Think it about adding one of these to the layout. Anyone know the furthest distance apart my 2 mainlines can be for it to fit ?
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Christopher-
The inside width between bases is 7"; deducting for the width of two tracks (1-1/4" x 2) leaves 4-1/2" of free space. Assuming equal spacing between tracks and the bridge bases (4-1/2" divided by 3) , there will be a 1-1/2" free space between the tracks and each track and the one of the bridge bases. In this configuration the center-to-center track spacing is 2-3/4" (sum of the track gauge and the free space), which results in very close clearances between tracks (and the risk of passing trains sideswiping each other).
For a greater center-to-center spacing reduce the distance between the each track and bridge base to 3/4", this leaves 3" between the tracks, for a much safer center-to-center spacing of 4-1/4".
Center-to-center spacing of up to 5-1/4" is possible, but too wide spacing will result in the trains sideswiping the bridge bases. You may need to experiment using your widest models to determine the optimal clearance. If the bridge is on or near a curve you will also need your longest models to ensure the model can negotiate the curve without colliding with the bridge base.
Hope this helps!
-John
If you're concerned about clearances, you could always purchase 2 kits and splice them together for whatever width you need. That's what I did. In the picture the front signal bridge is modified and the the one in the background is original (except for the custom paint job. )
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Hi Christopher!
Great to see you posting again. I hope you and yours are doing well.
If there will be any crossovers between your two mains, if you can mock up a crossover with the switches you intend to use (a pair of 042's, or 072's, etc), that will tell you all the dimensions you will have to work with in regards to an overhead signal bridge in close proximity.
Unless you specifically want to stay with a Plasticville signal bridge, should you go with Lionel's #68374-0 "Double Signal Bridge", then the clearance between the bases will be generous:
https://www.trainworld.com/med...;width=&canvas=:
Andre
The other thing you want to be aware of is the height of the signals for twin stacks. I increased the height of the signal by cutting a small piece of wood to fit under the bridge on each side.
Marty
Plasticville signal bridges are great. Your track spacing will be dependent on your equipment. I usually have a few “test cars” that I use when any potential clearance issues may be present—longest freight, passenger car, largest loco, etc.
The attached photos show my most recent PV bridge mod, using older Walthers signal heads. The original bulbs are wired with 330 ohm resistors to prolong bulb life. The feed is 18V from the track. The photo with the lights was not carefully exposed. 
Since my New Haven Railroad is set in the late 60s, the bridge is painted with Rustoleum (ironically) camouflage brown, which gives a good sense of old rusty iron.
Additional wash and powder weathering should be as you prefer.
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@Don Sierakowski 111617 posted:Since my New Haven Railroad is set in the late 60s, the bridge is painted with Rustoleum (ironically) camouflage brown, which gives a good sense of old rusty iron.
Additional wash and powder weathering should be as you prefer.
< Slight thread drift alert >
That is a cool scene! ^^^
(I'm a sucker for urban settings.)
Andre
Thanks, Andre
@Don Sierakowski 111617 posted:Plasticville signal bridges are great. Your track spacing will be dependent on your equipment. I usually have a few “test cars” that I use when any potential clearance issues may be present—longest freight, passenger car, largest loco, etc.
The attached photos show my most recent PV bridge mod, using older Walthers signal heads. The original bulbs are wired with 330 ohm resistors to prolong bulb life. The feed is 18V from the track. The photo with the lights was not carefully exposed.
Since my New Haven Railroad is set in the late 60s, the bridge is painted with Rustoleum (ironically) camouflage brown, which gives a good sense of old rusty iron.
Additional wash and powder weathering should be as you prefer.
That scene is awesome!
Thanks for the responses everyone. I measured the distance between my mainlines and unfortunately they are too far apart to add one.
Thank you Chris. I just viewed your photographs—quite impressive composition there!
Your bridge concern can be easily (and inexpensively) resolved buying a second bridge and cobbling them together to any width you need.
Christopher
As you have found out, 3 inches center rail to center rail is the widest distance the pair of tracks can be and have the signal bridge have the legs be straight up and at 90 degrees from the bridge itself.
I also had my layout rails laid for operation and space requirements with no attention given to installing a Plasticville signal bridge. After about 35 years of having the layout on the floor for two or so months of use and the removing it for storage each year, signal bridges could now be installed over two tracks wider than 3 inches ct to cr.
The first signal bridge location had 4 5/8 center to center rail distance. I considered widening the bridge distance from its 8 1/8 width but decided it would be a big pain to scratch build a new section in. Getting another signal bridge and cutting out a section to be used to widen the original bridge is the better option but I did not have a junk or spare bridge to operate on. I decided to just spread the bridge legs out to make it fit over the two tracks. By the way I have a 1950's style toy layout so realistic is rather rare and un used term!
The signal bridge legs were too close together to span the distance over the pair of tracks and I had to spread the bases out making the legs slightly bowed. I may cut the bottom bridge supports from the legs to allow the legs to straighten out and re-glue them to the bottom supports with a small wedge added to make the legs straight.
Spread over 4 5/8 inch center rail to center rail tracks
The second set of tracks had 6 1/8 inch center to center rail distance.
The attachment of the legs and the bridge was separated and 1/16 inch blocks were added on the bottom bridge joint. This allowed the legs to be straight but were attached on, at an angle and looks more acceptable and believable than bowed to me. This option was chosen verses adding two inches to the width of the bridge which was much more involved and difficult.
The signal lights could not be seen by the engineer at the control panel as it was not facing in that direction.
It was decided to make them visible to engineer and hook up the track sections under the signal bridge to indicate when power is applied to the track section. They will not be used as real signal bridges.
Angled light assemblies to make more visible at control panel
Maybe the above will give you some more options to consider.
Charlie
Art,
How did you wire your signals? Are you using GOW bulbs or LEDS? Track power with resistors or a separate power source? Are the signals tripped by insulated track or photocells. Sorry about all the questions, but I’ve seen some of your other work, and I think we can benefit from your skills!
@Don Sierakowski 111617 posted:Art,
How did you wire your signals? Are you using GOW bulbs or LEDS? Track power with resistors or a separate power source? Are the signals tripped by insulated track or photocells. Sorry about all the questions, but I’ve seen some of your other work, and I think we can benefit from your skills!
Thanks, Don. We used LED's and are controlling them with the Atlas Signal and Interlocking boards. We use a separate power source to the Atlas boards. The occupancy is from detector wires soldered to insulated sections of the outside rail. The signal heads and railings are all 3D printed as are the fresnel lens which give a brighter and more focused light. And we laser printed planking for the tops and bottoms of the signal bridges to give them strength and also to add brackets to secure the brass poles that the signal heads are mounted on.
Art
Splicing multiple bridges together is the way to go. If you look at Norm Charbonneau's layout you'll see Plasticville bridges spanning more than 2 tracks.
Jan
