184,50 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



75 



In consecinonco of the ililliculties experienced througli tlie defective 

 law of expropriation, a petition for its revision was presented to tlie 

 States General, and, from ils lavourable reception, it is presnmeil, 

 that such a law will be passed, as will facilitate the formation of rail- 

 ways throughout the kingdom, and will cause the speedy extension of 

 the present one as far as Rotterdam, thus uniting two cities bo long 

 celebrated in the annals of commercial enterprize. 



1 



Fig, 1.— Plan of rail, longitudhiul timbcrfl, sleepers, nnil wedges. 



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^"'g' ^'.—Section of sleepers, showing the joint-plates, and mode of idstening the rails, 



Fig. 4.— Section of the foundation for the walls of the Leyden station. 



The rails used in the permanent way (Figs. 1, 2, and 3) are of a 

 bridge form, weighing GO lb. per yard ; they are fixed by scrmvs, upon 

 longitudinal timber bearings of Riga timber, caulked down upon 

 sleepers of the same timber, and secured by oak wedges. The ends 

 of tiie rails are fastened by nuts and screws, through the longitudinal 

 bearings, with joint plates and cramps. This method of fastening is 

 stated to be Tery complete, and the motion of the carriages over the 

 joints is without shock. The gauge is G feet G inches from centre to 

 centre of the rails; and the cost of each single line of railway laid is 

 £2394 lOs. per mile. The dimensions of the various pieces, their 

 number, weight, and price are given in the paper in minute detail. 



The general width of the top of the earth-work for the rails is 29 

 feet inches. The inclination of the slopes of the i-mbankment, is 

 twice its vertical height. The side benches vary in width between 3 

 feet 3 in. and G feet G in. The ditches are 13 feet in width, and the 

 ballasting is composed of sea-shells (schulpen). 



In marshy spots all the earth-works are laid upon beds of fascines, 

 more or less extensive according to the nixture of the ground, In those 



silnations wliere the railway traverses pools of water, the fascines al- 

 ternate with beds of rubble,' and arc hold together by stakes and wat- 

 tles, until the weight of tin; earth is laid upon them and the mass is 

 consolidated. The earth-work is chiefly composed of sand from the 

 sea-beach, and is covered with turf. 



The station at the Amsterdam terminus is a semi-circular building 

 of brick and cut stone, with pri.jecling wings, and sheds on iron 

 columns, founded on piles in the usual Dutch manner. The station at 

 the Haarlem terminus is also of brick and stone, but is not founded on 

 piles, as the ground was sunicicntly solid to bear a building. The 

 Leydcn station, which is of the same construction as the others, stands 

 on such bad ground, that it was necessary to construct a raft, placed 

 upon oak piles, to receive the foundation of the building (Fig. -1.) 



The station at the Hague resembles tin- others, but being conslructed 

 on good ground, piles were not necessary. 



The bridge over the Spaarne at Haarlem (Figs. 5,0, 7,8, 9, and 10) 

 consists of six arches of 2G feet 3 inches span each ; four are fixed, 

 and the other two are occupied by a cast iron swing bridge, which 

 generally remains open for the convenience of the navigation, and is 

 only closed at the times of the passage of the trains. The machinery 

 for turning this bridge (Figs. G, 7,8, 9, and 10), and forsimultaiieously 

 opening or shutting both arches, is situated on the centre pier, which 

 is constructed, like the others, of brick and cut stone, upon piles of 

 fir. A self-acting signal is attached to this, and all the other swing 

 bridges, in order to show their position. 



The bridge-keepers reside in two small wooden lodges, built in the 

 river, opposite to each end of the centre pier. The bridge being 

 equally balanced upon the pivot, the labour of working it is small, as 

 compared with that required for working a half-arch swivel-bridge; 

 and it possesses the far more important advantage of perfect stability 

 and freedom from vibration, when once fixed between ils bearmgs — 

 an indispensable condition for a railway bridge. 



Fig. 5 is a side elevation of the bridge, showing the two centre 

 openings and the piers of brickwork with stone facings. The founda- 

 tion piles of the piers are from 8 inches to 11 inches square, and 2G ft. 

 3 inches long. On these piles, are laid flie longitudinal beams of a 

 timber apron, which traverses the whole of the openings, and extends 

 above and below the bridge, to the extremities of the cut-waters, and 

 on these are placed the transverse bearers of the piers. The whole 

 of the foundation is of white deal. All above the dotted line iu the 

 figure is iron-work. 



Fig. 6 is a plan of the iron framing of the swivel-bridge, consisting 

 of five long girders, connected by transverse and diagonal pieces, sup- 

 ported by six rollers, working on a circular rail or bearing-plate j con- 

 centric with the latter, is a lixed circular rack for a travelling pinion, 

 shown on a larger scale in Figs. 8, 9, and 10. 



Fig. 9 is an elevation of one of the piers, and a section through the 

 roadway. The brickwork on the facing is 14 and 2 bricks thick, of 

 bricks of the best quality (clinkers) set in strong tarras cement : and 

 the inside is of bricks of inferior quality set in bastard tarras cement. 



Fig. 10 is a transverse section of the swivel-bridge, showing the 

 transverse pieces bolted, through their flauches, to the girders. The 

 operation of working the bridge will be at once understood by an ex- 

 amination of this figure, in connexion with figs. 7 to 10. The antion 

 of the hand-wheel is transmitted by bevelled gear to the shaft of the 

 travelling pinion, and the bridge is thus made to revolve on its centre, 

 supported by the six rollers. The bushes of all the roller axles are 

 adjustable, by an ap|)aratus shown in figs. 8 and 10, by means of which 

 they may be screwed down to a point, at which each roller carries its 

 due share of the weight. 



Figs. 7 and 8 show the machinery for securing the bridge, when 

 closed. The pinion on the axle of the hand-wheel, fig. 9, works the 

 sector rack. A long connecting rod is jointed at one end on an arm 

 of the rack, and at the other on the arm of an axle, which carries three 

 eccentric or cranked rollers. The hollow in the section of each roller, 

 corresponds to the convex section of a bearing-block, upon which it is 

 brought down, by an alteration in the position of the crank which car- 

 ries it. When the bridge is secured in this position, the eliect of 

 which is to give it a firm bearing at each end, by distributing the 

 weight over the two ends and the centre, it is evident, that it can 

 have no lateral motion, and still greater security is given to it by the 

 bo:ts, which are shot into their mortices, by means of a projecting arm 

 on the connecting rod. 



The foUowinjr are the principal dimensions:— 



'' Ft. In. 



Thickness of the centre pier . . . . i'l lU 



„ piers nearest to the centre on each Bidi . 7 4 



„ piers nearest to the abutments . .66 



Lengthof the ii on swivel-bridge , . . . 77 6 



Width of ditto . . . . . 20 1» 



Length of the middle girder . • • . 77 6 



„ Intermediate pair . . . . "fi S 



,, outside pair , i , , 74 9 



10* 



