1 MARCH 2000
(2) Strictly defined, hardwood and softwood refer to a type of tree and not the hardness or density of
the wood. However, the hardwoods listed above are denser and generally more durable than the listed
softwoods and thus usually more desirable for ties. While softwoods are sometimes preferred on open
deck bridges to help absorb impact, they are not recommended for use in turnouts or in sharp curves
(over 8 degrees) where the better spike-holding ability of the denser woods is needed.
(3) Hardwood ties are often sold in species groups such as mixed hardwoods or oak. The mixed
hardwoods may comprise, for example, 40 percent oak and 60 percent assorted hardwoods, including
gum. Gum is not a preferred species, but is commonly used. The oak group is usually a mix of red and
white oak and typically costs more than the mixed hardwoods.
(4) For track with annual traffic volumes of 5 MGT or less, as is common at military installations,
wood ties are more likely to fail from decay rather than mechanical wear or loss of spike-holding ability. In
such cases, tie selection should lean toward available species that readily accept deeply penetrating
preservative treatment. Information from the engineering department of the serving commercial carrier,
from regional tie suppliers, and from local experience should help in selecting the most appropriate ties.
b. Cross-Section and Length.
(1) The two common cross sectional sizes for wood track ties are 7 in. thick by 9 in. wide or 6 in. thick
by 8 in. wide.
(2) 7x9 ties are recommended for areas with higher traffic volumes and wheel loads as well as in
(3) Track ties are commonly produced in 8.5 or 9-ft lengths. The 8.5-ft length will be used when most
(4) Ties for turnouts vary from 9 to 16 ft long and will be ordered as indicated in table 6-9.