Addington Water Tower. BUILT OF FERRO-CONCRETE NEARLY A QUARTER OF A CENTURY AGO.

Progress, Volume I, Issue 8, 1 June 1906, Page 200

Addington Water Tower. BUILT OF FERRO-CONCRETE NEARLY A QUARTER OF A CENTURY AGO.

Building in concrete and steel, known as ferroconcrete, is coming to the fore, and will receive a great impetus from the late sad disaster in California ; but it is not generally known that the process is by no means new. We give herewith a print of the drawings of a water tower built in 1882 at the Addington workshops ot the Government Railways. The tower was designed by Mr. Peter Ellis, then chief draughtsman of the railways, but now a draughtsman in the service of the Welling-

ton Harbour Board, and the work was carried out by his brother, Mr. J. A Ellis, of Chnstchurch, who was a foreman of works in the Government service at the time. The whole mass of the tower is of concrete and steel, built to an excellent design, and it stands as a unique work evidencing boldness and originality. At the time the work was proposed the Public Works Department would not entertain it, and the whole responsibility was cast on the designer ; but the correctness of his judgment is seen in the splendid solidity of the work to-day, not a crack or fault being visible Several tons of scrap steel were embedded in the concrete in layers at every foot of height, making a mass which would take a great force to disintegrate, and which of course improves in

solidity with time. The design was worked out so that the centre of gravity was very low, even with the tank full of water, i.e.: 23,000 gallons. A lurch from an earthquake or suchlike would have to be very severe to capsize it. The designer had in his mind the common child's toy, with lead at one end and cork at the other, that always turns upwards which ever way it is laid — a cardinal principle for statical bodies, and vice versa for tractional moving bodies, as in the bicycle. The design shows also a bold departure in the matter of foundations, as will be seen from the drawings. It extends a very short way below the surface of the ground, the reason for this being the fact that a considerable depth of quicksand was found about six feet below the surface, and instead of penetrating through the overlying clay stratum, the step was taken of just skinning off the upper loam and building direct on the layer of clay overlying the quicksand, and the designer informs us that he watched with keen interest the sinking of the tower as the weight of the building increased, until actually nine inches of settlement took place by the time it was completed, and his faith in its stability was upheld by the knowledge that the work, being balanced around its vertical centre, would settle equally, and finally rest safely. This demonstrated that quicksand or any other sand was a good material to build on, provided it cannot get away from beneath the structure. There is no doubt that a great future lies before ferroconcrete construction and the work mentioned is another instance of advanced ideas in the minds of thinkers, long before those ideas are accepted by the multitude ; and there is hardly any work of modern times but has heretofore had a fore shadowing in the brain of some inventor.