A journal following the history, design, construction and operation of Bernard Kempinski's O Scale model railroad depicting the U. S. Military Railroad (USMRR) Aquia-Falmouth line in 1863, and other model railroad projects.
©Bernard Kempinski All text and images, except as noted, on this blog are copyrighted by the author and may not be used without permission.

November 16, 2009

Adding Arches to Potomac Creek Bridge

Work continues on the bridge. I finished making the arches and swaybacks. I started adding them to the bridge trusses. Each span gets four. With 3 spans I need twelve arches.

Both trusses are complete. I also prepared the floor beams and made a trip to Pearl Arts and Crafts to pick up some long sticks for the stringers. I could have cut them on the laser, but decided to use some scale lumber. They are supposed to be 5" by 10" by 32 feet. I couldn't find that exact set of dimensions, so I went with 1/8 by 1/4".

The bridge will be about 2 inches lower than in this bottom photo. I have not yet cut away the ground where the abutments will be, so the bridge is riding a bit high.

When I installed the arch cover plates I noticed that the bottom pieces that cover the sway backs are too short. They should extend to the below the bottom chord and abut the adjacent arch. I can cut new ones and install them separately, so it's not a big deal.


  1. Bernie,
    That looks fantastic! I think you mad ethr ight choice with your scaling.

    When will Alkem release the N-Scale version? It would make a dramatic photo pices for roster shots and the lick, regardless of the road you model.

  2. An N scale version would be interesting. The chords would be 0.075 by 0.075 inches, while the braces would be 0.0625 by .012 inches. The treenails wound be 0.018". It could be done to the full size. Would probably have to use birch plywood for strength. If you want one let me know and I'll try making the conversions.

    1. Although I realize this is quite an old thread, I was curious if an N scale version had ever come to fruition? I am very interested in acquiring one. Thanks