A STUDY OF THE UNITED STATES NAVY'S MINESWEEPING EFFORTS IN THE KOREAN WAR by STEPHEN DWIGHT BLANTON, B.A.

A THESIS IN HISTORY Submitted to the Graduate Faculty of Texas Tech University in Partial Fulfillment of the Requirements for the Degree of MASTER OF ARTS

Approved

Accepted

August, 1993 ACKNOWLEDGEMENTS

I would like to take this opportunity to thank those people who have helped in the research and writing of this paper. Foremost, I want to thank Dr. James R. Reckner for his patience and aid in guiding my work. I would also like to thank Dr. Donald Walker for looking over the paper to help refine it. The aid, given to me by Dr. Edward J. Marelda,

Cathy Lloyd, and everyone else at the Operational Archives of the Naval Historical Center in locating documents, was invaluable. Without the help of these people, this paper would not have been possible.

ii TABLE OF CONTENTS

ACKNOWLEDGEMENTS ...... ii

LIST OF TABLES ...... iv

L I S T OF FIGURES ...... v

CHAPTER

I . INTRODUCTION ...... 2

II. POST-WAR TO THE KOREAN WAR ...... 11

III.FORMING OF A NEW STRATEGY ...... 38

IV. THE SIEGE OF WONSAN AND THE FLOATING MINE THREAT ...... 77

V. AFTERMATH AND CONCLUSION ...... 97

ENDNOTES ...... 105

BIBLIOGRAPHY ...... 117

APPENDICES

A. UNITS ASSIGNED TO CTG 95.6 MINESWEEPING FORCE DURING THE KOREAN WAR ...... 122

B. SHIP STATISTICS ...... 125

C. TASK ORGANIZATIONS FOR THE INCHON, WONSAN, AND CHINNAMPO SWEEPS ...... 127

D. AVAILABLE MINESWEEPERS IN THE FAR EAST ...... 129

E. MINES SWEPT ...... 130

F. UNITED NATIONS SHIPS SUNK AND DAMAGED IN KOREAN WATERS ...... 132 LIST OF TABLES

1 ESTIMATED INFLUENCE OF OCEANOGRAPHIC FACTORS IN MINE WARFARE...... 4

2 COMPARISON OF OCEANOGRAPHIC CONDITION ON COASTS OF KOREA...... 2 0

3 COMPARISON OF MINE WARFARE OPERATIONS ON COASTS OF KOREA...... 22

4 NUMBER OF FLOATING MINES SIGHTED ...... 95

iv LIST OF FIGURES

1. THE SITUATION DURING THE FIRST YEARS OF THE WAR...... 2

2. MODIFIED MOORED SWEEPING GEAR AND MAGNETIC SWEEPING GEAR...... 2 6

3. P'OHANG-DONG SWEEP ...... 27

4. THE MINE SITUATION IN 1950...... 33

5 . KUNSAN SWEEP ...... 3 7

6. WONSAN APPROACHES...... 42

7 . WON SAN...... 56

8 . CHINNAMPO SWEEP ...... 59

9. CHINNAMPO APPROACHES ...... 61

10 . CHINNAMPO...... 6 5

11 . HUNGNAM ...... 6 7

12. EAST COAST COASTAL SWEEP FROM YANGYANG TO SUWON DAN...... 7 5

13. EAST COAST COASTAL SWEEP FROM SUWON DAN TO SONGJIN AREA...... 7 6

14. MINE SIGHTINGSS AND DESTRUCTION, 1950 ...... 87

15. MINES SIGHTED AND SWEPT, 1950-51 ...... 89

16. MINES SIGHTED AND SWEPT, 1951 ...... 90

17. MINE SIGHTINGS, 1951 ...... 92

18 . MINE SIGHT INGS , 19 51 ...... 9 3

v CHAPTER I

INTRODUCTION

The main problems the United States Navy faced when the

Korean War began on June 25, 1950, were a lack of equipment, a lack of ships, and a lack of experienced personnel (see

Figure 1) . The causes of these problems were military demobilization after World War II and the massive budgetary cutbacks drafted by Congress in the post-war years in an attempt to realize a "peace dividend." The combined effect of demobilization and fiscal constraint upon the navy's efficiency immediately became apparent when the United States entered;the Korean War. Admiral Charles K. Duncan, Commander in Chief, Atlantic Fleet (CINCLANTFLT) during the war, considered ludicrous the idea that the United States only needed to maintain an amphibious or mine force on one coast to maintain and develop the retained technologies and skills, yet

