Editing Sturgeon-class submarine (section)

==Noise reduction==
Several ''Sturgeon'' boats and related submarines were modifications of the original designs to test ways to reduce noise.
*{{USS|Puffer|SSN-652|2}} was outfitted with Raytheon Harmonic Power Conditioners which eliminated an electrical bus noise problem that was inherent in the class. This was done by harmonic conditioning of the power system.  This successful feature was later outfitted on the entire class.
*{{USS|Batfish|SSN-681|2}} and {{USS|Bluefish|SSN-675|2}} among others were outfitted with SHT ([[Special Hull Treatment]]) during a non-refueling overhaul, which reduced noise and the submarine sonar profile.
*{{USS|Glenard P. Lipscomb|SSN-685|2}}, a one-ship class, was completed using [[turbo-electric transmission|a turbo-electric system]] for main propulsion rather than a [[gear|reduction gear]] drive from the steam turbines. The massive motor and associated generators required her to be lengthened to {{convert|365|ft|0|in|m|abbr=on}}. The ''Lipscomb'''s trial of turbo-electric propulsion was not considered successful due to lower speed - top speed was {{convert|23|kn|km/h}}, 5&nbsp;knots slower than the ''Thresher/Permit''s - and a lack of reliability, and she was decommissioned in 1989.<ref name="auto"/>
*{{USS|Narwhal|SSN-671|2}}, the quietest submarine of her era, had a similar but distinct design to the ''Sturgeon''-class submarines. The ''Narwhal'' ([[Ship Characteristics Board|SCB 245]]) and the ''Sturgeon'' class ([[Ship Characteristics Board|SCB 188A]]) were developed simultaneously. Forward the ''Narwhal'' resembled the ''Sturgeon''-class submarines, but with a relocated diesel generator and slightly greater beam. Aft she had the [[natural circulation]] [[S5G reactor]] and a direct-drive turbine, along with several other quieting features. Unlike the ''Sturgeon'' class, the ''Narwhal'' did not fully comply with [[SUBSAFE]] regulations due to her unique main seawater system.<ref>Friedman, pp 143–149</ref>