|Jimmy Fiedler posted|
Dennis DeBruler John LaRochelle I understand switches and derails. What are "locks?" If I see semaphores in a picture, I assume they were also "armstrong" controlled.
John LaRochelle Dennis DeBruler : 'Locks' where the blue colored pipe-connected levers that mechanically insured, thru a plunger at the switch or derail, that the switch or derail points where properly aligned for safe movement thru the switch or derail. In a pinch, a good tower operator would go down to the out of alignment switch/derail, and could use a spike puller as a fulcrum to move the point enough for the plunger to slide in, and then would be able to return to the tower to pull the signal lever. In a completely mechanical interlocking red colored levers were pipe connected. In an electro-mechanical interlocking the red levers activated relays to electrically power the signal. Large terminals and multiple track (3, 4, ,5, 6, etc., tracks sometimes utilized electro-pneumatic pistol grip interlocking. Switches and derails went over with a 'WHOOSH TICK". Sorry , I misspelled 'compensators', devices used to change the pipelines direction and force. Freezing rain wasn't much of a problem, but snow was definitely a pain the rear. Chicago Ridge used the old method, smudge pots to keep the switches and derails clear. Today, at manned/remotely controlled interlocking propane/natural gas burners are used.
|From MC Tower|
The device used to change the direction of a control line was called a 'compensator.' Below is a closeup of the one at the end of a pipeline from Tower NJ.
|Excerpt from below|
|From Tower NJ|