POURED INTO A MOULD.

Gisborne Times, Volume XLVIII, Issue 4601, 3 July 1917, Page 7

POURED INTO A MOULD.

BUILDING CONCRETE SHIPS

SAMPLES FROM NORWAY

Though the construction of concrete ships mav seem strange it is a problem that has already been overcome in other parts of the world. Shipbuilders in Norway recently turned out a reinforced concrete vessel of ovei 6000 tons, and it is claimed to be a success. If such ships can be produced in Noiway, there is no reason why Australian engineers cannot make a success of’the same class of work. , A few years ago the Sydney Hai b-u Trust took up the idea of building concrete pontoons, and when the - new jetties at Circular Quay were being built several of the old wooden beit.is were replaced by concrete. The one m use at Milson’s Point jetty is the biggest of its kind in Australia. It was constructed at the Glebe, and though, doubt was expressed as to whether it would float, the launching was a complete success. The new pontoon was towed into position at the-Quay, and has not since given the slightest trouble. It. floats just the same as the wooden ones, and doubtless many travellers' are unaware that it is built of concrete. . , . The method of constructing ships or pontoons of concrete is just the same'as that applied to a- reinforced concrete building. All modern. steel structural buildings are merely battleships upended. In the building ot these ships it is necessary to lay down the -frame very much m the same way as is the case with the present ships. Moulds are made of wood and oonstructed to the design of the ship which is to he, built. . These moulds arc laid down in sections round the frame, of the structure and bolted together. Inside these there will ,he again placed the reinforcing material, such as steel bars or wire extensions. The concrete is mixed in the usual way, sand, grit, or gravel being used It is then put into the moulds and stamped down. After the lapse of a few days, when the cement mixture is dry, the moulds are removed, and the next section proceeded with. The reinforcing material is carried on in such a. way that there is no possibility of preventing it binding into a solid mass almost as hard as steel itself ’The impervious nature of this material and its absolute strength are proved by the qualities of the floors in most modern buildings which are. made of the same material. It is fireproof, and of greater resisting strength than any other materials. With a concrete ship it is a case of one mould, many ships. The vessels are built in sections, each having its own mould, so that any vessels of any particular design can be constructed once a complete set of moulds is made As each part has set, the mould can be removed and shifted to the spot, and again filled'with concrete which in turn would be emptied, and 1 berome part of a great line of ships, all of which would be ready for launching within a few weeks of each other. No area of water front-would be. top big or too small for the construction of this class of ship. The materials foi the making" of cement abound througl out the whole of Australia, and there should be no great difficulty in provid. mg the steel' reinforcement require! for this work, it not being of the na‘ ture of high-grade steel. * ' ‘ ' ' ‘A e