From: jishnu@nospam.verizon.net   
      
   On 3/18/2016 11:16 AM, Joseph D. Korman wrote:   
   > On 3/11/2016 4:02 PM, hounslow3@yahoo.co.uk wrote:   
   >>> A clarification of the Transit Call-On (at least in NYC):   
   >>>   
   >>> Not only does the tower have to activate the white light (R/R/W), the   
   >>> train operator must push a button or lever on the signal head to lower   
   >>> the stop arm.  If the tower hadn't activated it, the button/lever will   
   >>> not work for the T/O.   
   >>>   
   >>>   
   >> What about a key-by? You can still do that with the fixed-block signals   
   >> on the Subway.   
   >   
   > Because of careless train operators over 30 years ago, the TO must call   
   > the command center to get permission to key by.  Most signals, with the   
   > latest round of upgrading, the signal block begins a few feet in front   
   > of the stop arm, so the train need only stop and proceed slowly to the   
   > arm to lower.  There might be some that still need to have a button   
   > pressed the make the arm lower.   
   >   
   >   
      
   I can't remember the details, but I seem to recall that when a home   
   signal is fleeted there is a special indication lamp on the signal which   
   converts it from an absolute stop to a stop and proceed, only for the   
   duration that the indication is lit. For the life of me I can't find the   
   details, but I have seen this happen on the NEC. Then again I may be   
   remembering wrong about the indication. Maybe they talk to the   
   dispatcher each time this happens.   
      
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