Issue 12

A comprehensive experimental investigation on the effects of natural winds on high-rise buildings is currently being undertaken at the University of Hong Kong. S. Mackey, Pius K.L. Ko and Louis C.H. Lam

The basic wind speed used for determining windloads for structural design is derived from continuous wind records from meteorological stations, adjusted as necessary to a common basis. Values represent the 3 second gust speed at 10 m (30 ft) above ground in an open situation. There are therefore a variety of factors influencing the starting point, namely, the 'adjustment as necessary', the actual height above and the nature of the ground and openness of the situation. Wind tunnel measurements are no more pertinent since each tunnel exhibits its peculiar characteristics. R.G. Taylor

The assessment of the likelihood of failure of a structure is a difficult matter which has for too long been neglected by the profession at large. It is surprising, for instance, that statistics relating to structural damage produced by various causes such as fire, explosions, variations in loading and strength effects, are not more readily available. It is encouraging that work is now proceeding, for example, at the Fire Research Station on the likelihood of fire damage. The probability of occurrence of a particularange of levels of severity of damage as shown by a probability density function can be obtained by looking at the past history of the total population of structure or class of structures. However, the problem of predicting the likelihood of an accident resulting in total or partial collapse of a structure is more difficult. Sir Alfred Pugsley has again produced an interesting and thought-provoking paper. As he has pointed out, resort has to be made to a subjective assessment. This suggestion at first sight may seem a desertion of objective scientific reasoning but of course engineering is not a science and relies heavily on personal experience and subjective assessment. It is obviously important that the type of assessments suggested by Sir Alfred are made by very experienced engineers and it is a direct use of their experience channelled to a new purpose. D.I. Blockley

The first President of our Institution was installed in 1908. He was the Earl of Plymouth and held the Ministerial appointment of First Commissioner in HM Office of Works in the Government of that day. Broadly speaking, that Department was the political ancestor of the present-day Property Services Agency, which is now within the Department of the Environment. Since that far-off date there has been, so to speak, something of a famine in representatives of central Government to hold the high office of President in our Institution. This is the first time that an engineer from central Government has been honoured in this way. L.R. Creasy

A client’s aim is to secure the maximum benefit from his investment. He therefore requires a maximum useful life from his structure without spending any more than is necessary on its construction and subsequent maintenance. K.W. Longbottom and G.P. Mallett