Abstract: An elongated structural member of substantially triangular cross-section incorporating either one longitudinally extending continuous passageway of circular cross-section whose center is located at or near the center of the cross-section of the member or a cluster of passageways whose center is similarly located with a member so constructed employed to transmit forces in compression, tension, shear, bending, torsion and any combination thereof and the passageway employed as conduit for air, water, electrical wiring and the like and in the construction of buildings such members specifically designed to serve as beams, columns, or struts.