gregc coming to the conclusion that it's nothing more than a remotely or manually operated device such as a signal or switch. i've been given the impression that it was much more than a signal, a route between signals in a interlocking/signaling system
coming to the conclusion that it's nothing more than a remotely or manually operated device such as a signal or switch.
i've been given the impression that it was much more than a signal, a route between signals in a interlocking/signaling system
That's the point Greg, on some railroads, in some eras, it would be each end of a large complex interlocking.
And in other situations it may just be each end of a dispatcher controlled siding on a single track line in the middle of no where.
Signaling is not an absolute science, and again, back in the day each railroad designed and built what worked for them.
I studied signaling for years before deciding how to model it. I studied the prototype, and I studied what others had done over many decades in the model world to simulate it.
My suggestion to anyone in this hobby interested in signaling a layout is to simplify whatever prototype they want to follow because our model situations simply do not lend themselves to the complexities of the prototype - even on the largest club layouts.
Our distances are too short, and most of our operators are not really interested in learning a complex system.
And not that many viewers will ever know the difference.
So why not make it practical in guiding operators, and interesting to viewers, and leave it at that?
On my layout, there are never more than two signal blocks between interlockings, and in many cases only one. All interlockings are "control points", although I don't really bother with that term. I simply use the terms "interlocking" and "signal block". All CTC trackage is one or the other.
The CTC dispatcher sets routes (turnout positions thru interlockings) and then gives authority (clear signal) - I use pushbuttons, not levers, and one or at most two buttons typically align all turnouts for a route. One additional button then assigns the next block to the train which gives it a clear signal. Once in a specific block, detection turns signals at both ends of the block to absolute stop.
Without a dispatcher on duty, walk around control allows engineers or tower operators to make these assignments at each local tower.
And if you run a RED/RED/RED signal, you will find your train has no power before it makes it all the way thru the interlocking.
And it does not even take a micro processor to do this...... but you could use one if you wanted to.......
Sheldon
gregccoming to the conclusion that it's nothing more than a remotely or manually operated device such as a signal or switch.
Primarily in the late 1950s and into the '60s there was a big economic push to eliminate signal towers or interlocking towers and reduce the manhours needed to move trains across the railroad.
Hundreds of manned towers were eliminated, replaced by relay cabinets and remote operated switches. Often they retained the name of the tower i.e. "Conpit" became C.P. Conpit.
Al Perlman on the New York Central was a "progressive" manager and he instituted a massive campaign to install CTC on the NYC and eliminate a gtrat deal of trackage and the associated sitnal towers.
Many of the Control Points are named for the milepost. Near me is C.P. 171 which is 171 miles west of Buffalo.
"Generally" where you find a control point there was once a signal tower there.
History:
https://ekeving.se/ctc/us/NYC_RS_1927.pdf
Throughout this 1927 article you will see the mention of remote control, as in controlled territory, controlled sidings and controlled signals. Thus you can see the extension of calling these specific locations — Control Points.
Regards, Ed
greg - Philadelphia & Reading / Reading
What is a rivet counter? Clearly it is the area in a hardware store where the selection of rivets is displayed.
maxman Doesn't work? Hmmmmm. Looks the same, but try this one: http://jcbd.com/rrterms.html If this doesn't work, let me know.
Doesn't work?
Hmmmmm. Looks the same, but try this one:
http://jcbd.com/rrterms.html
If this doesn't work, let me know.
Maxman, I think the original link had a comma included in the link after the .html
York1 John
What is a "rivet counter"?
I'm looking for a complete, correct and unambiguious description.
And, don't refer me to that link. It's not on it.
Alton Junction
Oh for goodness sake. Sometimes I think folks are being argumentative just for the sake of being so. It's a list, it gave a simple definition, and it was concise.
Go bother someone else.
Well, that's fine, that is pretty much the same as what myself and others said.
But who generated that list? Who are they? Who put them in charge of railroad terms? There is no ownership info on the page?
maxman I thought it was a reasonable question. From this list of railroad definitions, http://jcbd.com/rrterms.html, a controlled point is "A location where signals and/or switches of a traffic control system are operated and/or controlled from a distant location by a train dispatcher.".
I thought it was a reasonable question.
From this list of railroad definitions, http://jcbd.com/rrterms.html, a controlled point is "A location where signals and/or switches of a traffic control system are operated and/or controlled from a distant location by a train dispatcher.".
It's a reasonable question, but all the "qualifiers" make you wonder what the agenda is?
And your link does not seem to work?
The overall problem with any discussion of signaling and/or CTC is that railroad, region and era effect everything in the discussion.
Not having a government controlled rail system, the US has had hundreds of similar but different signal systems on the hundreds of different railroads.
Applying the same terms to all of them, in every era, simply will not work.
The principles are all the same, the details are almost always different.
And then scaling them down to our models is another problem........
So Greg, once again I would suggest to you that you might get better answers if we knew the reason for your question? You always want to know why? Well I want to to know why you want to know.
Personally, I hate when people ask a leading question that is not the real question or does not contain all the info.
gregc i'm looking for a complete, correct and unambiguious description
i'm looking for a complete, correct and unambiguious description
Good luck with that.....
All the answers so far are correct.
Generally a series of absolute signals, generally on either side of an interlocking, controlled by a tower operator, dispatcher, or CTC operator.
It is the point of absolute control - do not cross on RED/RED/RED indications.
And yes the term seems to be, or have been, more common on east coast roads.
As an example, my simplified CTC for modeling only uses control point or "absolute" signals and their advance signals. Intermediate permissive automatic block signals are not modeled.
Greg;
I believe the term "control point" is used to designate a location where a dispatcher can exercise route options, using manually controlled signals. This may be a passing siding, a junction or simply crossovers between two or more main tracks. The General Code of Operating Rules, effective on UP and SSW on, April 28, 1985, effective on the SP and ATSF on October 28, 1985, as well as the BN, CNW, DRI&NW, LS&I, SOO/MILW, and Minn. Trfr on April 27, 1986 makes no mention of a "control point". It does explain the definition of, controlled sidings and, controlled signal, as used on a CTC piece of railroad. I don't ever recall hearing the term control point used on any place but along the east coast. It must be regional usage just like a can of Coke is a "soda" in one state, a "pop" in another, and a "tonic" in another very small region of the country-yes New England, I mean you.
Hello All,
gregci'm looking for a complete, correct and unambiguious description
HERE!?!
I know this won't help!
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
PC used to also use them as a location to tell someone about an issue in that vicinity.
Joe
Since its used by many different railroads you may be out of luck for one single definition.
NORAC 2003 : A station designated in the Timetable where signals are remotely controlled from the control station.
GCOR 2010 : A location of absolute signals controlled by a control operator.
The term doesn't appear in the half dozen or so rule books I looked at that dated 1980 or earlier.
Basically its a place where the signals are manually controlled.
Dave H. Painted side goes up. My website : wnbranch.com