Here goes Mike,
For the double track bridge I use two blocks to basically key in the position of the bridge on the tray. A couple of hand hold slots and a pedestal on which to mount the fixed end tracks.
For removal and replacing of the bridge you never have to touch the flimsy plastic.
Indexing dowels guarantee rail alignment. The ends make a nice mount for micro switches. Cabinet magnets matched together double the magnetic grab.
I use either Anderson power poles or feed power through the brass dowels.
For the base I use 1/2" multiply. it is a high quality cabinet grade with 7 or 9 plys. I route the edge with a 1/4" X 1/4" step so at to mute the "hunk of wood " essence. Flat black finishes it off. Tain't exactly right but it is durable.
These bridges were uses on the last layout and did not fair well. Awaiting replacement repair pieces.
What is the best glue to use on this bridge plastic?
When you go to buy the cabinet magnets check each pair so as to get the North / South as you need them. These magnets are intended to go against a ferrous plate so no attention is paid at assembly as to polarity. Sometimes the need to be mounted on the same plane sometimes on opposite plane. So check which ones you have before purchase.
For securing the end fitter pieces I like to use non flex rigid snap track and glue them in place with a 1 1/4" Masonite alignment strip:
Note the four tracks of wire molding around the basement door. Three are for RR track power usage and one is for several 110Volt circuits supplying outlets and power packs on separate breakers.
These single track bridges have track power fed via the brass dowels. Power to each approach track is controlled with micro switches.
