Modeling the B&O in the 50-60's
In general, dwarf signals are used on secondary lines like passing sidings or in low-speed areas like switch yards.
BTW don't confuse them with signal indicators, which show say green when the switch is routed for the mainline or red when routed for a diverging route. Dwarf signals are used as block signals or interlocking signals. The signals above in UpNorth's example are probably interlocking signals since they have two heads (interlocking signals generally use two or more heads, whereas block signals are often just one head) and are at a junction where it appears two lines (perhaps a mainline and a siding) come together.
Red over Red means either the route ahead is occupied, or the turnout is thrown so that the train can't go thru it without derailing.
Dwarf signals are used for sidings, passing tracks, and some yard tracks as described by Stix. For signals on the mainline, they should be the standard size. The locomotive should not pass them when a "stop" is indicated, so just place them to make sure the loco or equipment will clear and not foul the other track when stopped.
Different RR's use different types of signals, so you should do some research on what types are around and what you want to use. Try this site for reference-- http://www.railroadsignals.us/
Even though you only want to use them for turnout indications doesn't lock you into that. As your layout and electronics progresses, as long as the signals are correct for the location and in the right place, you can always connect their wires differently to serve a different purpose later on.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
KidatHeart06 wrote:... Great site! Thanks. George
... Great site! Thanks. George
Guess where the picture came from !... All I know is it was a dwarf, the only one I found on that site.
My Digitrax signals are more Nscale. I'm running HO so I set up the signals low and just go with the flow.
KidatHeart06 wrote:I plan on having some dwarf signals for my turnouts. Newbie Questions: Where should I put them? How far up or down the track should they be? On just the Mainline? Or on the diverging line as well? I'm pretty much going to run the trains in one direction, so do i only need it/them facing one way? I may or may not have Block signals at some point in the future. Thanks for any advice! George
Signals protecting a powered turnout in a Centralized Traffic Control system application must protect ALL entrances to the turnout -- there are three entrances.
Signals protecting an interlocking plant must protect ALL entrances to the interlocking plant -- but not necessarily turnouts within the interlocking plant.
Signals at the end/beginning of signalled territory, e.g., the exit from a yard, must protect only the direction for trains moving into signaled territory.
Distant signals, which are outside of signaled territory and only indicate the indication of the block signal ahead, are one-way signals only for trains approaching the block signal ahead.
Intermediate signals between control points on single-track railroad are often offset from each other in order to improve sight distances or because they follow a wiring scheme (now obsolete) called Overlap Signaling. However, with rare exception, and except in Overlap, intermediate signals always come in pairs, even if they're offset. (A control point is a power turnout in CTC, or a controlled interlocking plant, or a hold signal.)
Signals in ABS (trainorder) territory were usually 100% mast signals. Two schemes exist, one where there is a pair of signals just outside the points of the turnout, and a "full offset" scheme where there are three signals, one at each entrance to the turnout, just like in CTC. There are some instances of full-offset ABS using dwarfs on the siding.
Double-track railroads that were signaled were signaled one-way only, current of traffic. A train running counter-current had no signal protection and either carried a track permit giving it the entire railroad between control points, or ran at restricted speed. Historically a double-track railroad was a current-of-traffic railroad whereas a railroad with CTC signaling and more than one main track was "multiple main tracks." This distinction has disappeared from recent revisions of railroad operating rules, in part because current-of-traffic double-track is disappearing from the scene. I've never seen a double-track railroad equipped with ground dwarfs but some had dwarfs on bridges or cantilevers. You'll often hear of a double-track railroad as "251 territory" or "D-252 territory" in reference to the operating rules that governed.
Different railroads have different standard dimensions for the offsets between turnout points and frogs and the location of the signal, and practices vary with time, and there are exceptions. In common practice today, the signal protecting the single-track entrance to a turnout is placed 45 feet from the points of the turnout (I think you could cheat this down a lot on a model railroad). Historically it was as little as 10 feet. The signals protecting the frog-side entrance to the turnout are placed not nearer than the fouling point.
