Would you necessary use a signal for an industry siding such as a coal mine or a factory complex of some sort with a search light signal or a simple switch signal? I’m modeling transition era very loosely no specific prototype. I’ve taken a page from Howard Zane’s book as my fictitious railroad buys a lot of older equipment from various railroads of the day,and it generally span from Appalachia to the coal fields of Pennsylvania. I know many railroads like the B&O, N&W and PRR had signals specific to their railroads.
Guess I just paint the picture with a pretty broad brush
highly unlikely. it would be the crew’s responsibility to know that no trains were due before they came back out on to the main. they could consult their timetable or call the block operator or dispatcher for permission to use the main. the switch stand might have a target or light on it to indicate switch position and if the main was equipped with signals, then, the switch throw mechanism might be interlocked to cause the signal on either side of the switch to go red indicating that the switch was open.
I hope I can explain this clearly. First, as others have said, there would not be signals at the siding turnout itself, but, on many railroads with Automatic Block Signals, throwing a manual switch on the mainline that leads to an industry, will change the block signal indication for the mainline block.
For example, imagine a 3 mile long block of single track mainline with only one industrial siding about half way along its length. Your crew enters the block from the trailing point end and proceeds past the turnout, stopping to set out cars there. When you entered the block, signals at both ends went to red, or already were red for opposing traffic with APS. You know that the crack passenger limited is do in 15 minutes, so you throw the switch and back your whole train into the siding to clear the main. Even after you are on the siding, and out of the track circuit for the ABS, the facing signal will show yellow or red (depending on speed limits, railroad practice) and the trailing signal red until you align the switch to the main. Then the signals will go green.
You wait for the passenger train, it passes by. Now your brakeman throws the switch back to your route so you can move back out on the main. As soon as the points align to the siding, the facing block signal will go yellow or red and the
As usual, things were done differently in Japan - somewhat.
The switches to a couple of coal mines I ‘minefanned’ in 1960 or so were interlocked with the (manually operated, staff-and-ticket) signal system that controlled the route. Signals were controlled and switches were thrown by station agents, using large, counterweighted levers mounted on the station platforms adjacent to (but outside of) the station buildings.
The smaller mines had dwarf signals facing the sidings. The one large mine was connected like a branch line and had a full-size semaphore signal controlling entrance to the main track. The several switches within the mine complexes were purely manual, thown by the brakemen and not interlocked.
There is one notable exception: if the industrial siding joins the main at (or very close to) a signaled interlocking. Then it might be tied into the interlocking plant and get a signal (usually dwarf).
Your explanation is pretty clear so if I am understanding you correctly the actual signal that is changing is the one located on the main line and the siding it self most likely would have a simple switch stand. I had already installed some dwarf signals that i had laying around but have yet to power them up etc. I now plan on removing them and replacing them with switch stands. I haven’t decided on a “signal system” yet as it seems there is a lot to chose from. So far my evaluation is signaling is sort of a sub part of model railroading. It’s definitely not as simple as it appears. The type of signal, block occupation signaling, dwarf signals train order signals, targets, search lights, semaphores bla bla bla. Just knowing what type of signal goes where and then what type for your prototype and then what is the correct location for your period/prototype/specific signal is an undertaking and then to get it all working properly.Whew! looks like there’s going to be a lot involved in this. I often wondered what the big deal was when I watched these video’s of great model railroads when they made a big deal out of working signals on a layout. Now I know why it’s such a big deal.
Thanks for the input and thanks to the rest for your comments and input. I am now only a little less confused then before but for me thats a good thing.
That does happen, but usually only if it is absolutely forced. More often the siding will be extended so the turnout is beyond the home signals of the interlocking (although still in the approaches). When the hand-throw switch is opened it just causes a track occupancy in the approach circuit.
To have it within the interlocking limits is not simply a matter of adding a dwarf signal. The switch usually has to be powered, so considerably more expensive. The interlocking logic has to be expanded to include the new routing pairs, each direction separately. Depending on the complexity of the trackage in the area (crossovers, junctions, multiple tracks) that one siding might be able to link to half a dozen or more possible routes.
In certain cases, however, it can be advantageous to keep it within the interlocking limits. By getting a signal to enter the main track the train can now run at track speed if it is continuing in that direction. If it is entering by a manual switch, typically it has to run at slow speed until it reaches the next signal.
So it is just another typical case of a general rule with many exceptions. Somewhere on the railroad network there was probably at least one prototypical example of nearly everything, which is perhaps fortunate for modelers contending with compressed areas.
