RAILWAY CONSTRUCTION. 287 



them will depend upon the number of sections to be served, and 

 the amount of waggons to be sorted. Sometimes the sidings are 

 laid with a slight falling gradient leading away from the main 

 shunting lines, to facilitate the running out of the waggons into 

 the respective sidings. 



An arriving goods train is first drawn out of the main-traffic 

 lines into one of the shunting lines, and then handed over to the 

 staff of men in charge of the sorting operations, who at once mark 

 the waggons according to the number or designation of the 

 particular siding into which they have to be placed. A suitable 

 engine is generally set apart for this work, and in a very short 

 time the entire train is divided out by one or more waggons at a 

 time, and distributed into the various sidings, representing 

 different sections of the line, or groups to be handed over to 

 neighbouring railways. When one of these sorting-sidings 

 contains a full complement of waggons, an engine is attached, 

 and the train despatched to its destination, leaving the siding 

 clear for another set of waggons. Where the trains to be sorted 

 are very numerous, two or more shunting-engines may be 

 engaged working at the same time on distinct sets of shunting 

 lines and sidings. Sometimes it may be expedient to have one 

 lot of sorting-sidings leading off the UP line, and another lot 

 leading off the DOWN line, to meet the requirements of trains 

 coming and going in both directions. With sidings well laid 

 out, and fitted with ample facilities, a well- organized staff can 

 carry out a very large amount of work both expeditiously and 

 economically. There are several of these sorting-sidings stations 

 in operation, where from one thousand to two thousand waggons 

 are sorted and marshalled into trains every twenty-four hours. 



The above diagram sketches merely illustrate the general 

 principle of the sorting-sidings, and may be modified and 

 enlarged in many ways to suit the traffic requirements and local 

 surroundings. 



Turn-tables. Turn-tables revolving on fixed centres are made 

 of various sizes according to their use for engines, carriages, 

 or waggons. The carrying-beams may be made of cast-iron, 

 wrought-iron, or steel, but the latter material is the most suitable 

 for tables of more than 20 feet diameter. For small turn-tables, 

 cast-iron beams will serve very well, for although more liable to 

 fracture, they will not suffer so much from rust and oxidization 

 as wrought-iron or steel. 



