At Catch or Trap Points
Trap points or catch points are designed to intentionally derail vehicles making an unauthorised movement. When a vehicle derails completely, its wheels cease to shunt the track circuit. Since the vehicle might still be foul of the track, it is important to maintain the track circuit in the 'occupied' state. To achieve this, a cast iron interrupter is fitted to one of the run-off rails such that it will be struck by the wheels of a vehicle that is about to be derailed. Since the track circuit is bonded via the interrupter, it is proved to be intact when the track circuit relay is energised.
Read more about this topic: Track Circuit Interrupter, Application
Famous quotes containing the words catch, trap and/or points:
“That is what we must make people feel... the catch in the throat, the wrench to steady the nerves, the determination to carry on.”
—John Dos Passos (1896–1970)
“And boys, be in nothing so moderate as in love of man, a clever
servant, insufferable master.
There is the trap that catches noblest spirits, that
caught—they say—God, when he walked on earth.”
—Robinson Jeffers (1887–1962)
“Every man has to learn the points of the compass again as often as he awakes, whether from sleep or any abstraction.”
—Henry David Thoreau (1817–1862)