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[Editor’s Note: LCDR Filipowski served aboard USS NATHANAEL GREENE (SSBN 636)(Blue) for four SSBN Deterrent patrols. He was redesignated as a Cryptologist in mid 1986 and deployed aboard USS BUFFALO (SSN 715), USS HA.WKBllL (SSN 666), USS LOS ANGELES (SSN 688), and USS HA.DDO (SSN 604). LCDR Filipowski graduated from the Naval War CcJilege in June 1994, and reported to CcJmmander Carrier Group 7 for duty.]

The Korean War was fought from 25 June 1950 to 27 July T 1953.  The United States Navy, especially surface and air forces,  played  a  much  publicized,  significant  role  in determining  the  outcome  of  the  war.   The  public  is  largely unaware, however, of the Submarine Force’s participation in the Korean War.  Although seldom appearing in the headlines, United States submarines performed an important and vital function in the war even though it was relatively minor in determining the war’s outcome.  The significance of the Submarine Force’s Korean War experience, however, was that it prepared the Force for its role in the Cold War and reconfirmed its value to the national security of the United States.

Following World War II, congressionally mandated reductions and reshaping of the United States military reduced the Submarine Force from the hundreds to 72 active submarines by 1950. Of these, approximately 30 were based in the Pacific.

As in World War II, the primary warfare mission of the Submarine Force in 1950 was anti-shipping. However, some submarines had been modified to perform specific missions including; troop and cargo carrier, polar picket, oiler, and guided missile launcher. In addition, the submarine was beginning to be used in an anti-submarine warfare (ASW) role to further enhance ASW capabilities against a rapidly expanding Soviet Submarine Force.

Before the war, Commander-in-Chief U.S . Pacific Fleet (CINCPACFLT) maintained a forward deployed task group of four submarines and one submarine rescue vessel in the Western Pacific (WESTPAC) on a rotating basis. Deployments lasted approximately six months. The submarines and rescue vessel comprised Commander Submarine Task Group (COMSUBGRU) WESTPAC (TG 70.9.). Its mission was to provide ASW training services to units of the Seventh Fleet and Commander Naval Forces Far East(COMNA VFE). The Task Group Commander was a Pacific Fleet submarine division commander who filled the billet for two to three months at a time. Well into the war, on 15 April 1951, COMNAVFE assumed operational control of COMSUBGRU WESTPAC and on 1 November 1951, the designation for the submarines changed to CTG 57 .6.

When war began, the four submarines deployed to WESTPAC (CATFISH, CABEZON, REMORA and SEGUNDO) were spread throughout the region; located in the Philippines, near Hong Kong, and in Yokosuka; and the submarine rescue vessel GREENLET was in Guam. On I July 1950, COMSEVENTHFLT ordered all submarines and GREENLET to Yokosuka. Yokosuka possessed excellent naval facilities and served as the major operating base for WESTPAC submarines throughout the war.

The role the Submarine Force would play in the war was unclear, however. Within a few weeks of the commencement of hostilities. United Nations Forces had established sea control around the Korean Peninsula, cutting the seaborne links between North Korea and the Soviet Union and Communist China. Enemy supplies arrived from overland routes. It was all too apparent that the Submarine Force would probably not be needed to conduct unrestricted submarine warfare as it had in World War II.

In the Eastern Pacific, CINCPACFLT ordered the deployment of five submarines from the West Coast to Pearl Harbor. Fearing possible Soviet naval involvement in the war, CINCPACFLT was preparing to handle all contingencies. When immediate participa-tion by the Soviets did not materialize, CINCPACFLT rescinded the deployment order. However, upon a request from the Marines, the troop transport submarine PERCH was sent to Yokosuka in anticipation of supporting raiding operations. Additionally, CINCPACFLT sent PICKEREL to augment COMSUBGRU WESTPAC.

In the Atlantic, several submarines were forward deployed to the North Atlantic to monitor Soviet naval and air activity in the Barents Strait and the Greenland, Iceland, United Kingdom (GIUK) gap, and provide indications and warnings information. Similar deployments were conducted by Pacific Fleet submarines in the Bering Sea, during summer months only, for the duration of the war. Soviet potential for involvement was a concern throughout the war.

