THE CAUSE OF SEA SICKNESS.

Shannon News, 30 January 1923, Page 4

THE CAUSE OF SEA SICKNESS.

Sea-sickness may be unknown in the near future. Interesting research work is being carried on in the experimental tank of the National Physical Laboratory at Teddington, Surrey, designed, amongst other things, to diminish the pitching of ships at sea. The tank is 520 ft. long, 30ft across and about 12ft. deep. A firm submits the shape of one of their boats to the tank. Here an exact model of it, cast hi paraffin wax is a clay mould, is constructed. - These models are used from 17ft. to 20ft. long, and weigh about a ton. The model is towed through the water at various speeds, and its resistance under every condition carefully recorded. By these tests it is possible to .tell whether the boat from which the model is taken' will be efficient in propulsion; and if it is not/ how or where it is defective. - ' •

There is an apparatus in the tank for creating-regular series of waves. 'Often quite innocent-looking waves will make a ship pitch heavily, while an ugly, choppy sea will not disturb her at "all. This is because the small fierce waves are broken* by the resistance of the ship, -while the long waves are not.

One of the most valuable results of these tests is that they demonstrate what improvements in the form of a vessel may be made to enable a reduction' in the effective horse-power needed to drive it. „