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(erielack) Erie Signals
WD Burt wrote:
2.) Advance Approach on ex-EL lines. I don't recall seeing this aspect on EL lines and believe that it was imported by Conrail. If I recall correctly, the aspect was still yellow-over-yellow at that time. As Gordon says,
NORAC changed yellow-over-yellow to Approach Slow. Advance Approach then became a flashing yellow. Typically it is used where the second block in advance is too short for a train to stop, taking into account the grade and track speed.
COMMENT: This function is more-or-less accomplished by "approach medium"; "advance approach" sounds like another way (the NYC way?) to institute "double approach", or "4-block" as you call it, esp. in instances where the blocks are short and you want an extra margin of safety (obviously needed given the speeds the NYC ran at on their main). On the EL, flashing yellow was reserved for Medium Approach at an interlocking signal (Rule 286C).
The EL probably could have defined flashing yellow at an automatic as Approach Medium, but it might have gotten too confusing.
Back to the rationale for "double approach" or "4-block": on the NYC, high speed was obviously a good reason. The EL didn't run at those speeds, but there were situations such as grades, territory where commuter trains make frequent stops, and advances to interlockings, where the extra safety factor was desired -- OR REQUIRED by the ICC (ah, back when there was an ICC).
WD Burt wrote:
Clear Medium was the best you could get for the westward crossover move (old main line to Track 1) at CBJ. But that Approach Medium on signal 382-1 might also mean a Medium Approach at CBJ.
COMMENT: Interesting again! I never thought about that -- what is the advance signal against a diverging route thru an interlocking with the next signal in stop (i.e., "medium approach", red over yellow over red, Erie style, or red over flashing yellow, DLW style, or one-arm flashing yellow (i.e., Rule 286C, not sure where that was used)? Obviously it was approach medium at Cuba Jct., perhaps in most other places on the EL.
MY QUESTION -- Does anyone know the rationale for EL Rule 284 (the "Berkshire rule"? just kidding), called
approach-slow, a 3 arm automatic with aspect yellow over red over green, meaning "approach next signal at not
exceeding slow speed", slow speed being 15 MPH. In a way, it's not as restrictive as "approach", you don't
have to prepare to stop at the next signal. But, you need to crawl.
My GUESS would be that this could be used as an advance indication to an interlocking signal where a diverging move onto unsignalled territory is expected, such as a switch into a yard. I.e., you'd see a yellow-over-red-over-green at the automatic in advance of an interlocking where your interlocking signal is already pulled off and is displaying "restricting", i.e. red over yellow. (Again, that's just my THEORY, wondering what the real deal is -- or was, back when the EL was still around.)
So you'd come up on the interlocking at 15 mph, and hopefully be in good shape to get down to restricted speed (i.e., prepare to stop short of obstruction on visual warning). I never saw a 3-arm automatic on the Erie / EL, although I was told that they existed. (The CNJ main east of Raritan had some of them, I did see those.) On most of the interlockings on the NY Div that I was familiar with, the advance to a "restricting" would be approach, i.e. yellow over red on a 2-arm automatic.
So, signal systems are interesting!
Jim Gerofsky
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