John, I watched some YouTube videos on similar projects. It doesn't matter what scale they are to get the concept and construction. So far they were way too elaborate for my situation since they were lifting up or swinging up a whole section with scenery. One of those in England had good ideas on the electrical interlocks to power tracks when the bridge is down and stop power before the bridge when in the up position. I think just making lift up bridges with no scenery would be best for both yours and my application. The more mass you want to lift, the more sturdy you have to make the lift section and where it hinges to the stationary layout to keep it from skewing. My thought so far is to make two bridges that operate separately. In your case of course you can use one double track bridge.
I'll send a private message later to discuss getting the DVDs to you. I think sharing ideas about each of our builds here benefits both of us, and could help getting others involved in the discussion. Discussing logistics of getting together works better on private message.