3.30.
MARKING AND THROWING TRACK
After the stringline calculations are complete, the track is marked or staked so that the track maintenance
gang will know how large a throw to make at each station. This should be done soon after the ordinates are
measured, within a week or so if possible. Likewise, the track should be thrown as soon as possible after the
stakes are set or the marks are made. The more time the whole process of measuring, calculating, marking, and
throwing takes, the likelier it is that the track will go farther out of line or that the stakes or marks will be
disturbed by passing trains. Marking and throwing the track are discussed in the following subparagraphs.
a. Marking. Track may be marked for throwing in one of two ways. One is used for marking double
track; the second is for either single or double track.
(1) Double track. A scratch board is used to mark one of two parallel tracks for throwing, as shown
in figure 3.7. The
Figure 3.7. Use of Scratch Board in Lining Curves.
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