Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Which Direction To Install Signals

16313 views
45 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Tuesday, June 1, 2010 5:06 PM

firstbelt

richhotrain

...

Incidentally, since my new layout will be "based upon the prototype", I need to select a time period to model, and it will be some time between the late 1940's and the early 1950's, so let's say 1948-1954. ...

Rich

You could try to pick up a book of operating rules at a train show, or find a website for a railroad's historical group.  That would give you a few ideas and historically accurate info.  The operating rules show signal aspects that an engine crew would encounter, and what they mean.  There are usually special applications spelled out, too.

Seems like you settled on searchlight signals; there are also semaphore and color position light signals.  Semaphore signals could have a lighted indication; I used to enjoy seeing them at night on the old Erie main across western New York.  That would give you something visible on the layout from either direction.  B&O and PRR had different types of color position light signals.

A railroad might have signals to indicate just block occupancy; most of the discussion so far has been about interlocking signals.  Interlocking signals need to be located outside the interlocking (in advance of switches), to allow an opposing move to cross in front of a train stopped for a stop signal.

When I eventually get a layout built, I hope to have control panel indications in addition to wayside signals.  A control panel would give you a way to "see" the signal operation.

One reason that I am considering searchlight signals is because I have so many of them on my current layout.  Another reason is that I am planning to model the area between Dearborn Station and Alton Junction in Chicago.  I want to emphasize the Santa Fe operations.  From Alton Junction to Dearborn Station, the Santa Fe used the C&WI tracks and the C&WI used a lot of searchlight signals and signal bridges.

Rich

Alton Junction

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Tuesday, June 1, 2010 5:09 PM

dehusman

richhotrain

On the prototype, where and when were single searchlight signals used versus double searchlight signals?

In my circumstances, if I am merely using searchlight signals to indicate the position of the turnout, would I always use single searchlights?  Or, how offensive would it be if I used double searchlights for crossovers and single searchlights for simple turnouts?

Searchlight signals are just a type or style of signal, they mean the same thing as any other type or style of signal in the same configuration.

The number of heads depends on the indication being communicated.  Normally multiple head signals are used where a train leaves a main track and goes to another main track or siding.  At a siding switch in CTC there would be 3 signals.  On the main track on either side of the switch and one in the siding.  All the signals would face away from the switch.  The signal on the main track closest to the points of the switch would have 2 heads and all the rest would have 1.

At a crossover in CTC there would be 4 signals, two on each track, one on either side of the crossover, all facing away from the crossover.  The signals closest to the points of the switch would have 2 heads and the signals on the frog ends of the crossover would have one head.

At interlockings it was common to have signals with 2 or 3 heads.

Switches to industrial spurs and yard tracks normally do not have signals.

Dave,

On my planned layout, Alton Junction to Dearborn Station in Chicago, when the Santa Fe (using ICRR tracks) crosses the C&WI tracks and the PRR tracks, there is a 3 head searchlight signal at the interlock, per your indication above.  What would be the function of each one of the three heads?

Thanks.

Rich

Alton Junction

  • Member since
    September 2003
  • From: Omaha, NE
  • 10,621 posts
Posted by dehusman on Tuesday, June 1, 2010 6:22 PM

richhotrain
On my planned layout, Alton Junction to Dearborn Station in Chicago, when the Santa Fe (using ICRR tracks) crosses the C&WI tracks and the PRR tracks, there is a 3 head searchlight signal at the interlock, per your indication above.  What would be the function of each one of the three heads?

The classic model railroader answer is that the top light applies to the main, the next light to the next track or switch over and the bottom signal to the next track or switch after that.  That is wrong from a prototype perspective.

All three lights have to be read as a whole.  The 1975 ATSF rules do not show any 3 head signals, so they must be operating on C&WI rules.

Basically all lights other than the top one red indicates that the train will remain on the same route.

The top light red and various combinations of yellow, green and lunar on the bottom two lights indicate the train will take a diverging route, the more yellows and lunar, the lower the lights are the slower the speed through the diverging route, the fewer the yellows and flashing yellows, the higher the speed.  In order to know what specific signals are indicated, you'd have to know what the tracks looked like beyond the interlocking ans what the speed was on each of the routes.

 

Dave H. Painted side goes up. My website : wnbranch.com

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Tuesday, June 1, 2010 7:14 PM

dehusman

richhotrain
On my planned layout, Alton Junction to Dearborn Station in Chicago, when the Santa Fe (using ICRR tracks) crosses the C&WI tracks and the PRR tracks, there is a 3 head searchlight signal at the interlock, per your indication above.  What would be the function of each one of the three heads?

All three lights have to be read as a whole.  The 1975 ATSF rules do not show any 3 head signals, so they must be operating on C&WI rules.

They may be operating on ICRR rules because ATSF trains use the ICRR tracks to cross C&WI at Alton Junction.

