STEEL SUBSTITUTE

Evening Star, Issue 23270, 19 May 1939, Page 11

STEEL SUBSTITUTE

NEW METAL PRODUCED A new light alloy metal, a substitute for steel, which may cause a revolution in shipbuilding, was discussed by the Institution of Naval Architects. It is called navalium, and it is made of alu- , minium and magnesium. Mr W. C. Devereux, who has had wide experience of aluminium alloys in aircraft construction, and Mr E. V. Telfer, a scientist member of the Council of the Naval Architects, presented a paper in which they discussed'the possibilities for steel. They annouftced that the aluminium industry will finance a research‘scholarship of thd value of £250 a year for young naval architects in order that problems arising out of the use of navalium in shipyards may be fully investigated. There are nt present six forms of navalium suitable for shipbuilding, they said, but as time proceeds even fewer will suffice. It can bo produced in plates one inch thick, and in angles, zed bars, girder sections, and channels up to 85ft in length. It can be riveted or welded. The factor of weight-saving ranges from “3” in low-speed warships to “ 6 ” in’ destroyers, and n® particular problem affecting appears to be presented. The principles of armour design, however, would require earnest consideration. Indent damage to the plating should be less likely than in steel, owing t® the much greater elastic deflection of the light alloy. The authors instanced experience with milk churns made of navalium, where, with deliberate misuse, surprisingly little damage had been, found, much less than usually sustained with steel churns. _ 'i’v • -v Regarding the ship design with ftew metal, the authors said that increased streamlining would, of course, be inevitable, but of far greater importune® was the possible return to auxiliary light-alloy sails. The masts and funnel would be replaced by streamlined structures, consisting of a mainsail, an adjustable tail-flap, a rotor nose, in association with a nose slot'of the Hand-ley-Page type, or, more nautical ly expressed, simply a jib sail. Such sails would prevent the 'wind causing ® wasteful resistance, which had to ba overcome, and would be auxiliary power to the main engines. Corrosion resistance of navalium could be shown to be much superior t® mild steel. Recent tests, quoted in th® paper, went to show that the corrosion of steel was five times as rapid as that. of the navalium alloy.lt required t® be covered with aluminium paint. . Solution of the problem of fouling of th® under-water hull was still outstanding. fhcreased production in the heavier units required for shipbuilding, it wa® contended, would produce in a few_ years substantial reductions in the price of navalium. The halving of the present ingot prices at least was reasonably to bo expected. If navalium cost thre® timse as much as steel, structural saviims in the cost of building would b® still enormous. li> warships they calculated that one ton of navalium.could save eight tons of steel in structural and machinery weights, as well as producing a? power and fuel reduction on account of the smaller size of the vessel for a given duty.