CHAPTER XXIII 
FLUMES AND LOG SLUICES 
Log and lumber flumes, and log sluices are built to transport 
lumber, erossties, shingle bolts, acid wood, cordwood, pulp- 
wood, mine timbers and saw logs from the forest to mills, rail- 
roads or driveable streams, and to carry products from the 
mill to market, or to rail transport. They are used to some 
extent in nearly every forest region, but are especially serviceable 
where stream transportation is not available and when the 
topography is so rough that railroad construction is costly. 
They have several advantages over logging railroads in a 
rough region: (1) they can be carried over inequalities in the 
ground, or across gulches on fairl}^ light trestles; (2) they can 
be operated on steeper grades; (3) they occupy less space than 
a railroad and hence require smaller cuts and tunnels and can 
often be located in narrow canyons where there is not sufficient 
space for a railroad. 
The disadvantages are: (1) the transport of crooked and 
long logs is difficult and costly; (2) the light construction ren- 
ders them more subject than railroads to damage by windstorms, 
fires, floods, falling timber and other natural agencies, although 
they can be repaired more cheaply; (3) they usually offer no 
means of transporting supplies from the railroad to the saw mill 
or forest; however, in some instances the edges of the flume box 
are used as a track over which railroad speeders are run, thus 
affording communication between the two ends of the flume; 
(4) the transport of lumber roughens the surface of planed ma- 
terial and also batters the ends of the boards which have to be 
trimmed after leaving the water so that planing mill work must 
be done at some point below the lower terminal of the flume. 
TYPE OF BOX 
There are two types of flume and sluice boxes. One is V- 
shaped and may have a "backbone"^ which makes a box 6 or 
^ A triangular strip fastened in the vertex of the flume box. 
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