FASTER OCEAN LINERS.

Auckland Star, Volume LXIV, Issue 232, 2 October 1933, Page 6

FASTER OCEAN LINERS.

Tf the- records made by the Rex, Conte di Savoia, Bremen and Kuropa are to bo exceeded by nioro than an hour or two it will not bo by packing more boilers and more powerful turbines into a' hull which, after all, is intended to earn money by carrying passengers.. Speed is more tlmn a matter of enorgr. The designer must reckon -with resistance. Higher speed by only 10 per cent must bo attended by an increase of power oF "0, 40, even r>o per cent, depending on .hull lines and other factors—an increase in power which menus higher fuel consumption, more expensive machinery and personnel, not to mention loss of dead-weight capacity. In order to iiiitl out how resistance can be reduced —water resistance — Admiral David W. Taylor built a tank in Washington, towed little, models through it under known conditions, and thus made very accurate measurements, with results that upset many traditions. Sharp prows, foaming wakes and swirling eddies, all the picturesque evidences of speed so" dear to the artists, mean high resistance.

Latterly designers have begun to pay some attention to the air resistance of the structure above water—a subject which also engaged the attention of Admiral Taylor in Ilia pioneering work. Thorn is reason to believe that fully 10 per cent of the resistance encountered by a fourday passenger liner comes from the air. If so, the Bremen and the Europa are more or less wasting about 1.1.000 horse-power when they are steaminsr at thirty knots. Hero we have th& inspiration for the work that Professor Troll is doing at the Folytechiunun of Hanover. Ger[many. He builds models of ships, and tests them in a wind tunnel after the fashion long followed by the designers of record-breaking aeroplanes. Before he started he knew that perfect streamlining is impossible on a, ship. Whatever the wind may teach, strength must be the primary consideration in a structure which is buffeted by wind and wave and must stand up when masses of water weighing hundreds of tons are hurled athwart the bow. So the best that ■pan be done is to round off bridges, funnels and similar projections and thus enable them to part the air more efficiently. It is not likely that the | record-breaking liner of the future will look very different from her present-day prototype. — "2STe\v York Times."