"that is exactly what was done and we paid heavily for it."1

Minesweepers comprised an important facet of the war effort. The reduced minesweeping force became part of the

United Nations Blockade and Escort Force. 2 Their job was to clear the assault beaches for amphibious landings and to sweep fire support channels so the battleships, cruisers, and destroyers could get close inshore to bombard the enemy. 3

Throughout the war the bombarding naval forces poured over 70 million pounds of high explosives onto enemy positions causing

1 SEA OF JAPAN

YELLOW SEA

-)60 f- (I) 4J i!3 Q:' " ~

-3~·

Figure 1. THE SITUATION DURING THE FIRST YRARS OF THE WAR source: CINCPACFLT Interim Evaluation Report J. 2 an estimated 57,000 casualties and a large amount of material damage. 4

It is accepted that "minable waters are considered to be those whose depth does not exceed 10 0 fathoms. " 5 In Korea this posed a tremendous problem for minesweepers as "nowhere

in the Yellow Sea is the water more than 60 fathoms in depth, and within 10 miles of the shore it is less than 20 fathoms." 6

This extensive minable area and the prevailing currents around

Korea created a virtual nightmare for minesweepers. The

currents, which reached speeds of five knots on the west

coast, tore up many mines' mooring cables and shifted other moored mines from their original positions. This created

irregular minefields, which were more difficult to clear (see

Table 1) . Many of the mines laid by the North Koreans and later

swept by the United States Navy were of Russian origin. Some

of the mines were of 1904 vintage, while the majority were

from the inter-war period, laid by fishing sampans and junks.

In tandem with these old moored contact mines were new ground

influence mines. By mixing the two types the enemy "presented

a new menace to the minesweeper. " 7 The ships found it

difficult to sweep one type in the presence of another.

Fortunately for the navy, the North Koreans were given

very few influence mines. "There is no doubt that if the enemy had sown a large number of pressure and pressure

3 T.lBLE 1

E!.'T~TED INYLUKNCE OF OCIUNOGRAPHIC FACTORS IN li.I1iE lURFJ.RE

lLI.NE LAY liiG NATUR.a.L DETECTION OF SWEE:PnG 07 lT'l'RITION ll10RED lli.NES MOORED !IJlES

~ ~ )IO

Bottom Will intert~ ChAracter rlth neep~ (topography & gear where ~ok;y composition) and irregul~.

Tide Great l&(ldinm ll~dilllll ran Jltditg Range llines can only l&ines are lr!inee ma.y be Can be neptj Where tide r8ll88 be lo.id at low oubject to exposed at at high tide i1 large there tide where variable low tide where but neep~ il greater IUiiiP­ ~ range is large. prensures. range ie large. ~:~ust be at ~- ot ain81 greater depth. boaoh.ing.

Tidal ~ Great ~ ~ ~ Currents Will interfere Currents of high Large dip 1n YJ.oater1 'rill be with nnvfeation velocity may drag Btrong cur- carried by cur- and mo.y cause the anchors or rents mAY limit rent1. difficulties in break mooring cnbles. peeping to handline of g1.1ar. alack water.

Wind U&dium Small Scali J!!!X!iUII ~ \'fill interfere Will interfere Floating ainee 'lfi th Mvigri.tion with navigation K1l dOW!J w1D4 and m.ay 06U8e and gear h&.nd- at about 2. s~ difficulty in ling. ot wind ~. handling. TABLE 1 CONTINUED

JUNE UilliG NATURAL DETECTION OP' S'lfm'DG 07 l&fiCfiOI 07 Jl"l'RITION I&JORED JliNES IIOORXD J!IBS n.oum ym

ll'avea Great Great Great QI!!! ~ Rough eeae Will contri- ww liait Rough aeu DetectioD br will stop bute largel;r detection by will aake rlsual n4ar and operations. to draggiDg visual, radar BWoepi.ng .anar~ and breaking and eonar dit!iaul. t O:D rlll be lUdted. o! cables. methode. True iaponible. by rough.-.. !or both ahipa and planes.

Trana- llediUJI Ln parency J.!urky water will reduoe rleibility o! m.1.ne s at ahallow depths.

