Editing Gato-class submarine (section)

==Postwar service==
At the end of World War II, the U.S. Navy found itself in an awkward position. The 56 remaining ''Gato''-class submarines, designed to fight an enemy that no longer existed, were largely obsolete, despite the fact they were only two to four years old. Such was the pace of technological development during the war that a submarine with only a 300-foot test depth was going to be of little use, despite being modern in most other aspects. Enough of the ''Balao'' and ''Tench'' ships, with their greater diving depth, remained that the ''Gato''s were superfluous for front-line missions. The [[Greater Underwater Propulsion Power Program]] (GUPPY) modernization program of the late 1940s largely passed these ships by. Only {{USS|Barb|SS-220|2}} and {{USS|Dace|SS-247|2}} received GUPPY conversions; these were austere GUPPY IB modernizations under project [[Ship Characteristics Board|SCB 47A]] prior to their transfer to the [[Italian Navy]].<ref name="List of GUPPY IB conversions">{{cite web |url= http://guppysubmarinetribute.homestead.com/Guppy1B.html |title= List of GUPPY IB conversions |date= April 2013 |archive-url= https://web.archive.org/web/20160622181946/http://guppysubmarinetribute.homestead.com/Guppy1B.html |archive-date= 22 June 2016}}</ref> However, the U.S. Navy found itself new missions to perform, and for some of these the ''Gato''s were well suited.<ref>{{cite web |url= http://guppysubmarinetribute.homestead.com/Tribute.html |title= GUPPY and other diesel boat conversions page |archive-url= https://archive.today/20120709042319/http://guppysubmarinetribute.homestead.com/Tribute.html |archive-date= 9 July 2012}}</ref> The last two ''Gato''-class ships active in the U.S. Navy were {{USS|Rock|SS-274|2}} and {{USS|Bashaw|SS-241|2}}, which were both decommissioned on 13 September 1969 and sold for scrap.<ref name="Alden, Part IV">{{harvnb|Alden|1979|loc=Part IV}}</ref>

===Radar picket===
[[Image:USS Raton;0827015.jpg|thumb|right|{{USS|Raton|SSR-270}}]]
The advent of the ''[[kamikaze]]'' demonstrated the need for a long-range radar umbrella around the fleet. Surface ships [[radar picket|refitted with powerful radar suites]] were put into service, but they proved vulnerable in this role, as they could be attacked as well, leaving the fleet blind. A submarine, though, could dive and escape aerial attack. Two ''Gato''-class ships ({{USS|Grouper|SS-214|2}} and {{USS|Finback|SS-230|2}}) received rudimentary conversions to radar pickets before the end of World War II, but were not used in this role. After further experimenting with the concept on four ''Balao'' and ''Tench''-class boats under Projects Migraine I and II, and realizing that a deep diving depth was not overly important in this role, six ''Gato''s were taken in hand ({{USS|Pompon|SS-267|2}}, {{USS|Rasher|SS-269|2}}, {{USS|Raton|SS-270|2}}, {{USS|Ray|SS-271|2}}, {{USS|Redfin|SS-272|2}}, and {{USS|Rock|SS-274|2}}) for conversion under [[Radar picket#Converted and purpose-built submarines|Project Migraine III]] (aka SCB 12A). They were lengthened by {{convert|24|ft|m}} to provide additional space for an air control center and had powerful air-search and height-finding radars installed, with the after torpedo room converted into an electronics space with torpedoes and tubes removed. They also received a streamlined "sail" in place of the traditional conning tower fairwater. Redesignated as SSRs, these ships were only moderately successful in this role, as the radars themselves proved troublesome and somewhat unreliable. The radars were removed and the ships temporarily reverted to general-purpose submarines after 1959.<ref name="Alden, Part IV"/><ref>{{cite web |url= http://www.public.navy.mil/subfor/underseawarfaremagazine/Issues/Archives/issue_14/coldwar.html |last= Whitman |first=  Edward C. |title= Cold War Curiosities: U.S. Radar Picket Submarines |magazine= Undersea Warfare |date= Winter–Spring 2002 |issue= 14 |archive-url= https://web.archive.org/web/20191220153433/https://www.public.navy.mil/subfor/underseawarfaremagazine/Issues/Archives/issue_14/coldwar.html |archive-date= 20 December 2019}}</ref><ref>{{harvnb|Friedman|1995|pp=90–94, 253}}</ref>

