A structural support that can be used as a truss girder bridge crane, or the like. The support includes one or more rows 13 of segments 15, that are arranged in side by side relation along the length of the support. Each row 13 has extending there through at least one tensioning element 14 which is anchored at opposite ends of the row and is pretensioned with respect to the row in order to hold the segments of the row together. A support preferably includes one row 13 of segments 15 in a lower chord 11 of the support and another row 13 of segments in an upper chord of the support. Vertical framework is mounted between the chords with ends secured adjacent the segments 15 by the tensioning element. The individual segments and the tensioning elements may be directed to a construction site at the location of use and assembled into rows and the appropriate structural construction.