398 



TIMBER RESOURCES FOR AMERICA'S FUTURE 



appears reasonable to expect that there may be at 

 least 400,000 miles of track in operation by 2000, 

 still 20,000 mUes short of the trackage being 

 operated in 1930. 



The laying of 1,000 miles of new track requires 

 about the same volume of new ties as that needed, 

 for normal annual maintenance of about 33,000 

 miles of existing track. (Ties salvaged from 

 abandoned track are not often used in laying new 

 track.) New track includes new lines and exten- 

 sions, conversions of single-track to multiple-track 

 road, passing tracks, sidings, and yard switching 

 track. The annual average mileage of new track 

 laid bv the Class I railroads dm-ing the period 

 1940-55 was 1,261 miles (table 228). Assum- 

 ing that the laying of new track by all other 

 classes of railroad was roughly proportional to the 

 mileage of road, the total new trackage laid must 

 have averaged around 1,350 mUes per year. 



Most new track is designed to speed traffic and 

 improve service. There is reason to expect that 

 the mileage of new track being laid by 1975 may 

 be around 1,500 mUes per year. By 2000, it may 

 be something like 2,000 miles per year — if, as 

 previously suggested, the net mUeage of railroad 

 track increases moderately between 1975 and 2000. 



The trend is toward more ties per mile of track. 

 When the railroads were first built, the standard 

 practice was to space crossties 2 feet from center 

 to center, or 2,640 ties per mUe. By 1940, the 

 number of ties under tracks maintained by the 

 Class I raUroads averaged 2,994 per mile. By 

 1955, that average had increased to 3,020 per 

 mile (table 229). At least one major railroad has 

 installed 3,250 ties per mile in new track. On the 

 basis of expected improvement of roadbeds in the 

 future, it appears reasonable to assume that the 

 number of ties under tracks by 1975 will average 

 around 3,050 per mile, and by 2000 around 3,100 

 per mUe. 



Table 228. — Miles of new track laid by Class I 

 railroads,^ 1940-55 



Table 229. — Miles of maintained track laid vnth 

 crossties and number of crossties in place, Class I 

 railroads, 1940-55 



Year 



1 

 Miles 

 laid 



Year 



Miles 

 laid 



1940 



697 

 1,147 

 1,879 

 1,623 

 1, 246 

 1, 119 

 1,065 

 1,202 

 1,433 



1949 . . . 



1,096 



1941 



1950 



1, 090 



1942 - - . . 



1951 



1, 387 



1943 



1944 



1945 - - - 



1952 



1953 



1954 _- .-_ 



1, 538 

 1,479 

 1, 001 



1946 



1955 



1, 172 



1947 



1948 



Average 1 940-55 _ 



1. 261 



' Railroads having annual revenues of $1,000,000 and 

 above. 



Source: U. S. Interstate Commerce Commission. Sta- 

 listics of Railways in the United States (annual issues 

 1940-53); Transport Statistics in the United Slates (1954, 

 1955). Washington, D. C. 



Year 



Miles of 

 track 



Number 

 of cross- 

 ties in 

 place 



Average 

 number 

 of ties 1 

 per mile 



1940 . - _ - _ 



Thousand 

 337 

 335 

 332 

 331 

 331 

 331 

 331 

 330 

 331 

 331 

 330 

 330 

 329 

 328 

 328 

 325 



Thousand 

 1, 008, 096 

 1, 003, 636 

 995, 140 

 995, 258 

 994, 314 

 991.388 



992, 440 

 991,828 



993, 212 

 992, 247 

 992, 173 

 991, 654 

 991,393 

 991, 025 

 988, 342 

 982, 806 



Ties 

 2, 994 



1941 



2,993 



1942 _ _- 



2, 996 



1943 - - 



3,005 



1944__ _._ 



3,002 



1945-. ._. 



2, 996 



1946 



3, 002 



1947 



3, 003 



1948 -- - 



3,002 



1949 



3,001 



1950 



3, 009 



1951 



1952 



3,009 

 3,012 



1953_. . __. .-_ - 



3, 020 



1954 



3,017 



1955 



3,020 



' Computed from track-mileage and number-of-crossties 

 data before rounding. Temporary reversals of the general 

 trend in number of ties per mile probably due to margin 

 of error in the basic statistics. 



Source: U. S. Interstate Commerce Commission. <Sio- 

 tistics of Railways in the United States (annual issues 

 1940-53) and Transport Statistics in the United States 

 (1954, 1955). Washington, D. C. 



Along with this increase in the average number 

 of ties per mile, there has also been an increase in 

 the average size of ties laid. In 1916 the average 

 crosstie contained about 32 board-feet. By 1955, 

 it had increased to 38.6 board-feet."^ With the 

 trend toward installation of heavier track, it 

 appears very likely that the average size of cross- 

 tie will continue to increase for some time, and 

 that the average crosstie laid in 1975 will contain 

 at least 42 board-feet and in 2000 at least 46 

 board-feet. 



The most important of all trends influencing 

 past railroad tie requirements — and one that has 

 almost run its full course — has been the replace- 

 ment of untreated ties with treated ties. In 1940, 

 about 18 percent of all crossties under rails in the 

 United States were untreated. By 1955, im- 

 treated ties had been reduced to about 4 percent 

 (table 230) . The average service hfe of untreated, 

 ties, under most conditions, is from 5 to 10 years. 

 Treated ties, on the other hand, can be expected 

 to last for 30 to 35 vears. 



"' Based on the number and cubic footage of crossties 

 treated in 1955. See U. S. Forest Service in cooperation 

 with the American Wood-Preservers Association Wood 

 Preservation Statistics, 1955, Washington, D. C. 1950. 



