I have installed a signal bridge on my HO DC layout but without the controling board and photo cells. Consequently, the lights (red, yellow & green) are sort of hard wired with yellow and green being turned on. If I want to improve my operation it will be necessary to learn more regarding the lights, the various combinations and the associated meanings. I have been searching for material on this but so far have come up empty handed.
Anyone have any ideas?
All you ever wanted to know about Railroad Signaling:
http://www.qbookshop.com/products/149727/9780760338810/Railroad-Signaling.html
There are different kinds of signals. A signal tower like that guards the entrance to an interlocking plant. The aspects of this kind of signal are:
Normal = RED
Diverging Route Aligned = YELLOW
Clear Route Assigned = GREEN
If it is a double headed signal, the top set is usually the BLOCK Signal (if the train is running in Block Signal Territory) and the loser head is the home signal through the plant.
Beyond these, it gets more complicated, and requires that signal book, or the operating rules of the railroad that you are modeling.
LION connects his signals to the tortoise switch machines, so a diverging route displays YELLOW, and a clear route displays GREEN, If approaching from the other direction the signal is RED if the switch is lined against your movement, YELLOW if you may move it from the diverging track, or GREEN if you approach from the normal direction.
My tower represents the 242nd Street / Van Courtlandt tower, and there I also have levers to directly control the home signals.
If you have some switches on the fascia to control your turnouts, it is a simple matter to add some switches to control the signals. In this case, switches in the down position represent turnouts in the NORMAL position, and signals in the RED position. Use RED switches for signals and Black switches for turnouts.
ROAR
You can also get some good info at this link:
http://www.waynes-trains.com/site/Signals/Model-Railroad-Signaling.html
Check out this website. Lots of good info.
http://www.lundsten.dk/us_signaling/index.html
Also, I have a pamphlet published by Kalmbach called “All About Signals” which is a reprint of articles written by John Armstrong in the June and July 1957 issues of Trains magazine. This would be a great candidate for a digital download. Lots of good info for the model railroader.
Interlocking signals - like where a branch line diverges from a mainline - often use two (or more) headed signals, whereas block signals are more often single headed.
So if you’re running a train approaching a switch where the branch leaves the main, a signal indication of green on the top signal and red on the bottom means your train is clear to continue on the mainline. Red-over-green means you’re going to go onto the branch line.
Red-over-red means STOP!!
In fact, since red-over-red always is an “absolute stop” (as opposed to a “permissive stop” sometimes indicated by block signals, where a train can proceed past the signal at reduced speed) railroads sometimes add a “dummy” 2nd signal that only shows red where you would think they could just use a one-head signal…like at a junction where two railroads cross each other but don’t have a way to go from one railroad to the other.
The signals are “interlocked” so that only one track can show a green-over-red “proceed” indication. The other track has to have a red-over-red “stop” indication. That way you can’t have two trains trying to occupy the crossing at the same time.
If it is not all red then it isn’t red at all
Unless you have a stop and proceed at restrictive speed…
You can have a track form from the dispatcher that reads :
To:MPPI" At CP Horn
3/1/93 @ 7:55 Pm
Permission to pass the stop indication at East CP Horn at restrictive speed looking out for the train ahead…"
Pittsburgh West Dispatcher Browning.
Thanx a bunch guys for all that input. This is far better than I could have imagined especially after the dismal results I got from doing searches. I have no doubt I will be busy for some time digesting the info.
Thanx again.
That is actually not true at all on any North American railway.
With a single head signal, Green = “Clear”, Yellow = “Approach” (prepare to stop at the next signal), and Red = either “Stop” or “Stop and Proceed” depending on the signal’s configuration and the current rulebook,
If the signal has multiple heads, you cannot read the individual heads separately. The entire combination of colours makes up the indication.
This site has a collection of various sets of signal indications from different rulebooks:
http://www.railroadsignals.us/rulebooks/rulebooks.htm
There are some differences between the different sets of rules/indications, so pick one and follow it. (If modelling an actual railroad, find the actual rulebook that applies to your railroad. If freelancing, choose one that is appropriate - either from a nearby railway or one that makes the most sense to you.)
With a single head signal, Green = “Clear”, Yellow = “Approach” (prepare to stop at the next signal), and Red = either “Stop” or “Stop and Proceed” depending on the signal’s configuration and the current rulebook,
If the signal has multiple heads, you cannot read the individual heads separately. The entire combination of colours makes up the indication.
Well, then, you have not yet read the NYCT rule book. The bottom head shows the direction of the switch, and the upper head shows the status of the block.
Green over Yellow = Clear on diverging route.
Yellow over Green = Approach on normal route.
Stop is always displayed as Red over Red.
Most signals on NYCT are block signals which indicate:
Green = Clear and next signal is permissive;
Yellow = Approach prepare to Stop at next signal
Red = STOP. Your timetable will tell you if you can “key by” the red signal, in which case your speed may not exceed 10 mph, and you must be prepared to stop within half of your range of distance.
HOME SIGNALS are controlled by the the tower. The lower head indicates the alignment of the switch, and the upper head is an automatic block signal, which will display RED until the tower clears the home signal.
At an interlocking plant without a block signal the aspects are:
RED = Stop and STAY
Yellow = Approach (as you said) but would only be displayed if diverging routes were set up.
