Then I learned something too. Thanks Nathan. We were all correct.
Fishbelly is a term used interchangeably for the triangular floorbeams on some bridges as well as deck truss bridges with a polygonal bottom chord, with a truss deeper in the center. Example: http://www.historicbridges.org/truss/millcr/
Yes, I have always understood the term "fishbelly" to refer to the type of floor beams used in this, and other bridges from the time period.
I am unfamiliar with the type of fishbelly to which Fmiser is referring. Might be something to check on before we add a category for this.
In my world thay are the floor beams with the triangle shape.
I'm confused. I thought the term "fishbelly" (as it applied to bridges) referred to polygonal or curverd lower chords, usually on a deck truss. But I don't see any curved lower chords in any of these photos. Do I have the definition wrong, or am I missing something in the photos?
Fishbellies do indeed rock Jules!