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The Structural Engineer

Construction work for two new footbridges across the Thames at Charing Cross is about to begin. Pedestrians crossing the river will soon have the benefit of wide, modem walkways and impressive views upstream to the Palace of Westminster and downstream to St Paul’s Cathedral. The bridges are unique and their design and construction present new challenges to engineers, architects and contractors. John Parker

The Structural Engineer

Dr W.W.L. Chan (F) I congratulate the authors (and thank them!) on their excellent and timely paper, drawing together some 25 years’ statistical data on gas explosions. At last we have a rational basis for reviewing acceptable risk and accidental design pressure!

The Structural Engineer

There is no doubt that fire safety engineering is an emerging new engineering discipline with a sound and developing scientific and research base. Fire safety engineering is becoming more mature and it is now possible to be a chartered fire safety engineer. There is also a growing commercial market and a heed for skilled engineers to be involved in a wide range of areas, which include: 1. Fire and smoke prediction 2. Psychology and speed of people movement 3. Means of escape 4. Management for fire safety 5. Performance of structure and construction 6. Appraisal of the performance of structure pre and post a fire event 7. Fire fighting 8. Performance of building services systems Michael Green

The Structural Engineer

The aim of the paper is to improve the current shape limitation requirements of BS 5400: Part 3, which are known to be unduly conservative, especially when applied to assessment of existing structures. A practical method for finding the local critical stress for plate/stiffener combinations, without limitations on section slenderness, is presented. The critical component is identified for all possible buckling wavelengths, which can vary between the length of the stiffened plate and the wavelength of an encastré plate or stiffener, depending on the section geometry. For each possible wavelength, the critical stress c$ the critical component is found, when restrained by the other component, using an iterative method thut is easily programed for a desktop computer. Validation is provided by 75 finite element (FE) solutions. The results will be incorporated in a methodfor design or assessment. S.K.G. Chou, J.C. Chapman and P.C. Davidson

The Structural Engineer

Due to their durability, aesthetic appeal and corrosion resistance, the use of stainless steels in construction is continuously increasing. Eurocode 3:Part l.4 covers the design of structural stainless steels and was issued in 1996. There is, however, a shortage of design guidance on the fire resistance of structural stainless steels, and this hinders the materials’ wider use in certain applications. Nancy Badoo

The Structural Engineer

Site safety John Rolfe, from South Africa, addresses an aspect of safety: I refer to the cover picture of The Structural Engineer for 20 April 1999.