NAVAL CONSTRUCTION.

Dominion, Volume 4, Issue 1125, 12 May 1911, Page 5

NAVAL CONSTRUCTION.

LAUNCH OF DOMINIONS' GIFT SHIPS. By Telcffraph—Tress Association-Conyrleht (Rec. May' 11,'lo.no p.m.) London, May 11. Mr. M'Kenna, First-Lord of the Admiralty, stated in the House of .Commons that the hull and machinery of the first naval airship cost «JCIO,S7G. The Minister also announced that the battleship-cruiser Invincible, recently reported to have been strained, in dock at Plymouth, would be ont of the hands of the dockyard on May 20. The battleship-cruisers Australia and New Zealand, now being built for the Dominions, would be launched in October, 1911, and July, 1!)12, respectively^ THE NAVAL AIRSHIP. It was announced about a fortnight ago that the new airship, which has accommodation for 20 persons-, had given satisfaction in its initial tests. The naval airship No. 1 is a decagon in shape —that is, a cylinder having ten sides. The nose is blunt, but aft she has a sweet run. The material is an invention of the contractors' metallurgists, and is a magnesium alloy of aluminium. It is slightly heavier than aluminium, and at one-third the weight of mild steel has an equal strength and hardness. The ten sides are built up of lattice girders, having vertical intercostal girders, the top and bottom booms of angles or tees, each bav with diagonal wire bracings. The cntrv is bluff and rather whalc-nose-like, a fiiie run to a point, a.t the. bottom of which is a fin, becoming deeper as it go;s aft. There are two gondolas with a connecting gangway, all of limber, the gondolas being shipshape forms, but rather bluff. They will float, owing to the material, and also from their hydrogen reservoirs. So if the airship tumbles into the sea the crew will be safe. _ Both the gondolas have, a ton-cylinder Wolsoloy petTol motor, with reversing clutch. The forward gondola has two propellers with two wooden blades; the alt gondola has a single two-bladed propeller. The structure is cased in a special silk envelope proofed by the 1010 process, and weighing 100 grammes per square metro (221b. per 1.190 Square yard). The length of the airship is 512 foot and the diameter iS feet. The dirigible's silk envelope is yellow, but the upper half is sprinkled with aluminium dust, which gives it a beautiful silvery appearance. This was done with the. view of deflecting the sun's ravs and so preventing the heating (and expansion) of the skin and interior pas bags as much as possible.. Inside the skin there are eighteen or twenty separate gas bags of hydrogen.