2io RAILWAY CONSTRUCTION. 



it is perishable from wear and decay. Were it not for this 

 defect, railway sleepers of wood might be considered as simply 

 perfect. 



With a view to greater permanency and durability, stone 

 sleepers were tried. These consisted of square blocks of good 

 hard stone, measuring about 2 feet wide each way and 12 

 inches thick. Holes were cut in the stone, and plugs of hard 

 wood inserted. The cast-iron chairs were then placed on the top 

 of the blocks, and the iron spikes driven through the chair-holes 

 into the wooden plugs. The elements of permanency were there 

 certainly, but a rougher road it would be impossible to conceive. 

 The stone was solid and unyielding, there was a total absence of 

 softness and elasticity, and the harsh noisy effect produced when 

 running over the stone-block road very soon became intolerable. 

 Stone-block sleepers were found to be a failure, and were all 

 removed. On some of our old lines, numbers of them, with the 

 chair marks plainly visible, may be still seen in loading banks, 

 buildings, sea walls, and other works for which they were never 

 originally intended, but for which their size and weight render 

 them very appropriate. 



Wooden sleepers are used in two forms, transverse and 

 longitudinal. In the former, as in Fig. 301, the sleepers not 

 only carry the rails, but also preserve the gauge ; in the latter 

 as in Fig. 302, the longitudinal sleepers only support the rails, 

 additional timbers and strong fastenings being necessary to 

 maintain the gauge. 



Longitudinal sleepers have been used to a large extent for 

 bridge rails, it being supposed that with the broad continuous 

 sleeper a lighter and shallower rail could be adopted, which 

 would be equally efficient as a heavier rail on cross-sleepers. 

 Excellent running roads have been made with longitudinal 

 sleepers, notwithstanding the difficulty of making a good bridge- 

 rail joint ; but it is well to bear in mind that almost all the lines 

 which originally adopted this form of permanent way have since 

 reverted to the ordinary cross-sleeper road. The longitudinal 

 sleeper road is an expensive road to lay down and maintain. 

 The main pieces are of large scantling, must be of good quality 

 of timber, and are consequently costly. The cross-pieces, or 

 transomes, must be carefully fitted and secured with heavy iron- 

 work. Where there is much traffic, the removal and renewal of 

 one of the long timbers is much more difficult than the renewal 



