1 MARCH 2000
(1) In addition to being good practice, the connecting carrier will usually require that a derail be
placed on the track leading to its line, along with a sufficient safe length of track between the derail and
the junction. The derail is intended to prevent cars from accidentally rolling onto (or blocking) the carrier's
track. As an option, derails may be desirable at the installation end of the interchange tracks.
(2) While derails themselves are not a design issue, their location is. Without a sufficient length of
track between a derail and the clearance point of the track being protected, a derail will be nearly useless.
The designer must allow for this safe track length as an addition to the length of track required for car
holding and switching space.
(3) The safe track length needed past a derail will vary with the grade of the yard tracks and the
configuration of the junction area. The designer should consult the connecting commercial carrier's
engineering department for guidance on placing a derail to protect their track.
f. Security. If the interchange yard is outside the main installation area or otherwise not located within
constant view, it is recommended that the area be completely enclosed with a security fence, including
lockable sally ports across the tracks (see paragraph 13). Lighting and guard towers may also be
required if security-sensitive cargo is regularly handled.
11. YARD, STORAGE, AND OTHER AUXILIARY TRACKS.
(1) Yard and storage tracks are intended for, respectively, the short and long term holding of cars.
Yard capacity is needed at least equal to the maximum number of cars that the installation is expected to
handle at one time. Storage capacity must at least accommodate the number of cars to be kept at the
installation over a longer term. Loading tracks are not considered available for storage, unless cars are
pre-positioned on them for loading.
(2) Auxiliary tracks include sidings, wyes, balloon tracks, crossovers, tail tracks, and other tracks
used for switching and maneuvering cars, allowing engines and cars to clear the main track for other
movements (as in a second engine switching or delivering cars), or to allow an engine to get around the
other side of a string of cars.
b. Yard Tracks.
(1) Especially where the interchange with the commercial carrier is several miles from the loading
sites, or where loading sites are within a separate a secure area, a yard may be required. A yard is
typically several parallel tracks, as in figure 8-1, which serve as a holding area for cars waiting to be
loaded or delivered to the interchange area.
(2) An example is used here of an installation with a mobilization plan calling for 60 loaded cars to be
picked up each day (and 60 empties to be delivered) by the commercial carrier, and with loading sites (12
miles from the interchange point) that can accommodate 30 cars at one time. This installation will likely
need a yard that will hold at least the second 30 cars waiting to be loaded, and subsequently, the first 30
after they are loaded -- to make room for the second 30 at the loading sites.