Automatic Operation
Many crossing loops are designed to operate automatically in an unattended mode. Such loops may be track circuited with home signals cleared by the approaching train. Some loops have the points in and out of the loop operated manually, albeit more recent examples have so-called self restoring switches that allow trains to exit a loop without needing to change the points.
Other forms of remote operation included Centralized traffic control, where a train controller changes points and signals from a remote office; and driver operated points, which enable train crews to use a radio system to set the points from a distance.
Read more about this topic: Passing Loop
Famous quotes containing the words automatic and/or operation:
“Natural selection, the blind, unconscious, automatic process which Darwin discovered, and which we now know is the explanation for the existence and apparently purposeful form of all life, has no purpose in mind. It has no mind and no mind’s eye. It does not plan for the future. It has no vision, no foresight, no sight at all. If it can be said to play the role of the watchmaker in nature, it is the blind watchmaker.”
—Richard Dawkins (b. 1941)
“It is critical vision alone which can mitigate the unimpeded operation of the automatic.”
—Marshall McLuhan (1911–1980)