RAILWAY CONSTRUCTION. 203 



been used, but laid longitudinally. For some descriptions of 

 traffic a much heavier section of rail has been used, having a base 

 sufficiently wide to provide ample bearing on a bed of concrete 

 without the intervention of either transverse or longitudinal 

 sleepers. 



Fio-. 278 is a sketch of the modern rail as laid down on a 



O 



rolled steel transverse sleeper, the rail being held in position 

 either by turned-up clips, wedges, bolts, or any of the devices in 

 use for similar duty in the rolled-steel sleepers for ordinary rail- 

 way permanent way. 



Fig. 279 shows a modern rail of a heavier section, with a wide 

 flange resting direct on a continuous bed of concrete. The gauge 

 is maintained by bar-iron tie-bars placed vertically so as to fit in 

 between the courses of the paving-setts, the ends being forged 

 and screwed to pass through holes in the vertical web of rail, and 

 secured in position by nuts. Both in this, and in type Fig. 278, 

 ordinary fish-plates are adopted at the rail-joints, as indicated by 

 dotted lines. 



In the last two examples above described all the materials 

 are of the most durable description, and the least liable to wear 

 or decay, but it will be necessary to guard against making the 

 fastenings and the bars too light for the duty they have to per- 

 form. There should be ample material in the head of the rail to 

 allow of a fair wearing down, and the continuous flange groove 

 should be sufficiently deep to meet this wearing away without 

 causing the wheel-flanges to strike the bottom of the groove. 



Fish-plates. In the first examples of the newly invented 

 wrought-iron fish-plates they were made to the depth to fit in 

 between the upper and lower tables of the rail, as shown in 

 Fig. 280, a small space or clearance being left between the inner 

 sides and the vertical web of the rail. Ordinary nuts and bolts 

 were used in most cases, but in some instances one of the fish- 

 plates was tapped, as in Fig. 281, forming one long continuous 

 nut, and in others both fish-plates were tapped, as in Fig. 282, 

 and right and left handed bolts were used. Neither of the two 

 arrangements of tapped fish-plates proved sufficiently successful 

 as to lead to their general adoption. When the bolts became 

 rusted in, or iron-bound, it was found to be almost impossible to 

 remove them without permanently damaging the fish-plates. 

 With the four right and left handed bolts the operation of 

 tightening, or removing, the fish-plates was very tedious, as each 



