Large Scale Central

Bob Hyman Memorial bridge (AKA RGS 45B)

This bridge was Something Bob spent a fare amount of time documenting his build back in his Sn3 days, and was the inspiration of my building a total of four of these RGS style bridges, for what ever reason 45bturned out to be the last. he had his PDF file up on the internet to share for many years.

I started this build in conjunction with repairs to bridge 44A, dug out all my spare bits etc. I am still working on the new foundations for 44A so that will get more detail as it gets done.

after cutting the needed material for bridge 44A I found I had enough left over to take this bridge on.

first up were the bents, shown below ready to be installed:

The stringers were laid out in Solidworks , then converted into a drawing file, which I was able to get printed full size at a local print shop.

The actual stringers were cut and fit to the template, and actually glued to it.

This template was made from the underside view so that the bents could be attached directly to them.

and what is a bridge without hand cut bridge ties. even this short bridge used over 100 ties.

I have assembled the decks without the completed walkway for a test fit into the space allocated on the railroad.

and we have the first short train out to the bridge, the walkway having been completed and the rails recently spiked in place.

Better view of the completed walkway. still needs some supports added but for now one step closer to having the railroad back open.

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Rather impressive!

Nice job.

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That is a very nice bridge to remember Bob for, he for sure was a master at modeling.

Great Job


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Thanks for all the lovely pics and the detailed description!

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Al, beautiful work, as always. And a beautiful tribute to Bob.

I haven’t seen that method of curved stringer construction. Totally makes sense, because it laterally braces itself in a way parallel stringers wouldn’t. Where’d you get the idea?

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that is how the prototype did it, plain and simple.


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