Manawatu Herald TUESDAY, NOVEMBER 5, 1918. LIFE OF CONCRETE SHIPS.

Manawatu Herald, Volume XL, Issue 1899, 5 November 1918, Page 2

Manawatu Herald TUESDAY, NOVEMBER 5, 1918. LIFE OF CONCRETE SHIPS.

THE United Slates Covernmenjjias decided t<* spend more than fld,000,000 on building 58 concrete ships of i . 500 tons capacity. .1 he peri'onnanccs of; the Faith, a 5,000tou reinforced concrete steamship launched a few months ago at San Francisco, have surpassed expectation:-. On her trials over a -10inile course, in spite of new engines and machinery, untuned by previous running, she made over 10 knots an hour, though only nine had been expected. Vibration under full speed was remarkably small, confirming the predictions of engineers iainiliar with the practical absence of vibration in railway bridges and other buildings of fcrro-concrele. The vessel was easily manoeuvred. Her voyages in actual service have been even more satisfactory. A re-cently-published statement by Mr IE J. Wig, chief engineer of the Division of Concrete Ships, United States of America, deals chiefly with the question of. durability. As the result of the investigations of his Department, Mr AVig says that they do not consider'that ‘The concrete ship may be classed as an experimental ship any longer. AA’e think it structurally just as sound as the steel ship. AA’e know that damage by the salt water of the sea need not be feared for three years, if at nil. This conclusion is based on examination of all the concrete structures in sea water of the Navy Department for a period of three yea is. I helped to make this inspection.” Mr AVig points out that the cost of concrete ships is about two-thirds of that of steel ships, while they can be built in much larger numbers than ships of steel or

wood, mainly ljocau.se concrete vessels do not require a largo plant, amt because the material is readily available. Even a small steel ship plant costs .CIOO.UOO. A concrete ship plant can be built for £3,000, and can be made so as to be portable. The principal machinery required is a mixer, a hoist, and a derrick.