202 RAILWAY CONSTRUCTION. 



especially for horse tramways, but not proving efficient, has been 

 superseded by other types of a stronger and more durable descrip- 

 tion. The rail was rolled with a continuous groove to provide 

 clearance for the flanges of the car-wheels, and the sides of the 

 rail were turned down so as to fit over the longitudinal timber 

 sleeper, to which the rail was secured by staple-dogs, as shown. 

 Cast-iron chairs, spiked on to wooden cross-sleepers, held the 

 longitudinal sleepers in position. The wooden sleepers were 

 favourable for smooth running, but the section of the rail, practi- 

 cally a light channel-iron laid on the flat, was most unsuitable 

 for carrying weight or for making a proper joint. Experience 

 proved this road to be very difficult to maintain in good order 

 for easy traction. The staple-dogs worked loose after a little 

 time, and the rail, having scarcely any vertical stiffness, rose and 

 fell during the passage of every car-wheel, resulting in most 

 uneven joints and a clattering roadway. 



With the view to obtain a stronger and more permanent 

 support for the rail than the longitudinal timber sleeper last 

 described, various forms of cast-iron chairs were devised. Fig. 

 277 represents one of these patterns. The rail, which is of T- 

 section with a continuous wheel-flange groove, is secured to the 

 cast-iron chair by the cross-pin, as shown. Although this cross- 

 pin may in time work a little loose, it cannot work out, being 

 kept in position by the paving-setts on each side. The cast-iron 

 chairs are placed at convenient distances, and being set in a bed 

 of concrete, do not require cross-sleepers or tie-bars. This type 

 makes a strong road, but the rail-joints cannot be made so even 

 or efficient as with the more modern form of rail. 



Rail manufacturers are now able to roll a section of rail com- 

 bining the vertical stiffness of the ordinary flange, or flat-bottom, 

 rail with the running-head and continuous wheel-flange groove, 

 considered the most suitable for heavy tramway traffic. The 

 introduction of this section of rail has contributed greatly to the 

 increased efficiency and durability of the permanent way for 

 street traffic ; and as the ends of the rails can be secured by 

 ordinary fish-plates, there is the great acquisition of even joints 

 and increased smoothness in the running of the tramcars. This 

 rail can be rolled of various weights to suit the rolling loads. 

 On some tram-lines a moderately heavy section has been adopted, 

 and secured to transverse sleepers of rolled iron or steel laid on a 

 bed of concrete. On others similar rolled metal sleepers have 



