72 



METHODS OF OOMMVNICATION FOR FORREST PROTECTION 

 8 SPECIAL TYPES OF CONSTRUCTION - 



In regions where there is little timber and practically no danger from windfall 

 a No. 3^ porcelain knob fastened to the tree with a 6-in. spike may be found satis- 

 factory. It should not be used, however, without the permission of the district 



4-Cemp/ete 



na stuff 



No. 5 00 



insu/otor 



6- Short turns. 



Pieces 6 wide /2"/ong 2" thick, either 

 sp//t, hewn or- sawed, f>n four sides of 



tree. Fasten So tree with 2~5in.na//s. 

 Dec/of- en ding on po/es- Omif protecting 

 pieces and reduce fore space to 3 inches. 

 Seiz/ng stuff may be fastened to po/es 

 with nai Is, or common fence stap/es. 



//eiser- dead-end a line of y eater weight 

 than SO ff. ofN<?.9w/re to bo//d/nq and 

 then dead-end on brackets and a/ass 



Fig. 33 Method of dead-ending on tree lines 



inspector. In this type of construction the spans should 1 average about 100 ft., with 

 from 10 to 15 ft. of sag, according to the length of the span. A No. 12 wire should 

 be used to tie the main line to the insulator, using the tie indicated in Fig. 26. 

 This method will be found 1 satisfactory only in large, open western yellow pine and 

 similar types where there is little windfall and almost no sway of the trees at the point 

 of attachment of the insulator. It should not be used for any but short branch lines 

 or on short, alternative routes. 



The spike should be driven into the tree for almost its entire length, leaving 

 only about l in. exposed. Since the weight of the wire falls on the top of the 

 insulator, the strain on the tie wire is small. The lower branches of the tree should 

 not be trimmed 1 , since they tend to prevent the line from grounding when a tree falls 

 on it. 



In some regions of excessive winds where deciduous species, such as poplar, are 

 used for tie trees, it has been found that the constant sway of the ties causes them 



