CONCRETE SHIPS

New Zealand Herald, Volume LXXVI, Issue 23521, 5 December 1939, Page 6

CONCRETE SHIPS

A BRITISH PROPOSAL CONSERVING STEEL SUPPLIES [from a special correspondent] LONDON, Kov. 10 Shipbuilders in England are planning to use reinforced concrete in the construction of steamers. Chief reasons for which this construction is urged are the small quantity of steel u.';ecf,the small B amount of skilled labour necessary, and the rapidity with which the vessels can be completed. Skilled labour will be released for work in other shipyards, where war vessels arc being built. Steejkand skilled labour will be freed for|Kthe same purpose. Prices of steel vessels are already mounting rapidly. Those of concrete will be much cheaper and the concrete is easily obtainable. A concrete vessel entails no upkeep costs for cleaning and painting. The equipment of a shipyard is simple—another saving. Beyond a slipway all that is needed is thejordi--narv gear and tackle of a building cbu-. tractor. A very high degree of know-S?K ledge of the theory and practice of reinforced concrete is, however, necessary, but once the moulds for the concrete are planned and made, the rest is simple. * Concrete ships have been built in tho past. During the last war France and Scandinavia gave a lead to Britain in their construction. But Britain was reluctant to adopt the principle. At Le Havre- a 300&-ton British concrete steamer is still in service and in good condition. Another was sold a few days ago by the London owners. Slipways to launch b these vessels must • be specially built to* bear, the extra weight. Frequently ships of this type axe launched upside-down. It is far cheaper and easier to construct the vessel keel'uppermost. "When launched the ship is kept afloat by watertight compartments. Then it is righted by flooding compartments on one side only until the ship turns turtle and floats on an even keel. A naval architect said this week that there were many argupients for and against thesfe vessels. "They are perfectly seaworthy," he said, " and cheaper to build than steel ships. The crews are safe and comfortable, although even the cabins are constructed of concrete. The vessels are a bit slow, however, but that would not matter in time of war. when so many ships are in convoy. There is no doubt that this method of ship construction has not been given a fair trial in this country. It has been very successful in Italy, America and other countries."