The Lateral-Torsional Buckling Strength of Hot-Rolled Stainless Steel Beams

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

One of the major challenges facing the new South Africa is that of providing shelter for its burgeoning urban population. Current estimates of housing needs vary considerably because of the differences in assumptions on which they are based. One of the most authoritative commissions in recent years, the de Loor Commission, concluded that the existing housing backlog is 1 299 000 units and the number of shelters to be put up for new family formations amounts to 198 000 units p.a. Thus in order to provide for new family formation and to eradicate the existing backlog over 10 years, approximately 300 000 units have to be provided p.a. R.B. Watermeyer