LOGGING IN THE DOUGLAS FIR REGION. 
119 
for the gear ratio involved in abolishing compound gearing. This 
type of yarder is also manufactured with 13 by 18 inch cylinder. 
The 11 by 17 inch engines cost about $5,500 and weigh about 55,000 
pounds. Steel cars cost about $2,000 ; when they are equipped with 
air brakes, $2,200. 
Lines and Chokers. — Lines and chokers are of the same grade and 
construction as those used with the ground yarding system. The 
lines in both systems are of practically the same length, since the 
distances yarded are about the same. The main yarding line of the 
ground system is, of course, a little longer than that of the high-lead 
system. It is claimed that it is practicable to use lines of a little 
smaller diameter with the high lead than with the ground yarding 
system. 
High-lead blocks. — While the desirability of a large lead block is 
clear, opinions differ as to the proper size. The sheaves of those in 
use range from 24 to 36 inches. One operator has found the smaller 
block satisfactory. There are several makes of high-lead blocks on 
the market. Figure 35 shows one of the autolubricating types. An 
ordinary butt-chain lead block was first used as a high-lead block, 
and some operators are still using the butt-chain lead block for this 
purpose. The size, weight, and net selling price of three sizes of 
autolubricating high-lead blocks are as follows : 
Table 21. — High-lead blocks. 
Number. 
Size of 
sheaves. 
Bearing. 
Biameter 
of pin. 
Oil 
capacity. 
Weight. 
Net selling 
price. 
1 
Inches. 
24 by 5.... 
30 by 5.... 
36 by 5.... 
Inches. 
7 
10 
Inches. 
3£ 
Gallons. 
n 
2 
Pounds. 
485 
835 
970 
$104 
2 
149 
3 
167 
EXTRA PARTS. 
Items. 
No. 1. 
No. 2. 
818. 90 
§21. 00 
6.75 
6.75 
2.00 
2.00 
38.00 
67.00 
6.00 
8.00 
7.00 
11.70 
47.25 
67.00 
No. 3. 
Tool steel shackle with clevis complete 
Shackle clevis and pin 
Shackle pin with automatic lock 
Pair steel block sides 
Hardened Steel pin 
Bronze bushing 
Manganese steel sheave, bronze bushed 
S22. 50 
6.75 
2.00 
72.00 
8.00 
11.70 
77.00 
The high-lead block is hung from 6 to 12 feet below the point 
where the guy cables are attached to the spar trees with a 1| to 2 inch 
plow steel strap, wrapped either once or twice around the spar tree. 
As a matter of safety an additional strap is placed through the yoke 
of the block and loosely around the spar or one of the guy lines. 
