RAILWAY CONSTRUCTION. 213 



a thoroughly dry sleeper will readily absorb from 2 to 3 gallons. 

 More could be forced into the dry sleeper if necessary, but a little 

 consideration will show there would be no advantage in doing 

 so. In railway sleepers there are two elements of destruction at 

 work one the decay of the timber, and the other abrasion or 

 wearing away of the wood itself from the constant pounding of 

 the passing loads. 



More particularly does this wearing-away take place with 

 the flange, or bridge, rails, their distributed bearing surface on 

 the sleeper being less than the cast-iron chairs. 



A thoroughly well-creosoted 5-inch sleeper laid originally 

 with a thickness of 4| inches in the centre of rail-seat, as in Fig. 

 306, will wear down 1 inches, the timber remaining quite 

 sound. 



The writer has had to take out thousands of sleepers where 

 the seats of the flange, or bridge, rails had been pounded or worn 

 down so deep into the wood as to leave too small a thickness of 

 timber to carry the rail with safety. These sleepers had to be 

 taken out of the road, not on account of decay, but because they 

 were actually worn down too thin to be of service. They had 

 done their work well for a long series of years, and were perfectly 

 sound when taken but. No increased quantity of creosote would 

 have made them last longer, and any increased quantity of 

 creosote would have been waste. 



Two and three quarter gallons of creosote is a very good and 

 suitable quantity for a 10 inch by 5 inch rectangular sleeper, but 

 not more than half this quantity can be forced in if the sleeper 

 is wet or unseasoned. 



Sleeper-blocks are generally cut from the upper part of the 

 tree, and do not therefore consist of the best portion of the 

 timber, yet sleepers made from the soft, coarse-grained Baltic 

 wood, properly creosoted, will last from twelve to eighteen years 

 in the line in this country, while uncreosoted they would perish 

 from decay in six or seven. The benefit is great when, by 

 adding from eightpence to a shilling for the cost of creosoting, 

 the life of the sleeper may be doubled or trebled. Of course, 

 there are countries, like the far west of America, where the lines 

 pass through vast forests, and where sleepers may be had for the 

 mere cost of cutting. Creosoting in those places would be out 

 of the question, and would cost four or five times the value of 

 the plain sleeper. It is found, also, that in tropical countries and 



