ENGINEERING FEATS.

Hawera Star, Volume XLV, 24 November 1925, Page 10

ENGINEERING FEATS.

HUGE WORKS IN SYDNEY. AN UNDER,WATERI PIPELINE. In these days of modern engineering achievements, the wonderful feats performed are merely the centre of a passing interest. Man to-day places great faith in the engineer who calculates to an infinitesimal fraction of an inch some arrangement on which depeds the safety of thousands. In a young country like Australia, with the rush of development upon her, this dependence on the engineer is particularly noticeable, and in the metropolitan districts of Sydney alone there are three great works which demonstrate what an important pant the engineer is playing in our life. The greatest of these is the huge harbour bridge, which will rank with the greatest of its kind in the world, and which now shows considerable signs of construction. This is in charge of a famous firm of English engineers, working to the plans of a Sydney-born and Sydney-trained designer, Dr. Bradfiekl. Another great engineering feat is the electrification of Sydney’s suburban railway system and construction of the city underground railway. The first electrified railway, the Iliawarra line, will be in commission by the end of the year, and the first section of the underground railway will start to cater for passengers early next year. Both those jobs receive continual publicity, chiefly because the public is hungrily awaiting their completion. But a third work, which is also going to benefit thousands of residents, especially on the northern side of the harbour, receives less notice in .the press. Yet, it, too, is no mean accomplishment. It is the northern suburbs outfall sewerage which, serving, a wide residential district of the North Shore, crosses the harbour bed at the Spit, practically at the mouth of Middle Harbour, the picturesque arm of the main harbour running inland almost opposite the entrance of Port Jackson. Of the sewerage construction, no part of it has been more difficult than this underwater pipeline. The laying of this was begun three years ago and the finishing touches are only now being put to it. The principal work was apportioned to divers, who had to join up 20 of the largest concrete pipes ever made. They were each 150 ft long and they were large enough in circumference to engulf a fairsized house. At the outset, great difficulty was experienced in laying a concrete pier to hold the pipes. The work would he well under way at the close of the afternoon shift, but when the job was resumed next morning, the pier would have disappeared —the shifting sand had covered it. The difficulty was surmounted by two divers working through from 7.30 a.m. one Friday until 11.30 a.m. the following day. With ishort breaks for meals they had worked right through the night. The exitraordnariness of ithis feat may be gauged from the fact that the customary divers shift in two hours, and two shifts comprise a day’s work. Diving authori- , ties are claiming the 27-hours shift as , a ■world’s record. Two other records are claimed for this Spit pipeline job. , Tihe same pair of divers worked against time by sticking at a block for seven hours. The third record was one of ; number —eight divers were down below on the same job at the .same time. No harbour, it is said, has known such an assembly underwater.