Ice Small Medium Uedium Modi WI

Will prevent visual Will illter!ere !la,y obscure ciJ:lea. detection of moored with navigation mines by aircraft. & gear handling.

Source: CINCPACFLT Interim Evaluation Report 1, volume 6, 1121- 1122. magnetic combination type mines, our countermeasure capability would have been severely taxed." 8

Despite the post-war cutbacks, the United States still maintained the strongest navy in the world. Yet, even with its offensive might its amphibious force was compelled to wait outside Wonsan harbor "while a few minesweepers struggled to clear it. " 9

When the Second World War ended, the U.S. Navy had over

500 minesweepers and about 33,000 men in the Pacific mine force alone. For the Korean War, the entire American mine warfare force totalled two divisions of destroyer minesweepers, two divisions of minesweepers, and 21 smaller ships. Many of these vessels were far from the theater of conflict. Pitifully few ships were available considering that

"around the embattled Korean peninsula, shallow, minable waters stretched for 11,000 miles." 10 By mid-October, without endangering any ships larger than the fishing junks and sampans used to lay the mines, "the Communists sank five U.S. and two Korean ships, damaged several more, and rocked the

Pentagon" when Chief of Naval Operations, Admiral Forrest P.

Sherman, received Rear Admiral Allen E. Smith's message reporting that the navy had "lost control of the sea."11

The reason America "lost control of the sea" could be seen in the force reductions imposed on the post-war navy by

Secretary of Defense Louis Johnson. The people's desire to demobilize brought on a vicious budget war among the

6 individual branches of the armed services in defense of their future roles. The newly independent air force claimed a strategic bombing ideal that captured the imagination of the country, thus, the navy received a disproportionately small part of an even smaller budget.

The Russians, whose interest in mine warfare was deeply imbedded in their traditionally defensive approach to naval problems, capitalized on America's self-imposed mine warfare weakness by taking this opportunity to inflict as much physical damage as possible on the American fleet. In the process they caused the United States to spend millions ~n new research and construction at a cost to the Soviets of only a few thousand antiquated mines. 12

The cost to the United States in lives and ships lost was tremendous. In fact, "mines caused 70 percent of all U.S. naval casualties during the first two years" of the 37 month war. 13 By the war's end, mines sank a total of six navy, four

South Korean, and one Japanese ship, and damaged six navy, three ROKN, and one Japanese ship. These losses could have been averted had it not been for the cutbacks of earlier years. The Russian fascination with mines is almost as old as the technology itself. They were especially adept at the use of defensive minefields and floating mines (floaters) . During the Crimean War (1854-1856), they used contact mines to protect their harbors. Later in the Russo-Turkish War

7 (1877-1878), mines halted the Turkish fleet and gave the initiative to the Russians . 14 Twenty-six years later, in 1904, the Russo-Japanese War broke out. Eighteen warships sank due to mines in that conflict. Russian and Japanese capital ships were lost to the Russian minefields. Defensive minefields kept the Japanese out of range of the Russian ports.

The extensive use of floating mines to wreak havoc with the enemy's supplies and lines of communication was directly responsible for the Hague Conference of 1907 banning their use. 15 Article I of the eighth Hague Convention required moored mines that broke loose from their moorings to disarm themselves automatically and mines laid without moorings to disarm themselves after one hour. 16 The disarming mechanism, called a sterilizer, could even be specifically programmed to disarm itself after a specified amount of time. 17

When World War I broke out in 1914, until his death in

1915, Russian Admiral Nikolai von Essen converted many vessels to minelayers, which formed the backbone of the Russian mine force for years to come. These ships laid offensive, as well as defensive, minefields. Their efforts harassed the German transports carrying ore from Sweden. 18 The Soviet Union continued to lavish attention on the mine warfare community throughout the inter-war years and during World War II. At the end of the Second World War, the Soviets captured and kept most of the German mine stocks, as well as their mine personnel. The Soviets saw to the expansion and modernization

8 of Admiral von Essen's fleet during this time. They built many new ships after the war and stressed mine warfare education for all line officers. 19 American naval mine countermeasures programs suffered by comparison. With many of the specialists in the Reserves and the few ships spread thinly, the United States fell far behind.

