Alusaf Hillside Aluminium Smelter, Richards Bay

The findings of an investigation into the lateral-torsional buckling strength of hot-rolled stainless steel beams are reported. The stainless steel beams under consideration were hot-rolled from a modified AISI type 409 stainless steel designated 3CR12, a corrosion-resisting steel. P.J. Bredenkamp, H. Barnard, G.J. Van den Berg and P. Van der Merwe

In the previous issue sponsored by the South African Division, in 1990, Trevor Geach (an ex Vice-president) commented on the changes which had occurred in South Africa since the creation of the Division by a group of enthusiastic members in 1937. At that time, and up to the end of World War 2, it was accepted that the sign of a competent structural engineer was membership of the Institution of Structural Engineers. A.E. Goldstein

The extent of ground movements and stress concentrations in the vicinity of the reef in the deep mineshafts used in the South African gold mining industry have led to the requirement that special tower structures be developed to span the reef intersection zone in several new shafts. In order that structural engineers are able to design these towers, the dynamic behaviour of conveyances traversing them has been modelled to provide a means of determining the magnitude of the forces generated. This paper describes the design procedures arising from this analysis. An equation is derived which gives the minimum tower length and the minimum second moment of area that are required to ensure satisfactory operation of the shaft. Finally, an example of a typical tower design is given. G.J. Krige