Item 04: Memoirs of a Colonial Boy by Robert Joseph Stewart, ca. 1971 - Page 399
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[Page 399]
156
began to be specialised and separated, and we "civils" started Surveying I under Professor Craig, who at the time was President of the Institution of Surveyors. This Third Year had only two terms, and when the second term ended in August, and we had sat for our finals, we all went off to various engineering construction jobs and consultants offices to have six months practical experience before Fourth Year began in March of the following year. We were allowed our own choice in this matter, and I elected to go to the Metropolitan Water and Sewerage Board, which took three students every year and paid them twenty five shillings a week: some employers paid less. I had three months in the drawing office and on dam sites, and then went out to Newtown to join the Resident Engineer's staff on the first section of the big pressure-tunnel job. This was a straight level tunnel, 10 miles 57 chains long, with a finished concreted bore of ten feet, between the storage reservoirs at Potts Hill and the pumping station at Waterloo. It passed beneath the Western Suburbs, and was formed by sinking seventeen shafts, an average depth of two hundred feet, into the solid sandstone that underlies most of Sydney, and driving tunnels, at the right level, in opposite directions, to meet between the shafts, a feat that called for very accurate surveying and levelling using specialised techniques. I was given the responsibility of taking over this task while the regular surveyor was away on leave for a few weeks: the Board paid me some extra salary while I was so engaged.
This was a major work, not quite half finished when I arrived and divided into three sections each in charge of a Resident Engineer and staff. The rock was blasted out to a bore of not less than thirteen feet, to permit the placement of a solid concrete lining with a minimum thickness of eighteen inches. To place the concrete inside special collapsible steel forms, a concrete "gun" was used. It was a long pointed cylinder from which the fluid concrete was shot into position through a moveable six-inch pipeline, by compressed air. It was the invent-