From: stephen@sprunk.org   
      
   On 02-Jan-16 17:38, Robert Heller wrote:   
   >>> Stephen Sprunk  wrote:   
   >>>> Sounds like this is coming west from Expo/Bundy Station; the   
   >>>> yard is on the left after the line returns to grade, but   
   >>>> according to the FEIR, the two mains are on the far right and   
   >>>> the only siding (a yard lead, plus the yard itself) is on the   
   >>>> left.  I don't see anything in the plans that would indicate a   
   >>>> crossover or other interlocking involvement on the right track,   
   >>>> but since the left track does and thus needs a two-headed   
   >>>> signal, they may have given the right the same for   
   >>>> consistency.   
   >   
   > It is a 'dummy' head.  It is used to indicate that the signal is an   
   > *interlocking* signal as opposed to a *block* signal.  The rules for   
   > block signals are a little different from the rules for a   
   > interlocking signal. Things like absolute stop vs permissive stop.   
      
   The left track has a switch to the yard lead, and that needs a home   
   signal.  According to the FEIR, though, the right track bypasses the   
   interlocking, so it seems like a block signal would suffice.   
      
   (This presumes LACMTA built what is shown in the FEIR; if the right   
   track actually has a crossover to the left track for yard access, as I   
   had expected, then obviously it would need its own home signal.)   
      
   S   
      
   --   
   Stephen Sprunk         "God does not play dice."  --Albert Einstein   
   CCIE #3723         "God is an inveterate gambler, and He throws the   
   K5SSS        dice at every possible opportunity." --Stephen Hawking   
      
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