A NON-ROLL SHIP

Taranaki Daily News, 30 November 1932, Page 8

A NON-ROLL SHIP

GYRO COUNTERS WAVE

STABILITY IN STORMS. AN OCEAN APPETITE. November the eighth was the date fixed for the beginning of the maiden voyage, from Genoa to New York, of “the new Italian liner that cannot roll,” the Conte di Savoia, 48,000 tons gross. Many people place the ship that cannot toll in the category of George Washingtons that cannot lie, but the “Scientific American” gives this Italian cherry tree story full credit, and says “there is no doubt whatsoever that she (the Conte di Savoia) will live up to expectations” as a non-roller. She will do so by virtue of carrying in her hull, just below the water-line, gyro-stabilisers. DEALS WITH EACH WAVE. The rolling of a ship is the result of the cumulative action of waves. It is not the result of the action of a single wave. “A single wave can only start the rolling; it takes a whole succession of waves to cause a violent rolling motion. The problem for the stabiliser, then, is but to counteract the force of each individual wave as it hits the ship.” To do this—to counteract immediately the effect of each wave, and thus prevent cumulative effect —does not require great force. “A relatively small artificial force, equal and opposite to the disturbing increment of each wave and applied the instant the wave starts, will be sufficient to counteract the wave’s force.” As it deals only with initial wave impulses the Sperry gyro-stabiliser installed in the liner “does not have to be inordinately large.” It is, however, a bit weightier than the implement that King Canute used against the waves. It consists, in the Conte di Savoia, of three gyroscopic units; the rotor of each unit is 13 feet in diameter (engineers have no unlucky numbers!); the total weight is 300 tons. The equipment weights only 1J per cent, of the total weight of the ship it stabilises—which shows how easily the tail can wag the dog, or, rather, prevent the dog from wagging. ON AN EVEN KEEL. Here is a ship kept on an even keel by a mere toy in its innards. All the same, this three-unit stabiliser is three times bigger than the biggest stabiliser plant already in use. It gives the sea a stability that is unknown to the land during an earthquake—or late on a Saturday night. But it has not yet been

; tested in an earthquake tidal wave. ' The days when the “Westward Ho” 1 folk were prepared to “run a Clovelly herring boat” to and fro across the Atlantic have not quite gone—because herring boats of some sort are still engaged in oceanic stunts—but the number of people who are not attuned to the rhythm of wave-motion is so great that stabilised liners are likely to be in demand. For such people ocean voyages have hitherto had digestive drawbacks. “With all the luxuries of the finest home ready for their enjoyment, and with a cuisine (that may be world-famed) ready to sate the most jaded appetite, passengers are forced to languish in their rooms, or (if somewhat more courageous) to parade the decks miserably.” No one seems to have tried to work out how much the cost of meals will be increased in a stabilised liner. It is assumed that the popularity of a liner will easily pay in fares for the cost of increased appetites. This comparative advantage may be lost when (if) stabilising becomes general. But the future looks after itself. LESS STRAIN, BETTER SPEED. “The Comte di Savoia’s passengers (states the Scientific American) will be able to ignore the storm, even to the extent of using the ship's two large swimming pools without fear of being sloshed about by rolling. Moreover, by maintaining steadiness of the ship the stabilising system gives greater speed in proportion to shaft horse-power, and reduces the strains and stresses on the vessel’s hull.” It also assists in maintaining an average speed, so that the ship “can also very nearly maintain her schedule io the hour.” (Bar fog, of course, and even that, they say, may be conquerable by the much-heard-of infra red rays.) Years ago marine architects advocated the big ship as being the most economical sea-carrier; but the Scientific American writer puts down the causes of the increasing size of ships as two: (1) “The competitive spirit between nations for the greater volume of business usually accorded a modern marvel of construction”; (2) also, and “principally,” the desire “to attain a greater degree of stability.” What big mass construction aimed at in stability, the comparatively small stabilising plant will give. Liners with stabiliser and fog-vision would mean a new era on the North Atlantic ferry. The Conte di Savoia is expected to exceed 28 knots. At tonnage 48,000 and 120,000 horse-power, she becomes the pride of the Italian merchant marine. Her generators produce sufficient electricity to light a city of 200,000 inhabitants. There are “24 non-sinkable lifeboats which can be launched from any angle, and which easily carry 3000 persons. A garage on the liner can accommodate 30 automobiles.”