Siegwart
1912 Siegwart Fireproof Floor Co established
SIEGWART in 1912. [1]
When I visited Grays, Mr. James kindly arranged the proceedings, and was my guide, familiar, and friend throughout the day. He told me that at Siegwart's, a pipe was to be made for my education. It was a pipe 15ft. long, 18in. diameter, and this was roughly the procedure:
Imagine a base of webbing; upon this a concrete forming. or, as technically called, concrete laths (Fig. 1), laid flat upon a framework of suitable height, with the longitudinal strengthening rods at the proper distance apart and of suitable diameter for the pipe to be made. The core of steel, made collapsible so as to be easily withdrawn, is laid upon the centre of the material. The core has an axle resting upon bearings at each end, and can be rotated, raised, or lowered by means of end pulleys.
Seven men were engaged in the operation, three on each side, and the acting foreman. With expert efficiency the men took hold of the sides of the material, lifting it on and around the core, then clamped it in position by broad clamps at intervals of about 2 feet.
The next operation was to make a good joint where the material overlapped. For this the mixed concrete was made very wet. The upper fold of the material was raised; this soft concrete spread, the fold brought down, and the whole tapped and smoothed to get a perfectly uniform section. External wires were then spirally wound round the formed pipe from end to end, and as this proceeded the soft concrete was placed over the wires, rubbed in by the aid of soft brushes, and more concrete added to completely bury the wires and give the thickness of materials required. Subsequently the pipe would be banded round and left to dry.
The core is removed, the pipe laid in the field, and watered daily to mature for a month or so. Then it has to be lined with an asphaltic mixture. This at the temperature used is poured in at one end of the revolving pipe, and forms a curiously uniform coating over the internal surface of the pipe. About 169lbs. of the mixture are required for a 15ft. pipe of 18in. diameter. The pipe is rotated some 400 revolutions per minute when the mixture is poured in; the slight incline and centrifugal action does the distribution. A sprinkling of concrete with fine flint as the aggregate forms the bed for the asphalt. Such, briefly, is the process the members of the Institution will see.
There are also on view completed pipes—pipes broken to show the texture and uniformity of section. We heard rumours to the effect that in the near future pipes of this length with sockets would be available, and, if so, another step in progress is made. Altogether, the manufacture is very interesting to watch, and the product, as many of our readers know, is very good.
The machinery, with tools for poles, is of a more complex character, and it is expected the members will see it at work. At the time of our visit we saw a number of poles intended to be used at the new Immingham Docks for the Great Central Railway, a considerable number being on order.
There seems to be hardly any limit to the use of reinforced concrete for the making of poles. For this reason, concrete does not rust, iron or steel does. Hence, wherever concrete can be adapted for poles it will probably supersede those of metal.
See Also
Sources of Information
- ↑ Notes on Grays