NAVALIUM.

Auckland Star, Volume LXX, Issue 112, 15 May 1939, Page 8

NAVALIUM.

USE IN SHIPBUILDING.

Navallum, a new light-alloy metal made of aluminium ami magnesium, was discussed as the future material for ship construction by the Institution of Naval Architects, in London recently.

Mr. "W. C. Devcreux, who has had wide experience of aluminium alloys in aircraft construction, and Mr. E. V. Telfcr, a scientist member of the Council of Xaval Architects, presented a paper in which they discussed the possibilities of the new metal as a substitute for steel. They announced that the aluminium industry will finance a research scholarship of the value of £2.~>0 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 at present six forms of navalium suitable for shipbuilding, but as time proceeds even fewer will suffice. It can be produced in plate 3 one inch thick, and in angles, Zed bars, girder sections, and channels up to Soft in length. It can be riveted or welded. The factor of weight-saving ranges from <- 3" in low-speed wart-hip.-; to ••(;"' in destroyers, and no particular problem affeetiug safety appears to Ik; presented.

Indent damage to the plating should be less likely than in r-lecl, owing to the much greater elastic dcllection of the Ji-rht alloy. The authors instanced experience with milk churns made of navalium, where, with deliberate misuse, surprisingly little damage had been found, much less than that usually sustained with steel churns. A Return to Sails? Regarding ship de-ign with the new metal, the authors s;iid that in*-: t-.i-cd stream-lining would, of course, be inevitable, but of far greater importance was the possible return to auxiliary light-alloy sail--.. 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 no*e slot of the Handley-Page type, or, more nautically expressed, simply a jib sail. Such saiU would prevent the wind causing a wasteful resistance which had to'be overcome and would be auxiliary power to the main engines.

Corrosion resistance of navalium could be shown to be much superior to mild steels. Recent testa went to show that the corrosion (if steel was live, times, as rapid as that of tiie navalium alloy. Tt required to l>e covered with aluminium paint. Solution of the problem •of fouling of the underwater hull was still out ~ta tiding.

Increased production in the heavier units required for shipbuilding, it was contended, would produce in a few years substantial reilii'-! ions in tlie pr'ce of navalium. The halving of tile present ingot prices at least was reasonably to lie expected. Tf navalium cn-l three times as. much as steel, structural savings in the cost of building would still be enormous. In wardiips they calculated that one ton of navalium could save eight tons jf .-teel ill 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.