The Critical Load of Unsymmetrical Welded Batten Struts

Recent changes in the design of the American office-block indicate a trend towards simplification of its layout and shape. At the same time the demand for larger and higher skyscrapers is still increasing. A new structural system meets these requirements. The traditional framework with its curtain-wall cladding is being superseded by a structure which consists of two concentric tubular walls, the hull and the core, with the floors spanning between them. Both walls are load-bearing and wind-resisting at the same time. During the past few years several such 'hull-core structures' have been built in the United States by leading American architects. Various external treatments in both steel and concrete have been employed. Although some of the structural problems concerning stability, stress distribution and stiffness are often complex, the hull-core structure appears to have a great potential for future development. E.W. Hirschmann

The paper describes the structural engineering aspects of the extension of British Overseas Airways Corporation’s wing hangar at London Airport to receive the VClO aircraft. The basic factors affecting the evolution of the final scheme are given, particularly with reference to future requirements. The reasons for the choice of reinforced lightweight concrete for the roof beams are stated, and the development of the design in this medium is described. Comparison is made between the permissible stresses adopted at the time of the design and those now permitted by amendment No. 1 to CP 114 : 1957. N.J. Payne and K.F. Shadbolt