OCEAN RECORDS.

Hawera Star, Volume XLVIII, 18 November 1924, Page 7

OCEAN RECORDS.

PRICE OF. THE EXTRA KNOT. Vice-Admiral Sir F. L. Field's sporting proposal to round off his nine months’ world cruise with the British Special Service Squadron by driving the battle-cruiser Hood home across the Atlantic in an attempt to set up a new steaming record raises the question -of the cost l of record-breaking (states the Daily Mail). The Admiralty declined to entertain the idea on the score of expense. The Hood is the heaviest warship afloat, and is capable of maintaining a maximum speed of 31 knots, or nearly 35 miles an hour. The thrilling sensation of speed in travel is probably best experienced in driving a 30,000 horse-power ship through a lively head sea; but the price of that extra knot required “to break all previous records” has to be considered. . Whatever the mechanism or fuel used in the development of power for propelling a ship, the power so expended is dissipated mainly in overcoming what is technically known as the “skin friction” of the ship, which in an ocean liner may amount to 60 or 70 per cent of the total water resistance.

The object of shipowners is to carry as much cargo and as many passengers and to earn as large a profit as possible for a given expenditure of capital and fuel. The economic speed is therefore determined by the class of vessel. But very high" speeds are unduly extravagant in fuel, the additional cost of an extra knot being out of all semblance of direct proportion to the time saved. For instance, the normal fuel cost of running an 18,000-ton coal-fired liner at 20 knots is of the order of £1250 per day. At 25 knots the daily cost would be £2650. The difference in fuel cost in driving the Hood at a moderate speed of, say, 26 knots and at her maximum of 31 knots would be. in normal circumstances, proportionately greater in the same ratio. But with a hull fouled with a profuse growth of barnacles and seaweed, as the Hood’s hull mnst inevitably be after her nine months’ cruise, the skin friction, and consequently the fuel consumption for a given speed, would also be greiitly increased. It can therefore readily be understood why the gallant Admiral was refused permission to drive his ship in an attempt at record breaking on the ground that such an effort would be a waste of fuel.