Per a previous thread I decided to take a crack at modeling a bridge near where I live. I guess first things first - I know I could have bought a kit off the shelf to do 98% of this, but I'm stubborn and wanted to improve my modeling skills (especially with styrene)...so, yeah 
It's certainly not going to be rivet-counter accurate - in fact I decided to omit the rivets entirely, given how much work it will be even without them - but hopefully it will end up being a fair representation for inclusion in a diorama or layout one day.
The first thing I did was to make a crude model of just the main girders using posterboard and thick CA glue to see how the size worked, and whether or not it would be stable enough.
I was pretty amazed at how sturdy it was, even with just a couple cross braces in the middle. I'm sure this is a testament to the wisdom of the I-beam design more than anything
I didn't do a good job taking pictures in the early part of the build, so this jumps ahead a little bit. I used 0.020" sheet styrene to cut the sides and tops for the girders. Then I added HO scale 2x6 pieces, with the thin side toward the girder, to simulate the ribs. The process of adding these was a total pain. I made a jig out of a piece of sheet styrene, adding some scale 6x6 timbers to each side to give the ribs something to "lean" against while I glued them in place. The spacing was a tiny bit off, so the distance between the last three ribs in the middle of the span is just a bit longer than the rest of them. Still, pretty darn close.
Those little triangles on the end are the "feet" where the bridge attaches to the piers. Here's a closeup of the real thing:
From the end-on view, you can see there are actually two per girder. The alignment on these is not great, but it will be improved when slotted into the "feet" on the concrete pier - and, it's going to be tough to see anyway
Here is a pic of the bottom part of the "feet". These each have three vertical pieces. Again, you can see the accuracy on these is not great at all - I find it really hard to get multiple small pieces of styrene to have exactly the same dimensions when they are irregular shapes like this.
Here's what they look like with both part of the feet connected with 1/16" styrene rod. I used a standard 5/64" bit (by hand) to drill the holes, being as careful as I could to make them all line up. Fortunately the styrene rod has enough play in it that the small errors I made aren't a problem.
Note that for final installation, I'll glue everything together, then trim the rods to length for each foot. Until then, it's easier to keep everything on the same long piece of styrene.
You can see from the pic above that I used a couple of scale I-beams as cross braces. I did this purely to improve stability - the actual prototype seems to use only 4x4 cross braces on top, bottom, and then diagonally. I opted to skip the braces on top, but did include those on the bottom:
I made some basic piers (sorry, no pics from this stage, but there isn't much to them), and snapped a pic of the bridge plus all four feet sitting on the piers. I had originally planned to build the piers using foam core, but I had a really hard time getting cuts that were both clean and with 90 degree edges, so I got pissed off and just did them in styrene instead. Way more time-consuming, but hey, they're done now!
Next up is building the concrete approaches to the bridge, but as I need to get some work done, I'll save that for another time
It's certainly not going to be rivet-counter accurate - in fact I decided to omit the rivets entirely, given how much work it will be even without them - but hopefully it will end up being a fair representation for inclusion in a diorama or layout one day.The first thing I did was to make a crude model of just the main girders using posterboard and thick CA glue to see how the size worked, and whether or not it would be stable enough.
I was pretty amazed at how sturdy it was, even with just a couple cross braces in the middle. I'm sure this is a testament to the wisdom of the I-beam design more than anything
I didn't do a good job taking pictures in the early part of the build, so this jumps ahead a little bit. I used 0.020" sheet styrene to cut the sides and tops for the girders. Then I added HO scale 2x6 pieces, with the thin side toward the girder, to simulate the ribs. The process of adding these was a total pain. I made a jig out of a piece of sheet styrene, adding some scale 6x6 timbers to each side to give the ribs something to "lean" against while I glued them in place. The spacing was a tiny bit off, so the distance between the last three ribs in the middle of the span is just a bit longer than the rest of them. Still, pretty darn close.
Those little triangles on the end are the "feet" where the bridge attaches to the piers. Here's a closeup of the real thing:
From the end-on view, you can see there are actually two per girder. The alignment on these is not great, but it will be improved when slotted into the "feet" on the concrete pier - and, it's going to be tough to see anyway
Here is a pic of the bottom part of the "feet". These each have three vertical pieces. Again, you can see the accuracy on these is not great at all - I find it really hard to get multiple small pieces of styrene to have exactly the same dimensions when they are irregular shapes like this.
Here's what they look like with both part of the feet connected with 1/16" styrene rod. I used a standard 5/64" bit (by hand) to drill the holes, being as careful as I could to make them all line up. Fortunately the styrene rod has enough play in it that the small errors I made aren't a problem.
Note that for final installation, I'll glue everything together, then trim the rods to length for each foot. Until then, it's easier to keep everything on the same long piece of styrene.
You can see from the pic above that I used a couple of scale I-beams as cross braces. I did this purely to improve stability - the actual prototype seems to use only 4x4 cross braces on top, bottom, and then diagonally. I opted to skip the braces on top, but did include those on the bottom:
I made some basic piers (sorry, no pics from this stage, but there isn't much to them), and snapped a pic of the bridge plus all four feet sitting on the piers. I had originally planned to build the piers using foam core, but I had a really hard time getting cuts that were both clean and with 90 degree edges, so I got pissed off and just did them in styrene instead. Way more time-consuming, but hey, they're done now!
Next up is building the concrete approaches to the bridge, but as I need to get some work done, I'll save that for another time
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