upon the same road were used two kinds of seventy-two pound rails, each five inches deep, and having a bearing surface of 2.7 inches in width. The one was worn out with a tonnage of 41,000,000 tons, the other of 22,000,000 tons; the difference being entirely in the quality of the iron.

Upon the Philadelphia and Reading Railroad there have been used forty-five pound rails of reheated and refined iron, which have lasted for eighteen years; and that with a very heavy traffic upon them. While upon other American roads, English sixty pound rails have required renewing in one, two, three, and four years.

The durability of rails is practically independent of time, and depends entirely upon the amount of work done. The repairs of iron, depending upon flaws and other physical defects, will be greater at the commencement of operations than afterwards. After the first one or two years the regular depreciation begins. The first Liverpool and Manchester rail weighed thirty-five lbs. per yard, and the locomotive seven and a half tons. As the traffic increased, so did the necessary weight of engines, and a corresponding increase in the strength and weight of rails was also rendered necessary. In 1831, the average weight of engines with tenders was eighteen tons. In 1855, the maximum engine with tender, fuel, and water weighed sixty tons; and in like manner the rails increased from thirty-five to eighty-five lbs. per yard.

Messrs. Stephenson and Locke, in a report to the London and North-western Railroad Company, in 1849, recommend the adoption in future of an eighty-five lb. rail.

Upon the roads of Belgium are used rails of fifty-five and sixty-four lbs. per yard; but it is asserted that an eighty lb. rail would allow of ten times more traffic.

For the average of American roads, when the iron is good, (in quality,) fifty-five, sixty, and at most sixty-five lbs., will probably be found ample for the heaviest traffic: the rail being of the form already given, and supported on ties not more than two and a half feet from centre to centre.

Mr. Belpaire, (of the Belgium engineers,) concludes, from many experiments, that in sixty miles, each engine abrades 2.2 lbs.; each empty car 4½ oz.; and each ton of load 1.4 oz.; the amounts being in direct ratio to the several weights.

Captain Huish, of the London and North-western Railroad, (England,) estimates (Report of April, 1849) that fifty trains per day, or 18,250 trains per annum, for twenty years, would wear out a seventy lb. rail.

The Belgian engineers have concluded that 3,000 trains per annum, for one hundred and twenty years, would wear out a fifty-five lb. rail.

Now 120 × 3,000 = 360,000 Belgian, and 20 × 18,250 = 365,000 English, a very satisfactory coincidence, as the different observers did not know of each other’s proceedings. The difference, 5,000 trains, being accounted for by the use of heavier engines upon the roads of England.

From the above results the following table is formed, showing the life of rails under from two to one hundred trains per day. American roads being less nicely finished, as regards the road-bed, will of course wear out rails faster than the roads of Europe. The table will serve as a base for estimates.

Trains per day.	Trains per year.	No. of years’ life of rails.
2	600	604
4	1,200	302
6	1,800	201
8	2,400	151
10	3,000	121
12	3,600	100
14	4,200	86
16	4,800	75
18	5,400	67
20	6,000	60
30	9,000	40
40	12,000	30
60	18,000	20
80	24,000	15
100	30,000	12

Probably one half of the above numbers of years would show the full life of rails upon American roads.

As those rails which are most used wear out the soonest, they should be made accordingly heavier. Such are those at depot grounds and at sidings.

Note.—From the reports of the Reading (Penn.) Railroad it appears that in 1846 153
209 of the damaged rails were split; and that in 1845 285
295 were split.

As regards the quality of railroad iron, it is generally notoriously bad, and its makers know it as well as those who buy it. Railroad companies are not willing to pay for good iron. Comparisons between American and English iron amount to little. First rate iron can be made in England or in America, and so can that which will last about two years. Time will convince companies that the most expensive iron is the cheapest.

TABLE OF THE WEIGHT PER MILE OF DIFFERENT RAILS.

Weight in lbs. per yard.	Tons per mile. (2,000 lbs.)	Tons per mile. (2,240 lbs.)
50	44.00	39.29
55	48.00	43.21
60	52.80	47.19
62	54.56	48.71
64	56.32	50.28
66	58.05	51.86
68	59.84	53.43
70	61.60	55.00
72	63.36	56.57
74	65.12	58.14
76	66.88	59.71
78	68.64	61.28
80	70.40	62.86

TRACK-LAYING.

289. As wrought iron expands 0.0000068 of its length per degree (Fahrenheit) of heat, a change of 130° will cause the following expansions:—

In a 15 feet rail .0135 ft.

In a 18 feet rail .0162 ft.

In a 20 feet rail .0176 ft.

and that the track may be kept in the right vertical and horizontal line, rails laid in cold weather must not be placed in contact; but separated by space enough to allow expansion to take place. In hot weather they may be placed close together. Calling 100° the maximum and -30° the minimum, we form the following table for the average lengths of rail, (20 feet).

At	100°	place the rails in contact.
	90°	at a distance of .00136 feet .016 inches.
	80°	at a distance of .00272 feet .032 inches.
	70°	at a distance of .00408 feet .049 inches.
	60°	at a distance of .00544 feet .065 inches.
	50°	at a distance of .00680 feet .082 inches.
	40°	at a distance of .00816 feet .092 inches.
	30°	at a distance of .00952 feet .114 inches.
	20°	at a distance of .01088 feet .131 inches.
	10°	at a distance of .01224 feet .147 inches.
	0°	at a distance of .01360 feet .163 inches.
	-10°	at a distance of .01496 feet .179 inches.
	-20°	at a distance of .01632 feet .196 inches.
	-30°	at a distance of .01768 feet .212 inches.

Fig. 140.

The proper distance of rails may be fixed by the use of the steel plates shown in figs. 140 and 140 A, which are marked with the temperature, according to their thickness, as in the above table.

To incline the rail base may be used, when the rail is not bevelled, wedges one foot long and six inches wide, spiked with the rail to the tie. When the chairs are of cast-iron, they may be cast to the required slope.

Fig. 140 A.