Future Requirements for Timber 



733 



ments can be got from thinnings made 

 in dense stands to relieve congestion 

 and give the selected saw-timber crop 

 trees more room for growth. Thus the 

 same stand that yields saw timber can 

 also yield poles without materially re- 

 ducing the output of the former. 



WOOD PILING ranges from about 30 

 feet to more than 90 feet in length 

 and from a top diameter of 5 inches 

 to a butt diameter of about 2 feet. 

 The best grades of piles are suitable 

 for heavy railway bridges and trestles, 

 piers, and other heavy construction; 

 the poorest grades can be used for light 

 building foundations, cofferdams, false 

 work, and various temporary work. 



Before the Second World War, con- 

 sumption of treated piling averaged 

 about 16.5 million linear feet annually. 

 Assuming that 60 percent were treated 

 (the correct percentage is not known) , 

 total consumption was about 28 mil- 

 lion. Potential annual requirements for 

 1950-55 have been estimated at 38 

 million linear feet, with a drop to about 

 23 million 50 years hence. 



As in the case of poles, this need not 

 be a heavy drain on the forest. Dense 

 stands of second-growth timber will 

 yield excellent piling through the re- 

 moval of trees in thinnings made to 

 improve the final saw-timber crop. 

 Such trees are slender in form and 

 have the dense wood desired in piling, 

 because they are crowded and partially 

 overtopped by the main crop trees. 



The species used for piling that was 

 preservatively treated in 1947 ranked 

 as follows: 



Percent 



Southern pine 74. 9 



Douglas-fir 20. 8 



Oak . 8 



Norway pine 3 



Western redcedar . 1 



Jack pine 



Ponderosa pine . 1 



All others 2. 9 



Total 100. 



FENCE POSTS are used chiefly on 

 farms, and most of them are cut in 

 farm wood lots. Many species are used, 



but the more durable and preferred 

 ones are Osage-orange, cedar, chest- 

 nut, locust, and catalpa; they have an 

 average life of 15 to 30 years or more. 

 Oaks, walnut, and cherry are some- 

 what shorter lived; some of the pines, 

 willow, and cottonwood are good for 

 about 5 years. 



Preservative treatment greatly in- 

 creases the service life of posts, but 

 as yet comparatively few posts are 

 treated. In 1947, about 12 million were 

 treated out of a total of several hun- 

 dred million put in place. A survey in 

 1937 showed that about 460 million 

 posts were put into use on farms in 

 that year; that does not include posts 

 for the highways, railroads, industrial 

 plants, and other nonfarm uses. 



The potential annual requirement 

 for posts in 1950-55 is estimated at 

 about 600 million, of which 80 percent 

 would be cut from sound, living trees. 



Posts can be cut from trees that need 

 to be removed in thinnings and other 

 cuttings in immature stands to im- 

 prove the quality of later saw-timber 

 harvests. Both fuel wood and fence 

 posts needed on the farm can generally 

 be got at the same time that the farm 

 wood lot is being improved. 



MINE TIMBERS,, hewed or round, in- 

 clude mine ties, pit props, legs and 

 posts, horizontal cross bars (or collars) , 

 lagging and cribbing, and caps used for 

 tightening props and legs. Certain 

 items are used both in the sawed and 

 in the round or hewed state. 



The quantities of wood used per unit 

 of mine output vary not only with the 

 kind of material mined bituminous 

 coal, anthracite coal, iron ore, or 

 precious metals but also with the type 

 of extraction, such as underground or 

 surface mining. One of the early sur- 

 veys, in 1905, showed a total consump- 

 tion of 165 million cubic feet of round 

 material and 435 million board feet of 

 sawed. Then pine comprised one-half 

 of the softwood round timber and one- 

 third of the softwood sawed timber; 

 oak was the leading hardwood species. 

 Of course, what species are favored 