I don't know how well this can be seen, but here is the interlock schematic at Alton Junction:

At the lower right, the SF tracks can be seen joining the IC tracks, then crossing the C&WI four track main line and the PRR tracks, then continuing through to the C&WI tracks beyond the interlock.  The 3 head searchlight signal can be seen above and left of the interlock

Rich

Alton Junction

  • Member since
    October 2008
  • From: Canada
  • 1,820 posts
Posted by cv_acr on Wednesday, June 2, 2010 3:16 PM

I don't know any about the location you're talking about, but under Canadian rules, 2 head signals at interlockings allow for Slow speed indications, while 3 head signals allow for Medium and possibly Limited speed indications, since under these rules signal indications include speed. Since the rules are different between railways, your mileage may vary.

A nice way I've heard it simplified is "All Red = STOP, anything else = GO but the more yellow lights or the farther down the pole it is the more restrictive the speed indication". Obviously a gross oversimplification for someone who wants to build signals, but sufficient for a fairly green _model_ train crew who doesn't know the 30 possible signal rules.

Like Dave H. says, the individual heads on any signal do not have any meaning on their own. The entire combination gives a specific instruction.

  • Member since
    April 2007
  • 55 posts
Posted by bladeslinger on Thursday, June 3, 2010 10:47 PM

signals are placed on the right hand side of the track whenever possible, and partly due to the fact that most railroads have locomotives that have the engineer operating on the right hand side fo the locomotive.  also in many places where operating in multitrack territory often the right hand track is assigned as the "normal" running direction, with the other track being "right" if you were coming from that direction.  nowadays a lot of this type running has been done away with, and it's typical to be running from the left hand track.

if the signals are ground based, then in double track territory you might have one on the left and one on the right, but if they're mounted on an overhead signal bridge, then generally the signal is placed directly above the track it governs, toward the right hand side.

if you were to encounter a situation where you have more than one track but not all are signalled, then the signal would generally be on the right hand side with what they call "doll masts" to indicate how many tracks you "skip" in order to determine the track signalled by the mounted signal.

Southern Gives A Green Light To Innovations! Southern Serves The South! Music links: http://www.myspace.com/afterliferock http://www.facebook.com/pages/AFTERLIFE/51753659017 http://www.reverbnation/afterlifemusic
  • Member since
    April 2007
  • 55 posts
Posted by bladeslinger on Thursday, June 3, 2010 10:51 PM

looks like a new installation that isn't in service yet.  once they're activated, they'll be rotated facing opposite each other

Southern Gives A Green Light To Innovations! Southern Serves The South! Music links: http://www.myspace.com/afterliferock http://www.facebook.com/pages/AFTERLIFE/51753659017 http://www.reverbnation/afterlifemusic
  • Member since
    February 2002
  • From: Mpls/St.Paul
  • 13,892 posts
Posted by wjstix on Friday, June 4, 2010 3:39 PM

 In the time in the OP's original question (1940's-50's) I don't believe the use of flashing singnals had started yet (many locations still had semaphores afterall). Also the use of multi-head signals to give speed indications wasn't around then either AFAIK.

That's always a problem with any area of model railroading when you're recreating the past, whether with buildings or roadsigns or signals or what have you...you always have to be careful not to assume that they way things are now are the way they would have been in the past. Smile 

Stix
  • Member since
    October 2008
  • From: Calgary
  • 2,047 posts
Posted by cx500 on Saturday, June 5, 2010 12:05 AM

 Flashing lights may or may not have existed, but I am certain there were masts with two semaphores (heads).  They could still be found in Marias Pass on the BN in 1973 at Nimrod (later Java East) where the double track became single for a bridge.  They were obsolete technology even then, and would likely have dated back at least to the 1940s.

Surviving semaphores in recent times have probably been intermediates which only need a single head.  If anything fails in the old machinery, the train can still proceed with minimal fuss.

"That's always a problem with any area of model railroading when you're recreating the past, whether with buildings or roadsigns or signals or what have you...you always have to be careful not to assume that they way things are now are the way they would have been in the past." 

John

  • Member since
    September 2003
  • From: Omaha, NE
  • 10,621 posts
Posted by dehusman on Saturday, June 5, 2010 6:34 AM

Technically the signal has nothing to do with the crossing.  If you will notice all the signals governing movement of trains from left to right are sublettered "R" and all the signals governing movement from right to left are sub lettered "L".  The switches are numbered, slip or double slip switches have more than one number (for each set of points).

The signal you are referring to is 32L.  So it governs movement of a train entering the terminal and sets the speed of the train going through those multiple slip switches.  It is a triple head signal so it can display a very restrictive signal such as "slow speed" R over R over G or "medium" speed R over Y over R.

Dave H. Painted side goes up. My website : wnbranch.com

  • Member since
    January 2007
  • From: Eastern Shore Virginia
  • 3,290 posts
Posted by gandydancer19 on Saturday, June 5, 2010 3:23 PM

 I see that you are getting a lot of answers and advice.

Signaling can be complicated or simple on a model RR.  However, you need to know the basics so you can decide how simple or complicated you want to make yours.  I will try and keep things simple for you.

