NON-ROLLING PASSENGER LINERS— OBSERVATIONS ON A LARGE 

 STABILIZED SHIP IN SERVICE, INCLUDING THE PLANT AND 

 ECONOMIES EFFECTED BY STABILIZATION. 



By Elmer A. Sperry, Esq., Member. 



[Read at the twenty-seventh general meeting of tlie Society of Naval Architects and Marine Engineers, held 



in New York, November 13 and 14, 1919.] 



Now that it has been adequately demonstrated in the case of a number of 

 important installations that a ship can be guaranteed against all rolling, a great for- 

 ward step is possible and a new era opened up for the American passenger-carrying 

 service. The traveling American demands the greatest possible degree of comfort, 

 and shipping interests will not be slow to meet this demand by the latest and most 

 up-to-date equipment cast strictly on American lines. 



We will have at no distant date the Service-de-Luxe on the Atlantic and prob- 

 ably also on the Pacific, or, in American travel lore, the "Pullman Service of the 

 Sea." Plans are already in progress for an extensive adoption of the new princi- 

 ple, so that the benefits and economies resulting from a ship guaranteed against roll 

 will be available to the traveling public. This great forward step has been made 

 possible by work going steadily on here in America for the past fifteen years. 



The point of large-scale demonstration has now been reached, and full stabiliz- 

 ing moments, requisite for preventing all roll of even the largest ships, have been 

 practically developed. The great principle thus finally established is that full sta- 

 bilizing moments can now be simply and effectively delivered to a ship that is quies- 

 cent and entirely free from motion. The motion of the ship itself having heretofore 

 invariably been relied upon to create the quenching moments, anything like full ex- 

 tinction of roll has of course been impossible. 



In all previous attempts to prevent rolling, the equipment has operated on the 

 passive principle, depending on a certain amount of roll for the stabilizing moments, 

 as stated; and the amount by which the roll has been reduced has never been satis- 

 factory, nor have the means themselves been practicable. Another difficulty is that 

 the phase lag is found to be insurmountable, the stabilizine efifect — such as it is — 

 arriving "the day after the fair." 



The active gyro stabilizer solves the problem and works entirely independently 

 of the motion of the ship. Delivering full counter-moments to a motionless ship, it 

 is thus free to deal directly with the wave slopes themselves, i. e., with the rolling 

 increments of the sea as they are in the process of developing, even before incipient 

 rolling has set in. The active stabilizer thus acts as a simple preventive of rolling, 

 working in harmony with the slow period of the ship, yet dealing alertly with each 



