Solid Wood Products 



2665 



180- 



Q 160 



Q: 140 



§it; i2o 



3: 5 100 



0$ 60 



^ ;^ 80 



40 



20 



1910 



1920 



1930 



1940 

 YEAR 



1950 



I960 



1970 



Figure 22-53. — Volume of crossties pressure-treated by three processes. (Drawing after 

 Bescherl977.) 



Annual production. — Annual production of pressure-treated crossties 

 peaked in 1930 at about 180 million cubic feet (fig. 22-53), reached a second 

 lower peak of about 150 million cubic feet during World War II, and was at a low 

 of about 40 million cubic feet in the early 1960's; by 1979 volume rose to about 

 122 million cubic feet. Figure 29-21 shows that the number of ties put in place in 

 the United States dropped sharply from over 40 million in the latter years of 

 World War II to about 12 million in 1961, and then rose slowly to about 24 

 million by 1979. Industry sources (Reynolds 1977) estimate that the market for 

 crossties through the late 1980's will range from a low of 20 million to a high of 

 35 million pieces; at 40 board feet each, sawn tie volume might therefore range 

 from 0.8 billion board feet to 1 .4 billion board feet — in any event probably not 

 exceeding 20 percent of total annual sawn hardwood volume. 



Species. — Oaks predominate in use for crossties (fig. 22-54); sweetgum and 

 tupelo sp. are also much used. Other pine-site species used for crossties include 

 ash, elm, and red maple. For an indication of relative durability of creosoted 

 crossties of these species, see figure 22-55 top. Although not charted in figure 

 22-55, hickory is also acceptable (Kemp 1951). Each railroad buys the species it 

 finds acceptable and affordable; they commonly buy all of the acceptable species 

 offered in the proportions they occur on the woodlands being cut. 



Sizes and specifications. — Each railroad has specifications for the crosstie 

 and switchties that they purchase, but they are not uniform among companies. 

 Some standardization, however, is provided by the National Hardwood Lumber 



