Students Paper. Permanent Way; Its Construction And

Papers.] GRINLING ON PERMANENT WAY. 333

(Students’ Paper, No. 555.)’ (Abridged.) ‘‘ Permanent Way ; its Constructionand Maintenance.” By ARTHURJOHN GRINLINO, Stud. Inst. C.E. PERMANENTway consists of rails, sleepers, andthe necessary fastenings, andthe term is used todistinguish the finished and permanentrailroad from temporary lines laid down duringits construction, for the carriage of materials. It willbe assumed thatthe necessaryearthwork has been completed, and the banks and cuttings finished to the proper width at formation-level, depending, of course, on the number of lines of way to be constructed. It is important that the formation should be 2 incheshigher inthe centre thanat the sides, to allow of efficient drainage ; and in cuttings provision must be made, either bymeans of open ditches, where there is sufficient width, or by pipes of sufficiently large section, for carrying off any water they are likely to collect. Bottom Ballast.-The bottom ballast is spread directly over the formation and constitutes the foundation for the permanent way. It should consist of hard, rough stone pitching, where this is avail- able, not more than 9 inches in width on any face, laid on edge, and hand-packedas closely as possible. Where it is difficult to obtain stone,broken brick or slag forms an efficient substitute. In soft clay cuttings, a layer of clinker or coarse gravel is sometimes spread over the formation to prevent the large stone bottom-ballast from squeezing intothe clay, andin a wet cuttingthis aids the drying up of the formation. It is also an excellent plan to spread 2 or 3 inchesthickness of good ashesimmediately on the top of the bottom ballast, as this helps to keep the road dry. The total depth of the bottom ballast is usually about 12 inches. Top Ballast.-A large variety of materials may be used for this

1 Paper read and discussed before a meeting of the Birminghanl Association of Students of the Institution, on 11 May, 1905.

purpose, and the material adoptedis usually that which can be most readily and economically obtained. The points to be aimed at are an easy-running road,good drainage, and a materialin which the sleepers can be properly packed ; absence of dust is also an important matter, in respect of both the life of the rolling-stock and the comfort of the passengers, and it is desirable that the material adopted should be one in which weeds will not easily grow. The principalmaterials used fortop ballast are : (1) granite chippings, (2) slag, (3) screened and unscreened gravel, (4) hard, well-burnt ashes, (5)burnt clay, and (6) broken stone. (1) Screened granite chippings form an excellent material for top ballast,as the sleepers can be evenlypacked, good drainageis obtained, there is hardly any dust, and weeds will not grow in it; but except in the case of a railway running through the neighbourhood of granite quarries thecost is against its extensive adoption. (2) Slag is now very extensively used for ballasting, and presents many advantages, but there is considerable difference of opinion as to how small it should be broken. A usual specification is that it mustpass freely througha 2-inchring. If it is too large, the sleepers, instead of being supported over their entire area, tend to rest on a few large lumps ; and it is also difficult to pick up slack joints.Many inspectors say that a road packed withlarge slag tends to get out of line, as the sharp edges form a kind of rocker- bearing for the sleepers to slide on. (3) Gravel, both screened and unscreened, is extensively used for top ballast. Thereshould be sufficient sandpresent to render it compact, but not enough to interfere with the efficient drainage of the road. (4) Ashes are frequently used for lines in the neighbourhood of collieries. Theyform a very elastic road-bed and affordexcellent drainage, but they are scarcely heavy enough to steady a road for heavyexpress traffic. Caremust be takenthat ashes arenot placed in contact with steel-work, such as the flooring of bridges, on account of thesulphur which theycontain. The same rule applies to slag. (5) Where economy has to be studied, and nothing more suitable can be obtained, burnt clay is frequently used for ballasting, but great care must be taken that it is sufficiently burnt, otherwise it will tend to consolidate into hard lumps under the influence of the weather. In the construction of a new line it is not true economy to cut down the estimate for ballast, as the outlay on a sufficient supply of good ballast will be amplyrepaid inthe subsequent maintenance of the line.

