Emergency Window - RailFans love it. Why? Go figure. - Anubharadwaj Maharshi

To stop runaway trains from uncontrolled descent . It is a descent backwards and once you reach the points, it is ascent again and the train will slow down. It will once again descend and go back to the catch siding and the see saw continues until the train loses momentum and stops. up down up down up down and then tired and stopped at last. Wanna experience one ? just jump the brake testing signal tongue emoticon(If a train loses control, and descend down ghats abruptly, Catch sidings are used to control)

---