RECENT PROGRESS WITH THE ACTIVE TYPE OF GYRO-STABILIZER 



FOR SHIPS. 



By Elmer A. Sperry, Esq., Member. 



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



New York, November 18 and 19, 1915.] 



It was due to the desire on the part of the officers of our navy to obtain re- 

 liable data at first hand that certain noteworthy experiments on board the U. S. S. 

 Worden with the active type of gyro-stabilizer were undertaken. The gyros were 

 fitted to her main deck solely for experimental purposes and for obtaining very 

 complete data and records having an important bearing on the question of stabi- 

 lization. The observations thus made were quite diversified as they were made to 

 include the stabilizer plant proper, all the features of automatic precession con- 

 trol, methods of producing artificial precession of the gyros, and also observations 

 on the ship itself under conditions of stabilization as to motion and behavior and 

 also the effect upon the structure. As a result of this work it has been established 

 that the gyroscope is useful in solving certain problems at sea, and orders have 

 been issued for fitting permanent plants, thus putting it into practical service. 



Since this work further investigations have been in progress. Among these 

 have been determinations of the exact amount of the true wave increment the 

 gyros are required to neutralize, involving the relation of the gyro-quenching in- 

 crement to the natural extension curve of roll of the ship. Some of this data was 

 touched upon in the paper presented to this society in December, 1913. 



Since this time further experience has been obtained and a number of experi- 

 ments have been undertaken to determine the relation of ship to gyro. It is grati- 

 fying to note that all of this work has proven the soundness of the basic formula 

 originally laid down by Naval Constructor Taylor, now Chief of the Bureau of Con- 

 struction and Repair of our navy, in course of which he points out that gyro mo- 

 ment of stabilizer equipment for ships varies directly as the characteristic of the 

 ship; i. e., the product of the displacement, the metacentric height and period of roll. 

 There is no variation from this rule involved in the fact that it has been definitely 

 ascertained that small boats require relatively larger moments or greater stabilizing 

 power than is the case with larger ships. This means that waves of given magni- 

 tude beleaguer small ships more than they do large ones, which is to be expected, and 

 therefore require relatively more roll quenching power to be fitted. Again, it is pos- 

 sible to adjust the plant in other ways to meet special conditions such, for instance, 

 as limited space, met with in the case of submarines; limited weight, which is the 

 case where the gyro is placed on deck, as in the motor yacht Widgeon, and which 



