Introducing the paper. Mr. Dent said he was very conscious of the fact that it contained very little on direct structural design. There were two reasons for this: firstly, the structural design work associated with oil terminals was conventional and straightforward with one or two exceptions which were dealt with in detail in the paper; secondly, the engineer was now finding it necessary to spend much of his time considering the broader aspects of engineering problems and the planning and economics of a structure were as important as its stability. Therefore he now intended to spend some time enlarging on general problems of planning and economics.
Mr. W. J. Larnach (Associate-Member) writes:- ‘This paper is of particular interest since it describes a method for the calculation of influence lines which in essence is identical with that which I have presented in an earlier paper1 and in my recent book. The only point of difference is the treatment of the effect of sidesway; the author uses an application of the reciprocal theorem (first proposed, it seems, in his reference 1) whilst I adopted the technique of shear balance.'
The following is an abstract of a paper which is filed in the Institution's Library (reference X(8)). Copies are available for borrowing by members of the Institution in the United Kingdom or can be consulted at the Institution. Several well-known forms of construction contain flexible cables as structural components, e.g. the guys of guyed masts, the suspension cables of suspension bridges, the wire ropes used on cableways, and the conductors of overhead electric lines. With all these structures it is a matter of common experience that the stiffness of the cable element is very much less in a transverse direction than in an axial direction. This feature has very important side effects since it makes it possible for the cable, if suitably excited, to undergo low frequency large amplitude oscillations in a transverse direction. In practice such phenomena are by no means uncommon and in the following work a theoretical and experimental investigation of the behaviour of a cable executing free oscillations in its own vertical plane are studied. Such problems arise when a cable carrying some arbitrary load system suddenly sheds all or some part of this. Approximate solutions are given based on two premises. In the first the self-weight of the cable and its applied loads are treated as a continuous distribution along the cable; this is referred to as the 'continuous mass model'. In the second the weight is considered concentrated at a finite number of equidistant points along the cable. This arrangement is referred to as the 'lumped mass model'. T.J. Poskitt
The paper discusses the more usual causes of structural failure and deterioration found by the authors in ancient structures. Seven particular problems and their solutions are described: The Divinity School and Bodleian Library, Oxford, The Church of St. Peter Mancroft, Norwich, The Woolhouse, Southampton, All Souls College, Oxford, Chichester Cathedral, Pembroke College, Oxford, Wells Cathedral. E.W.H. Gifford and P. Taylor
The paper describes the structural design and construction of the National Stadium built in Jamaica primarily for the Central American and Caribbean Garncs held in 1962. The most interesting feature is the grandstand and the design of the arch frames and cantilever roof is described in detail. The considerations of differential deflexions which affected the design and methods of construction are discussed and calculations for the design of the arch frames as a two-hinged arch are given in the Appendix. C.J. Evans