(6) Broken stone, like slag, if broken small enough and free from dust, forms a good material for top ballast, but stone that weathers rapidly should be avoided for ballasting. Sleepers.-The purpose of sleepers is todistribute the weight supportedby the railsover the face of the ballast. Wood is the material used for sleepers in this country. Baltic red-wood is the timber most generally used, although someCompanies use memel, Scotch fir, and red pine. Foreignhard woods, such as Australian karri-wood, are now being experimented with. Beech has also been recommended as avery suitable timber forsleepers, and has been used with good results onseveral Continental railways. Sleepers are usually 8 feet 10 inches in length, 10 inches in width and 5 inches in depth. They should consist of thoroughly seasoned wood, as far as possible free from sap, large or loose knots, cracks, shakes, or other defects. There are several methodsof treating sleepers before placing them in the road, so asto increase their life. In this country they are creosoted, the operation being carried out in the following manner. The sleepers, havingbeen sawn totheir properdimensions, are placed in a hermetically-closed cylinder; the air is then pumped out, and creosote is allowed to flow in, and is finally forced in by pumps until the fibre of the wood is saturated with it. Section and Weight of Rails.-Hitherto the rails used by different Railwaycompanies have been of slightly different weights and sections, but in future renewals these differences will be abolished by theintroduction of BritishStandard sections. The following are general dimensions and weights of British Standard rails:-

No. of "B.S."I Height of Width of Nominal l Section. Rail. Head. Weight of Rail. I 1 Inches. 1 Inches. 1 Lbs. per Yard. I I 85 ~ 595 ~ 24$ 85

Chairs.-On all English railways using bull-headed and double- headed rails, the rails are supported in cast-iron chairs, fastened to transverse sleepers by means of various kinds of fastenings which will be described later. The iron must be of good quality, so that in atransverse bending-test a bar 1 inch in widthand 2 inches in depth, placed on bearings 3 feet apart, shall bear a load of 30 cwts. in the centre without breaking, and show a deflection of at least 4 inch. The castings should be sharp and clean, and free from all blow-holes, sponginess, and broken surfaces. In designing a chair

for heavy traffic it is essential to give it a large bearing-area, so as todistribute the weight as much as possible over thesleeper; otherwise the chairs will tend to sink into thesleeper and damage it. The bearing-area and the weight of the chair vary considerably on differentrailways; the latter should be not less than 40 lbs. for heavy trafEic. TheGreat Northern Railway, intheir recent renewals of permanent way, have introduced a new form of chair on either side of therail-joint, in order tostrengthen it. These are known as inter-joint chairs. They are similar tothe ordinary chairs so far as the jaw is concerned, and hold the rail in exactly the same way ; but the rail-seatis cast with a projection onwhich the rail rests,thus considerablyreducing the unsupported length at the joint.This chair is designed to reduce therisk of fractured fish- plates, but at the same time it has the advantage of not interfering with the elasticity of the road, as the ends of the rails are left free. On the main line a 12-inch by 6-inch sleeper is placed under these chairs. Fa&enings.-The fastenings which are used to connect the chairs to the sleepers are of various kinds, comprising solid oak treenails, spikes, coach-screws, andfang-bolts. The Board of Tradereqnire- ment is that at least one fastening of each chair must be an iron spike or bolt. A veryusual method of securing a chair tothe sleeper is by means of two wrought-iron spikes and two compressed oak treenails, placed diagonally. Spikes are usually about 6 inches in length and $ inch to inch in diameter. The spike is considered to be strong enough to resist any shearing-stress that may occur, and the treenail, which is not considered to be so strong, is supposed to swell underthe influence of the weather andto fill up the hole completely, thustending to keep thechair perfectly tightand prevent it having any lateralmotion. Rail-Joints.-The form of joint almost universally adopted in this country is of the " suspended " type, the rails being connected by two fish-plates bolted together through the rails by four fish-bolts. Fish-plates are now made much shorter than formerly, in order to bring the chairs and sleepers at either side of the joint as near to one another as possible, 18 inchesbeing the usuallength. The bolt-holes areeither square, circular, oval, or pear-shaped.The corresponding holes in the ends of the rails are larger, to allow for expansion andcontraction, and it is usual to specify thatthey must be drilled,whilst those inthe fish-plates arefrequently punched. Eolts for Fis7~-pbateu.-Fish-bolts are usuallycup-headed, with square or pear-shaped shoulders to prevent the bolt turning round

