SELECTING THE TYPE OF CONSTRUCTION 31 



stands for tree-line work, and the jack pine stands of the East. Somewhat less favour- 

 able are the stands of eastern red pine, of western larch and western yellow pine in 

 mixture, Douglas fir on the drier soils, and some of the larger-sized pure poplar stands 

 both East and West. 



Next to these species in ease and low cost of tree-line construction are such stands 

 as western white pine (where relatively pure), eastern white pine, mixed hardwoods 

 in the East, Engelmann spruce and amabilis fir at high elevat.'ons, and the larger- 

 sized western yellow pine and Douglas fir o>n dtry sites. In the first three the under- 

 brush is likely to be heavy and the bark thick on old trees or the branches abundant 

 on young trees. In large yellow pine and fir some difficulty is experienced in climbing 

 trees because of their size and loose bark, and where trees stand in the way of the 

 line they are very costly either to fell or to trim up. High-altitude stands are usually 

 fairly clear of underbrush and the trees are a fair size if usable at all, but the branches 

 are dense. 



The most difficult types through which to build tree lines are Do'iiglas fir on wot 

 sites on the Pacific coast, white spruce or red spruce, Engelmann spruce at low ele- 

 vations, cedar, and, above all, hemlock, especially western hemlock. The mixed coni- 

 ferous forests of the moister regions of British Columbia come under this head, as 

 well as a great deal of the northern forest belt and the eastern spruce forests. The 

 difficulties encountered in these types arise from the large amount of underbrush* 

 that has to be cleared, the density of the timber, and the low-branching habits of these 

 species. Hemlocks are particularly bad because the lower branches are excessively 

 long and have a very pronounced downward sweep. Often large branches of hemlock 

 have to be cut from trees standing 15 to 20 feet fco one side of the line in order to free 

 the wire. 



2 YOUNG TIMBER 



In building lines through very young- timber or reproduction of any species there 

 is often no choice as to type of construction, that may be employed, since none of the 

 young trees may be large enough to serve as supports. Very often, however, there are 

 standing dead snags as remnants of the original forest, which may be so utilized. 

 Unless the necessity for economy is very great or poles are extremely inaccessible, the 

 use of such snags for long lines is not advisable. If used, care should be taken to see 

 that as many as possible of the dead trees adjacent to the line are felled, that abundant 

 slack is left in the line, and that it is made easily accessible for the purposes of repairs, 

 as maintenance charges are likely to be high. The continued felling of nearby snags 

 should be made a part of the regular work of the protection staff and a gradual replace- 

 ment of the tree line by a pole lime should be the object of the maintenance work. 



If young timber, of such a size that trees large enough to furnish supports are 

 available, is encountered very careful consideration should be given to the advisability 

 of adopting pole-line construction. A decision will be based largely on the cost of 

 right-of-way clearing which is determined by the size and especially by the density of 

 the young stands. Where these are very open, pole lines will usually be preferred. 

 A makeshift method of construction sometimes adopted under these and similar con- 

 ditions consists in making the necessary right-of-way clearing, often in the form of a 

 wagon ro'ad, but leaving at the required intervals suitable trees to serve as the sup- 

 ports for the telephone line. These trees should not be topped. The cost of making 

 arid- setting poles is thus saved but it must be realized that a line thus located is likely 

 to interfere with the use of the road and that provision for replacing these supports 

 with poles must be made a part of the work of line maintenance. 



A similar situation is often met by the builder of forest telephone lines, even in 

 certain species of timbers of commercial size in the forests of the Prairie Provinces 

 and of the East. This is most likely to be the case in poplar or jack pine stands. 

 Both species frequently grow in rather open forests, and where they occur in such 

 stands righl-of-way clearing is comparatively inexpensive. Moreover, unless th 



