Sperry's First Triple Flow Steering Systems Installed At NASSCO

Sperry Marine Systems has delivered four 24,000,000-inch/ pound steering systems to National Steel & Shipbuilding Co.

(NASSCO) for the 188,500-dwt San Diego-Class tankers. These systems are the first triple flow systems delivered in Sperry's expanding steering system business.

The triple flow system, which is based upon Sperry's proven dual flow design, utilizes three stages of oil flow to provide smooth rudder motion. Three rudder servo amplifiers control two directional valves or a dump valve to provide three rudder rates. The valves are operated as a function of the difference between ordered rudder and actual rudder angle which is rudder error.

For rudder errors less than 3 degrees, an oil flow of 90 gpm is provided, giving a rudder rate of approximately 1.2 degrees per second; for rudder errors between 3 and 5 degrees, an oil flow of 147 gpm is provided for a rudder rate of approximately 1.9 degrees per second, and for rudder errors in excess of 5 degrees, 222 gpm is provided for a rudder rate of approximately 2.9 degrees per second.

Sperry Marine Systems is providing a Total Steering System for NASSCO's San Diego-Class tankers, consisting of Sperry's MK-37 Gyrocompass, Dual Gyropilot System, Rudder Angle Indicating System, Course Recorder, Rate of Turn Indicator and the Triple Flow Clevis Mounted Steering Gear.

Sperry Marine Systems, a manufacturer of steering systems for over 50 years, can provide Total Steering Systems from 10,000 ft./lbs. rudder torque. For further information, contact Henry H. Johnston, Assistant Marketing Manager, Sperry Marine Systems, Worldwide Headquarters, Great Neck, N.Y. 11020.

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