Green = Clear. Your train is clear to pass through the interlocking plant on its normal track.
The signal levers in a GRS plant have two positions RED (normal); and NOT RED (lever pulled). The aspect of the NOT RED signal is determined by the position of other levers in the interlocking machine.
Thus is the Reality expressed by the LION: Your reality may vary.
Lion offers a 100% money back guarantee on his information. If it is not correc
Is that a subway system? That sort of scheme is totally different than any above-ground freight railroad signalling.
If you are modeling the NYCT then Lion may be correct. If somebody is modeling anyplace else then Lion is definitely incorrect. Location, location, location.
Also one has to be careful about what means about stop signals. There are stop signals and there are absolute signals but there is no “absolute stop” signals. Most of the time when somebody talks about an 'absolute stop" signal they really mean a stop signal in CTC or at an interlocking or possibly a stop signal not in ABS territory.
A stop signal in block territory (Not NYCT, but maybe on LIRR) means stop and proceed. (This is indicated by the presence of a number plate, IIRC)
But a home signal is controlled by an interlocking plant, and the signal lever in the interlocking plant has only two positions: Normal or Reverse. A signal lever in the NORMAL position displays a RED signal. An absolute stop and stay signal.
Once the interlocking plant is properly aligned for a particular alignment, the signal lever becomes unlocked and can be pulled to clear the signal. The aspect of such a signal may be determined by the other lever arrangements that set up the route through the plant.
Where am I wrong on this?
ROAR
Absolutely not.
A stop signal in any territory means just that, stop.
A stop and proceed signal means stop and proceed.
Two completely different signals. Two completely different actions.
Switches have “normal” and “reverse” not signals.
A signal is cleared for a direction or not. Until the route is requested and cleared the signals may be stop. Even after the signals are requested the signals may be stop.
There is no such thing as an "absolute stop and stay "signal. Just stop. In every case there is a rule that covers moving a train past a stop signal. In some cases the crew can get themselves by a stop signal, in other cases they need authority from somebody else.
Just kind of curious. Are the rulebooks uniform regarding signalling across the Country (or continent)? Or are there variations between individual railroads?
There are all sorts of differences. Everything from what the signals are indicating (route vs. speed) to physical arrangement (semaphore, position light, color position light, color) to variations by era (stop and proceed is now restricting on many roads). Some rule books have separate signals for block systems (ABS, CTC) and interlockings, others combine interlocking and block signal rules.
There are general concepts that apply everywhere, stop means stop, approach is normally the same and the signals generally instruct the train to incrementally reduce the speed of the trains to make sure they are at the proper speed to pass through restricted track or routes or to be able to stop prior to passing a stop signal. Generally, there is only one indication that does not allow the train to proceed (stop) and only one that allows the train to proceed without restriction (clear). Every other signal allows the train to proceed, with some sort of restriction.
If you want to know specific details, your best be is to get a rule book for the railroad and era in which you are interested.
What appears to be a RED signal may not be a “Stop and Stay” signal. The presence of a number plate on the signal is part of the aspect of the signal. It may, depending on the railroad, actually mean "Stop and proceed at restricted speed, prepared to stop at any obstruction.
Yes, switches have normal and reverse. SIGNALS also have levers in the tower. This lever is interlocked with the other levers in the machine. It cannot be pulled until there is a clear route aligned through the plant. Once a route is available the signal lever may be cleared and the train can proceed.
The signal lever has two positions: “Normal” and whatever you want to call the other position. I called it “Reverse” because it keeps the language in the tower simple and understood. You can call it something else if you like.
On my layout, Lever 3 controls the signal on the northbound track at Dyckman Street. In the NORMAL position the signal reads RED, and it means “STOP and STAY” The motorman cannot “key-by” this signal. The Track Stop is raised and any train that tries to pass it will be tripped.
When I clear this signal the train can proceed to 242nd Street, which is the last stop on the line.
Lever 1 controls the inbound switch at the 242nd Street crossover. In the NORMAL position the train would enter the station on track 1. If this lever is in the REVERSE position the train would enter the station on track 2.
Once Lever 3 is cleared for a train movement, Levers 1 and 2 are locked and cannot be moved until the train is in the station and Lever 3 is released to be returned to the normal position.
If the Switch controlled by Lever 1 is in the normal position the signal at Dyckman Street will be Green over Green. If Lever 1 is reversed, the Dyckman Signal will display Yellow over Yellow.
That is the way it works on the Subway.
ROAR
There are as many different signal aspects as their are railroads. More or Less. The engineer and conductor must be absolutely qualified on all signal systems on the railroads they are certified to operate trains on.
An AMTRAK crew operating between BOSTON and NEW YORK must know the signal systems used by Metro-North, they must also know and be qualified on the NORAC rules. They also must know any rules in effect on railroads in the Boston area if those are different from the NORAC rules. The NORAC rules are uniform rules established by a consortium of railroads operating in the North East.
The NORAC rules specify the various aspects displayed on these railroads… BUT these railroads are made up of many different predecessor lines using all different kinds of signaling equipment including PRR POS signals; B&O POS signals; searchlight signals; and many more.
Other railroads have other rules. I suspect that the basic aspects are pretty much the same, but they certainly do have differences.
ROAR