436 LOGGING 
The box of a V-flume for lumber and crossties has sides ranging 
from 15 to 18 inches high and is from 30 to 3G inches wide at 
the top (Fig. 158 A and B), while those for floating large logs 
may have a top width of 60 or more inches. The backbone when 
added is made from a 6- by G-inch or 8- by 8-inch timber sawed 
diagonally. The side boards of the box are 1 inch in thickness 
for sides up to 30 inches in height, 1| inches if from 30 to 36 
inches high, and 2 inches if from 36 to 48 inches high. The 
cracks are battened with 1- by 4-inch or 1- by 6-inch strips. 
The boards range in width from 8 to 14 inches, but are usually 
from 12 to 14 inches. The lengths are commonly 16 and 24 feet. 
Box Flumes. — These are used for lumber and dimension 
stock (Fig. 158C), shingle bolts, pulp wood, and logs.^ They are 
more expensive to construct than a V-flume because the greater 
weight of water carried necessitates a heavier trestle and the box 
is more difficult to fashion. Where the water supply is abundant, 
boxes of this character are sometimes used for lumber transport. 
A box flume^ in California transports 300,000 board feet daily. 
From five to six boards are clamped 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 
10-inch bottom, 20-inch sides, and 24 inches across the top is 
sometimes used. In Northern New York a flume of this size 
handled 60 cords of spruce pulpwood per hour. As a rule, how- 
ever, they are larger with a base of approximately 20 inches, 
sides from 16 to 20 inches high, and a width across the top of 
1 See note, page 450. 
2 This flume was started in 1891 by the Fresno Flume and Irrigation Com- 
pany for irrigation purposes, connecting the sawmill at Shaver with the 
planing mill and shipping depot at Clovis. Near the head, the flume box 
is rectangular and has sides 12 inches high and a width of 48 inches. On 
the steep mountain pitches the sides are 32 inches high, and on the lower end 
48 inches high. The maximum grades are 4^ per cent and the minimum 
grade on the flats 0.5 per cent. 
^ The clamp, which is patented, is a bar of i-inch half-round iron, with a 
1-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. 
