The literary digest . ly uni-form, as they would be on acommercial vessel; but with thewide range of speeds desirable on?a ship-of-war, electric control isfound to combine flexibility andeconomy in a greater degree thanwhere the drive is purely me-chanical. Our quotations arefrom a report in The ElectricalWorld (New York, .January 11).Said Commander Foote in histestimony before the committee: In the main, sir, the bigadvantage of the New Mexicoover any other ship of her size isthis: Of course, when you cometo the big-powered ships of thatclass, the reciprocating engines generator, which is the
The literary digest . ly uni-form, as they would be on acommercial vessel; but with thewide range of speeds desirable on?a ship-of-war, electric control isfound to combine flexibility andeconomy in a greater degree thanwhere the drive is purely me-chanical. Our quotations arefrom a report in The ElectricalWorld (New York, .January 11).Said Commander Foote in histestimony before the committee: In the main, sir, the bigadvantage of the New Mexicoover any other ship of her size isthis: Of course, when you cometo the big-powered ships of thatclass, the reciprocating engines generator, which is the prime mover, of course, is as to the speedof the motor inversely as the number of poles. You know in themachines you have there are many electric poles. For instance,in the motor you have two poles and in the generator you havethirty-two poles, and your speed of the motor is as one to sixteen,so you step down yom* electric windings. Now, then, you can rigyour motor so that you can throw a switch and have thirty-two. ««» THE NEW MEXICO, WHOSE MOTORS DEFY TORPEDOES. Destroy half your motive power . . and the other unit will drive that ship still at 17 knots. practically reach their hmit, in view of the size and . Now, it is a fundamental principle of the turbine that itsefficiency depends upon a high rotary speed, and the converseis true in regard to the ships propeller; the ships propellerto have a high efficiency wants a big diameter and low , if you have a turbine running at its maximum effi-ciency, you have to have a high speed, and to have the propellerrunning at its maximum efficiency you have to have a low speed;and if you hook the two directly together, you get a very pooroperating efficiency. At that time the mechanical reductiongear and the electric connection were devised. . With themechanical reduction gear, with the ship always running at onespeed, you could get a very high efficiency. If you have oneof the big hners running back and
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