238 



ON THE DURABILITY OF RAILROAD IRON. 



[18ii5. 



a gradient of 2 inches rise in the chain thi-ough its whole length, and 

 contains curves so low as 3 chains radius. The wagons employed weigh 



3 tons 12 cwts. when empty, and 7 tons 1 cwt. when loaded. They are 

 mounted on 4 cast iron wheels, 30 inches in diameter, keyed fast on 

 the axles, and have outside bearing brasses, but neither buffer, draw 

 nor bearing springs. The motive power consists of locomotive engines 

 weighing from 14 to 16 tons each exclusive of tender. The rate of 

 hauling ranges from 10 to IG miles an hour. 



This line was originally laid in avery temporary manner, with bridge 

 rails 2-5 inches high, 2 inches wide at the top or bearing part, and 6 

 inches at the foot ; and Aveighing 36 lbs. per yard lineal. They were 

 fastened by sjpikes through the flanches to cross sleepers, 6 inches by 



4 inches, by 6 feet long, at intervals of 4 feet. The ballasting con- 

 sisted of the clay and peaty soil excavated from the side di-ains, and 

 distributed in a layer one foot thick under the sleepers. 



After two years' wear, with the engines and wagons described above, 

 the original rails were laminated to an extent that rendered their 

 renewal a matter of necessity. The gross traific that passed over 

 them during that period, amounted to 1,822,800 tons. Had these rails 

 been supported by larger sleepers at shorter intervals, and these 

 sleepers packed up by proper ballasting, they would have stood the 

 wear and tear of from twice or three times the above quantity of traffic. 



Case 2. — The railroad previously described, was relaid with T rails 

 3-75 inches high, 2-5 inches wide at the head, and 3-5 inches broad 

 at the foot ; and they weighed 63 pounds per lineal yard. The small 

 sleepers were replaced by others, averaging 9 inches wide, by 9 feet 

 long, at the reduced distance of 3 feet apart from centre to centre. The 

 rails were also supported on shallow cast iron chairs, which were 

 spiked to the sleepers, and the clay ballasting was sirengthened by the 

 addition of a thick layer of broken stones. The new rails with the 

 altered mode of laying, have now been in use ten years, during which 

 period the gross traffic over them has been 9,710,000 tons. 



The height of these rails when new, was 3-75 inches, as previously 

 stated, but by wear and abrasion from the rolling of the above weight, 

 their height has been reduced to 3-63 inches. Taken collectively, 

 these rails have endured very well, and with the exception of a very 

 few crushed and bruised bars, which will require immediate renewal, 

 they will, probably continue fit for the trafBc for at least three years 

 again. Hence their duration may be estimated as equal to the move- 

 ment of 12,600,000 tons. 



To show the ill effects which must result from inattention to the state 

 of the sleepers, at different places on the line, a sleeper was per- 

 mitted to remain without support. After a lapse of a few days, the 

 rails immediately over the slackened sleepers, were found crushed and 

 flattened for a length of 6 or 7 inches, so as to reduce the depth of the 

 bar from 3-63 to 3 '2 inches. Similar results followed, when the dis- 

 tance between any two sleepers was increased to more than 4-5 feet ; 

 thus showing the necessity of having, under the rails, a firm and rigid 

 support at very short intervals, to prevent as far as possible all inju- 

 rious deflection. 



In those rails which have broken down, either from lamination, or 

 during the foregoing experiments, the impropriety of using any other 

 than puddled iron in the top surface of the rail was fully displayed. 

 These rail bars were manufactured from piles of the ordinary quality 

 and description, with a top plate of the so-called "best iron," one inch 

 in thickness. This plate in the course of rolling was reduced in thick- 

 ness, to 16 of an inch in the finished bar. Now, all the lamination 

 which has yet been discovered, has occurred with this superfical coating 

 of "best iron," which has often pealed off, in long narrow strips or 

 splinters, of several feet in length. 



Case 3. — Mineral railroad, consisting of a steep incline plane of the 

 4 feet 8. .5 inches guage, with a double track of rails, each 480 yards 

 long, and falling 6-7 feet per chain. — The direction of the traffic being 

 downwards, this portion is worked by the gravity of the descending 

 full wagons, which are made to draw up the empties, by means of 

 ropes, working over rope rolls and friction drums, revolving on gud- 

 geons at the incline top. The rails were of the bridge pattern, 2.5 

 inches high, 2 inches wide at top, 6 inches broad at the foot and weighed 

 57 pounds per yard. They were supported on flat cast metal chairs, 

 which were spiked to transverse sleepers of 8 inches wide, by 8 feet 

 long, placed 3 feet apart. — Under the sleepers, there was a thin stratum 

 of clayey soil as ballast. 



The wagons described in case 1, roll over this section, also at velo- 

 cities averaging 12 miles per hour. The rails on this section were in 

 use for eleven years, during which time the traffic over them amounted 

 to 8,087,000 tons, equal to 4,043,500 tons over each track. The in- 

 jm-y which results to the rails from the absence of adequate support 



under the sleepers was manifest in this case, and undoubtedly was ^he 

 means of shortening their duration fully one-half. 