Back at Yokosuka, PICKEREL arrived in mid-July and relieved CABEZON. On 18 and 19 July 1950 respectively, CATFISH and PICKEREL deployed from Yokosuka and made the first submarine war patrols of the Korean War. Augmenting surface and air units of the Seventh Fleet, their mission was to conduct reconnaissance of the China coast and appraise COMSE-VENTHFLT of any communist threat to Formosa, significant changes in the pattern and volume of coastal traffic, and of any large movement of seaborne traffic in the area. These patrols were terminated on 30 July due to poor communications connectivity with the submarines and the determination that surface and air units could better provide the information desired.

At the beginning of the war, communications to and from submarines on patrol were seriously hampered by the lack of a separate submarine broadcast and the saturation of existing fleet broadcasts. Although interim measures were put into effect to minimize this problem, it was far from optimal. It was not until 1 October 1952 that a WESTPAC VLF transmitter and submarine communications center, for a separate submarine broadcast, was established at COMSUBGRU WESTPAC at Yokosuka. This finally improved submarine communications.

On 23 July 1950, REMORA deployed to the La Perouse Strait to conduct a reconnaissance war patrol. The La Perouse Strait was of strategic significance because all Soviet seaborne traffic, both warships and merchant vessels, transited the strait enroute to, or from, the Soviet naval base and shipping facilities located at Vladivostok, in the Sea of Japan. Some Chinese ships transited the strait as well. The patrol marked the first of 31 conducted in the area during the Korean War. 1 This became the mainstay for submarine operations thereafter.

The nature of the war in Korea quiclly relegated the role ofthe Submarine Force to essentially that of a threat in being.2 The primary function of the COMSUBGRU WESTPAC submarines 1 CINCPACFLT Interim Evnluation Report Number Six, Chapter 6, Submarine Operntions,p. 6-22. were reconnaissance war patrols and ASW training services. Employment of the submarines evolved into a routine of maintain-ing one submarine on patrol and one in upkeep. Two submarines provided tame submarine services to ASW Forces and Hunt-er/Killer Groups. The ASW training was considered especially important because of the potential threat posed by the large number of Soviet submarines based at nearby Vladivostok, and the possibility of them entering the war.

As these operations dragged on along the periphery of the Korean War, a sense of frustration permeated the Submarine Force. It was best summarized by Rear Admiral William D. Irvin, USN(Ret.), who had been a staff officer for Commander Submarine Force U.S. Pacific Fleet (COMSUBPAC) Staff during the Korean War. When asked about the role of the Submarine Force in the war, he said:

The Chief of Staff cautioned that the Submarine Force should sit back quietly and say nothing and do nothing-obviously there was nothing for the Submarine Force to do during the Korean War. I said, “This is crazy. We sit back and say nothing and do nothing and watch all the resources being poured into this Korean Conflict that will have to be taken from our already shrunken force and they will take it from the plush and those that are not needed. Now, if you take the attitude that you’re not going to participate, it won’t be five minutes before the powers that be will strip you of your forces and give it to the others that are actively engaged.”

Here we were just sitting on the line and starving fast. I begged to be allowed to go to Tokyo and perhaps explore and find somebody who would be amenable to using a submarine for anything. If we could just get them into action, perhaps something would develop . So I went to Tokyo and I don’t know if I was particularly successful but we did get a few submarines into the act. The submarines were sent up the coast doing some observing, watching some coast lines, etc. We tried getting the amphibious forces into some acts of landing but it wasn’t very success-ful. The general attitude that prevailed was that this was the war that didn’t need any submarines and to go mind your own business. So I came back to Pearl pretty much discouraged and sat moping because I couldn’t see that there was any future in this outfit at all. We were getting nowhere on the minuscule things like the GUPPY SS and air warning types. The Regulus wasn’t getting anywhere because there wasn’t any support for it from the air boys-in fact, they were doing their damndest to kill it. I could see little or no hope for the Submarine Force in its present mood and present mode. 3

Despite these feelings, and the minimal involvement of the Submarine Force in the war, its covert operating capability proved its value.

