Torwar

Prof. Zalewski was the inventor of a system of structurally efficient roof beams whose profiles are based on the funicular shape, that taken by a chain under the same conditions of supports and load. Beams of funicular shape do not need interior diagonals or a web. The beams he designed in collaboration with Stanislaw Kus were intended to be cast on site, using rising formwork, in stacks of six. The stacks were left to cure for several weeks before the beams were lifted and installed.

Torwar, the structure shown here, is a grandstand roof for a stadium for ice hockey and other uses built in Warsaw in 1960. It features an expressive cantilever of 12 meters (almost 40 feet), and tensile reinforcing cables along the tops of these long funicular beams were post-tensioned after being lifted into place. It is one example from a family of analogously-shaped beams that were widely used in industrial construction in Poland. Although this may appear to the casual observer to be a Vierendeel truss design, it is fundamentally different. A Vierendeel truss is arbitrarily shaped and is made stable by bending action in its nodes. In contrast, this truss is funicularly shaped, which therefore results in an absence of bending. The shape of the beam element follows the shape of the bending moment diagram, which produces constant forces throughout the straight members.

[This project is included in the 2006 exhibit "Waclaw Zalewski: Shaping Structures" which opens at the Massachusetts Institute of Technology in April 2006. The entire exhibit, reviewed by Prof. Zalewski, has been created by: Edward Allen, Visiting Professor of Architecture, David M. Foxe and Jeff Anderson.]