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 diokers. — 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 hlocks. — 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 hlocks. 



Number. 



Size of 

 sheaves. 



Bearing. 



Diameter 

 of pin. 



Oil 

 capacity. 



Weight. 



Net selling 

 price. 



1 



Inches. 

 24 by 5.... 

 30 by 5.... 

 36by5.... 



Inches. 



1 

 7 

 10 



Inches. 

 3i 

 . 3J 

 3i 



Gallons. 

 2 



Pounds. 

 485 

 835 

 970 



$104 



2 



149 



3 



167 







EXTRA PARTS. 



Items. 



No. 1. 



No. 2. 



$18.90 



$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 



Hardenefi E'teel pin 



Bronze bushing 



Manganese steel sheave, bronze bushed 



$22. 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. 



