I purchased 4 Woodland Scenics double track tunnel portals. I will have 2 sections on my layout where I will have double tracks entering tunnels. What should be the spacing of the tracks when they enter the tunnel. The opening measurements for portals are 4 5/8" wide, 3 13/16" high. When I look at the portals it looks like it will be too tight entering the tunnel with the double track. I am modeling in HO scale and will not be wunning any over sized cars.
Maybe you could set a couple of pieces of track side by side, with a car on each track, and see what spacing fits the portals.
Mike.
My You Tube
For straight double track , 2" track centers allows adequate clearance. You may be able to go to a max of 2 1/4- 2 1/2", But as mentioned do test w/ track/ roadbed if you plan to go wider.
This spacing of 2 1/2" @ the bridge, narrows to 2 1/4" @ this portal
However this portal placed on a radius and using 2 1/2" track centers, the portal will need to be widened. This thread explains this http://cs.trains.com/mrr/f/11/t/216329.aspx Selector cut and added a section, I decided to use 2 portals to accomplish this
Modeling B&O- Chessie Bob K. www.ssmrc.org
Two inch track spacing measured from center to center.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
Woodman, I'd have to agree with Mike's reply. Some just like to see it. I laid out my track because I felt like you. It just seemed so tight. And to make matters worse, I am modeling in N-scale in which the parameters were even smaller. And then the thought of a double double main going into a mountain on a curve seemed even harder. Now I noticed you said you will not be running any over sized cars, but for me, I took some liners .. just to see the actual clearance. But like Mike suggested, just lay them out, and see what you've got. Some just like to see it.