1 MARCH 2000
c. Vertical Curves.
(1) Maximum vertical curvature in a summit should normally be 0.4 percent change in grade in 100 ft,
but may be as high as 2.0 percent change entering (or exiting) loading, storage, or other spur (dead end)
tracks. Corresponding values for sags are 0.2 and 1.2, respectively. Where track space is available and
no interference occurs, use the lower values. The higher values are sometimes needed to avoid putting
vertical curvature through a turnout, road crossing, or alongside a loading dock.
(2) It is best to avoid locating turnouts in vertical curves as sometimes problems with point fit or
d. Horizontal Curves. Track curvature should not exceed 12 degrees in terminal areas. Where number
9 or 10 turnouts are the smallest recommended size, curvature elsewhere on the track should not exceed
e. Track Layout. Design guidance for the layout of turnouts, curves, ladder tracks, and track
connections is covered in chapter 6.
4. CLEARANCES AND USABLE TRACK LENGTH.
a. As terminal track is typically closely spaced near loading docks, buildings, access roads, parking and
staging areas, parallel tracks, etc., awareness of clearance requirements is especially important.
Clearance requirements are covered in paragraph 6-4.
b. The maximum usable track length for positioning cars extends from the end of track (for spur tracks)
to the clearance point, or (for sidings) between two clearance points, as indicated in figure 6-9.
5. VEHICLE TERMINALS.
a. Purpose and Facility Requirements. A vehicle loading terminal is generally designed for transferring
tracked or wheeled vehicles on or off flatcars, or in the case of smaller wheeled vehicles, auto racks
(trilevel cars). A vehicle terminal will contain: loading tracks to position the flatcars; a nearby staging area
to hold the vehicles; end ramps or multilevel ramps for transferring the vehicles to and from the railroad
cars; a crew and communications facility; and a storage building for blocking and bracing material.
b. Track Spacing. When the loading tracks in a vehicle terminal are laid out parallel to each other (as
is often the case), the tracks should be spaced far enough apart to accommodate one-way vehicle traffic,
as shown in figure 8-2. If cranes are required between the loading tracks, every other track should be
spaced at 50 ft.