RAILROAD CONSTRUCTION 



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Culverts. — These are used where the grade crosses very small 

 streams, or slight depressions where it is necessary to have 

 drainage from one side of the grade to the other. 



They are ordinarily made by placing logs from 18 to 30 inches 

 in diameter across the right-of-way on either side of the stream 



Fig. 80. — A Spur Logging Railroad corduroyed with Poles. Arkansas. 



and covermg them with slabs split from 12- to 18-inch timbers. 

 Brush is often piled on top of the slabs to prevent the dirt from 

 falling through, and the grade is then built over the culvert. 

 Box culverts made of plank are seldom used because of the 

 greater cost for material. Round galvanized iron culverts are 

 now used on some main lines. 



