RAISING THE AUSTRAL.

Thames Star, Volume XIV, Issue 4428, 14 March 1883, Page 2

RAISING THE AUSTRAL.

The following is a description of the process which was used to raise the Austral, which appears in the Melbourne Age:— __- " The steamship lies in about 32fl^b^ water at the deepest part. No part of the\ deck reaches the surface. The forepart is only 18in. under water at low tide, but in theafterpart there is, in one corner, 26|ft. of water washing over the upper deck. The cofferdam commences at the upper deck, and will when finished reach above the surface the full length of the vessel. It is being made of planks of kauri pine strongly fitted together, and forming a wall lOin. in thickness. It is made in sections 16ft. in length. Each section, when completed, is lowered and strongly secured in its place by divers. Already the fore part of the ship has been treated in this way, but the heaviest work .' has yet to be performed in theafterpurt, where there is from 20 to 28 feet of water ■ to contend with. The fixing of this cofferdam or wall is, however, by no means the most difficult part of the work. While the ship is full of water, the outer pressure against'this wall, is at present neutralised by the resistance of the water on the .inner side, but when the puinpsare put in ' operation this resistance will of course be removed and the wall will Tiave to withstand the enormous lateral pressure of 91b to the square inch. " In' order therefore, to prevent a collapse the two walls which will extend along the ship from stem to stern will have to be shored up on the inner sides. In the fore part ! of the ship this has already been done. Not only are there great strong beams extending horizontally from side to side, but there are numerous powerful supports extending .across the vessel diagonally. This same thing will be done the full length of the ship, the wall or coffer dam being also shored against 'the' msits - wherever practicable so that it will be for all practicable purposes as strong as the permanent sides of a ship.. When this - walling is completed it will, instead of being caulked, which would be a work involving great delay, be made water-tight ' by means of an outer covering of caanvas. For this purpose 26,000 square.feet of canras will be capable of pumping 230 tons per minute. . ..-.,-,-