Tag
Author
Date published
Price

Contents page

The Structural Engineer

Swanage Bay is land-locked for an arc of 245 degs., extending between bearings, measured from a point approximately in the centre of the bay, of 47 degs. E of North to 28 degs. E of South, or, roughly, N.N.E. to S.S.E., and, within the limits of this arc, is surrounded by steep hills. From the same position in the centre of the bay the open sea thus subtends 115 degs. Swanage is protected from the full force of easterly winds by the Isle of Wight, distant some 25 miles due East, and is, therefore, only affected by winds blowing from a point or two South of East to East-South-East. It is consequently very well sheltered, and the air is mild, and the waters of the bay are generally at a higher temperature than that of the sea outside at any season. There is a double tide at. Swanage, which has a period of three hours between high waters. The maximum rise at springs is 6 ft. 6 in., and the average 6 ft. 1 in. Major F.M. Du-Plat-Taylor

The Structural Engineer

The paper, which has already been published, was illustrated with a pressure distribution diagram (printed with the paper) and a number of excellent concrete specimens, photographs of which, now available, are shown here. During the discussion it was urged that a perfect concrete or reinforced concrete road hnd not yet been found, but it was allowed that rapid progress was being made. Frequently, with regard to foundations and subsidence, there was the question of proper tipping of embankments. Made ground should be filled in definite layers and properly consolidated.

The Structural Engineer

To the Editor, “ The Structural Engineer.” Dear Sir,-It has been a long time since the writer has read any papers with greater interest than Mr. Hakin’s "Wind Bracing in Structural Frames" in your December, 1928, issue and the discussion thereon in the February, 1929, issue. His own latest thought is embodied in an article, "Wind Stresses in Many-Storied Buildings," in "Engineering," issue of May 25, 1928. Two methods of calculation are there presented : the “cantilever” method and the “portal” method. (Let it here be stated that the writer sponsors these methods; he did not originate them.) The cantilever method, in which direct stresses in columns due to lateral wind pressure are proportional to their distance from the neutral axis, is evidently preferred by one of your correspondents. This method has much in its favour. Incidentally, in the unique 33-story Foshay Tower at Minneapolis, Minnesota, described in the current issue (March 7, 1929) of the “Engineering News-Record" the wind stresses were calculated in accordance with the cantilever method. While this method may be more in accordance with the theoretical distribution of stresses, the portal method is simpler and duplicates more connections. A few years ago the writer designed with great care a 20-story buildmg in accordance with the cantilever method. He later found that the working drawings showed all end connections of girders in the same floor to be alike. The detailer had taken the average of the bending moments of a floor and designed his connection accordingly. This gave connections and stresses more in accordance with the portal method than with the cantilever method.

The Structural Engineer

Mr. W.Y. CHAMBERLAIN (Deputy Chief Engineer of the Belfast Harbour Board) said: Mr. Chairman and gentlemen, in the first place I would like to thank you for according me the privilege of being present here tonight to listen to the excellent and most interesting paper submitted by Major Du-Plat-Taylor. I am sure you will bear with me when I tell you that I am totally unaccustomed to speaking in public, and especially before such a distinguished engineering audience as I now have the honour of addressing.

The Structural Engineer

The Chairman, Mr. R. H. H. Stanger, said that the Institution had had an extraordinarily interesting lecture from Dr. Hatfield, who, as the head of the Brown-Firth Research Laboratories in Sheffield-the laboratories which discovered stainless or rustless steel-was well known to all the members. He thought he could say that the high tensile steel which Dr. Hatfield mentioned in the early part of his lecture waa still rather expensive for ordinary building construction.

The Structural Engineer

Dear Sir, That there should be a permanent and lasting Memorial of affection and esteem for the late Sir Alexander Kennedy is a feeling common to all who knew him or his work.

The Structural Engineer

I should like to say a few words at the outset with regard to your position as structural engineers. You are in the habit of taking a metal which is produced to the extent of millions of tons in many civilised countries, and using it as an engineering material. It is produced, from the economic point of view, at the very minimum cost. One reason why we cannot as a nation adopt a really respectable fiscal policy is the fact that we still persist in importing huge quantities of structural steel at slightly above £6 a ton. I mention this because the economic side is apt to appeal to you so strongly as to restrict your mental outlook from a truly engineering point of view. Do, please, regard that as being said in the kindest way. If you go into the big works which are producing the kind of steel which you use you will see evidence of mass production, large casts of steel being made and paased through the rolling mill, and you will have to realise that those steel works from the economic point of view are dependent for their success upon the turning out of a huge quantity of this material always in competition with the Continent and in face of an attrition effect, bringing down the price to the lowest economic point. Dr. W.H. Hatfield

The Structural Engineer

Under this title are published five lectures, delivered by Dr. Rudolph Steiner to the builders, during the building of the First Goetheanum at Dornach, Basle, in Switzerland in 1914. The first Goetheanum, destroyed by fire, was built largely of wood. The second Goetheanurn, the subject of the illustration, is in reinforced concrete, and was still being built when Dr. Steiner died. On this account he never saw the completed work, nor has it been given surface treatment.