On30 PGB – Pt II

Start Modeling
Here are the girders all ‘sliced and diced’. Note that the ends of the Rail Bearers (1/4″ Evergreen #227 I-Beam) are notched to fit into the Cross Girders (5/16″ Evergreen #278 I-Beam). This is where it’s worth the time to – take your time and make this fit as good as you can since a good fit means a good weld (cement) and that is important for the overall structural integrity of the bridge .. much the same as the full size one.
Just to give an idea, here are the measurements that I used to make my various girders.
Gluing up
Since I had the bridge designed in Sketchup, it was easy to print a full size drawing of the girders. I could then tape that to my favorite working surface for something like this .. a 12″ sq. marble floor tile. You simply align, weight and cement.
Once the girders were glued up I turned to the Lateral Bracing. Again, I printed off the bracing so I could use that full-size print to align and glue the Lateral Bracing together. In the photo I have center Lateral Bracing in place on the girder assembly and I am gluing together the next one. Each X-Brace is made up of paired .060″ Angle glued to make a “T”.

Those hair-clip thingies are excellent for such clamping. A quick trip to the local beauty supply store netted me a box with enough to last me for a long time.

Here, I have the last Lateral Bracing glued up. The various brackets I am adding here are actually doing what they would REALLY do .. and that’s reinforcing the joints.

To be honest, you can’t really see much of the underside of the structure with the bridge mounted on the layout – just vague shapes so I could have left off the rivets and no one would notice.

That having been said, here’s a close-up look at the center of the Lateral Bracing/X-Braces. The rivets were formed using a Polger. It worked pretty well with me lacking one of those riveting presses. The hardest part with making rivet impressions using your hands to press a tool into the plastic is that It is harder to keep the tool tip vertical .. and .. the biggest thing .. equal depth of impression each time.

This photo is after I finished some weathering using the hair-spray technique.



Comments

On30 PGB – Pt II — 2 Comments

  1. Congratulations on your background research on bridges, your excellent modelling- and your willingness to share the info for the benefits of others.

    Cheers from Tasmania

    • Peter – thanks. To be completely honest I get as much pleasure out of the research as the modeling. I think that is a good thing! My sharing at least in part was a hope that using a WordPress blog I could get comments and suggestions from others. I’ve always thought that the “more the merrier” was certainly applicable to such modeling. Occasionally someone will point out that I have something wrong .. and if for example it is part of a ship and the person responding spent 20 years as a sailor I am more than happy to accept that since my own knowledge is mostly from that research. Fun times. 🙂

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