While forming another mineral railroad, crossing under this section, 

 it became necessary to evacuate an opening, 10 yards wide, over which 

 the rails were carried by four pieces of pine timber ; one being placed 

 under the centre of each rail bar. The deflection of the beams by the 

 passing of the loaded wagons, was from 2-5 to 3 inches, and from this 

 cause alone, the whole of the rails on these pine stringers were battered 

 and laminated so as to require renewal in the short space of two months, 

 and after they had borne a traffic of no more than 61,300 tons. 



Case 4. — Mineral railroad, on a dead level throughout, consisting 

 of a single tx-ack bridge rails, the same as those described in case 1, 

 but spiked directly to sleepers, averaging 6 inches wide, by 6-5 feet 

 long, placed 3 feet apart on broken limestone, as ballasting. The 

 wagons previously described, work over this section also, but the 

 motive power being horses, the rate of travelling rarely exceeds three 

 miles an hour. The rails on this section have now been in use 11 years, 

 have borne a traffic of nearly 4,900,000 tons, and with the renewal of 

 the wood-work of the line, will probably last for a similar period, and 

 for the passage of an equal quantity of traffic. Their duration 

 may, therefore, be assumed to be equal to the transport of 9,800,000 

 tons. 



From the foregoing examples it will be seen, that while bridge rails, 

 weighing 56 pounds per yard, were destroyed with the passage of 

 1,822,800 tons, hauled at a velocity of 12 to 16 miles an hour, by loco- 

 motive engine, weighing from 14 to 16 tons each; with the same 

 wagons, but at the reduced speed of 12 miles an hour, they have stood 

 under the passage of 4,033,500 tons ; and with the same wagons, but 

 at the still further reduced speed of 3 miles an hour, they have stood 

 the wear and tear from the passage of 4,900,000 tons, without material 

 injury. 



Case 5. — Railroad for the conveyance of coal, consisting of an in- 

 clined plane, falling 7 inches per yard, forming a double track of rails 

 of the 4 feet 8-5 inches guage, 400 yards long, and worked by station- 

 ary steam power at top, through themedium of ropes and drums. The 

 rails are of the inverted U pattern or Evans' patent, weight 90 lbs. per 

 yard, were 3-4 inches high, 2.74 inches wide at the head, 4 inches 

 wide at the foot, rolled in lengths of 15 feet, and supported at intervals 

 of 3'5 feet, by cast iron chairs resting on massive blocks of limestone. 



Each track of rails is traversed by a single wagon, mounted on foirr 

 cast iron wheels, 2 feet diameter, keyed on wrought iron axles, and 

 revolving in brass fitted plummer blocks bolted to the frame work of 

 the wagon. The weight of the wagon when empty is 7 tons 2 cwts., 

 when full, 13 tons 16 cwts., and it is drawn at an average speed of 8 

 miles an hour. 



These rails have now been in use seventeen years, and the gross 

 traffic which has passed up and down the plane, amounts to 11,016,000 

 tons, or 5,508,000 tons over each track. The result of this traffic has 

 been to reduce the height of the rails from wear and abrasion, from 3 '4 

 to 3'26 inches. — In other respects they are in good condition, and will 

 probably sustain a further traffic of 3,500,000 tons, makiug their dura- 

 tion equal to 8,000,000 tons. 



Case 6. — Railroad for the conveyance of limestone, a single track 2 

 1-2 miles long, worked by horse power. The rails were of the fish- 

 bellied section, 5 inches high, 2 inches wide at the head, and .75 inches 

 thickness of centre web, weighed 55 pounds per yard, and were laid in 

 in cast iron chairs resting at intervals of 3.5 feet on limestone blocks 

 of from 2 1-2 to 3 cwts. each. 



The wagons, which were made wholly of wrought or cast iron, 

 weighed, when light, 1 ton 19 cwts., and when loaded, 8 tons 10 cwts. 

 each. The wheels were 2 feet 6 inches in diameter, and turned loosely 

 on the axles, which were bolted to the under side of the carriage. 



These rails stood for nine years with an average annual traffic of 

 180,960 tons, or a gross total of 1,628,640 tons, when they were re- 

 placed by stronger bars. 



Case 7. — Raih'oad consisting of an inclined plane, with a double 

 track of rails raising 9.7 feet per chain forward. Rails of the bridge 

 pattern, weighing 56 pounds per yard, 2.375 inches wide at head, and 

 5.625 inches at the foot ; spiked directly to cross sleepers 9 inches 

 wide, by 9 feet long, at distances of 3 feet 3 inches apart. The sleepers 

 repose on a thick deposit of broken scoria, from the blast fm-nace in 

 the neighborhood, which is found to be an excellent material for ballast- 

 ing the permanent way of railroads. 



The wagons running on this road are of wrought iron, mounted on 

 4 cast iron wheels, 30 inches in diameter, turning loosely on their 

 axles, and are without springs of any kind. They weigh when light. 

 1 ton 8 cwts., and when loaded, 4 tons 16 cwts. ; and are drawn by 



