I have a lift-out section at the doorway into my layout room. Sorry I don't have any pictures, but it's simple as can be. Because the track across the doorway is on a curve, I used a piece of 3/4" plywood, about 12" wide and 36" long. On the layout facia on each side of the doorway, I fastened a 3/4" piece of plywood, about 15" long, and as deep as the facia (about 4"). Before installing these pieces, I made a cut-out in the top edge, 3/4" deep and wide enough to accomodate the width of the "bridge". These two pieces were attached to the facia, with screws, so that their top edges were flush with the top of the roadbed on either side of the doorway. The plywood "bridge" was then placed into the cut-outs, with its top surface flush with the top of the roadbed. With the "bridge" in place, track was laid around the curve on the layout on one side, across the bridge, and around the curve on the opposite side of the layout. This was done as one continuous piece, with the flex track soldered together to get the required length. After everything was spiked down, I added some individual spikes, of the type used to handlay track, on each rail and on both sides of where I intended to cut the rails. Because my track is curved, several ties needed to be cut through on an angle, so these were also spiked down individually. When everything was secure, I used a cut-off disc in my Dremel tool to sever the rails. Before removing the bridge, I dropped a couple of feeder wires through the plywood from the rails, then soldered them to a small, multi-pronged plug (it only plugs in one way, so the polarity will always be correct on the bridge), then dropped feed wires from the layout track at one side of the doorway and routed them to the female counterpart of the plug, mounted on the layout facia. I don't normally operate with the liftout in place, as it's only used when somebody just wants to "see the trains run". Normal operation is point-to-point. If you need the bridge in place for the regular operation of the layout, you could install a similar plug-in connection to the layout on the opposite side of the doorway. What I did, to ensure that the layout on the opposite side of the door had a reliable source of power, was route a power-supply cable up behind the backdrop, across the ceiling above the door (hidden above the suspended ceiling panels), then back down behind the backdrop on the opposite side. By the way, when you cut the rails, leave the ends on the lift-out section extending past the end of the plywood: mine extend about 1/4" on each end. That way, there are no rail ends protruding into the walkway when the bridge is not in place, waiting to snag on loose clothing. Mine has been in service for at least 10 or 12 years, with no repairs or adjustments required. Just remember to use care when putting in in place or removing it: it must be dropped into place, not slid, or you'll bend the rails.
I just recalled that I
do have a picture, at least of the bridge support at one side of the bridge. It's not the subject of the photo, and just barely made it into the frame at the extreme right edge.
Wayne