SPEEDY WORK

Wairarapa Times-Age, 17 June 1942, Page 4

SPEEDY WORK

CONSTRUCTION OF MERCHANT SHIPS OUTPUT BY UNITED STATES. COLOSSAL PROGRAMMEThe United States Maritime Commission aims at constructing 2000 tankers, freighters and cargo-passengep' ships by the end of 1943, says the “National Geographic Magazine.” One hundred were in service toward the end of 1941. A substantial number 1 have been launched this year and in 43 shipyards, strategically located in 21 States, the colossal programme is being carried forward at a speed' which once would have been considered impossible. Contributing machinery and equipment required are no fewer than 503 industrial concerns located in 31 States. ’ ” *' It was recently reported that a shipyard in Oregon had launched a ship 60 days after its keel’was laid. The size and type of the vessel were not given, but if it were of a standardised type it might well have been of average tonnage. The secret of speed lies in the prefabrication of large sections and in welding them instead of using rivets. It is held that welding is stronger than riveting and that a welded ship, particularly a tanker, will travel faster than a similar one that has been riveted because of the absence; of the friction that is caused by rivet heads. Travelling cranes pick up prefabricated sections of remarkable size, carry them to the growing ship, and loyver them into position where the next phase of welding or riveting takes place. At the present time as much as 50 per cent of some classes of ships may be prefabricated, and thanks to this one tanker which would have required 200 days to be built under the all-rivet system, was launched in 75 days. The average ship on American stocks today is 85 per cent welded. A 30-ton prefabricated bulkhead, or a whole stern floating through the air on crane gear are not uncommon sights today. The American programme includes 600 new tankers. In one popular type the cargo space is divided into 24 compartments to enable the ship to carry a wide variety of oil or oil products. Some of the new ships have as many as 12 masts which are known as king posts, to permit the use of more derricks and the swifter handling of cargo. These masts are hollow and cylindrical in shape and ventilators at the top of each carry fresh air into the body of the ship. About 50,000 officers and men man the existing American merchant fleet of vessels above 1000 tons. Tire ships of the new programme will require about 15,000 more officers and 60,000 more seamen. The training of many thousands of new personnel is being carried out in many institutions.