Discussion. Mountain Railway

54 DISCUSSION ON MOUNTAIN RAILWAYS. [Minutes of Discussion. Sir Douglas Sir DOUGLASFox, Vice-President, wassure it would be the Fox. wish of the members that the thanks of the Institution should be heartily accorded to the Authors of the Papers. The subjects on which they treated were most instructive, not only as dealing with rather exceptional features, but also because theyrelated to various parts of the world, and showed how the same principles had, in the several cases, and by different engineers, been prac- tically applied to overcome similar difficulties. Mr. Collett. Mr. ALFREDCOLLETT mentioned that his special object in writing the Paper had been to show the load hauled by different classes of mountain engines in actual practice on various gradients. It had come underhis notice that some engineshauled less than they were calculated to haul, a result due to want of steam, to too small heating-surface, andto other reasons. Hethought it would be of interest to give a Table of the principal dimensions used on mountainrailways and engines in different parts of the world. They consisted of ordinary adhesion engines, Fairlie engines, and the Abt, Riggenbach, Fell, and wire-rope systems. He had carefully collected details as to the loads actually hauled, and the weights of the engines, calculating their ratio, of which the Table on p, 29 gave afew examples. The 1 in 28 gradient referred to the Dsrjeeling Railway, and the 1 in 16.7 gradient tothe Harta Railway, havingan engine of a similartype to thatat Eisenerz. The 1 in 12.5 referred tothe Trincheras incline of the Puerto Cabello Railway, theengine having four cylinders, all working on the pinion-wheels. The 1 in 8 referred tothe Visp-Zermatt Railway, on theAbt system. The l in 4 referred to the Pike’s Peak Railway in Colorado, using an engine similarto the Montserrat engine. He hoped that points of haulage and gradients might be specially taken into account in the discussion. sir Guilford Sir GUILFORDMOLESWORTH observed thatthe Papers covered a Molesworth- somewhat wide field, reaching as they did from avalanches down to rack- and rope-traction. It had been stated by Mr. Berg that almost all risk of the occurrence of avalanches might be disre- garded on a well-wooded hillside. This statement did not accord exactlywith his experience. He had seen in theHimalayas traces of huge avalanches throughthe forests, leavingtracks Downloaded by [] on [13/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] DISCUSSION oh’ MOUNTAM RAILWAYS. 55 50 or 60 feet wide, and at the bottom of the valley a huge pile, Sir Guilford perhaps 30 feet high, of shattered trunks of trees. In the Rocky Molesworth* Mountains and on the Central Pacific Railway snow-sheds were putup, some of themvery strong and expensive, extending forconsiderable distances-nearly half a milein length. The distancesbetween reverse curveshad been referredto by Mr. Berg. The Ceylon incline of 1 in 45 afforded a good object lesson. Re had ordered thatthere shouldbe a certainlength of straight betweeneach reverse curve. In one instance it was inadvertently lessened. One of thetrains going up the incline fell short of water. The driver, who was new to his work, wanted to go on and fetch water. He uncoupled his engine, backed upon the train, settingit in motion, with the result thatit went 6 miles down the incline, over a succession of reverse curves of 660 feet radius, until the end of the train was switched off at the very pointwhere the length prescribed had beencurtailed. He had used steeltransverse sleepers, and found them extremely satisfactory. Thegeneral tendency was, however, to use too light sleepers with the idea of saving metal. There should not be for the ordinary gaugeless than a certain weight, say14 cwt. for each of the sleepers, which should be strengthened, and not stamped out of simple flat plates, but out of rolled plates thickened up wherethe fastenings would come. Therewas one pointwith regard to mountain railways which he wished to emphasize. It , was a common practice of engineersto place culverts on side- long ground at thebottom of the ravines. The plan he had adopted on the Ceylon incline was to run the culverts on the contour of the ground with a fall not steeper than 1 in 50 or 60, although the bottom of the ravine might fall about 1 in 4 or 5. The rocky nature of the country enabled this to be done very easily. Out of ninety-seven culverts on the Ceylon incline, of a length of 12 miles, there were only three that could not be dealt with in that way, and they all proved very satisfactory. This arrangement not only effected a largesaving in the length of the culvert, but also lessened the destructive rush of water on the masonry. In one case he had put in a 20-foot culvert,throwing the outlet into another ravine, so as to take it right away from the toe of the embankment. The out.let wasgenerally arranged so asto spill over rock. There could be no hard and fast way of dealing with mountain railways. Therewas the ordinary adhesion system; the adhesion with the corkscrew or spiral curve, which was gene- rally a very expensive one, although the ground might in 8ome cases lend itself to this mode of construction. The zigzag system Downloaded by [] on [13/09/16]. Copyright © ICE Publishing, all rights reserved. 