spur signals on siding (in CTC territory)

 Hi!

 I'm trying to figure out which signals to put where.

I (try to) model the 50's, western US. And the (freelance) station is in ctc territory.

 It features a station and a freight house. the freight house is on a spur off the siding. The question I have is where to put the signals? and what kind...?

In the picture, I believe that 

A) has two (searchlight) heads

B) has one searchlight head.

C) Two heads, the upper for straight ahead (the spur)m and the lower one when entering the mainline? this one really has me puzzled

D) Dwarf or none perhaps?

I'd appreciate your input!

 /Ulf

Double head signal at A.

Single head signals at B and C.

No signal at D.

Since its a stub ended spur and you would either be entering by passing C.  If you for some reason tied up an engine in the spur, you would be initiating a move within the outer opposing  signals of a control point ans would need verbal permission of the control operator (dispatcher) to do it so no signals would be required.

A real railroad wouldn't use that arrangement of tracks and signals, they would put the switch to the freight house outside the control point so no "D" signal would be required.

Hi Ulf,

You don't need a signal on the spur at D at all, and only one head on signal C. Entry into industrial spurs is typically not controlled by the dispatcher in CTC. Most likely a railroad would have a hand-operated switch with an electric lock for the freight house spur, connected so that when the switch was unlocked the dispatcher wouldn't be able to line a route in or out of the siding. It would be better practice to have the freight house switch to the right of signal C in your diagram, so the move into the spur wouldn't be governed by that signal. When the crew was through switching the freight house they would restore the swtich to normal and lock it, and then the dispatcher would have control of the siding again.

So long,

Andy 

Thanks guys!

So an arrangement like this would perhaps be better?

Doubles at A, and singles at B and C.

(Switches at spurs with electric locks)

/Ulf

Hi Ulf,

Again, it would be better to put the house track switch to the left of signal B at the right end of the siding. The turnout and three signals at each end of a CTC siding form remote-controlled interlockings known as OS sections or control points. The railroad's signal engineers will do their best to keep anything that's not supposed to be under the dispatcher's control out of those interlockings. 

There's a good article on where to place trackside signals online on this Web site. Look under "Articles" and "Layout design and operation." It was written by a profesional signal engineer who's also a model railroader, so he knows what he's talking about.

Have a good weekend,

Andy
 

 Hi Andy!

Thanks for the input. My 'bad', I was way too eager there 

Drawing corrected.

I'll look at that article!

cheers!

/Ulf

Instead of a single-ended spur for the freight house/house track, a more common prototypical arrangement would be a double-ended spur (superficially looking like a passing siding) running either behind the station or between the station and main track.  Also, if the industry was adjacent and parallel to the tracks, the industry spur would also be typically double-ended too, and be longer than necessary than to serve the one industry.  A longer siding would allow space for additional industries to be added and provide trackage for just parking a few railroad cars.  The quintessential small-town, rural track arrangement for a town in my part of the country would be combination depot, double-ended house track, main track, passing siding (optional) and double-ended industrial spur. 

Below is a Southern Pacific plan showing the track layout for Walnut Creek, on the San Ramon branch.  The arrangement here is combination depot, double-ended house track/industry track where the two functions are separated by a cross-over, main track, and double-ended industry spur (note that distance from main track varies in this instance).  There is no passing siding. 

Mark

Hm, where would the signals be put here (Walnut creek) ? Would it be just the 'outer' switches. No dwarves?

My previous freelance track plans are basically from John Armstrong's 'Track Planning for Realistic Operation (p.125). So I assumed

they'd be fairly prototypical... 

/Ulf

markpierce:

Below is a Southern Pacific plan showing the track layout for Walnut Creek, on the San Ramon branch.   

Actually, with as small as this siding is (not to mention its on a branch), there wouldn't be any CTC and there wouldn't be any signals.

ulf999:

 Hi!

 I'm trying to figure out which signals to put where.

I (try to) model the 50's, western US. And the (freelance) station is in ctc territory.

 It features a station and a freight house. the freight house is on a spur off the siding. The question I have is where to put the signals? and what kind...?

In the picture, I believe that 

A) has two (searchlight) heads

B) has one searchlight head.

C) Two heads, the upper for straight ahead (the spur)m and the lower one when entering the mainline? this one really has me puzzled

D) Dwarf or none perhaps?

 

I'd appreciate your input!

 /Ulf

 

Let's get back to drawing one and a little rules class.

IF the switches of the crossover at A and  C were hand throw switches, as well as the spur switch and siding itself, then A and C might simply exist as single head intermediate signals (with a number plate) as might B.  D would not exist, due to the hand throw switch (we may assume it is not within  CTC).  These signals in this scenario would be automatic block signals that would be in use within CTC limits.  However......

If the crossover was powered, AND the siding beyond C was a controlled siding, i.e., one within CTC limits, but the spur remained outside CTC, then the signal configuation would change.  A would be double headed, B would be single head and C would become a double unit signal, possibly a dwarf or pot signal capable of displaying as its lower unit only a restricting indication, i.e., lunar or flashing red, and D would then need to exist to protect entry into CTC limits, owing to the power switch.  All of these signals would be controlled signals, i.e., controlled by the train dispatcher or a local tower operator. 

I think I covered it....it's been a long night.......

dehusman:

Actually, with as small as this siding is (not to mention its on a branch), there wouldn't be any CTC and there wouldn't be any signals.

The purpose of my posting the Walnut Creek plan was to illustrate common prototypical practice for small-town track layouts (and thus help avoid designing one's layout to look like a model railroad rather than a real railroad).  In reality, there were no signals here, CTC or otherwise.

The prototype Walnut Creek plan contains no passing siding.  If the line was signaled for CTC, I presume any signaling at this location would be no different than a location with spurs created by five turnouts.  Now if there was a passing siding with CTC, the siding would be controlled by interlocked signals and turnouts.

Mark

Speaking for myself, even after studying various model and prototype sources on signaling, I'd hire a prototype-railroad signalman/model railroader for locating signals on all but the simplest of layouts.  Fortunately, my planned layout will have only three signals because it is dark territory: a signal each at both ends of a tunnel to protect the approaches (like on the SP Owenyo branch), and a train-order signal.  I can handle that.  The signals will be lower-quadrant semaphore type -- got 'em already and they're beautiful.

Mark

markpierce:

The signals will be lower-quadrant semaphore type -- got 'em already and they're beautiful

Who are they manufactured by?  I need about twenty.

Thanks for all the input and thoughts!

New version

Now with a local tower controlling the 'inner switches'. No extra signals (dwarf or others) needed?

A,B,C signals controlled by remote CTC. 

Can I assume that the double ended house track would be level with the main track and that the siding would be slightly lower than the main line?