trussed tube
A system in which the perimeter walls act as a rigid tube and are reinforced by vertical trusses.
Pictured: 780 Third Avenue
A trussed tube system strengthens a building against lateral forces by reinforcing the perimeter walls with vertical trusses. Diagonal beams cross the spandrels and columns of the walls, producing the same effect as a framed tube but allowing the columns to be spaced farther apart.
The diagonal members reinforce the perimeter as a tube resisting lateral forces. Their structural contribution allows wider column spacing than the closely spaced perimeter columns of a framed tube.
The tube action depends on the reinforced perimeter walls. Diagonal bracing elsewhere in a building does not by itself establish a trussed tube.