===Hunter-killer===
[[Image:USS Bluegill (SSK-242) underway during the 1950s (NH 78979).jpg|thumb|right|{{USS|Bluegill|SSK-242}}]]
The threat of the [[Soviet Navy]] building hundreds of [[Type XXI submarine|Type XXI]]-derived submarines (eventually the 215-strong {{sclass2|Whiskey|submarine|4}} and dozens of others) in the Atlantic led the U.S. Navy to adapt submarines to specifically hunt other submarines, a radically new role for the 1950s. Concluding that this role did not require a fast or deep-diving submarine (this line of thought would quickly change with the advent of nuclear power), seven ''Gato''s were converted to [[Hull classification symbol#Submarine type|SSK]]s ([[hunter-killer submarine]]s) between 1951 and 1953, joining three purpose-built [[United States Barracuda-class submarine (1951)|''K-1''-class SSKs]] entering service at that time. The ''Gato'' class was chosen because large numbers were available in the [[United States Navy reserve fleets|reserve fleet]] should rapid mobilization become necessary, and the deeper-diving classes were more suitable for GUPPY rather than SSK conversions. A streamlined GUPPY-style sail was installed, a large sonar array was wrapped around the bow (losing two [[torpedo tube]]s in the process), the ships were extensively silenced including the removal of the two forward diesel engines, and they received a [[Submarine snorkel|snorkel]]. {{USS|Grouper|SS-214|2}} was converted under project SCB 58 as the test ship for the concept, having her sonar array at the forward end of the sail instead of the better position at the bow. The other ships in the program included {{USS|Angler|SS-240|2}}, {{USS|Bashaw|SS-241|2}}, {{USS|Bluegill|SS-242|2}}, {{USS|Bream|SS-243|2}}, {{USS|Cavalla|SS-244|2}}, and {{USS|Croaker|SS-246|2}}.<ref name="Alden, Part IV"/>

Eventually more advanced sonars were installed on the new nuclear subs: {{USS|Tullibee|SSN-597|2}}, commissioned in 1960, introduced the bow-mounted sonar sphere. ''Tullibee'' was an attempt to develop a slow but ultra-quiet nuclear-powered SSK equivalent; no others were built due to her unexpectedly high cost relative to the more capable {{USS|Thresher|SSN-593|2}}, and the SSK mission was folded into the regular attack submarine role.<ref>{{harvnb|Friedman|1995|pp=80–85}}</ref> The slow and less capable diesel SSKs were decommissioned or reassigned to other roles in 1959, and all except ''Croaker'' and ''Cavalla'' (eventually preserved as memorials) were scrapped in 1968 and 1969.<ref name="Alden, Part IV"/>

===Guided-missile submarine===
[[File:USS Tunny (SSG-282) Regulus launching sequence c1956.jpg|thumb|{{USS|Tunny|SSG-282|2}} fires a Regulus I missile]]
The [[Regulus missile|Regulus]] nuclear [[submarine-launched cruise missile|cruise missile]] program of the 1950s provided the U.S. Navy with its first strategic missile capability. {{USS|Tunny|SS-282|2}} was converted under SCB 28 in 1953 to house and fire this large surface-launched missile and was designated SSG ([[Cruise missile submarine|guided-missile submarine]]). She could carry two of the missiles in a cylindrical hangar on the aft deck. She made [[Regulus missile submarines|strategic deterrent patrols]] with Regulus until 1964, when the program was discontinued in favor of [[Polaris Missile|Polaris]].<ref name=DANFSTunny>{{harvnb|DANFS ''Tunny''}}</ref>

===Transport submarine===
With the retirement of the Regulus missile system in 1965, {{USS|Tunny|SS-282|2}} was converted into a troop transport in 1966. She was redesignated as an APSS (transport submarine), replacing {{USS|Perch|SS-313|2}} in this role. Her Regulus hangar became a lockout chamber for [[Underwater Demolition Team|UDT]], [[SEAL]], and [[United States Marine Corps Force Reconnaissance|Marine Force Recon]] teams in the [[Vietnam War]]. On 1 January 1969, ''Tunny''{{'}}s designation was changed to LPSS (amphibious transport submarine); however, she was replaced by {{USS|Grayback|LPSS-574|2}} and decommissioned in June of that year.<ref name="Alden, Part IV"/><ref name=DANFSTunny/><ref>{{harvnb|Friedman|1995|pp=177–178}}</ref>

===Submarine oiler===
[[Image:USS Guavina (AGSS-362) fueling a Martin P5M-1 Marlin of VP-44 in the open sea off Norfolk, Virginia (USA), in 1955 (80-G-709414).jpg|thumb|right|''Guavina'' (AGSS-362), refueling a [[P5M Marlin]] flying boat in 1955]]
{{USS|Guavina|SS-362|2}} was converted under SCB 39 to a SSO in 1950 to carry fuel oil, gasoline, and cargo to amphibious beachheads. She received additional "saddle" tanks wrapped around her outer hull to carry these fuels and a streamlined sail. After a few tests, the concept was dropped in 1951 as impractical, and ''Guavina'' served in the test role for a few years under the designation AGSS. In 1957, she converted back to the oiler/tanker role and carried the designation AOSS. This time, she experimented with refueling seaplanes at sea, which was potentially important, as refueling the nuclear-capable [[Martin P6M Seamaster]] at sea could improve the Navy's strategic strike capabilities. However, this mission, too, was dropped and ''Guavina'' was decommissioned.<ref name="Alden, Part IV"/><ref>{{harvnb|Friedman|1995|pp=89, 230}}</ref>

