THE JOURNAL OF GAS LIGHTING, WATER SUPPLY AND SANITARY IMPROVEMENTS
SOUTH METROPOLITAN GAS-WORKS.
THE THREE-LIFT GASHOLDER.
THE seventh and last plate, which appears with to-day’s JOURNAL, shows the principle, and gives the details of the ties at the top of the framing. So far as this writer is aware, ties of this kind were first introduced by Mr. Paddon; but they consisted simply of Straight, bars of iron, each with a stretching screw connecting alternate columns, thus forming a series of triangles all round the top of the framing, great rigidity and equalizing the strain, which, with the old system of radial rollers alone, is of great importance. Under the system of combined radial and tangential rollers, the stress of the gasholder on the framing is so far equalized that the top ties for this purpose are unnecessary. They have been added in this case for the purpose of giving absolute rigidity to the- framing when the holder is empty. It will be seen from the drawing that instead of simple ties a series of trusses has been adopted, which greatly increases effectiveness, and reduces the strain on the ties to one-fourth of what, it would be if they were carried in a straight line. Another difference is the use of two steel-wire ropes, each extending in an unbroken line all round the top, with only one joint, tightened by means of stretching screws, when the gasholder is quite full, and secured by clip. The rope is securely dipped to the angle iron on the top of each standard, and at the inner end of each strut there is an arrangement for adjusting the truss to the required tension should there be any little irregularity in the strain. Newall’s steel rope, 3 1/2 inches in circumference, is used, which, according to their list, has a breaking strain of 33 tons. The actual maximum calculated strain is under 3 tons.
In this plate is also shown the hand railing fixed on the top of the framing, which will enable adventurous persons to enjoy a promenade round the top on a fine day, and will give facilities for periodical examination and painting…
It may be observed that in the -whole structure there is not the slightest attempt at ornamentation. It was originally intended to have an ornamental finial on the top of each standard, and for this purpose a number of wooden models were made and placed in position; but instead of pleasing everybody, they pleased no one. In fact, criticism appeared to exhaust itself on these finials until one day Major Dresser visited the works, and said, “Don’t spoil the thing by those useless ornaments. There is nothing in the shape of ornament in any other part, therefore leave it out here. This advice was followed, with the result that the hand railing finishes the top of the framing, and thus supplements the objectionable finals.
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