RAILWAY-SLEEPERS. 



571 



there shall be no bad knots on the sleepers just where the 

 chairs are fixed to them. Tr.] 



In Germany first-class sleepers are 2*7 m. long and 16 by 

 26 cm. in section ; second class sleepers are 2*5 m. long and 

 15 by 25 cm. in section. On the average a sleeper contains 

 0*10 cu.m. (3^ cu. feet), and if the waste of wood in sawing 

 them is considered each sleeper requires 0'13 cu.m. (4*55 cu. 

 feet). In Belgium, France and Holland the sleepers are 2'50 

 to 2'75 m. long and with sections 13 by 26, 14 by 28, 15 by 

 30, 16 by 32, 18 by 35 cm. ; as already stated, their shape 

 need not be regular. They are therefore cheaper than 

 English or German sleepers. It should be noted that the 

 height of a sleeper has more effect on its durability than 

 its width. 



In 1902, the total length of railway lines in Germany was 

 53,000 km. (33,125 miles). There are on the average 1,300 

 sleepers per kilometer, averaging O'l cu.m. of wood. As the 

 sleepers last about 10 years, every year about 6,890,000 

 sleepers have to be replaced, requiring 689,000 cu.m. of wood. 

 Also about 900 km. of new lines are constructed requiring 

 120,000 cu.m. of wood. Hence the annual demands for wood 

 for the German railway-sleepers are about 800,000 cubic 

 meters, or 28 million cubic feet, which if the waste in sawing 

 the sleepers is included means a drain on the forests of 36 

 million cubic feet, the annual produce of about a million acres 

 of woodland ; of the German sleepers 55 per cent, is conifer- 

 ous, 40 per cent, oak and the rest chiefly beech. 



It is evident that the greatest number of sleepers should be 

 sawn from wood in the round. Experience has shown that in 

 the sleepers 2J m. long and 16 by 24 cm. in section the follow- 

 ing sleepers can be cut from round logs. 



