Services and Air Conditioning for Tall Buildings. Discussion on the Paper by J. R. Kell, M.J.Mech.E.

The Hardy Cross, or Moment Distribution, method of frame analysis offers interesting possibilities, when used on an automatic digital computer. For a number of years the analysis of elastic hyperstatic frames by computer has been mainly carried out by methods which require the explicit solution of large sets of simultaneous equations. If conventional techniques are used to solve the equations, the storage space required in the memory of the computer is approximately proportional to the square of the number of joints in the frame. This means that in practice, with present-day computers, only relatively simple frames can actually be analysed by these methods.

Mr. M.Z. COHN The background of Professor Neal's paper is to outline a very interesting property of redundant structures, which consists in conserving constant deflexions at the point of collapse, above a definite critical value of joint (or support) flexibility.

MR. KURT H. GERSTLE The author's method of analysing braced frames will be welcomed by structural engineers. This discussion will touch on two different aspects of the paper: First, the effect of column continuity, and, secondly, the suitability of the proposed method to the various example problems presented.