Issue 13

Large steel finger joints in a motorway, necessitated by expected large ground movements, had exhibited lively dynamic behaviour and developed multiple failures due to fatigue, the frequency of which was related to the direction of the traffic. Apparent causes are identified and short-term remedies, which were extraordinarily successful, are described. J.M. Rolfe

A wind tunnel study undertaken to investigate large oscillations observed on a microwave tower is reported. It is found that large oscillations can occur for a narrow band of wind directions, which are produced by vortex shedding from the microwave reflectors. R.V. Milford and A.M. Goliger

The paper describes the design and construction of the Hugo's River Viaduct, and reasons are given for the choice of a viaduct instead of an embankment. H.B. Mills

This paper describes the structural design and construction of the surge tank for the Palmiet pumped storage scheme. The free-standing portion of the tank is 62m high and 21 m diameter and is prestressed vertically and circum ferentially. The particular design problems and their solutions are described in detail, together with the methods of analysis used. K.M. Price

The sponsorship of this issue of The Structural Engineer by the South Africa Division is seen by members at the southern tip of Africa as a very real privilege. For those of us who have had many years of close association with the Institution, to a degree that our livelihood and careers have been influenced by our membership, there is a particular desire to record, at this time, our appreciation of this association with the establishment at 11 Upper Belgrave Street in London. T.T.W. Geach