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B&O CPL signals on double track for parallel running
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   Author  Topic: B&O CPL signals on double track for parallel running  (Read 101 times)
stevej
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B&O CPL signals on double track for parallel running
 
« on: Aug 19th, 2017, 1:53am »
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G'day,
I am interested in understanding the sequential display of CPL signals when utilized on double track with parallel running. When identical signal displays exist on both tracks on approach to either restricted indications or turnouts. I possess some information detailing B&O (subsequently CSX) CPL signals, including individual rule indications. But, I don't have any information about the sequential displays possible.
Thank you,
Steve.


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HwyHaulier
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Re: B&O CPL signals on double track for parallel running
 
« Reply #1 on: Aug 20th, 2017, 4:19pm »
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Steve -
 
Indeed, a most thoughtful and obscure query about the classic B & O CPL Systems. To begin let's agree it was one very good, state of the art  
engineering exercise. More. Your writer a quite seasoned old hand, largely as Baltimore resident. Also, your writer with a copy of, and familiar
 with the operative B & O Rules book.
 
In your example, and to begin, the parallel mains scenarios obtained on not all that much mileage. Much of the B & O had single track mains,  
wherein it set up for bi-directional running. As for instances of parallel mains, assume one WB, the other EB. Else, opposite track by definition  
was "wrong way" running.
 
This thought just crossed my mind today. Seems to me, the Rules Book would counsel? The usual, default main would display signals for the  
primary main by direction. There would have been a comparable signal head, displayed along side the primary main signal head group.
 
So that? The Rules Book would advise to observe the signal indications displayed for the track, seen by the operating crew. So that the added  
signal group, for the secondary ("wrong way"?) main also  seen, but it not controlling of the parallel "wrong way" movements.
 
Think on it. B & O CPL always a work of pure genius...
 
Kindly also see:  http://www.railroadsignals.us/signals/cpl/index.htm
 
..................  Vern  ....................


« Last Edit: Aug 20th, 2017, 4:44pm by HwyHaulier » Logged

Ticket Agent serving...Pacific Stage Lines...Washington State System...Mt. Hood Stages...Pickwick Stages...Transcontinental & Western Air Lines.... Admitted Gold Bug..... Observant Orthodox Mossback..... H.M.R.A.O. Curmudgeons......
stevej
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Posts: 5
Re: B&O CPL signals on double track for parallel running
  Double_track_CPL_signal_indication_question.jpg - 13603 Bytes
« Reply #2 on: Aug 22nd, 2017, 2:40am »
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G'day Vern,
Thanks for your response to my question.
I have viewed the web page that you had given the link for. Yes, there is a lot of B&O CPL information included. I also possess the B&O, plus CSX signal rules as available via the www.  
The particular photograph that has intrigued me has the adjacent track signal displaying the identical indication.
From my understanding of the B&O rules, the display is Approach Medium.
I could understand the situation if both signals displayed Approach, or if one displayed Approach and the opposite another indication. To my limited understanding, Medium signal indications are utilized at turnouts. So, this joint display of Approach Medium seems to infer that the subsequent signals would display a Medium indication for turnout.
I do realize that with the B&O CPL signal system, numerous other restricting indications are possible; Medium Approach Medium, and Medium Approach Slow, Approach Slow, etc.
This is why I am eager to discover the possible sequential display of subsequent signals showing restricted indications.
The basic sequence of Clear followed by Approach followed by Stop is naturally easily understood.
Here, on double track with Bi-Directional signalling, parallel signals naturally cannot both indicate approach to a main line turnout. With double overlap circuits, a parallel running train must be stopped two signals before the turnout. Therefore, the parallel signal indications on approach to that turnout would be different.
Steve.


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HwyHaulier
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Posts: 3440
Re: B&O CPL signals on double track for parallel running
 
« Reply #3 on: Aug 24th, 2017, 12:04pm »
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Steve -  
 
TKS! Here, it would be nice if one of our members, with much past experience at B & O, might happen in and provide counsel.
 
Your writer believes you were also intrigued with photo with a signal head of the main line. About eight  feet or so to the left another signal head. Some conjecture here? The "main line" signal could display a center white over green. The left side signal head could also display green. Provided there was no move, in "home" or "distant" blocks wherein one of the trains was not to cross over to the adjoining main...
 
In the photos in the link? Bear in mind some of the more unusual displays seen in the busy Baltimore area, which also site of the B & O General Offices. The line had its ways of dealing with notable "high speed" lines. Example in the running between Willard OH, and South Chicago. In travels on B & O marquee #5, it carried dome cars. One could see along the line displays of center white over green for many blocks ahead...
 
B & O #5 one of the "do not delay" schedules. West of Willard it became very obvious. We may infer that signal displays in reverse direction had "full stop" indications...
 
Beyond that? Truly need a veteran B & O guy to better explain all of it. Seems to me the system demanded solid and tested knowledge of the Rules Book. On a basic level, the engine crew needed to comply with signal display, immediately ahead controlling the current "home" block...
 
.................... Vern  .........................


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stevej
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Posts: 5
Re: B&O CPL signals on double track for parallel running
  Parallel_Bi_Di_signal_display_diagram.jpg - 122837 Bytes
« Reply #4 on: Aug 26th, 2017, 3:43am »
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G'day Vern,
I am not sure just what the location of the photo is that features the double track with both CPL signals displaying approach medium.
The signals being identified by the numbers, 1305-2 for the left hand track signal and 1305-1 for the right hand track signal.
But, I have come up with a potential solution for that display.
Should the main line turnouts one signal in advance be diverging and not converging, then there would not be any conflict.
I have scoured the NSW bi directional signalled territory for any possible similar signal display sequence.
And, have found one location where parallel running trains could approach main line turnouts, Wollongong yard.
I have worked through Wollongong many times, but never witnessed this possible display.
The parallel signal indications only possible for each of the trains to enter the respective Refuges.
The turnouts being diverging.
Such an event would most likely only occur due to a network failure, where trains could not continue.
I have made a diagram to display this potential parallel signal sequence.
The usual purpose for bi-directional working here is during track work, or to pass a fast train around a slow train.
As mentioned before, on approach to converging turnouts, one train must be stopped two signals before the turnouts.
Yes, it would be of assistance to my understanding of the B&O CPL system to encounter a B&O veteran.
I am also fascinated by the Pennsy PL type signal.
I understand the PPL signal indications far better than the B&O CPL signal indications.
Steve.



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