MIL-HDBK-1005/6
Section 5:
TRACK
Rail Specifications. Choose sections conforming to AREA
5.1
recommended sections. Use 115 RE rail for new construction and major
rehabilitation projects unless quantities of larger sizes are stockpiled.
For
minor replacement or repair work match existing size rail where adequate.
Material. Rails shall be manufactured to specifications for
5.1.1
hydrogen eliminated standard rail steel as recommended in the AREA Manual,
Chapter 4, Rail, Part 2, Specifications.
Rail Drilling. Rails shall be drilled according to AREA Manual,
5.1.2
Chapter 4, Rail, Part 1, Design, Table 1, Recommended Rail Drillings, Bar
Punchings and Track Bolts, for new construction and major rehabilitation
projects. For minor replacement or repair work, match existing where
adequate.
Curved Rail. Where conditions are such that curves of 20 degrees
5.1.3
(288-foot radius) or more are absolutely necessary, rails should be pre-bent
to the design radius prior to installation.
Gage. For straight track and curves up to 12 degrees (478-foot
5.2
radius) use a gage of 4 feet 8-1/2 inches measured between the inside heads of
rail 5/8 inch below the top of rail. For curves greater than 12 degrees
(478-foot radius) widen gage 1/8 inch for each additional 2 degrees (except
through turnouts) to a maximum allowable of 4 feet 9 inches. Gage tolerance
should be minus 1/4 inch to plus 3/16 inch.
Spikes. Use 6-inch by 5/8-inch cut spikes conforming to
5.3
specifications as recommended in the AREA Manual for track spikes, including
0.20 percent copper, soft-steel or high carbon, Chapter 5, Part 2.3, Spikes.
The smaller 5-1/2-inch by 9/16-inch cut spike may be used in sidings where 6
by 8-inch cross ties are used.
For size, see AREA Manual, Chapter 3, Part
5.3.1
Holes Bored for Spikes.
1.9, Timber Cross Ties.
Spike Quantities. Use two spikes per side per tie plate on tangent
5.3.2
track and curved track with not more than 6 degrees of curvature (radius 955
feet or larger). On curved track with not more than 6 degrees of curvature
that has some superelevation and heavy loads operating at slow speeds use
three spikes per side per tie plate. Use three spikes per side per tie plate
on curved track with more than 6 degrees of curvature (radius 955 feet or
less). Use four spikes per side per tie plate where traffic, curvature,
speed, and superelevation indicate a need, with care being taken to minimize
"spike killing" of the tie (i.e., weakening of a tie where spike holes are too
close together).
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