On 14 August 1950, PICKEREL deployed from Yokosuka to conduct a close-in photo-reconnaissance war patrol of the East Korean coast North of Wonson. PICKEREL’s mission was to obtain periscope photography of potential landing sites for an amphibious operation being planned for PERCH. The PICKEREL patrol marked the first venture of an American submarine into the waters of an armed enemy since the conclusion of World War n. While conducting the patrol, PICKEREL sometimes came within 100 yards of the Korean coast. The photographs provided by PICKEREL proved invaluable for determining the landing location. In addition, PICKEREL brought back vital information on the location of minefields in the area. On 1 October 1950, PERCH earned the distinction of conducting the only designated submarine combat patrol of the Korean War. · Armed with PICKEREL’s photographs and a detachment of Britain’s Royal Marine Commandos, PERCH deployed to an area off the East Korean coast near Wonson to covertly deploy the commandos. Their mission was to destroy a vital North Korean railway installation, thereby cutting an escape route to, and a supply route from, North Korea. The destruction of the installation was important due to the rapid advance of United Nations Forces following the Inchon landings. PERCH executed its mission as planned. The commandos encountered enemy resistance but were successful in destroying a railroad culvert and mining two railroad tunnels. Subsequent information revealed the destruction of one of the tunnels.

After the PICKEREL-PERCH patrols, no further submarine war patrols were conducted against the Korean coast due to the large proliferation of mines.

PICKEREL did, however, conduct another unique patrol. Deployed on 14 September 1950, PICKEREL executed a Sea of Japan-La Perouse Strait patrol in support of the Inchon landings. Operating near the Soviet naval base at Vladivostok, their primary mission was to provide indications and warnings information on Soviet warship movements toward Korea, possibly in reaction to the landings or other offensive operations. On 26 September 1950 PICKEREL sighted several Soviet submarines heading south in the general direction of United Nations Forces conducting offensive operations off the Korean east coast. Withdrawing from the vicinity of the sighting, PICKEREL transmitted a contact report to alert the United Nations Forces. It was later evaluated, however, that the Soviet submarines were enroute to Vladivostok. PICKEREL also reported on other suspicious Soviet activity during its war patrol.

SCABBARDFISH conducted the only other unique patrol in December 1952. Deployed to the South China coast, SCAB-BARDFISH conducted a reconnaissance war patrol to monitor and provide indications and warnings information on possible hostile Communist China ship movements.

La Perouse Strait war patrols were the operational mainstay of the Submarine Force during the war. They were conducted to maintain covert surveillance of, and provide indications and warning information on, Soviet and Communist China warships, and the volume of their merchant vessels, transiting the strait. In addition, they monitored Soviet Air activity. Patrols lasted 30 to 45 days.

The patrols uniquely and significantly contributed to the overall intelligence picture of the war by collecting tactical, operational, and strategic intelligence information not available by other means. This supplemented intelligence acquired via other sources. The covert operating capability of the submarine allowed for not only the monitoring for possible hostile intentions, but enabled the collection of vital photographic and acoustic intelligence, and operating procedures, of Soviet and Chinese ships.

Patrols in this area were conducted continuously from July 1950 through the end of the war, and were continued after it. However, due to severe winter weather conditions, and the lack of credible shipping during this period, the patrols were usually suspended for the duration of the winter.

The following is a quoted excerpt from a submarine war patrol instruction that details a La Perouse Strait war patrol.