whilst the nut is being screwedup. The nut of the fish-bolt may be eithersquare or hexagonal, and lock-nuts are now generally used. Keys.-Double-headed and bull-headed rails are held in position bymeans of woodenwedges, OK’, asthey are technicallytermed, “ keys.” Both hard and soft woods have been used for this purpose. Soft-woodkeys are usually compressed in order todrive out all moisture before they are placed in the road, the ideabeing that when driven into position the key will absorbmoisture from the atmosphereand expand; but in spite of thistreatment wooden keys are liable to shrink and drop out during a spell of very dry weather. Oak and teak are both very suitable woods for keys.

CONSTRUCTIONOF PERMANENT WAY. Plate-lt.cying.-The plate-laying, as far as new lines are concerned, cannot be commenced until after the completion of the earthwork. The bridges must also have been finished, or temporary structures erectedto allow for the conveyance of materials.The work of laying a new line, so far as permanent way is concerned, may be subdivided into three stages :- (l) The conveyance of the materials to the places where they are to be used. (2) Linking-in of the materials. (3) Lifting, straightening, packing and boxing the road. In thecase of a new line of considerable length, the materials are sent down in train-loads and unloadedat suitable spots, and are thence taken introlleys to theexact place where they are tobe laid. In relaying or widening an existing line, the materials are loaded up at a district depot, and, where the distanceis not too great, the gangwhich loads the materialsgenerally travels onthe train, andunloads them at the other end. In relaying a line, the materials areunloaded between the times of the ordinary trains, by the side of the old track, where theyare subsequently to be laid. Sleepers andrails are usually loadedin specially-constructed wagons. Thenumber of platelayers required on a new line depends upon the rate of progress desired ; themen must bewell organized and supervised,otherwise when working with a large gang there will almost certainly be some con- fusion. As far as possible the men should be divided into sets, each set having a certain work allotted to it. Assuming that the bottom ballast has been already laid down, the first operation will be to lay the sleepers approximately in position [THE INST. C.E. VOL. CLXVII.] Z

Downloaded by [ University Of Wollongong] on [16/09/16]. Copyright © ICE Publishing, all rights reserved. 338 GRINLING ON PERMANEST WAY. [Selecten on it. In modern practice the chairs are attached to the sleepers before the latter are sent out. If the sleepers are to be placecl in the ground with their sawn side downwards, they are first passecl under two revolving cutters in order to ensure the chair-seats being perfectly level ; theyare then passed underanother machine by which revolving angers are broughtdown on thesleeper, and the holes forthe fastenings are bored out.This ensures a uniform gauge. The chairs are next placed in position on the sleeper, and driven or screwed home, depending on the nature of the fastening; this is sometimes done under pressure, to make the fastenings take a firm grip. Attaching the chairs to the sleepers before the latter are sent outsaves a great deal of time on the ground. Wherethe chairs are attached to the sleepers on the ground, the holes for the fastenings should be bored to a template, in order to ensure uniformity of gauge. The old-fashioned method was to attachone line of chairs, and spike the other line to gauge after the rails had been placed in position. Most railway companies place their sleepers in theground with their sawn side downwards, the advantage being that anydamp tends to runoff the sleepers, whereas if they areplaced with the heart side upwards the damp has a tendency to penetrate, ring by ring, intothe fibres of the wood, and so cause the sleepers to rot. Sleepers placed sawn side upwards look neater, and the chairsdo not sink so readily into the heart-wood as they do into the sap. The sleepers and chairshaving been laid approximatelyin position, the railsare picked upwith suitable rail-tongs and dropped into their places. The old-fashioned method of liftingwithout tongs requires more men per rail, and the risk of injury to the men is much greater, as theyare more liable tolet the rail drop. The spacing of sleepers varies with different Companies, eleven or twelve sleepers to a 30-foot rail being a very usual arrangement. The joint- sleepers should be placedcloser together than the others, and the space between the second and third sleeper from the joint is usually a little less thanthat between theothers. The positions of the sleepers should be marked off on the rail by means of a divided rod, which serves as a template, a chalk mark being made on the rail at the centre of each sleeper; the sleepers are laid at right-angles to the rail by means of a large square. In fishing two rails together, an expansion-piece is placed between the ends of the rails, and the latter art3 driven close up. The space leftfor expansion varies between inch and 8 inch according to the length of the rail and the temperature at the time the rails are linked in. The two middle fish-bolts are screwed up first. Care should be taken that the rails are in line and level before tightening the bolts, otherwise the strain

