Lawrence has been back in touch with his O scale lift bridge:

“Hi Al

I am starting a new section of my layout.

I have two O scale, one N scale and numerous HO scale Engines. My concept is to build the O scale lift bridge at a height of 22 inches. And put the HO and N at a height of 39 inches (where it will connect with my Lincoln Nebraska rail yard).

All wiring will come out to the edge of the layout and run in a designated wire run tube, nothing underneath. I am presently working on the lower level at the present.

I plan on two separate loops with a run of 30 feet between the ends, 24 inches wide on the long runs. This means that the long run will have four tracks side by side, I decided not to have a cross over between the ends. After watching many utube videos on lift bridges I decided I wanted one of them for access purposes. The lift bridge is what this is about.

After looking at many bridge designs on the web I decided on one. Then by measuring the height of the tallest item, on a track, I figured out the height required for the bridge framework.

The first picture displays the type of bridge and the design drawing. The drawing is made to the actual size required for the structure.

I did a similar sequence for the top of the structure. I used regular wood glue to attach the pieces. Then it was easy to size and cut the square balsa wood, from Michael’s. With four tracks, I wanted two bridges each covering two tracks.

Then build the structures and brush painted them with acrylic silver paint. Just for a check I put the two on the layout with the tallest items underneath. My initial idea was to make the top ten inches wide. Doing the measurements, I decided it was too wide. I tore the structure apart and made it eight inches wide. This turned out to be the correct size for train spacing and layout structure.

The next picture shows where the layout has been cut out. I decided on three hinges to help ensure no rotation of the bridge in the future from usage. The upper board in the picture has been beveled so the hinges are perfectly level with the top of the board.

The next picture shows the track base board connected to the brace board. The brace board is needed as a back stop for the rotation of the bridge. The layout is built with 2×2’s and a 2×2 is used for the legs as part of the leg is displayed in the picture.

The brace board is a 2×4 so it sets it back from the layout frame. But it is also the width of the track base board so when installed it comes out to the edge of the layout and leaves a space at the back for clearance when the bridge is lifted as shown later.

The next picture the rotator section is installed (hopefully the only time I will have to lay flat on the floor) and the foam put in place. The foam on the rotating section needs to be cut back for rotating clearance. The track foundation boards are installed with the bridge side pieces and for alignment. Had trouble with the height of the foam at this point causing the layout track and the bridge track having a height differential of one eight of an inch. Replaced the one-inch foam with ¾ inch foam and problem corrected (not shown in the last picture).

The next picture shows the bridge structure attached to the track base boards. Also attached is two aluminum cross pieces to help ensure the bridge is lifted as one unit and there is no rotation of the tracks with each other. But of course, the cross pieces are the walkway between tracks for the workers.

The far end of the bridge layout is cut out of the foam so the bridge lays flat. Had a slight problem here as the near end board would not lay flat. As it turned out by carful adjustment of the screws, at the right of the picture, the problem was corrected.

Final testing. The next two pictures show the lift bridge working as it should. This gives me a two-foot access. The picture shows a close up of the rotating section. Also note that the bridge framework does not impact the layout.

The last picture displays the track in place with the tallest and widest O scale item I own. Plenty of height spacing available and enough width spacing. This bridge is 2 feet long. The next problem way in the future is building the bridge for the upper layout at 39 inches. Might have to make that lift bridge 3 feet long.

Final note, nothing I perfect. The height of the track of the layout comes out to be 1/32 of an inch lower than the track on the bridge. Because of the bridge rotation no joiners at either end can be used. Lifting the layout track to match the bridge is just a minor problem.

The wiring of the bridge track will be the only under track wiring between the bridge and the layout. But with the bridge lifted I can sit in a chair next to it and wire it up with a rotation loop at the layout end.

I hope this has been helpful for anyone willing to take on this enterprise. It was a real learning experience for me.

Lawrence”

A huge thanks to Lawrence for sharing his O scale lift bridge- it’s a real pleasure to see the pics and the progress of a project like this. I do find myself reading them again and again. Clever stuff.

That’s all for today folks.

Please do keep ’em coming.

And don’t forget, if today’s the day you start on your very own journey, the Beginner’s Guide is here.

Best

Al

PS Latest ebay cheat sheet is here.