Maintenance of Plymouth Breakwater

THE CHAIRMAN, in proposing a vote of thanks to the Author, said that the subject of plate girder design, and in particular the web design, had received several waves of interest over the years, some of them very well known and others less known. The most recent wave of interest prior to that of Dr. Rockey was the aeronautical one just before and running into the war, leading among other things to the work of Dr. Leggett. At that time it was obvious that there were still a good many gaps to be filled, even for aeronautical use, let alone for gcneral structural use, and it was very pleasing to see that Dr. Rockey had filled so many of those gap so well.

This paper contains a brief description of electronic digital computers and the manner in which programmes are prepared for them. Two examples of their use in structural engineering are included: (i) The elastic analysis of plane rigid frames first tackled by Livesly. (ii) The calculation of influence coefficients for an aeroplane wing considered as a cantilever plate. D.M. Brotton

The subject of this paper is the prestressed concrete pipe and its structural elements. Pipes of this description are used as high-pressure conduits, mainly for water supply, with a diameter range from 18 ins. to 108 ins. I. Alterman