APPLES 



111 



Fig. S. A Stump Puller That Lifts the Stump 

 Vertically Out of the Ground. 



The Donkey Engine 



More land has been cleared in West- 

 ern Washington b.v means of the donkey 

 engine than b.v any other agency since 

 this method came into use. As a rule in 

 Washington outfits for clearing have been 

 used-up logging rigs, and as a conse- 

 quence, results have been less favorable 

 than they otherwise might have been. 

 Equipment should consist of a large dou- 

 ble drum engine (10x12 to 12x14 cylin- 

 der) with tackle consisting of 1,000 feet 

 of IVs-inch main cable. 2,000 of %-inch 

 haul-back line, four 1-inch guy lines, two 

 10-inch pole blocks, four 8-inch blocks for 

 haul-back line in the field, lead lines, 

 chokers, extras and tools. 



Logs and stumps should be piled as 

 high as possible for burning, hence a gin 

 pole 60 to 100 feet high is most com- 

 monly used. The crew is made up of en- 



li:^^ 



i'iK. !). A Tall Gin Pole and a Good Pile That 

 Will Burn Well. 



gineer. fireman, pile man (except where 



automatic self-releasing choker is used), 



hook tender, and assistants. Tracts to 



be cleared should be slashed and burned 



and stumps previously blasted so as to 



split and loosen them. The gin pole can 



be set in the center of a 10-acre tract, 



or at a center where not over 500 feet 



of haul is made. 



Gin pole and engine are guyed to 

 stumps or "dead men" sunk four to six 

 feet deep. The accompanying diagram 

 illustrates method of setting. 



The following specifications and esti- 

 mate for a donkey engine outfit are taken 

 from the article by Harry Thompson in 

 r. S. Bureau of Plant Industry, Bulletin 

 No. 239. 



A compound-geared yarder, with two 

 speeds to the main drum, giving appro'xi- 

 mately 100 and 250 feet per minute, with 

 the haul-back geared to run at 300 to 

 350 feet per minute, Is required. The 

 cylinders should be 9x10 or 10x12 feet. 

 The hauling drum should be fitted with a 

 steam friction. The boiler should be ex- 

 tra large. There should be 1,000 feet of 

 1 %-inch main line of six strands of 19 

 wires each and 2.000 feet of ''s-inch haul- 

 back line of six strands of 19 wires each. 



Estimate of Cost of Donkey Engine Outtit 



Engine and boiler '. . $3,500 



Main line 



Haul-back line 



Bull block for gin pole 



Six self-releasing chokers (■'4 -inch, "s-inch and 1-inch) 



Four haul-back blocks, hooks and swivels : 



Four 1-inch guy lines, 250 feet each ■. 



One lead block for haul-back line 



Electric-signal outfit 



Tools, extra hooks, blocks, etc. 



Total 



200 



150 

 75 

 60 

 70 



150 

 35 

 10 



150 



14,400 



