Dwarf Signal Lights.

[tetters]

Originally Posted by puddlejumper

There is one thought that I'm surprised no one has mentioned- yard limits. Your layout is mostly yard and secondarytracks so why not just make it all within yard limits. Within yard limits there are no signals, all movements are made at restricted speed and all switches are supposed to be checked for proper alignment before being used.

You can even have multiple crews using the same tracks because at restricted speed you are supposed to be looking out for other trains.

I can't ever remember operating in a yard that had any signals at all except for one on the main track for entering the yard, and another for exiting the yard, at each end of the yard.

Ahhhh the voice of reason! See, in a way, this is kinda of the answer I've been looking for. I was beginning to wonder if I was getting a little carried away or what not. Now I think I understand where signals would be required for my purposes.

[puddlejumper]

Originally Posted by tetters

Ahhhh the voice of reason! See, in a way, this is kinda of the answer I've been looking for. I was beginning to wonder if I was getting a little carried away or what not. Now I think I understand where signals would be required for my purposes.

Yeah, I kind of thought so. Your first post seemed to indicate you thought each switch needed a signal. In fact, while signals do convey either speed or direction, they do not necessarily have anything to do with the position of the points.

Now, in the old days and in few rare cases now, the switch stand has a globe with a light inside it which indicated the position of the points. The globe would be green or yellow for straight route, when you threw the switch the globe would turn 1/4 turn and be yellow or red.

Dave

[tetters]

Originally Posted by puddlejumper

Yeah, I kind of thought so. Your first post seemed to indicate you thought each switch needed a signal. In fact, while signals do convey either speed or direction, they do not necessarily have anything to do with the position of the points.

Now, in the old days and in few rare cases now, the switch stand has a globe with a light inside it which indicated the position of the points. The globe would be green or yellow for straight route, when you threw the switch the globe would turn 1/4 turn and be yellow or red.

Dave

Yeah. Now I am thinking that as I swap out the ground throws with the tortoise machines, I was going to place one of the old style throw mechanisms with the red and green plates to indicate the t.o. position. Save me a ton of wiring hassles, thats for sure!

[puddlejumper]

Originally Posted by tetters

Yeah. Now I am thinking that as I swap out the ground throws with the tortoise machines, I was going to place one of the old style throw mechanisms with the red and green plates to indicate the t.o. position. Save me a ton of wiring hassles, thats for sure!

That is also what you will see in a modern day yard. Sounds like a win-win.

[acsoosub]

Exactly, yard tracks don't have signals. Within a yard, or on any sidings or spur tracks that have manually thrown switches, you'll see the red (or yellow) and green targets on the switch stand that indicate which way the switch is thrown. On mainline signalled trackage you don't have this, but you'll be governed by signal indications.

And you don't have 1 signal/switch either. If you have a simple crossover between tracks, or two in a row, or a siding switch, or something a lot more complicated for a set of multiple tracks, you have one signal on each track in each direction, regardless of the complexity of switches in between the signals. The whole location becomes what's known as a "Control Point", or sometimes "OS Section".

[kutler]

Signaled yard tracks are quite common.

While the vast Majority of the Nickel spur is other than main track a small portion where this track gains entry to the Cartier Sub is signaled through a cross-over track.

IIRC the best indication for a westbound move to the Cartier Sub would be a Slow Clear indication, which means proceed through the turnout at slow (15 MPH) speed after which time you may proceed at track speed as the block is clear. For movements to continue on the Nickel spur the indication would be a restricting signal. (max 15)

In general pot signals usually convey slower indications such as Medium and Slow speeds through cross overs or turnouts.

Pot signals often called dwarf signals are often employed as economy or where it's desired to avoid confusion for main track movements. I.E. Some railroads signal the ends of siding tracks with Pot signals.

A good book to read is called "Railroad Operation and Railway Signaling" by Phillips. It was originally published in 1941, reprinted and reasonable to obtain, the information still applies to modern railway signaling principals.

C

[acsoosub]

Originally Posted by kutler

Signaled yard tracks are quite common.

