Trestle Bridge Jig

I started working on the trestle bridge for the garden railroad today.  Many years ago...  hmmm...  perhaps many decades ago...  I designed and built a small N scale trestle bridge.  This trestle bridge I am building now is a little different because it is so much larger.  This garden railroad trestle bridge will be approximately eight times larger in scale alone...  and far longer..  and far taller...  and on a sweeping compound curve.  That N scale bridge was tiny, short, and only a very mild curve...  I think I only needed to make four bents (trestles) while I am now needing 14 giant large scale bents that will take up a lot of space.  

I ripped a bunch of wood on the table saw and then built a jig.  The jig will make it easy to accurately replicate each bent so they will all be the same.  The height of each will be different, however, because the ground slopes downward throughout this rather long compound curve.  I plan to cut each to its finished height on the table saw.  I will build each bent to a rough height approximately an inch taller than its finished height.

Below is a sample bent in the jig after partial assembly.  

Once the glue dried enough, I removed the sample bent from the jig.  It looks pretty good but I plan to make a change which was the purpose of making a sample.  The sample allows me to make some changes before building all 14 bents.

The vertical timbers are made of 5/8" x 5/8" wood.  For this sample bent, I also used the same wood for the cross pieces but these cross pieces don't look right being the same dimensions as the vertical timbers.  I think I'll rip more wood at 3/8" x 5/8" to use for cross pieces as well as for the diagonal bracing (which was not added to the sample bent in these photos).  

Below is a closer view of the sample bent albeit unfinished.

I found that I'm very short on brads and screws so I'll need to pick up more of those at Lowes when we head up to Burlington.  I'm torn between getting brads for my air compressor nail gun or getting brass brads to hammer in myself.  The brass brads will provide a nicer finish but will require more time and effort.  Right now, I'm not sure the nicer finish is worth the extra time and effort in this case so I'll probably go with the brads for the nail gun.  

Once I get all the wood ripped and cut to size, making the 14 bents will go very quickly.  Well, it will go quickly assuming the glue dries quickly.

In the end, it was a productive day but not without its frustrations.  It was one of those days when I kept dropping things, making mistakes, and having to go in and out of the house a million times because I kept forgetting to grab something.  That being said, I managed to get through the day without injuring myself so that is good!