do model RRs need signals other than STOP, APPROACH, CLEAR?

i’ve found basics signals to be surprisingly helpful on a large layout where the next block is hidden around a corner or inside a tunnel.

do model RRs need more than the 3 basic signals except to possibly more realistically model a particular prototype setting?

is there some value is route signalling to possibly confirm for a knowledgeable operator that switches aren’t aligned properly?

My turnout leading off the main and into the staging yard will show a ‘diverging approach medium’ (Red over flashing Yellow over Red) when the facing points are set for the diverging route. I used a Circuitron FRED flasher unit to make the middle signal flash. As the engines pass the signal it will drop to red as the block becomes occupied.

It is handy for operators to know the switch is set for the yard.

Regards, Ed

Prototype signaling as you know is very complex and varies considerably depending on era and railroad.

There were many great modelers in the past who believed all that is not nessasary, or even valueable on our model layouts.

I use a streamlined signaling system on my ATLANTIC CENTRAL.

My signals are based around only using the absolute or interlocking (control point) signals of a CTC system.

You mention the term route signals, but with route signaling in CTC, the same signal also conveys all three pieces of information - route, occupancy and permission. This is actually easy to do on our models and is easy for operators to understand. and like Ed’s example, my siginals confirm turnout position, and in my case confirm control authority.

Being a DC operator, signals need to instruct operators when they must stop, and when they can proceed.

I do have some intermediate signals that make the system appear to be more advanced than it is, but given the operation needs of a model railroad and our relatively short distances (even on a layout of considerable sze) I agree with those old timers like Ed Ravenscroft, there is no need for prototype level complexity - espeically for those modeling older historic systems.

My ATLANTIC CENTRAL is set in 1954, from what I understand there were few if any flashing indications in that era as just one example.

I would be happy to explain later what indications I do use and how they are generated if you are interested.

Sheldon

this sounds useful. without adding a 2nd head, flashing yellow can indicate that the switch is aligned for the diveging route and it is clear while yellow simply mean approach along the non-diverging route.

I could be wrong, but Ed’s description sounds like a multi head signal?

Sheldon

The signals on my layout indicate what’s going on in the next two blocks, for either the main route or for the diverging route. Green indicates that the next two blocks (straight or diverging) are clear. Yellow indicates that the next block (straight or diverging) is clear, but the following block is occupied or the next turnout is thrown against traffic. Red indicates red.

Is this needed? Not really, I suppose.

yes, understood

but i’m being pragmatic about what would be useful on a model RR without the expense of multi-headed signals.

again, yellow means APPROACH on the non-diverging track. flashing yellow means the switch is aligned for the diverging route and is clear, that the block on the diverging route is un-occupied.

is this SLOW APPROACH, rule 288

412

Not by my understanding, rule 288 implies two heads except as a dwarf in a yard or other slow speed situation.

Here is the thing, just because you put two heads on a mast, does not mean you have to actually light all the colors.

I have signals that have three aspects one of them never lights up.

Also, railroads often only installed two color heads where the third color would never be used.

I use type D signal heads (two or three vertical lights), a diverging route that is always speed restricted would only have yellow and red. The main route head above it would have green, yellow and red.

If the turnout is set for the diverging route and the detection is clear on the diverging route the signal will display red over yellow. This confirms both pieces of information, the turnout is set for the diverging route, and that route is clear of traffic.

A train ahead on the diverging route would set the signal red over red.

The top head would stay red any time the turnout is aligned to the diverging route. The bottom head would stay red any time the turnout is aligned to the main route.

Only the head for the selected route would respond to occupancy conditions ahead.

To explain my comment above about asects that never light, at a typical high speed interlocking a crossover would be protected by two heads in the direction of travel thru the crossover.

I do not use approach aspects at control point signals based on a train in the second block ahead - that is too far away to be of use to the operators, they are going to see two more signals before they get to the second block ahead.

So those are three aspect signals because they would be on the prototype, but they only show red over red, green over red, or red over green.

Here is the trap that you and others fall into - trying to match up the aspects you use to those “rule numbers”.

Your operators are not going to learn that stuff.

All

right. i now see that it’s a single dwarf. but ADVANCE APPROACH, rule 282-a is a sigle lamp flashing yellow. Finally pulled out my book (Solomon).

but i hope you understand i’m not trying to be prototypical, just want to convey useful information to a modeler operating on a model layout. if they intend to take a diverging route, they should see flashing yellow, not green or yellow

596

I understand, but in my view flashing is just extra complication. Are you thinking that because you only want to use one signal head?