Different RR's use different signals.  Remember there are always exceptions, but Western roads used searchlights and Eastern roads used three separate lights per head.

In the steam and early diesel years, signals were on the right side only.  So there were two signals on each side of the track for a single line that was traveled in both directions.

Two signal heads on one mast were used: 1- when coming to a place where the track branched, except for dead end sidings.  2- Also when entering a yard where there were no more signals, (a signal was located there to tell you that. (restricted speed)).  3- At a draw bridge there would be a signal with two red indications.  4- Where two or more tracks crossed each other.  The rest of the signals could be a single head on one mast.

There are no RR signals that just showed green for straight and red for diverging routes at turnouts.  There were illuminated switch stands that showed this, but not signals.

Try this link:
http://mysite.verizon.net/vzescsbb/HO_MRR/Signals/Signals_getting_started1.html

This is going to be more information that you want, but use just the parts you want.
When you decide what RR's signal system you want to use, look up their indications (called Aspects) on the Internet.

For my layout, set in the East, I decided to use C&O type signals.  C&O had some signals with three heads, but I decided not to use more than two heads on a single mast.  Because it is MY railroad, I can do that.

I hope this helps cut through the information you have received.

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.

  • Member since
    February 2002
  • From: Mpls/St.Paul
  • 13,892 posts
Posted by wjstix on Saturday, June 5, 2010 6:17 PM

cx500

 Flashing lights may or may not have existed, but I am certain there were masts with two semaphores (heads).  They could still be found in Marias Pass on the BN in 1973 at Nimrod (later Java East) where the double track became single for a bridge.  They were obsolete technology even then, and would likely have dated back at least to the 1940s.

 

Actually, three head semaphore signals were common 75+ years ago. My point was that the use of two heads solely to indicate speed, and not track routing thru an interchange, seems to be fairly new (like in the last 20 years or so). In forums like this, working railroaders have mentioned how two- or three-head signals indicate speed, I have books on signals and railroading going back to the thirties and had never heard of that until reading about it on these forums. 

Stix
  • Member since
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Saturday, June 5, 2010 6:45 PM

 Back to the original post. If you can't see the actual lights when operating, simply use dummy signals with no wired lights.  What good are they if you can't see them anyhow?  Try to position any lighted one you do install correctly and in a way that can be observed/showed off.

Springfield PA

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Monday, June 7, 2010 11:06 AM

dehusman

Technically the signal has nothing to do with the crossing.  If you will notice all the signals governing movement of trains from left to right are sublettered "R" and all the signals governing movement from right to left are sub lettered "L".  The switches are numbered, slip or double slip switches have more than one number (for each set of points).

The signal you are referring to is 32L.  So it governs movement of a train entering the terminal and sets the speed of the train going through those multiple slip switches.  It is a triple head signal so it can display a very restrictive signal such as "slow speed" R over R over G or "medium" speed R over Y over R.

Dave,

A continuing thank you to you for the information you have provided, especially the info on the actual signals shown in the diagram. That will be invaluable to me.

I don't want to slight nyone else who has also contributed here to my knowledge about these signal systems.  Thanks again to all who have contributed here.

Rich

Alton Junction

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Monday, June 7, 2010 11:08 AM

gandydancer19

 I see that you are getting a lot of answers and advice.

Signaling can be complicated or simple on a model RR.  However, you need to know the basics so you can decide how simple or complicated you want to make yours.  I will try and keep things simple for you.

Different RR's use different signals.  Remember there are always exceptions, but Western roads used searchlights and Eastern roads used three separate lights per head.

In the steam and early diesel years, signals were on the right side only.  So there were two signals on each side of the track for a single line that was traveled in both directions.

Two signal heads on one mast were used: 1- when coming to a place where the track branched, except for dead end sidings.  2- Also when entering a yard where there were no more signals, (a signal was located there to tell you that. (restricted speed)).  3- At a draw bridge there would be a signal with two red indications.  4- Where two or more tracks crossed each other.  The rest of the signals could be a single head on one mast.

There are no RR signals that just showed green for straight and red for diverging routes at turnouts.  There were illuminated switch stands that showed this, but not signals.

Try this link:
http://mysite.verizon.net/vzescsbb/HO_MRR/Signals/Signals_getting_started1.html

This is going to be more information that you want, but use just the parts you want.
When you decide what RR's signal system you want to use, look up their indications (called Aspects) on the Internet.

For my layout, set in the East, I decided to use C&O type signals.  C&O had some signals with three heads, but I decided not to use more than two heads on a single mast.  Because it is MY railroad, I can do that.

I hope this helps cut through the information you have received.

Great information, thanks.  I also appreciate the link.  Super information there.

Rich

Alton Junction

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Monday, June 7, 2010 11:09 AM

Hamltnblue

 Back to the original post. If you can't see the actual lights when operating, simply use dummy signals with no wired lights.  What good are they if you can't see them anyhow?  Try to position any lighted one you do install correctly and in a way that can be observed/showed off.

Your point is well taken and is something to keep in mind as I install signals on my new layout.

Alton Junction

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!