Permanent Way
The temporary way is so called because it is the temporary track often used for construction purposes which is replaced by the Permanent Way (the structure consisting of the rails, fasteners, sleepers/ties and ballast (or slab track), plus the underlying subgrade) when construction nears completion. In many cases a narrow gauge track was used for a temporary way because of the convenience in laying it and changing its location over unimproved ground.
In restricted spaces such as tunnels, the temporary way might be double track, even though the tunnel will ultimately be single track. Thus the Airport Rail Link in Sydney had construction trains of 900 mm (2 ft 11 7⁄16 in) gauge which were replaced by the permanent tracks of 1,435 mm (4 ft 8 1⁄2 in) gauge.
During World War I trench warfare had led to a relatively static disposition of infantry forces requiring considerable logistics to bring them support staff and supplies (food, ammunition, earthworks materials, etc.). Dense light railway networks using temporary narrow gauge track sections were established by both sides for this purpose.
During World War II, it was proposed to expedite a Yunnan-Burma railway using a gauge of 1 ft 3.3in, since such a small gauge facilitates the tightest of curves in difficult terrain.
Read more about this topic: Rail Gauge, Temporary Way
Famous quotes containing the word permanent:
“Let a man learn to look for the permanent in the mutable and fleeting; let him learn to bear the disappearance of things he was wont to reverence; without losing his reverence; let him learn that he is here, not to work, but to be worked upon; and that, though abyss open under abyss, and opinion displace opinion, all are at last contained in the Eternal Cause.”
—Ralph Waldo Emerson (1803–1882)
“The English were very backward to explore and settle the continent which they had stumbled upon. The French preceded them both in their attempts to colonize the continent of North America ... and in their first permanent settlement ... And the right of possession, naturally enough, was the one which England mainly respected and recognized in the case of Spain, of Portugal, and also of France, from the time of Henry VII.”
—Henry David Thoreau (1817–1862)