116 BULLETIN 711, U. S. DEPARTMENT OF AGEICULTUEE. 



lion of high-lead yarding on a considerable scale is very recent, but 

 has gi'own in popularity. It appears, in fact, to have follovs^ed the 

 success of the overhead system, which does away with the necessity 

 of constructing landings and has demonstrated advantages in log 

 transportation. 



High-lead yarding has been employed in the East for many years. 

 A number of operators on the Pacific coast have no doubt used this 

 system in a modified form at different times for short periods for 

 several years. As early as 1906 a logging company in British Colum- 

 bia used a high-lead system of the type used in the East ; that is, with 

 the yarding and loading engine mounted on a swivel-truck car. 

 This installation was not immediately followed up by others. About 

 1912 another logging company in British Columbia started to use a 

 high-lead yarding system that resembled those in use at present. It 

 seems that the company's major reason for trying the system was to 

 get away from the construction of landings. They found that the 

 system, in addition to obviating the necessity of using landings, in- 

 creased their yarding output. In 1916 a large number of operators 

 were using the high-lead yarding system, and it looks as though it 

 would supersede the ground system to a great extent. 



The chief advantage of the high-lead system over the ground 

 system is that there is a lift to the logs as they come in, so that 

 they are not stopped so much by stumps and other obstructions, and 

 travel faster. This advantage is greater the higher the lead block is 

 fixed, but is lost in practice when the yarding distance exceeds 500 

 to 600 feet. Within these limits the front end of the log is elevated 

 sufficiently to prevent nosing in soft ground and to provide free 

 movement past stumps and windfalls. In working across canyons 

 the high lead reduces the time lost through logs nosing into the 

 bottom of the canyon or plowing into the opposite slope. Another 

 advantage is that the landing place is kept relatively free of chunks, 

 tops, and other trash, a source of trouble and expense with the 

 ground system. It has been indicated that the high-lead system does 

 not require landings, the resultant saving just about offsetting the 

 extra expense of preparing the spar tree and swinging the lead 

 block. In addition, yarding may proceed more constantly because 

 the logs delivered at the landing place may be piled one on top of the 

 other for some time, regardless of whether loading is going on or 

 not. 



When hauling down a steep slope the high-lead system probably 

 is not so satisfactory as the ground system. In the case of side-hill 

 work the logs have the same tendency to roll behind obstructions. 

 It must be borne in mind also that much of the timber now being 

 logged does not afford trees high and stiff enough for spar trees, 

 and that it is expensive to maintain a rigging crew in some camps. 



