Twinco Mfg. Co Inc.

ensures compliance of restrictive signals variety of layouts available approved by : new york city transit chicago transit authority massachusetts bay transportation authority the train stop is used in conjunction with wayside signals in rapid transit systems to ensure observance of, and compliance with, restrictive indications. Failure to comply with the rules reqarding such indications results in activation of the train's braking system. Operation is completely automatic, entirely independent of any action on the part of the motorman. the system functions by mechanical contact between a wayside trip arm and a trip cock lever on the underside of the train. The wayside trip arm is lowered when the signal is clear and is raised when the signal is at "stop" or "danger". In the raised position, the trip arm will engage the trip cock lever of any train attempting to pass the signal, thus bringing it to a stop.