of bringing the rail into exact position will fall on the plates and bolts. Thelatter shouldbe oiled before being used. In fishing together rails which do not quite correspond in section, as in the case of relaying, where a new rail must be joined up to one that has become worn, or to a rail of lighter section, it is necessary, in order to get the jointperfectly level, to use junction fish-plates, one-half of the plate being deeper than the other to make up for the difference in the height of the two rails, In keying-up it is now considered best, in order to prevent creep, to drive the keys in the direction of the traffic, on a double line, and in the direction of the heavier traffic, if there is any difference, in the case of a single line. The effect of the passing of a train is then to tighten the keys, not to slacken them. In order that the joint-sleepers may be brought as near to one another as is permissible, consistent with easy packing, one of the keys at the joint will have to be driven in the reverse direction. Packing.-In packing a road, the joint-sleepers should be packed first. The main object to be aimed at is to have the sleeper resting evenly over the ballast, and not merely supported on a few large lumps. Packing is best performed with a shovel ; if a beater is used the packing is almost sure to be harder in some parts than inothers, and this is against easy running. The joints having been accurately levelled, the next operation is to pick up and level the intermediate sleepers. Afterthe roadhas had timeto be consolidated, it is lifted still further by additional packing, until the rails are at the requisite finished level ; 2 inches to 3 inches is quite sufficient for a single lift. Boxing-in.-The ballast which is not actually packed, but lies on and between the sleepers, is termed "boxing." On some lines the ballast is brought up flush with the top of the sleepers, thus leaving the surface of the sleeper exposed. Covering the sleepers with ballast to a depth of 1 inch to 2 inches tends to keep them at a more equal temperature, andalso to prolong their life, as decay is no doubt accelerated by leaving the top surface exposed to the alternation of damp and heat. The ballast should extend about 18 inches beyond the ends of the sleepers, and from this point it should be trimmed down to formation-level. The cesses should be finished to line, as this gives a much neater appearance to the road,

MAINTENANCEOF PERMANENTWAY. The maintenance of permanent way includes keeping the line in repair, and the renewal from time to time of defective and worn- out material. For purposes of maintenance the line is divided into lengths of about 2 miles, withthree to six men toalength, depending on the nature of the length. In every gang there should be a ganger, and also a second man who is competent to take the ganger’s place in his absence. It is usual to have a permanent-way inspector to every 15 to 30 miles, also depending on the nature of the line, thework of maintenance beingmuch heavier onsome sections than on others. To every ten gangs, say, there should be asmall extra gang of five or six men, for strengthening the length-gangs for special work, such as lifting a considerable length of the road, watching theline in time of flood, repairing slips, etc. Each inspectorshould have a time-keeper to relieve him of all clerical work, and to assist him in the supervision of the men. Where it can be arranged, the regular men should be kept entirely to their own lengths, and not taken off, except in cases of great emergency ; when it is necessary to relayor renew importantpoints and crossings the help of theextra gang should becalled in.This extra gang is quite distinct from the small extra maintenance-gangs mentioned above. It should consist of twenty-fourto thirty men,under the charge of aforeman, who should be thoroughly skilled in all permanent-way operations, and an assistant-foreman ; and severalmen should be specially trainedfor such duties as keying, fishing rails, spacing sleepers, etc. It is desirable that the extra gang should contain a nucleus of permanent men, and where the work of a divisioncan be arranged this shouldconstitute as large a portion of the gang as possible, as the extra trouble involved in arranging the order of their work is amply repaid both by the qualityand the quantity of the workdone ; and such menwill carry out the work with greater safety to themselves and to the public. In all operations the protection of the men engaged must be well provided for, flagmen being placed where necessary. The men themselvesshould be acquaintedwith the Company’s rules, and more especially withthose which directly affect them.Flagmen should be carefully chosen with regard to their competenceand their physical capacity ; good hearing and eyesight a.re very important. The following are particulars of the daily routine of work of a maintenance-gang. The ganger is responsible for his length of the line being kept in good order. He should walk over it twice a day, once early in the day and again in the afternoon ; the second man

