Custom Built Truss Bridge

So, the other day, I built a retaining wall for the front side of our little garden railroad and wrote about it here in this blog previously.  That new "model" retaining wall looks great and I have to say it was a brilliant idea to add this detail.  Today, I started working on building a truss bridge for the back side of the garden railroad.  

I've been sketching different ideas over the past couple of months because I always knew I wanted one of these bridges on this garden railroad but I finally decided on a plan this morning.  Once I had the plan sketched and figured out all the dimensions of each of the parts, I immediately headed outside to start cutting lumber and building a truss bridge.  My civil engineering days are long behind me but, if I remember correctly, this would be a Warren Truss bridge due to the equilateral triangles across each side of the bridge.

Designing this bridge required me to test my geometry and trigonometry skills (and my memory).  Other than needing a bit more time to think and remember, I had no problems with the math.  All my dimensions worked out perfectly so that is some good news.  

This little bridge-building project reminds me of my engineering school days...  One project we had to do was to design and build a bridge out of paper.  There were all sorts of specific specifications but it needed to span 48", I think.  During a lab class, we tested each student's bridge.  My bridge collapsed embarrassingly soon.  I could still list each of the reasons why my bridge failed so soon so this means the project was a success (and my conclusions in my after-report gained me an A on this project).  I now won't make those mistakes again.  

So, for this project, in all, I currently have 48 pieces of treated wood cut and assembled.  I cut all of these pieces out of cheap, treated fence boards.  I will likely add another eight diagonal cross-pieces for the top of the bridge but I think I am done for today.

First, I assembled each side separately.  This was a little frustrating, to be honest.  I wanted to glue each joint so that meant I needed to work quickly enough to get it all assembled and clamped before the glue was too dry.  After laying out the first side, I drilled holes where needed for small finishing nails.  I didn't want any of these pieces splitting so I pre-drilled the holes.  The glue will do most of the work holding these parts together but the nails will help structurally especially while the glue is drying and curing.  So, I assembled the first side and clamped it together...

The second side went a bit more smoothly than the first since I had some experience under my belt after gluing up and then nailing together the first side.  

After letting them dry for an hour or so, then I clamped each of the assembled sides in place (the red clamps in the photos below) on the railroad.  Once I had each side clamped in place, I added the top crossbars...

The most frustrating thing outside today is it is thick mosquito-land out there.  I keep spraying YardGuard every couple of hours but that doesn't seem to phase the mosquitoes one bit.  They are still swarming.  This is a rather dangerous problem since we have a large population of mosquitoes infected with the West Nile virus as well as two types of encephalitis.  Vermont, New Hampshire and Massachusetts are seeing some hospitalizations (along with COVID and tick-bite hospitalizations) but I think only one person from New Hampshire has died...  so far, anyway.  As if the massive abundance of ticks and COVID wasn't enough!  I already had a nasty tick bite, illness, a couple of courses of antibiotics as well as COVID for the sixth time this season.  I definitely don't want to get any other virus or neurological illness from the mosquitoes.  The tick bite was brutal and I'm still struggling to get past this latest bout with COVID.  Considering my luck lately, if someone is going to get bit by an infected mosquito, it will most likely be me.  

So, today was a productive day.  I still feel like crap but at least I accomplished something useful.

I'm thinking of staining this new bridge a dark charcoal color.  The roadbed holding up the track will be stained a darkish brown color.  I'm not sure just how dark it will be though because I had to grab a gallon of "transparent" deck stain since that is all that was available so I expect it to be lighter than the paint chip depicts it.  We'll see.  I wanted to get a semi-solid stain but the paint counter at Lowes over the weekend was too busy while we were there so I opted to grab the transparent stain since it was already on the shelf ready to go.  We'll see how it looks.  I hope to get to some staining tomorrow morning.