736 



Yearbook, of Agriculture 1949 



Farm housing requirements for the 

 next decade are estimated at 150,000 

 units annually, with an average of 14,- 

 000 board feet of lumber per unit, or a 

 total of 2.1 billion board feet. About 5 

 billion board feet is needed annually 

 for normal replacements and repair of 

 farm buildings, and about 1 billion for 

 other farm uses, making a grand total 

 of 8.1 billion board feet. If we assume 

 that 20 percent of the lumber in the 

 buildings torn down will be used again, 

 the net potential annual requirement 

 for all farm uses in 1950-55 is about 

 6.5 billion board feet. 



Fifty years hence, even with a total 

 population 20 percent greater than at 

 present, the farm population is not ex- 

 pected to gain any; some forecasters 

 think it will decline further. But it is 

 generally held that the average size of 

 farms will continue to grow, which 

 means more or larger buildings per 

 farm and consequently more lumber 

 required per farm than now. Taking 

 those various counteractive factors into 

 consideration, requirements are esti- 

 mated at about the same level as in 

 1950-55. 



RAILROAD CONSTRUCTION AND MAIN- 

 TENANCE includes requirements for 

 sawed ties (which are classed as lum- 

 ber), railroad car lumber, and all 

 railroad maintenance. There are 

 about 1 billion cross ties in Glass I 

 railway tracks throughout the United 

 States and about 24,000 miles of track 

 laid with switch and bridge ties. 



Although no satisfactory substitute 

 for the wooden cross tie has been 

 found, many changes have taken place 

 in its use during past years. In 1920, 

 nearly 86 million cross ties were laid, 

 56 percent of them untreated. Today, 

 the number laid is from 45 to 50 mil- 

 lion, and the percentage preservatively 

 treated is nearly 95. Preservative treat- 

 ment has nearly doubled the service life 

 of ties, so that a treated tie properly 

 laid is good for 25 to 30 years. 



Changes in the percentages of the 

 different tree species used for making 

 ties that are treated are not so striking, 



Species 



as shown by the following compari- 

 sons: 



1914 1947 



Percentage Percentage 



Oak _1 37 36. 



Southern pine 24 18. 



Douglas-fir 18 8. 9 



Gum 2 8. 8 



Ponderosa pine 5 1.6 



Lodgepole pine 1. 3 



Tamarack ( larch )__ 2 1.5 



All other 12 23.9 



Total 100 



100.0 



The source of the 1914 figures is 

 the Division of Forest Products of the 

 Forest Service; the 1947 figures came 

 from the Forest Service publication, 

 Preliminary Wood Preservation Sta- 

 tistics, June 1948. 



As to future requirements for cross 

 ties, the continued improvement in 

 highways and the increased use of 

 motortrucks is offset to some degree by 

 the need for more tracks on many lines 

 that have an increased traffic. De- 

 mands for greater speed in transporta- 

 tion makes greater the needs for 

 multiple-track lines. 



It is estimated that for 1950-55 the 

 potential requirements for cross ties 

 will be at the rate of 143 ties a mile 

 (135 for replacement and 8 for new 

 trackage) for some 365,000 miles of 

 track, or about 52 million cross ties 

 annually. That compares with nearly 

 48 million preservatively treated in 

 1947 (treated ties comprise nearly 95 

 percent of all ties) . Because the aver- 

 age cross tie contains about 35 board 

 feet, the total volume required is about 

 1.8 billion board feet. Assuming that 

 30 million ties are sawed and 22 mil- 

 lion hewed, the total annual require- 

 ment for ties made by sawmills would 

 be about 1.05 billion board feet. Po- 

 tential requirements for switch and 

 bridge ties in 1950-55 are estimated 

 at 200 million board feet annually. 



As for lumber for cars, some marked 

 changes have occurred during the past 

 few decades. Since 1925 there has been 

 nearly a 25 percent decrease in the 

 number of freight cars in use; since 

 1928 the use of lumber in their con- 