  1. Rauting~ – (SS) depart Yokosuka…and proceed without escort in …accordance with Submarine Notice via East Coast of Honshu and Tsugaru Strait to patrol area. Make transit of Tsugaru Strait on the surface during darkness to avoid detection.  Be alert for floating mines.  . ..
  2. Patrol Area- Two joint zones have been established …. Joint zones V and VI do not include any waters within twelve miles of USSR controlled territory …. Patrol of Joint Zones V and VI will be conducted East or West of the restricted area (due to mining). Passage between area V and VI will be made only on the surface, using only the U.S. swept channel given above, due to the possibility of the presence of submarine mines ….
  3. Conduct of Patrol – (SS) will conduct a reconnaissance patrol within the limits of Joint Zones described above. An undetected surveillance will be maintained in the vicinity of the La Perouse Strait. The prevalence of fishing vessels in the swept channel between Joint Zones V and VI, and in Joint Zone VI, may prevent an undetected surveillance in Joint Zone VI. If this is the case, and unless directed otherwise and at the discretion of the (SS), conduct patrol remaining in Joint Zone V. Commencing as soon as practicable, a record of the seaborne traffic in the area will be maintained. Endeavor to obtain periscope photographs of Russian shipping. The prime consideration in selecting nhotQgraphic ranKes js the necessicy to remain undetected. Attention is invited to the fact that in periscope photography with the Mark IV camera, an average merchant ship substantially fills the camera field in high power at a range of .1.S.QQ yards; a closer range therefore in unnecessary except under very poor visibility conditions. All shipping in La Perouse Strait has been lighted at night. Patrol in the area will be conducted submerged during daylight, unless in the opinion of the Commanding Officer, visibility conditions will permit undetected surface ruMing. It must be assumed that the USSR is aware of a submarine patrol being main-tained near La Perouse Strait, therefore keep in mind the possibility of attack by (a) Submarine, (b) Aircraft, (c) Patrol Craft. At all times remain at least twelve miles from Russian occupied territory. Except under the most unusual conditions, this Operation Order should not be violated to secure intelligence information. . ..

The importance of radio silence on a reconnaissance patrol is stressed. Carefully consider the value of the information to higher command before breaking radio silence while in the patrol area. You are directed to report immediately, however

  1. Abnormal variation in pattern or volume of shipping.
  2. Departure from use of normal running lights by USSR shipping.
  3. A contact report.
  4. Any indication of hostile action against the United States or friendly nations.
  5. Any emergency necessitating early departure from station requiring Submarine Notice. .. .

By the end of the Korean War, 28 submarines and 4 submarine rescue vessels had deployed to WESTPAC in support of the war. Not a single submarine was lost or damaged due to enemy action. By the conclusion of the war, the United States had increased its Submarine Force to 110 submarines, 38 more than they had in 1950. The number of submarines in WESTPAC also increased from four to six. The increases stemmed in part from the role the Submarine Force played in the Korean War and the blossoming of the Cold War

Although it entered the Korean War as a minor actor, in an unclear role, the Submarine Force ended the war as a rising star-a proven asset to the national security of the United States. What caused this? First, the Submarine Force made vital and extremely valuable intelligence contributions to not only the Korean War but the fledgling Cold War effort as well. It emerged from the war with a preeminence in covert intelligence surveillance and reconnaissance operations that equaled its World War II counter-parts’ anti-shipping role. Both of which were extremely important in maintaining the national security of the United States. Second-ly, submarine crews gained valuable experience while conducting covert wartime reconnaissance patrols and operating in extremely cold weather conditions. This helped identify operational and material shortcomings (communications connectivity. periscope head window fogging, camera deficiencies, torpedo and mine deficiencies, and habitability considerations) that enhanced submarine design considerations and the operating procedures of the Submarine Force. Both factors, when combined with the advent of the submarine ASW mission, nuclear power, and the Polaris program, secured the viability of the Submarine Force for years to come.


Lieutenant Commander James W. Ahern, USN (Ret.)

Commander Lionel J. Goulet, USN(Ret.)

Rear Admiral Frederick Gunn, USN(Ret.)

Rear Admiral Karl G. Hensel, USN(Ret.)

Captain George H. Laird, Jr., USN(Ret.)

Rear Admiral William T. Nelson, USN)Ret.)

Rear Admiral Murray J . Tichenor, USN(Ret.)

Rear Admiral Carl Tiedman, USN(Ret.)

Naval Submarine League

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