Whatever is being signalled I think that five things always apply:-
What the regulating authority/authorities require.
When the original equipment is put in and by whom (which RR). This involves actual and anticipated traffic.
Frequency/weight of traffic. This applies to both the Main and the siding. A quiet siding on an extremely busy main may get signalled (in whatever way) while a busy - for the line - siding on a quiet main may get little or nothing.
The cost of any installation whether it is put in with the original connection or later if/when traffic increases plus the cost of maintenance.
The cost of taking any installation out if traffic disappears. Sometimes where the installation is electric the wiring will be adjusted out-of-sight while the physical elements are removed.
There may be a 6th factor. If there are particular local issues, proximity to an interlocking being just one of them, then signals may, or may not, be provided.
For signalling in general life gets much easier when one settles on a RR company and date. Another thing that simplifies matters for small RR is to decide that they have bought in any signalling they have from Westinghouse or one of the other suppliers of “off the shelf” signalling systems.
It may also depend on the “siding”…Let’s say the U.S Steels Buzzards Roost coal mine is 5 miles up a hollow…In this case there may be a signal protecting the main line…I know of several examples where the main was protected by a signal where a mine spur entered the main.
More food for thought…The Spore Industrial has 2 signals protecting the crossing where SI crosses NS’s Sandusky main line at Col/San here in Bucyrus.This industrial branch serves National Lime Stone at Spore.
Yes, as others have also commented and elaberated on.
As you can see there are no simple rules, it is all based on the situation, the railroad and the time period.
For me as a freelancer, the fun part of signaling beyond using them for operation, is being able to be my own engineering department and simply design my own plausable system - who’s to say its wrong?
Yes, it can get pretty involved, especally if you model some of the more complex systems used over the years and want them to be correct.
Actually there are. Industrial spurs don’t have signals at the switch. 99.999% of the time that will be true.
More close to 90% of the time if you want to include mine load outs that is well off the main…Then you have urban and other industrial areas that can be well off the main line…These would have signals protecting the main by a absolute stop indication.There are thousands of such examples…
Dave, you obviously took my post completely out of context. I answered the orginal question VERY SPECIFILY, and was simply commenting to 2-6-6-6 about the obvious complexities of signaling in general.
“design my own plausable system” - The operable word here is PLAUSABLE, the statement clearly implies following “FRA (but I model a pre FRA era), industry practices, signal rules and common sense”. What it does NOT require is following the specific historical practices of lines like the B&O or PRR or other line that had their own complex or unique variations.
Sheldon,Every urban industrial branch I worked had a signal protecting the main line and we would use the call box (line phone) to let the local operator know we was ready to depart (say) Fisher Industrial.When he threw the switch we would get a slow approach on the pot (PRR for dwarf signal).
Here is an industry switch close to my house. ABS signaling on this line.
The box on the left headblock tie has a switch in it. There is a rod that goes from it to the track, and a conduit going out the other end.
When the switch is turned, it sends a signal to the system and the two close by signals drop to red. (Maybe it interrupts the circuit, I’m sure exactly how it works.)
Some switches also have a facing-point lock. To turn the switch, you need to press on the pedal, then go and turn the switch (and hope the pedal doesn’t spring back up on you). Many mainline switches have the locks as extra protection, especially on higher speed lines.
I think this one is clamped closed. There were track machines tied up on the siding when I took the picture.
Larry, I understand, and don’t disagree. The difference here may be “industrial branch” versus “indivdual industry”.
The difference being an “individual industry” siding may only hold a small local at best (as in my orginal example) whereas an industrial branch may go miles from the main line (as in your mine branch example).
I would expect a “branch line” to be interlocked where it joins the main, but not a one or two industry siding that is likely completely right along the main.
I also realize that some railroads, like the PRR, went to great lengths to NOT put industrial sidings right off the main, do to their high traffic levels. This is a whole nother aspect to this that also varies with era, locale and railroad.
But, 2-6-6-6 was not asking an era or railroad specific question, so he got mostly generic answers, which seem to be more than enough for him at this point.
All the answers were good but zugmann does make a good point. If the indusry track happened to be within the boundries of an interlocking plant it would possbily have a signal on the spur.It was avoided as much as possible but sometimes could not be avoided. Usually the RR would avoid it by running the spur off a noninterlocked siding or just outside the interlocking limits. When I was in Kentucky recently I found a few coal mines that had track coming off the mainline with a wye. I recall one that had a dwarf signal but it was on a mainline siding that happend to be connected to the wye that led to the mine.
