Response to Viewpoint on The Associate-Member: is the Institution doing Enough? by Philip Beadle

Dr. N. G. Bunni: The paper is a very interesting one. It provides some useful information to the design engineer on comparative costs of structural steelwork in the form of portal frames, lattice girders, trusses, and space frames, incorporating the nodus jointing system. Where space frames are concerned, however, an impression is given that those frames incorporating the nodus jointing system are typical of all space frames in respect of cost, weight, and size. (See last paragraph of p177, the legend in Fig l, the comment made in para.2 of p178, and later in item (g) on p181.) J.F. Horridge and L.J. Morris

Shortcuts in design It may seem to our readers, as it did to us, that we receive a large number of letters giving shortcuts to the design of reinforced concrete in bending. It appears, however, that we published only one letter on this subject last year, from Mr P. H. Gregory, which appeared in October in outline only, since it set out two programs for a ‘home’ computer. We have now received the following offering from Mr R. N. Morgan of Edinburgh: I have identified an expression that can be used for the direct calculation of A, that is applicable to the rectangular concrete stress block of CP 110 and also to the ‘Beeby’ stress block of BS 8110 as well as the so-called ‘exact’ rectangular/parabolic stress blocks applicable to both Codes. The derivation of the expression is enclosed for your information. Verulam

Since 1972, our profession has been divided over Codes of Practice between those who favour ‘limit state’ Codes based on partial safety factors, such as CP110, and those who prefer permissible stress Codes such as CP114. Today the argument about the merits of the two methods is no nearer resolution; CPl14 is still preferred by many engineers and is widely used, whereas the new partial factor Codes for masonry and steel (BS5628 and BS5950) are raising as much controversy in those fields as CPllO did in the field of concrete. It is not only structural engineers who question the philosophy of partial factors-civil and municipal engineers have strongly supported moves to retain permissible stress Codes, and their interests must not be forgotten.