===Sonar test submarine===
[[File:USS Grouper (AGSS-214) underway c1961.jpg|thumb|''Grouper'' after conversion to a sonar test submarine]]
The development of advanced sonar systems took on a great deal of importance in the 1950s, and several fleet ships were outfitted with various strange-looking sonar transducer arrays and performed extensive tests. Two ''Gato''s, {{USS|Flying Fish|SS-229|2}} and {{USS|Grouper|SS-214|2}} (previously the prototype hunter-killer ship) were assigned to these duties and proved to be key players in the development of new sonar capabilities. ''Grouper'' had all her forward [[torpedo tube]]s removed and the space was used as berthing for technicians and as a sonar lab. ''Flying Fish'' was decommissioned in 1954, but ''Grouper'' continued in the test role until 1968.<ref name="Alden, Part IV"/><ref>{{harvnb|Friedman|1995|pp=69–73}}</ref>

===Naval Reserve trainer===
Interested in maintaining a ready pool of trained [[United States Navy Reserve|reservists]], the Navy assigned numerous fleet ships to various coastal and inland ports (even in [[Great Lakes]] ports such as [[Chicago]], [[Cleveland]], and [[Detroit]]) where they served as a training platform during the reservists' weekend drills. Twenty-eight ''Gato''-class ships served in this capacity, some as late as 1971. In this role, the ships were rendered incapable of diving and had their propellers removed. They were used strictly as pierside trainers. These were in commission, but classed as "in commission in reserve", thus some were decommissioned and recommissioned on the same day to reflect the change in status.<ref>{{harvnb|Friedman|1995|p=285}}</ref><ref>All post war data from {{harvtxt|Alden|1979|loc=Part IV}}</ref><ref>{{cite web |url=http://www.submarinesailor.com/Boats/Reserve/Reserve.asp |title= Reserve Training Boats of the U.S. Submarine Service |date= n.d.}}</ref>

===Foreign service===
The large numbers of relatively modern, but surplus U.S. fleet submarines proved to be popular in sales, loans, or leases to allied foreign navies. While most of these ships were of the more capable ''Balao'' and ''Tench'' classes, some ''Gato''s went overseas, as well. Italy received two ({{USS|Barb|SS-220|2}} and {{USS|Dace|SS-247|2}}), which received the only GUPPY conversions given to ''Gato''-class ships (Guppy IB).<ref name="List of GUPPY IB conversions"/> Japan received one ({{USS|Mingo|SS-261|2}}), Brazil two ({{USS|Muskallunge|SS-262|2}} and {{USS|Paddle|SS-263|2}}), Greece two ({{USS|Lapon|SS-260|2}} and {{USS|Jack|SS-259|2}}), and Turkey two ({{USS|Guitarro|SS-363|2}} and {{USS|Hammerhead|SS-364|2}}). The ships transferred to Japan and Brazil did not receive any modernizations (streamlining and snorkels) prior to transfer, but the four ships sent to Greece and Turkey did receive snorkels and partial streamlining to the fairwater.<ref>{{harvnb|Alden|1979|loc=Part V}}. '''Note''': Alden makes a rare error here. ''Guitarro'' and ''Hammerhead'' '''did not''' receive the standard U.S. Navy "Fleet Snorkel" conversion '''prior''' to transfer, as he stated in the Part V addenda. See [https://navsource.org/archives/08/265/0836321a.jpg USN Photo NY9-21880-7-54 for Guitarro] and  [https://navsource.org/archives/08/419/0836472b.jpg Navsource.org photo 0836472b for Hammerhead]. Although they did receive full snorkel installations, ''Guitarro'' and ''Hammerhead''{{'}}s conversions were very similar to ''Jack'' and ''Lapon'' in that their conning tower fairwaters and snorkels received only a partial streamlining. The periscope shears and covered wagon ribs were left exposed. The official Fleet Snorkel conversion had a GUPPY-style fully enclosed and streamlined fairwater/snorkel, hence called a "sail". The confusion probably stemmed from the fact that in post-transfer overhauls (probably done in the U.S. but paid for by the Greeks) both ships received GUPPY-style sails.</ref>