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
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.
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.
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.
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.
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 e
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.
You might have to or want to widen the track centers because of the location of signal B (looks like signal D is being removed). Don’t want an Owie.
Another approach is to bulge the siding out to get around signal B.
Or you might move the signal from between the tracks–that would be “down” on your plan. I’ve seen this arrangement (without the spur track) at East Cooks on the BNSF. There’s no station at or near the East Cooks switch–I’m not sure whether that would matter in your case.
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.
I have the Tomar lower quadrant semaphore train order signals, and my single-semaphore block indicator signals are handmade by Andy Carlson who sells on ebay. Andy’s cost two or so times more than Tomar’s.
Using operating semaphores on a model railroad can get quite expensive if one has a significant number of signals. Besides the cost of the signals and installing the control/detection system, one also has to provide motors/mechanisms to move the blades. I’d estimate an operating semaphore signal will cost between $10 to $40 more than a signal simply using lights; nevertheless, semaphores move.
Close. ANY switch that is powered (has a switch motor) will require a signal to protect movement over it and beyond.
Suggestion: any switch leading to the house track should be a hand throw switch. No signals required for them. Forget the interlocking tower. Switch to Imperial Foods should be hand throw–no signal. ABC signals are positioned properly.
House tracks will be generally lower than both siding and main track, as it will be laid with lighter rail than either. Exceptions do exist, and in some quantity,so lay te track as you see fit.
Train or engine wanting to enter main track from house track will obtain authority from train dispatcher, who will hold signals at stop as protection, providing either track and time or single direction movement authority.
Thanks. I’ve got an overabundance of SwitchMaster motors, and I have bags of detectors and signal drivers from a previous layout. All the previous signals were GRS searchlights and upper quandrant semaphores, but those won’t fly for the SP layout I am working on now.
Here are early twentieth-century photos of the Walnut Creek and Concord (nearby town) depots showing the house track running between each depot and main track.
Note that the house tracks aren’t substantially different in height compared to the main tracks. The house tracks are buried up to the tops of the rails to allow for easy passage of passengers and baggage/express carts. There appears to be a box car at both the Concord and Walnut Creek house track adjacent to their freight platforms. I suppose the engineer of the train arriving in Concord will stop the train at the point the baggage car’s door aligns with the milk cans.
Likely that the house track and the main track were laid on virtually the same grade and with identical weight rail, and since the photos are of a relatively new installation, they would both appear to be on the same level, or thereabouts. The views of the Castroville Depot, taken in the mid-70’s here http://wx4.org/to/foam/sp/castro/ville.html have the benefit of almost a century of track raising, as well as substantial rail replacements over the years, and as such, and as seen in the final photo of the group, the house
