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The inspiration for my concrete arch bridge

Walnut Lane bridge over the Wissahickon creek

The Walnut lane bridge was certainly most of my wanting to reproduce something similar in HO scale. Although the Walnut lane bridge is a roadway bridge with cantilevered sidewalks, the main structural elements for a railroad bridge would be similar, and I did not try to reproduce an exact copy this bridge, which is right in my neighborhood.

Walnut Lane bridge from creek walking path

The bridge was built in 1908 and at that time was the longest masonry arch span in the world, just now finishing a restoration.

Continuing my Concrete arch bridge

After the second pour was cast and fully cured, I started to detail and assemble the bridge.

Adding stone seam lines stage 1

Then enlarging the grooves with a file, and then a steel rod of the right diameter.

Filing the stone lines

Steel rod in the 3rd stage of scribing the stone lines

I also filed bevels on the vertical edges of the small arches

Filing relief angle on small arches

I then painted the inside walls of the bridge with aged concrete

Testing assembled bridge ( no exterior paint or weathering)

In a future post I’ll talk about painting, weathering and installing the bridge in the layout

Pretty interesting article in the New York Times about a new Model railroad Museum to be designed by Architect Frank Gehry

The Extreme Model Railroad and Contemporary Architecture museum in North Adams Mass. 83,000 square feet with 40 foot ceilings to accommodate 35 foot tall Empire State Building.

The article can be accessed here  Extreme Model Railroad and Architecture Museum

 

COOL