Page:Popular Science Monthly Volume 90.djvu/284

 The Swiftest and Biggest

The power plant which drives New York's subway trains develops 65,000 horsepower—less than 40% of that required to drive our

Our new battleships are the most daring ever proposed. They will have a length of 850 feet between perpendiculars and an over-all length of 874 feet. What that means is shown by thq

FEW months ago the United States Navy Department announced that it would build battle cruisers with a length of 850 feet and a speed of thirty-five knots—forty miles an hour. Only shipbuilders and naval officers realized the full meaning of the Department's program. England is said to have completed battleships of about the same size but never have we attempted to build a fighting vessel so huge. The battles fought by the British and German fleets in the North Sea were object lessons. They showed that sea fights are won by speed and hitting power. And so the Navy Department determined to build the fastest battle-cruisers and to arm them with the most powerful guns.

What is a battle cruiser? It is a ship which is faster than a superdreadnought, but not so heavily armored. Battle cruisers were lost in the last North Sea battle largely because they had not the protection of a superdreadnought. But although they went down, they saved the day for England. They kept the German fleet in action, until the British Grand Fleet with its superdreadnoughts could appear on the scene. And so we decide that battle cruisers we must have.

It is one thing to design a battle cruiser 850 feet long with a speed of thirty-five knots; quite another to build it. It would seem simple enough to magnify existing models and to put in bigger engines. That