I know your not trying to be prototypical, but if you look at the list of aspects I use, I simply use the most basic prototype aspects and ignore the complex prototype aspects.

And I ignore permissive signals, except for my intermediate signals which give the appearance of permissive block signals between control points but require no extra logic because in function they are approach signals for the control point siginals.

We had this conversation once before, I don’t understand why anyone would bother with signals and then try to define their function as a stand alone function and not link them?

But the linking can be basic, not complex like the prototype.

Even simplified, I think of it as a whole system, not just what a single signal does.

Sheldon

that’s all we have

don’t understand what “define their function as a stand alone function and not link them”?

689

Never mind.

I believe - unless reproducing prototype signalling is really important to you - that having signals that are as simple as possible to get the job done is a good idea. My situation was different from the OP’s; although my layout covers a lot of space, it’s basically an around-the-walls shelf layout and only sees one train at a time, so block signalling wasn’t really necessary. However, to see the positioning of turnouts 10-15 feet away, I found using two-head interlocking signals helped a lot - especially since I want to be able to run the layout at night. I connected the mainline turnout motors to decoders so I could throw them with my radio handheld controller from anywhere in the basement.

The signals I used are from China via ebay - they’re pretty cheap, and come pre-wired with resistors for the LEDs. I did use a few two-light dwarf signals too.

what signal aspects do you use that help indicate turnout position?

what makes a two headed signal an “interlocking” signal?

I suspect he is doing EXACTLY what I described above.

Generally speaking signals with two or three heads are interlocking or “control point” signals.

There are other uses for signals with multiple heads, but that is more advanced prototype stuff…

Greg, your second question shocks me in that with all the study you seem to be doing, you don’t understand this concept regarding signals.

This is an over simplification, but in my view it is the best way to start understanding interlocking signals.

EXAMPLE - You are approaching an interlocking with three possible routes.

Those routes are:

  • Continue straight on the mainline.
  • Go thru a crossover to a parallel track.
  • leave the mainline and enter a branchline or yard trackage.

You have a signal above or to your right with three heads.

The top head has three aspects - G/Y/R

The middle head has three aspects - G/Y/R

The lower head has two aspects - Y/R

In simple terms, the top shows the status of the straight thru route, the middle head shows the status of the crossover route, and the lower head shows the status of the branchline/yard route.

That status includes turnout position, occupancy ahead, and in CTC territory, permission from the dispatcher.

Assuming no trains in the next two blocks ahead, and no CTC,

sorry if i wasn’t clear. i was trying to ask if there’s a difference between a two-headed signal and a two-headed interlocking signal?

Well that depends.

A permissive automatic block signal will generally have a number plate, or the designation “I”. Absolute signals, which include interlocking (control point) signals will have no number plate or will be identified “A”.

The problem here is there are endless prototype variations on various roads at various times in history.

Other than that, simply knowing where you are on the railroad is an important indicator.

As I have explained many times, it is the opinion of some with considerable experiance that model layouts don’t really need permissive automatic block signals - our distances don’t really support their function in most cases.

So a good approach is to use mostly or solely absolute signals on model train layouts - so nearly all the siginals will be interlocking signals.

Pretty simple idea, you come to a turnout or group of turnouts, two routes, two heads. Three or more routes, three heads and possibly some additional markers, dwarf signals, etc.

And again, interlocking signals do all of the jobs:

  • indicate the route, or the correct speed for a group of possible routes
  • grant permission in the presence of CTC
  • protect trains from entering occupied blocks

So why not use them to indicat

it’s not clear to me how signals indicate route. at least on one listing of signals (NORAC ed.7 Solomon) i see the following

  • G/R/R (green over red over red) Clear
  • R/G/R or R/G Medium Clear
  • R/R/G Slow Clear

this site, General Code of Operating Rules has

  • R/G Diverging Clear
  • R/Y Diverging Approach

can signals have different meanings depending on location? or would operator understand the implied meaning of a signal depending on location?

because we don’t want the expense of multi-head signals

Stop looking at those charts and find a more complete book on signals.

At an interlocking that is what “Medium Clear” means, you are set for one or more higher speed dirverging routes.

R/R/G or R/R/Y means you are set for a slower speed more restricted diverging route.

G/R or G/R/R means you are clear for the primary high speed route.

So, common sense says that if there are only three routes, and there are three heads, each route is indicated by the conditions described above unless there is a train ahead that makes the signal go more restrictive.

If the interlocking is set for the mainline

which one are you looking at?