Solid Wood Products 2675 



parallel-laminated- veneer railroad ties — from veneer in thicknesses up to 0.4 

 inch from Grade 3 logs of various hardwood species with or without butt joints 

 (8.5- and 4-foot-long veneer lengths) — possessed physical properties consistent 

 with the current specifications for solid wood ties. Species evaluated were 

 northern red oak, white oak, water oak, sweetgum, black tupelo, hickory, and 

 American beech (Fagus grandifolia Ehrh.) 



Performance characteristics were being observed in three separate in-track 

 test groups in 1979 (longest time interval, 5 years), at which date all were 

 satisfactory. Creosote preservative treatment was adequate for all species and 

 treating time was only about half that for solid wood ties. Tschemitz et al. 

 concluded that the greatest problem in any manufacturing operation would be 

 the maintenance of glue bond quality and hence shear strength, and that the 

 viability of the product will likely depend on the economics of manufacture, not 

 on the performance characteristics, which seem good. In 1979, the authors 

 computed a manufacturing cost of $16.44 per untreated 7- by 9-inch crosstie. 



Recycled crossties. — In the Cedrite process old crossties are recycled by 

 reducing them to flakes, adding resin, forming the flakes, and pressing them into 

 a high-density 7- by 9-inch crosstie that weighs 250 pounds (compared to a 

 softwood crosstie which weighs about 160 pounds). Each tie contains two steel 

 bars for reinforcement, one near the top and the other near the bottom; both are 

 out of the spike driving area and reportedly do not interfere with signal circuits. 

 Details of the process have not been published, but initial tests appear promising 

 (Anonymous 1977). 



Crosstie manufacture. — Manufacturing alternatives for producing crossties 

 and timbers are numerous. Some of the headrigs available are described in 

 sections 18-9 through 18-11. Drying procedures are described in chapter 20, and 

 treating procedures in chapter 21. Readers interested in economic feasibility 

 studies are referred to sections 28-18 and 28-32 in this text, and to Monahan 

 (1976), Koch (1976b), and Garrett (1969). 



Lumber and residue yields in crosstie manufacture. — Monahan (1976) 

 related yields of lumber and residue to lumber recovery factor (number of 

 board feet of lumber recovered per cubic foot of log, abbreviated as LRF), when 

 cutting crossties and lumber from 13-inch diameter, 8-foot red oak logs having a 

 density of 63 pounds per cubic foot. From a gross log weight per 1 ,000 board 

 feet Doyle log scale of 14,063 pounds, he found that lumber recovery varied 

 from 4,889 pounds at an LRF of 4.0 to 9, 100 pounds at an LRF of 7.4 (table 22- 

 24). Chapter 27 contains additional data of this nature for a range of log 

 diameters and lengths (see page 3287 and tables 27-100, 27-109, 27-112). 



Concrete crossties. — Howe (1979) reviewed the history of concrete crossties 

 in the United States and Canada and found that their use was minimal in North 

 America until 1972. In 1972, however, the Canadian National Railroad installed 

 10,000 British Rail type F-23 concrete ties in mainline track west of Jasper, 

 Alberta. From October 1973 to December 1974, an additional five major test 

 sections were installed in the United States and Canada. In the fall of 1976, 

 Canadian National contracted for 1,500,000 additional concrete ties, and in 

 1978, AMTRAK awarded a contract for 1,100,000 concrete crossties to be 



