AERIAL LOGGING 



83 



the lower end of the standing line. 



without breakage of logs. — 1,500 feet of 1 '/s-inch cable are used in the "standing line;" the upper end of this 

 line runs over a 16-inch sheave attached some 40 feet above ground to a tree standing at the brink of 

 the plateau; it is made fast to a stump nearby. The slack is taken out by a purchase line, running 

 from a stump at the millpond to a 9' j-inch by 11 -inch donkey engine over a 16-inch tackle block forming 



The trip line, 3,000 feet long, runs from the donkey engine over a 

 series of sheaves, the last one attached to the 

 tree at the brink some 8 feet above ground. The 

 trip line ends in a "travelling block carriage," 

 with swivel and hook and "buttchain" 7 feet long, 

 to receive the load of logs with the help of a 

 wire rope "choker." 



Raising load: -By taking up slack from 

 standing line through purchase line. 



Dropping load into pond: -By slackening 

 the purchase line until the logs hit the water, 

 when the hooks binding the choker open auto- 

 matically. 



(B) THE LIDGERWOOD SYSTEM:-On 

 the Pacific Coast, in the Appalachians and on the 

 Atlantic Coast, the Lidgerwood cable way aerial system is used, on a 

 rapidly increasing scale, in connection with spur lines run at distances 

 1,800 feet apart. Where the ground is particularly rough or particularly 

 Head spar tree for aerial skidding. swampy, the "flying machines" are at their best. 



Tail spar tree for 

 aerial skidding. 



,IEAO SP»R ^t' 



Arrangement of cables in aerial 



skidding, as devised by the 



Lidgerwood Mfg. Co. 



Aerial skidding, with "flying machine" standing on the track. 

 Lidgerwood Mfg. Co., Liberty St., New York. 



