Yes someone has thought of this before, and it is ME. I have that contact technique in operation on my layout now and have for about 2 1/2 years. I used a small 5 lb weight from Walmart under the wood to add the needed weight to keep the contacts in place so the engine does not stall when going over it. I actually used 4 screws to do this. Two screws on the top were drilled in about 1/4 inch deep and the two screws on the botom (where the wood lies on) is about 1/4 higher. I also added solder to the tops of both scres so that I could adjust the height by adding solder or removing it if needed. The bridge works 100% Perfectly too. I have had a couple years of ease in lifting out and putting it back one without any problems. Then I have rerailers on both ends of the lift out section and on the layout.
Does anyone have an illustration or photo of this that can be posted?
I will try to set up some sort of online picture hosting site and post some pictures of the bridge later tonight. The cool thing about the bridge is it is very very easy to build. I used a 1x4" pine board and cut it to the length that I wanted Then Had the sections of the layout made to the length of the board. Made the supports to hold the board before I do the screws into the board or anything. Lastly I lay the track after it is all even and fits in and out correctly. took me less than two hours from start top finish to build
ELECTRICAL metal/metal contacts need a wiping action.
Think of an old ‘knife blade’ switch. The blade decends into ‘V’ shaped phosfor bronze contacts. Still in use (and a favorite of Dr, Frankenstein’s successors (“that’s Frahnken-STEEN”) - since 1931).
A 'fixed blade into self-centering sprung ‘V’ contacts should do it.
That principle is what I used for the swing gate on my layout:
http://gmcrail.freeweb7.com/swing_gate/swing_gate.html
The only problem I see for a liftout would be getting enough pressure to ensure a solid contact. It would require the use of a locking mechanism (similar to the barrel bolt rig I used for the gate) which solidly locked the section down, applying positive pressure to the contacts.
