02-23-2009, 11:21 AM
You are getting a lot closer, both bridges would still tend to "rack" lengthwise under load. Think of a card table with no folding braces. The braces on the first bridge would work better if the bracing between the upper and lower stringers went full length to fully triangulate the bridge into a truss. Then the bracing between the legs and the bridge should start about 1/2 way up the leg or so and go directly to the center of the span.
On the second bridge you should add braces between the outside legs and the inside legs of the bridge so that the entire bridge is one piece. You need to have it so that if you pick it up to install it in the layout without ties or track, the bridge is a one piece structure. Think in terms of the bridge supporting the track and not vice versa.
On the second bridge you should add braces between the outside legs and the inside legs of the bridge so that the entire bridge is one piece. You need to have it so that if you pick it up to install it in the layout without ties or track, the bridge is a one piece structure. Think in terms of the bridge supporting the track and not vice versa.