400 LOGGING 



transports 300,000 board feet daily, a quantity three times as 

 great as the maximum for a V-flume. This increase is made 

 possible by clamping^ from five to six boards together into a unit 

 which is floated singly on the steeper grades toward the head of 

 the flume. On the low grades near the lower terminus from 

 twenty-five to thirty units are "dogged" together with manila 

 rope and floated to destination. 



For shingle bolts, acid wood, and cord wood a box with a 

 lo-inch bottom, 20-inch sides and 24 inches across the top is 

 sometimes employed. In northern New York a flume of this 

 size handled sixty cords of spruce pulpwood per hour. As a 

 rule, however, they are larger with a base of approximately 20 

 inches, sides from 16 to 20 inches high and a width across the top 

 of from 30 to 32 inches. The boxes are supported on trestle work 

 similar to that used for the V-flume, although the construction is 

 stronger. 



The boxes of log sluices (Fig. 123, E) are of larger size than those 

 for luniber flumes and carry more water. They are used chiefly 

 to supplement stream driving by transporting logs through rocky 

 gorges where an excessive amount of water would otherwise be 

 required or where boulders prevent the profitable improvement of 

 the stream for loose driving, and for transporting logs over 

 stretches of streams whose banks are so low that the flood 

 waters scatter the logs over the lowlands. They are also 

 used in connection with log haul-ups to transport logs from 

 one watershed to another, and, in some cases, to transport 

 logs directly from the forest to the mill. They have been 

 employed frequently in the Lake States and occasionally in the 

 Northeast. 



On account of the large amount of water they must carry to 

 float logs and because of the wear-and-tear they receive, the 

 boxes are made of strong material supported on cribwork which 

 is kept as near the ground as is feasible. 



1 The clamp which is patented is a bar of ^-inch half-round iron, with a i-inch 

 flat face having recurved points at each end. The boards are made into piles with 

 the ends flush with each other, a clamp is slipped over the end, and a wedge driven 

 between two boards near the center of the unit. This drives the points into the 

 outer boards and binds the whole load together. 



