Permanent way
The permanent way is the elements of railway lines: generally the pairs of rails typically laid on ties ("sleepers" in British parlance) embedded in ballast, intended to carry the ordinary trains of a railway. It is described as permanent way because in the earlier days of railway construction, contractors often laid a temporary track to transport spoil and materials about the site; when this work was substantially completed, the temporary track was taken up and the permanent way installed.
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