When I first built the W&N I cut out the streams and rivers and then just bridged over them with flex track.  Most bodies of water were fairly narrow, less than 9 inches so it really wasn't a problem and let me get operating before spending the time to build a full bridge.

However, after several operating sessions, some of the operators were giving me cra….. er feedback about the "bridges" because the flex track would, well, flex under the weight of an engine.  So I decided to create some quicky bridges out of balsa until I could get around to a more permanent solution.

Here is the "bridge" at the north end of Coatesville over the Brandywine Creek before the project started.

I dug out my trestle data pages from an old MR article a decade ago.  Based on the information there and the size of the opening I decided on about a 12 ft span with trestle bents with 5 piles.  I drew a quick elevation drawing of the bent, then redrew that on a scarp of plastic sheet and made a jig to hold the 1/8" balsa strips.

I used the jig to make 6 bents for two bridges using white glue, while watching college football.  A couple pieces of basswood 2x10 were used for diagonal braces.  I used 1/16 x 1/8 balsa for the floor stringers and assembled the bridges using white glue.

The bents were sanded a bit using an emery board to get the bridge to just slip under the track.

I spray painted the bridges a base coat of Rust-o-leum  camo brown.  They were then dry brushed with a light grey paint to lighten the dark colors.

The bridges were then installed under the flex track.  They are quick and dirty bridges but for a couple hours and less than $3 in materials, they are more than adequate until the scenery crew (me) can work their way around to Coatesville.