A Swing Bridge instead of a Duck Under

[ngauger]

Now for the horizontal support:

Look at the pic below. You have full weight support on the hinge side, but the other end "floats" in space.

   
You need an "Alignment Block" (shown below) at the other end of the layout "Permanently & Securely" attached!! This can't move!!! Did I say it plainly enough??? It CAN'T Move!!!! -- Why?? because "If" it moves, when you go to close the bridge - your rails will be Mis-aligned!!

......................can you say "trains on the floor"!!!
   
This bridge has lasted on my layout for over 6 years with very minor adjustments being made. I really can't believe how sturdy this is.

In G - I have 1 mm to mess with Is that wider than an N rail??????

Also look at that picture & notice the "triangular 3/4" piece of wood (Blue Arrow). It's the "Cutoff" from the 1 X 6. It is permanently & Securely attached. This acts as a "stop" for the bridge when it closes and also aligns the railheads.

You will also note the "Pressure switch" (Green Arrow) and the "Throw Bolt" (Red Arrow) - The switch is wired to the power side of the tracks and is Normally Open. The tracks have insulators on the Power side - 2 feet on either side of the bridge. That way - "if" you don't have the tracks aligned - no train can "fly off into the sunset"!

........... and as stated elsewhere - all couplers will work perfectly as the train flies off the layout taking the engine and as many cars as "Murphy" sees fit.