Fitzroy Dry Dock, the oldest in Australia, was constructed in the days of sailing ships. Time and water pressure had eroded some of the jointing material, and sea water was entering the dock in a number of places.
In one of the deepest drilling operations in British coal mining history, plans called for the sinking of two 3,000-foot shafts, one to be used as a main coal-hoist shaft with skips, the other to house a conventional cage hoist.
A six- foot diameter tunnel, 139 feet long, had to be driven through a cinder-slag fill with voids estimates as high as 70 percent. The tunnel dropped 25 feet over its length and terminated in a cofferdam about 23 feet below river level.
Problem: A city water supply pipeline, 126 cm. in diameter, has to be placed under the Keiyo Highway in close proximity to an irrigation channel. The water supply pipe had to be placed without disturbing highway traffic.
In this project, two 12- foot diameter by 270- foot long tunnels were to be driven beneath thirteen sets of live railroad tracks on the property of the New York Central, New York, Susquehanna, and Western Railroads.