Battle Cruisers in the World 



proposed battle cruisers at a speed of 35 

 knots. Never in our naval history has 

 such a power plant been installed in a ship 



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comparison with New York's Public Library and adjacent Fifth Avenue buildings in this 

 picture. They will cost $16,500,000 each. It will take 180,000 horsepower to drive one at 35 knots 



is not the way ships are built. The 

 Lusitania made twenty-five knots with 

 70,000 horsepower. To make fifty knots, 

 it might be supposed that it would be 

 necessary merely to double the size of the 

 engines. Battle cruiser building* would be 

 easy if that were all. Each additional knot 

 is purchased at the expenditure of thou- 

 sands of horsepower. Our naval engineers 

 estimate that 180,000 horsepower w'ill be 

 required to develop thirty-five knots in 

 one of the new battle cruisers. Never 

 have marine engines of that power been 

 built. As a result, American shipbuilding 

 companies are loath to bid on the cruisers. 

 The builders say that they will not bid ex- 

 cept with the understanding that they will 

 receive the cost of building plus ten percent. 

 A similar plan of paying for ships was 

 worked out in Germany when the giants 

 Imperator and Vaterland were built. The 

 Naval Appropriation Act of Aug. 29, 1916, 

 permits this method of bidding. Our 

 shipbuilders maintain that even on the 

 ten-percent-plus-cost basis they will prob- 

 ably be losers because the Government will 

 undoubtedly copy their successful models, 

 and build ships in its own yards after the 

 hard work has been done in private yards. 

 To develop a speed of thirty-five 

 knots — forty miles — an hour, turbines must 

 be employed. A steam turbine works on 



the windmill principle. Steam spurts 

 against blades on a long shaft. The old- 

 fashioned steam engine — ''reciprocating en- 

 gine" in engineers' language — is very tall. 

 Its pistons work up and down in the 

 cylinders, as everyone knows. Recipro- 

 cating engines take up much space, so 

 much, in fact, that a ship like the Lusitania, 

 which was driven by them, was practically 

 all engines. The steam turbine requires 

 \ery little head room and very little floor 

 space, so that great economies can thus be 

 effected. Moreover, oil will be used as 

 fuel, which can be carried in the double 

 bottom of the cruiser, thus further releasing 

 space which would otherwise have to be 

 taken up by coal bunkers. Moreover, 

 steam turbines are lighter than recipro- 

 cating engines. They can be heavily 

 overloaded, should emergency arise- 

 On the other hand, the use of steam 

 turbines is not all plain sailing; for turbine 

 engines, unlike reciprocating engines, are 

 non-reversible and special means must be 

 provided for backing. Furthermore, the 

 most efficient speed of revolution of a 

 boat's propeller is very much lower than 

 the most efficient speed of the shaft of a 

 turbine engine. Therefore it is not the 

 most efficient proceeding to couple the 

 turbine directly to the propeller-shaft. 

 Gearing and a novel method of driving 



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