Effect of Heavy Seas Upon Large Vessels
Professor Tennant, in considering the effect of heavy seas upon vessels of 400 to 600 feet long, remarks that the waves of the Atlantic are stated, by some captains of American “liners,” to attain an elevation of 20 feet, with a length of 160 feet, and a velocity of 25 to 30 miles per hour. Dr. Scoresby, in his paper on Atlantic waves, gives about the same mean elevation for the waves in rather a hard gale a-head; on one occasion, with a hard gale and heavy squalls, some few waves attained a height of 43 feet, with a length of nearly 600 feet, and a velocity exceeding 30 miles an hour. Other authorities assume even more than those heights and distances. The amount of strength, to resist the impact of such waves, must vary with the length and size of a ship, and the materials of which it was constructed; and as the experience of the Britannia Bridge shows, that a weight of 460 tons, at a velocity of 30 miles per hour, could be borne by a cellular tube of 460 feet span, it was demonstrated, that by the use of iron, almost any amount of strength could be given to a vessel; and as stability could be imparted by proper proportions, efficient vessels could be built of any dimensions, as has been exemplified by the Great Britain, which after remaining ashore on rocks for several months, had been got off without serious injury.