may,however, frequently make the latter journey. Before leaving his men in the morning the ganger should start them on the work theyare going to do. Whilstmaking his tour of inspection he should carry with him a keying-hammer and a spanner,and examine the line for any defects, such as broken rails and chairs, slack keys and fish-bolts, broken and worn-outfastenings, rectifying small defects by driving in slack keys and screwing up loose bolts as he goes along. He should walk alongon one side of the track,and return on the other. Each gang should work along their length of theline in a systematicmanner as far as possible. Theirduties are :- (l) Keepingthe road trulyin line, and at its proper level. Thisinvolves straighteningthe road, and packing the sleepers from time to time, as may be necessary. (2) Keeping all drains and culeerts free from obstruction. (3) Cleaning and oiling points and keeping the point-rods and signal-wires clear of dirtand weeds, but leaving the actualrepairs of anyportion of theapparatus to the signal department. (4) Trimming the cesses and removing all weeds and rubbish from the line.

The ganger should pay great attention to any damp places that may occur on his length ; it may be necessary, after heavy rain, to open up the road in order to get rid of any accumulation of water, and such places should be attended to with as little delay as possible. The ganger should bring to the notice of the inspector any defects, not only in the permanent way itself, but in the various structures onhis length that he may notice inhis daily inspection. The principal duty of a maintenance-gang consists in keeping the road in as good conditionas possible ; they should not, however,be encouraged to undertake heavier work than they can manage efi- ciently, but should apply for help from the small extra gang when necessary, as? for example, in lifting a considerable length of road, pulling back rails, etc., for if they spend too much of their time in one place the rest of their length is liable to suffer. Creep of Rails.-The readjustment, or pulling back, of rails which have crept, and so caused the joint to get outof square, comes under the head of maintenance, and in some cases it is a very troublesome matter to deal with. Rails always tend to creep or travel along the line of least resistance. The trouble arises from the lateral grip of the fish-plates beingtoo tight,thus preventing each rail from travelling independently, and causing a creep to be transmitted from

rail to rail. It is almost impossible to give any reason for the creep taking place in a particular direction, as what occurs at one place is almost certain to be contradicted at a similar place elsewhere. Creep is supposed to be influenced by the temperature, the direction of the traffic, and the gradient ; and also by the position of the fish-bolts in the holes, for if they are tight up against the rails at one end, and therefore have plenty of room to expand at the other end, this in itself might be quite sufficient to cause the rails to start creeping in that direction. It is probablynot wise to go too far in measuresfor the prevention of creep, for fear of buckling the road, as the force of expansion is so great that if the rails are not left free to expand in the direction of their length they have no other alternative than to buckle laterally, and so throw the line out of gauge. Sometimes the right- and left-hand rails travel in opposite directions, and even where bothlines of rails creep in the samedirection, one will almostinvariably creep more than the other.Creep must not be allowed to go toofar before being attendedto, or it will be necessary to pull back the rails for a very considerable length. In conclusion, the Authordesires to express his indebtednessto Mr. Alexander ROSS,M. Inst. C.E., Chief Engineer of the Great Northern Railway, for much of the information contained in this Paper.