While the vast Majority of the Nickel spur is other than main track a small portion where this track gains entry to the Cartier Sub is signaled through a cross-over track.

That's really not the same thing as signalled yard tracks. The branchline has that short piece which is CTC controlled along with the adjoining crossovers on the mainlines. On either side it's all uncontrolled, and as per the original discussion in this there are no switches at all in the yards to indicate the directions of switches in the yard. Yard crews throw their own switches within the yard and have to be able to tell which direction they're thrown themselves, by looking at the switch stand targets or points. (This is why speed limits in yards are always restricted speed - have to be able to stop in half your line of vision or short of switches and obstructions.) Tracks joining the mainline or other signalled tracks will have signals controlling the junction, but that's usually pretty much it.

[kutler]

I take it were not on the same page here. The subject of this thread is dwarf signals. What's relevant to the topic then is the track which is CTC controlled(signaled) and not the unsignaled spur (not branch) beyond. Incidentally the Nickel Spur is named the Sudbury yard lead immediately east of the CTC control location.

In railway rules tracks have to be designated for the purpose of issuing authorities like TOPs and slow orders. CROR rule 51 specifies the naming of main tracks. Likewise other than main tracks have to be designated using such names like running track, running lead, long lead, or other terms to describe a signaled yard track where such authorities are issued.

In your earlier posts you made two other remarkable comments suggesting that there are not hand thrown switches on signaled main tracks, and Tracks joining the mainline or other signaled tracks will have signals controlling the junction, both false.

If you had meant to say yard ladder tracks or yard classification tracks are not usually constructed as signaled yard trackage, it would be more factual.

Yard tracks that are commonly signaled are hump leads, arrival/departure group tracks, shop leads, spur and junction connections such as our example above. These are prime locations for dwarf signal placement.

C

[acsoosub]

kutler:

OK, I think we weren't really talking about the same thing there. The original discussion in this thread talked of using dwarf signals to display the direction of switches in the yard proper which certainly wouldn't be done in prototype practice.

I guess I was far too broad in my other statement, and in doing so made it inaccurate. Tracks joining other signalled tracks would be pretty much the only place to find dwarf signals; but you wouldn't find them on every track entering a signalled mainline, which looking back at what I wrote previously is what my statement implies. That's definately inaccurate and I misspoke there. Dwarf signals would mostly be at dispatcher controlled switches (or tower or otherwise centrally controlled), and certainly not at any hand-thrown spurs etc.

An example; at Guelph Junction, where the CPR's Hamilton subdivision meets the Galt, the switch for the east leg of the wye is controlled by the dispatcher and is protected by a dwarf signal on the connecting track. The west leg only handles a few trains and is not protected. You can often hear on the scanner trains getting a rule 568 permission to enter the main track at that mileage.

I don't believe I ever suggested there are never hand-thrown switches on the mainline, just that switches in the yard itself would pretty much all be hand-thrown. (Except obviously at a hump for example).

[kutler]

Originally Posted by acsoosub

kutler:

I don't believe I ever suggested there are never hand-thrown switches on the mainline, just that switches in the yard itself would pretty much all be hand-thrown. (Except obviously at a hump for example).

I don't understand what you mean by this statement then.

Originally Posted by acsoosub

Within a yard, or on any sidings or spur tracks that have manually thrown switches, you'll see the red (or yellow) and green targets on the switch stand that indicate which way the switch is thrown. On mainline signalled trackage you don't have this, but you'll be governed by signal indications.

[kutler]

Originally Posted by acsoosub

kutler:

The original discussion in this thread talked of using dwarf signals to display the direction of switches in the yard proper which certainly wouldn't be done in prototype practice.

In some larger yards there are route indicator signals, while looking similar to dwarfs, are often controlled by someone, but don't usually convey authority to use track. CN Symington has extensive route indicated switches. I believe that colours used are green and yellow to indicate route. Not likely used in this application is Red, which under most circumstances means stop.

CP Calgary yard has a interlocked dwarf signal within the yard. This signal has been violated numerous times by crews who assume it's just another indicator light.