Dwarf signals are used for two major reasons: because they don't impinge on clearances, and because they're cheaper than a mast signal. Mast signals today require minimum 20' track centers. Historically, railroads allowed as little as 18' track centers for mast signals, but since track centers historically were often 14 feet or even a little less, the installation of a signaling, as well as the right-hand signal rule, meant that in order to equip a siding the ends had to be thrown out to get a signal between the track and still have adequate clearance. (Until approximately 1960, all signals had to be placed to the right of the track they governed.) The dwarf signal got around this problem. Most -- but not all -- railroads would not use a dwarf signal for a main track because it is more likely to be damaged or obscured by drifting snow, sand, or weeds, or ballast pushed up. So for a typical siding on railroad that allows a dwarf on the siding (we'll pick east-west orientation for convenience), the east end of the siding would have a mast signal outside the main track (right-hand to the main track for an eastward train) and a dwarf signal between main and siding (right-hand to the siding for an eastward train). The west end of the siding would have a dwarf outside the siding (right-hand for a westward train, and a mast signal between main and siding, with the siding bowed out around the mast signal. The entering signals on either end of course would be right-hand outside the track.
Railroads that used dwarf signals on the main track included Kansas City Southern.
Today dwarf signals have fallen out of favor because of the vandalism and visibility issue, and the preference is to erect a signal bridge or cantilever to get around the clearance issues that occur.
FYI, there's no difference between a siding and a passing track. The preferred terminology is siding.
RWM
Hi KidatHart06
If its point indicators you want make sure thats what you get they will have a red green indication facing both ways
They show green when the points are set normal ie for the main line and red when set in reverse ie for the siding or secondary route iether of these routes may or may not be straight depending on what set of points they are.
Point indicators are located oposite the front spreader bar of the set of points this stems from the mechanical days when thats what drove it, from the model point of view in line with the point spreader/drive bar is close enough to the right place.
Make sure when the indicator is wired in that it gives the same indication facing both ways and that the indicator is installed on the side of the track that a signal would be installed.
Signals and point indicators are not the same thing what a signal aspect indicates the driver must do, a point indicator only says this is the way the points are set it gives no Authority to do anything.
Remember you will not allways be on the same side of the set of points during an operating sesion so make sure the indications are correct or it could get expensive after the derailment you did not plan.
regards John Busby
No a point indicator is one unit with indicator lights facing both ways.
So as you approach the set of points from the facing direction (the toe of the blades) the indicator will be in your case on the RH side.
Remember its an indicator not a signal so the set up is slightly different.
Hope this clears things up a bit.
Now that you have a bunch of information you have to make some decisions.
Are you modeling a prototype arrangement or are you modeling something for your model railroad? About 75% of the signal systems discussed on this list end up being model railroad devices rather than functioning signal systems.
You also have to indicate whether you are indicating route or switch position. Switch position is purely binary (normal or reverse). Route really has four options: Trailing point move switch lined for the route, trailing point move switch lined against the route, facing point normal route, facing point diverging route.
If you are modeling a CTC system you need 3 "heads", one for each route into a turnout. If you are using the signal head as a switch indicator, then all you really need is a head for each direction the switch can be viewed. Putting in all the signals may be cool, but if they face away from the operators where the operators will never see them, they are a waste and defeat the entire purpose of installing them in the first place. So if the switch is running parallel to the edge of the layout, you can approach it from the right or left so you need a signal facing each way. If the switch is on a track deep in the layout and you can only view it from essentially one angle, then all you need is one head.
One other option is to mount a bicolor LED near each switch that shows green for normal and red for reverse. That would simulate a switch stand lantern (which is basically a switch indicator). Since the LED would point up, it would be visible from all directions.
Dave H.
Dave H. Painted side goes up. My website : wnbranch.com
How's this for a dwarf close to a turnout... This was taken this week at a yard a walk away from my house. It's a yard to mainline acces.