The basic forms for steel connections have been established for quite a long time (endplates, seating cleats, and web cleats), and they are usually of fairly standard proportions. However, in recent years, the author has noted the appearance of a significant number of connections that are oddly proportioned or unorthodox in concept. There is no harm in novel ideas if they are well executed, but unfortunately the opposite is often the case. Some examples (obviously anonymous) are illustrated (Figs 1-3). Of course, they are not typical of the majority of current steelwork practice, but such poor connections display a serious lack of understanding of engineering principles, and their appearance in significant numbers suggests that present-day detailing standards are not all they might be. A.N. Beal
The partial collapse of Ronan Point in 1968 alerted the construction industry to the problem of progressive collapse arising from a lack of positive attachment between principal elements in a structure. This resulted in amendments to both the Building Regulation and the UK’s steelwork design Code. Essentially, these changes take cognisance of this failure and require structures to have a minimum robustness to resist accidental loading. One method of achieving this is by tying all the principal elements of a structure together. This means that the beam-to-column connections of a steel frame must be capable of transferring a horizontal tying force (in a simple structure they must also be designed to transmit the vertical shear) in order to preserve the integrity of the structure and prevent progressive collapse in the event of accidental damage. G.W. Owens and D.B. Moore