EP stands for Electro-Pneumatic.
EP Interlockings began to become widespread towards the close of the 19th Century.
They were used at most major railroad terminals in the United States a few of them
are still in service today. The Placement of the control valve which is off to the side
of the switch machine itself varies considerably. EP switches throw very quickly
there biggest problem is that they are not dual control switches. That is if the machine
fails to indicate a switch position a train crew on the ground can not hand operate them
only a signal maintainer can. By the standards of the day they were very reliable.
If they do fail they can cause catastorphic consequences to train operations as these
machines were deployed at major rail terminals like Penn Station, Los Angelos Union
Passenger Terminal, Grand Central, etc. The trend is towards rapid retirement of this
technology.
Тип: Стрелка