Railroad engineers are always trying to find the easiest path from point A to point B. Many times these railroads need to cross a ravine, road or waterway and have no other option than to span the obstacle with a bridge. As model railroaders, we often use bridges to add visual interest to our scenes or span aisleways. Whatever the case, we have so many kits to choose from that it is easy for us to add them to our layouts.
I model a railroad that was constructed in the Northern California foothills. That means small creeks and hills that will need to be crossed to keep the grade at a reasonable level. Most of the shortlines in the area used wooden trestles to cross spans and I wanted to add a large bridge to my layout.
My freelanced railroad crosses Cherokee Creek just west of Angels Camp and thought this could be a good location to build a trestle. I also planned it that this would be the first scene that visitors would see when entering my basement. So, I wanted to make sure it was as detailed as possible.
Since this was my first attempt at building a structure of this size, I was feeling a bit nervous. However, with all the research I was doing, I soon discovered that it was going to be easier than I made it out to be. With documentation in hand, I began a drawing; first on paper. When I was happy with the basic structure, I drew a final rendering in Adobe Illustrator.
Next, I ordered all material I would need for the build as well as a little extra, just in case I made any mistakes.
I then made a jig to build the bents using scrap lumber and stripwood I had on hand. I drew the bent on the wood, then glued the stripwood to the board. When dry I sprayed everything with dark grey paint to seal the wood.
Beginning the Build
As you can see from the first drawing of the overall bridge, there will be a girder spanning the creek and so I plan on building the bridge in three parts; short approach, girder then long approach.
I began with the stringers and ties to determine the actual length of the short trestle. The backstory of my railroad is that it was built in 1900 and lighter equipment was used. The trestles were rebuilt in the 1930s to support heavier equipment. Typical for that period were three stringers. My layout is set in 1974, three stringer trestles would be able to support the light modern equipment I will be running so I decided to stick with three. I use stripwood to gap the stringers and then glue them together. I will then add my ties and then the timber guards.
Once that was done, I measured the tallest bent to set the overall height and began building. Now that I have the first approach height and length determined, I cut woodblocks which the bents would rest on, then secured them in place. The remaining bents were built and test fit in place.
Now that my first set of bents are roughly built, I can finish them and add details.