56 DIfiCUSfiION ON MOUNTAIN RAILWAYS. [Minutes of sir GUilford was open to the great objection of over-running its zigzags, as Molesworth' was done in the case of the Bhore Ghat.Then there were the rack, the rope, and electrical systems,each having its par- ticular merits and being adapted to different conditions. In the case of the Ceylon Railwaythe question of rope inclineswas carefully considered. Jt wasfound from carefulsurveys that the character and features of the country were such that nothing wasgained in length by the use of therope incline system, andthat in first cost it was the more expensive. The rope inclines weretherefore abandoned, andthe railway constructed withan incline of l in 45 for ordinary adhesion. On the St. GothardRailway the locomotives were placed inthe rear of the train, as stated by Mr. Berg, a practice usually adopted on Alpinerailways, and also inthe United States. For his own part,he considered thisarrangement the safest for continuous inclines, because if both engines were placed in front, the strain on the draw-bars was exceedingly great. The train was apt to part, and then there was nothing to prevent theescape down the incline of that part of the train behind which the couplings had parted. In descending the incline it was of course necessary to place theengines in front. Forpushing, it was desirable to adopt an automatic signal, actuated by compression of the buffers, so that the driver on each engine could see whether he was doing more or less than his proper share of the work. The more power- fulincline-engine should be placed in front, andthe ordinary engine,which brought the train up to the foot of the incline, behind. On the Ceylon Railwayan object lesson was aEorded from the fact that, as the train was going round a sharp curve it ran into a slip. The engine-driver behind did not see what was going on infront of thetrain which was out of sight.This happened before the automatic signals were adopted. The driver of thepushing engine went on, put on more steam, butthe only result was, the engine and train were stopped, and no harm was done. It was notdesirable to have thesecond engine behindif there was any partof the lineon which the gradient mightbe the reverse way of the general inclines. In some cases there might be an incline, on which, to overcome some difficulty, a portion of the incline was the reverse way. Of course, there was a danger in having the engine behind in sucha case. It was therefore desirable, ifit could possibly be arranged,to have the inclinecontinuous, and as nearly possibleas one steady gradient. The use of continuous brakes was sometimes found to be a difficult matter for working inclines. Foreign Downloaded by [] on [13/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] DISCUSSIONMOUNTAIN RAILWAYS.ON 57 stock came over theline, and in some cases the goods stock Sir GuiIford was notfitted for acontinuous brake. The system whichwas adopted in Ceylon, and on some of theIndian State Railway inclines,was to use weighted brakes, which werefound very effective. A weight of 56 lbs. washung on thelevers of the brake wagons, and the vibratory motion of the levers enabled the wheels to rotate slightly, so that they never skidded. The plan adopted was to weight the brakes to such an extent at the top of the incline, that it required a slight draw of the engine to start the train; then the engine brakes, and also the brake-van brakes,were in reserve in case of emergency. The Ceylon line was worked for twenty-eight years in that waymost satisfactorily. Theusual number of loaded wagons taken down wastwenty- four. As manyas forty had been takenin one train,but that was against orders, and it was undesirable to take so many. On one of the Indian State Railways he hadadopted Khat was termed a test incline,that was, a short piece of incline succeeded by a short piece of level, just sufficient to hold a t.rain, before entering on the main incline. The object was, that incase of the train overpower- ing the engines, it couldbe stopped on the level. No difficulty was ever experienced in this respect on the Ceylon incline, but asthe ground favoured that construction on theHolkar State Railway he had adopted it.

Load more