This past weekend was notable for the Superbowl but it also was a two-day weekend where I had no real projects going on. Thus, I was able to do little things around the house and work on the layout. We have friends coming over next week and they will likely want to see the layout run, so I wanted to get it in operating shape. That meant rebuilding the lift entrance bridge into the layout. The old one worked fine most of the time, but the layout sections sit loose on the l-girder benchwork and sometimes shift apart more or less depending on the weather, causing the gaps at the end of the bridge to be large. In those instances, I need to physically pull the layout sections together to safely allow trains to pass. What it needed was a locking mechanism.
Originally, the bridge swung down on top of the far layout section and maintained its alignment through via a set of small wooden blocks. Wanting to get away from this, I decided to have the new bridge supported from below by a wooden block which would leave the topside of the open for the locking mechanism. Not wanting to go to the lumber yard, I found a piece of nice 1" x 6" cedar wood in the garage which was left over from some raised garden beds I built for my wife. A little cutting with the chop saw and sanding on the belt sander and the support block was ready to install. I didn't glue it in case I had to remove it in the future to reuse the benchwork section.
The bridge itself is more of that cedar wood, which was flat and wide enough for the locking mechanism pieces to mount to. And, it smelled nice in cutting it (which my wife commented on during construction). The very bottom edge of the end that swings up was beveled slightly to prevent any binding on the side of the layout. I planned to use two latches on the bridge, one on each side, but after installing them I discovered that both were unnecessary so one was removed. The roadboad is cork in the middle but plywood at the ends to allow the track a firm place to nail to. This is very important as rail alignment at the joint is critical to having trains make it over the bridge without derailing.
Then, the hinge block areas were cut and installed. I made sure check swing clearances by using a large piece of rolling stock, in this case some I..H.C. coaches which were remarkably difficult to keep on the track during a test run. Still, they served their purpose of confirming that the bridge was wide enough for trains to safely pass through. The hinge blocks are necessary to raise the pivot point of the bridge or else the bridge binds when lifting. Had I used a different style of hinge I could have avoided them, but that would have meant a trip to the hardware store. Maybe if I rebuild the bridge again...
The track was secured with a combination of wood glue and nails. I reused the Atlas rerailer sections from the older bridge and filled in the rest with new flextrack. Joints were not soldered, as I discovered that the ability to allow the rails to slide a little was a good thing here. Wiring was a simple matter of of soldering two wires onto the rails and then dropping the feeders down and through the edge of the benchwork section, with enough extra wire on the inside to allow things to work well. There is no electro-mechanical lock-out mechanism for the bridge which means that if it is up a train can run right off the layout. However, it swings up and blocks one side of the entrance which cuts that probability in half. It will take a spectacular train crash to get me to change my mind. Once I was done with the wiring, I called in the chief Quality Control Officer (Clover) to review the wiring. Apparently, it met with her approval as her only follow up comments were that she wanted a dog treat and some belly rubs.
Side rails to prevent trains from tipping or falling off the bridge sideways were made from some 1"x2" lumber stock that I did have to purchase at the store. If I had a table saw though I would have ripped some from the cedar stock I had been using for the rest of the project. These were glued to the sides and clamped until dry, and then everything was painted the brown color that I use for the top of the layout. In hindsight I think the edges should probably be the green that I use for the fascia, but right now I like how it sort of blends in with the rest of the layout. In the past I used to dread using the bridge because I could never ensure it would work, but now I am excited that the project is done.
The only downside for the project was that I had my chop saw in the garage and every cut meant putting on my sneakers, opening the garage door, running to the garage, plugging in the saw, unlocking the blade, cutting the lumber, and then reversing the process. I did that at least a dozen times as various pieces were cut, beveled, and re-cut. Clover jumped up and followed me around for every trip, which tired us both out! But, seeing the first train over the bridge (sans the sides... don't tell the safety committee) was a complete success!
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