Belgian truss

Fink truss, Belgian truss, French truss

A symmetrical truss, esp. used in supporting large sloping roofs; in the form of three isosceles triangles—one in the center with its base along the horizontal tie, and each of the outer two having its base along the sloping sides of an upper chord.

finned tube

Fink truss, above; long-span Fink truss, below A metal tube having fins (i.e., metal plates, jointed to the tube, perpendicular to its length) to transfer heat from the tube to the surrounding air.