how would the following 4 switch (1 crossover) and signals be numbered. i read the switch/signals are odd/even numbered.
consider crossover at milepost 14.7 and switch at right at milepost 14.1
greg - Philadelphia & Reading / Reading
"What are they being numbered for?"
The reason I ask is that can be numbered differently depending on the what context and who's looking at it.
For example, from the crew's persepective, its possible that none of the switches or signals in the picture are numbered. The manual switches might have the track number on the target.
From the dispatcher's perspective, only the powered switch will and the 3 signals will have a number (the dispatcher won't even know the other tracks or switches are there from his board), but only for use with the CTC machine and the crew won't see or know those numbers.
From the engineering dept.'s perspective probably everything has an audit number, but that won't be used by the crew's or the dispatchers.
Dave H. Painted side goes up. My website : wnbranch.com
please assume everything is powered and controlled by a dispather/CTC panel
There are a hundered different ways it could be numbered. Based on the way that signals were typically numbered, this is one option based on my experience. Signal numbers are in black, switch numbers in red.
NONE of these number would be in the field, there would be no number plates on any of the signal masts. This numbering would only be used by the dispatcher in his use of the CTC machine.
wow, that's pretty simple. so the numbering has nothing to do with location
i was hoping for something more methodical so that by seeing a switch or signal ID i could locate it easily on a layout or track diagram
here's another description
Signals in CTC territory controlled by the dispatcher have the prefix on the control machine L or R. This comes from the days when the operators were located in cabins along the tracks. As you might imagine L signals were to his left and R signals were to his right. When CTC began to be installed, L signals became westbound and R signals became eastbound. Most railroads list the tracks in their timetables as east and west, even though they may geographically run north and south. In the event that the tracks do run north and south, north becomes west and south becomes east. In conjunction with the L or R prefix signals are numbered evenly, 2, 4, 6, 8, etc. For example, a westbound signal at the east end of the siding could be labeled L88. The eastbound signal would be R88. Switches and electric locks are labeled with odd numbers, 1, 3, 5, 7, etc. so the switch at the east end of the siding would be 87.
i had thought the numbers come from mileposts and switches are parallel tracks might be 87, 87A, 87B
and that the L/R signal prefix is needed on a CTC panel
Like I said there are a hundred different ways to do number it. I have seen at least 4 or 5 generations of CTC panels from a half dozen vendors on a dozen different railroads. The dispatcher panels I was familiar with stopped having "left" and "right" signal indications on the diagrams 35-40 years ago when the dispatcher still had the big green and black panels. The majority of the dispatch offices I worked with had keyboards and computer terminal interfaces.
On a model railroad you have a very small number of switches. On a real railroad you can have a couple thousand control points and you can have a mp 14 on a dozen different subdivisions.
In my example the control point is the mile post, and the letter is the subdivision.
If you have a favorite prototype or method you want to number them, knock yourself out.
Intermediate signals that are permissive, that is allowing a train to pass it when displaying it's most restricted aspect and indication, usually would have a number plate. The number plate would usually correspond to the mile post location. Signals for westward or southward moves would use an odd number, eastward or northward signals would use an even number. For example, a signal installation at mp 153.5 might have the westward signal numbered 1535, the eastward number 1534.
Jeff
jeffhergertFor example, a signal installation at mp 153.5 might have the westward signal numbered 1535, the eastward number 1534.
looking at prototype CTC panels, it seems conventional that switches are typically labeled with even numbers and signals with odd numbers.
corresponding signal pairs (e.g. #44) facing west/east are controlled from a CTC panel switch moved to the left or right , L/R allowing west/eastward movement. only one signal indicates to proceed
looks like most CTC panels use no more than 2 digit numbers, either the switch or signal numbers run sequentially and there may be gaps in sequences of one or the other when there is no corresponding switch for signal and visa versa.
don't see how #s correspond to mileposts. not sure there's a correspondence between how levers on a CTC panel are labeled and actual switches and signals by the engineering/maintenance dept
Amtrak's THORN Tower panel looks like a non-trivial example
459
gregcnot sure there's a correspondence between how levers on a CTC panel are labeled and actual switches and signals by the engineering/maintenance dept
There isn't a unique switch number over the whole railroad. There is a unique combination of switch/signal number AND control point/station/interlocking.
For example on the UP there are maybe a couple thousand 'signal 11's, but there is only ONE CP A014 signal 11.
On a model railroad, since you only hae a couple dozen signals, you can number them sequentially. On a real railroad, that doesn't work as well.
On computer screen CTC panels you want 2 digit numbers because its faster to type in, and since you are only looking at the size territory that fits on the screen, you don't need larger numbers.
gregcdon't see how #s correspond to mileposts.
They don't. The only signals that correspond to mileposts are like Jeff H said, the intermediate signals that have a number plate and are automatic signals that the dispatcher does not control. Control point names/numbers may have a correlation to milepost on some railroads (but not all), but the switches and signals inside that control point do not.
Railroads have multiple layers of numbering depending on the purpose and who the audience is (for example most cars have 3 or 4 different "car type" codes : AAR letter designation, AAR modern code, mechanical class, system car type code). Same with signals and switches. In the vast majority of cases the crews will never know that switch 45 is switch 45. Only the dispatcher sees or uses that number. In the vast majority of cases the crews will never know that signal 84L is signal 84L. Only the dispatcher sees or uses that number.
There have been a few complicated interlockings or control points where the railroad has put up signs that number the switches the same as the dispatcher's panel to make it easier for the crew and dispatcher to identify which switch is which when the dispatcher instructs crews to put switches in hand operation. But the majority did not as of 2015 or before.
dehusmanOn computer screen CTC panels you want 2 digit numbers because its faster to type in, and since you are only looking at the size territory that fits on the screen, you don't need larger numbers
2 digit #s on manually operated CTC panels makes sense, otherwise the panel might be too wide, require 50+ columns
not sure if more than one CTC operator would be located in the same building because hardwired CTC panels and control lines need to be located relavitvely close. seems that model RR panels might have more than 50 switches
dehusman In the vast majority of cases the crews will never know that switch 45 is switch 45. Only the dispatcher sees or uses that number. In the vast majority of cases the crews will never know that signal 84L is signal 84L. Only the dispatcher sees or uses that number.
But the 45 switch has 45 painted right on it. Use it enough and you'll learn. Or maybe I'm weird.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.