Just a quick question about signaling. Is there any websites or books that will give me some info on modern signaling? I’m wanting to add signals to my layout but I don’t know much about it. Somehting that will tell me where signals go and what the signals mean.
Have a look in the Electronics and DCC forums on this site, there are a couple of threads there with some good links.
cheers
For a good generic description of signals try this page.
You can start here:
http://www.waynes-trains.com/site/Signals/Model-Railroad-Signaling.html
HI
The links from other posters are good; you may have to read them a couple of times to fully understand what is needed. There are multiple types of signalling systems and I can tell you a little about ABS and CTC over ABS ( Automatic Block Signal; Centralized Traffic Control ).
Signal placement is the fun stuff. The main line is broken up into blocks with what is called Intermediate Signals protecting each end of said block. Where there are passing sidings, junctions, diamonds and maybe a draw bridge or two, the signals that are placed in those locations and are called Control Points. Control Points control something that protects the main and allows ( in the case of a siding ) a passing move. Junction is something like a automobile traffic light which allows movement from one direction or the other while protecting that movement. A bridge usually doesn’t have a turnout, but is protected if by chance the bridge is up or open. Diamonds are static, but both routes are usually signalled to prevent two trains on them at the same time.
So now for the big question you must ask yourself. How in depth do you wish to go? A fully signalled main line can be spendy; and not just for the signal mast and heads - you need detection, turnout logic and some sort of logic or application to monitor what is happening and forward that information to the signal system. Bruce Chubb has/had a working system using TTL/CMOS logic IC’s which got pretty complicated. Nowdays with JMRI (and others ) you can communicate with your railroad via computer and there are modular detectors along with turnout logic included with the switch machine. You still need
As has been said before there is a lot to signalling. The basics have been mentioned.
Automatic block signal systems (ABS) have signals that indicate track occupancy and condition, but do not convey authority (with a couple exceptions). There is a variation called automatic progressive blocks (APB) that is ABS with enhancements. It is so common on prototype railroads that pretty much any railroad that has ABS has APB. If you have just ABS then you will need train orders, track warrants, DTC, etc. to give trains authority to move. all the switches are manually controlled.
Centralized Traffic Control (CTC) has manually, remotely controlled signals and switches at certain locations (siding ends, junctions, etc) called control points with ABS in between. In CTC signal indications convey authority to operate on the main track.
The physical arrangement of signals differs between CTC and ABS. At the end of a siding there will be different numbers of signals, in different locations between CTC and ABS. In CTC you will have three masts, three signals, each governing an entrance to the siding switch. In ABS all you may have is one mast, past the points of switch on the single track, with a signal head in each direction.
In addition to those, there are also interlocking signals, which are very similar to CTC control points, but control a relatively small area of one junction. If its just a crossing, with no other routing possibilities, it may even be an automatic interlocking with no manual control.
You will have to decide how complicated you want to go. Some people install signals just to be switch position indicators. Other install the full detection of switch position and track occupancy . Others install full CTC. One consideration is how many blocks you will have, with a block being the track between control points or
Depends too on what era you are modeling.
The GRS machine controlled turnouts and signals within the confines of the interlocking plant.
Signal levers were to the right and left of the row of levers, and were painted red. Those levers on the left controlled all movements across the model board from left to right, those on the right, right to left.
In the middle were the switch levers usually painted black, crossing gates painted yellow and derails painted blue.
In the old US&S “Armstrong” days tow levers were needed to move the switch. The first moved the switch points and the second locked them. If they would not lock you would have to go down to the roadbed to clear ballast, ice, or whatever was blocking the switch.On the GRS machine, the lever would only make half its travel, and then when the points were locked you could finish the movement of the lever, which you had to do before you could move the next lever.
Once the plant was properly aligned, then, and only then could a permissive signal be displayed.
If you can see a tower nearby then what you are looking at is probably an interlocking plant. It is protected by signals on all tracks approaching the plant. Today such things are all computerized from a central control place, perhaps in Ft. Worth if you are lucky, or maybe in Bangolore, India, if your railroad has gone cheap on you.
In the time period that the LION models, the GRS machines ruled the BMT and were common on about half of the IND. The IRT mostly used US&S pneumatic machines. Even into the 60s and 70s there were a few US&S Armstrong machines still in use on the IRT and BMT.
thanks for all the info. I’ll be reading up and figureing out how I want to do my signals. I’ll be modeling an Area here in GA near where I live.