One of the most trying facets of mine clearance was dealing with mines equipped with ship counters, devices which enabled the mine to detonate after a preset number of vessels had safely passed over. Defeating the ship counter required additional check sweeps of already cleared areas. These check sweeps required additional time and removed valuable ships from combat, or first run, sweeps of other areas. Such additional demands were particularly important for the United States Navy, which was ill-equipped to meet the basic mine clearance requirements. 20 Soviet directed defensive mining of North and South Korean waters was carried out as the only available counterbalance for the preponderant United Nations naval strength. The North Korean Navy was insignificant and the Soviet Navy, which had not yet begun its buildup to challenge the United States Navy, was still weak and also faced political constraints upon the exercise of its power. The defensive minefields were established to prevent United

Nations vessels from making amphibious assaults. 21 If that

9 could be done, the North Korean Peoples Army (NKPA) could fight on more equal terms with the U.N. forces.

The Conununists used mainly chemical horn and inertia contact mines and also a few magnetic mines. Floaters were used prolifically and constituted the major mine threat after the war stalemated. Due to the United States forces' unpreparedness to conduct mine countermeasures, initial losses were very high. In the first few months, many small ships were sunk or damaged, including five destroyers. 22 Mines also caused delays, which were favorable only to the enemy. At

Wonsan, a fleet of 250 ships was delayed five days beyond their scheduled landing date because of mines. 23 In modern warfare where any delay might have catastrophic results, this five days' delay constituted an unacceptable risk. The United States Navy's minesweepers, always far too few, acquitted themselves remarkably well. In order to compensate for the chronic shortage of minesweepers, American

Navy men were compelled to improvise under fire and radically alter minesweeping procedures. These efforts were vindicated when the new method proved itself under fire.

10 CHAPTER II

POST-WAR TO THE KOREAN WAR

During the Second World War, the United States Navy had had between 525 and 550 minesweepers 1n the Pacific minesweeping fleet at any one time. 24 For the naval share of the Normandy invasion, Operation Overlord, in June, 1944, the allies had massed 306 minesweepers to clear the assault beaches. Due to the ongoing demands of Pacific naval operations, only 32 of the Overlord minesweepers were

American. In April, 1945, United States mine warfare forces assigned to support the assault on Okinawa included 75 minesweepers and 45 assisting ships. They spent their first week clearing 222 mines; over the next two months that total was raised to 510. 25

When the Second World War ended, there was little interest in keeping the massive military then in existence. The great majority of the men who had enlisted "for the duration," or who had been drafted, desired nothing more than to return home to civilian life. And the Congress, which had authorized massive deficit spending to conduct the war, now sought to drastically reduce expenditures and return to pre­ war funding levels. In the ensuing budget struggle over the dwindling resources, the newly created air force prevailed because of the glamour of the aircraft and the appeal of

11 their vision of limited warfare with planes doing all the fighting, thereby reducing the horrifying casualties to our own forces. The army and navy then had to fight over the scraps in a desperate bid for survival, a situation which, in hindsight, should never have developed.

Many of the ships of the massive wartime navy were sold, scrapped, or placed in reserve fleets. 26 In the Far East, the army cut back from 50,000 men to a mere 500 in the Republic of

Korea (ROK) . Immediately after the war "U.S. military strength was reduced in an attempt to reach pre-World War II levels, which had little connection with U.S. post-war commitments overseas. " 27

Of the 374 minesweepers the navy had in the Pacific at the beginning of 1946, a mere fourteen remained by the end of the year. Their job was to observe the Japanese minesweepers as they cleared the American and Japanese wartime minefields in Japanese waters, after the Japanese sweepers completed their sweep around the Philippines. 28 In March of that year, the Mine Force Pacific Fleet command moved from Japan to San

Francisco. The navy scrapped almost all of the mine locator ships (AMCU). The minesweeper tenders were soon to follow.

By 1950, two divisions of destroyer minesweepers (OMS), two divisions of minesweepers (AM), twenty-one auxiliary minesweepers (AMS), and two minesweeping boats (MSB), a total of 37 minesweepers, comprised the entire available

12 minesweeping force. 29 An additional 143 units remained in reserve. 30

Degaussing, a process whereby the magnetic signature of a ship is reduced to a minimum as protection against magnetic influence mines, "had not been kept up to date and there was no degaussing range West of Pearl Harbor. " 31 Paravanes, which cut moored contact mines allowing them to be destroyed, thus protecting following ships, were removed from the ships.

Budget restraints limited training. 32

In 1947, Chief of Naval Operations (CNO) Fleet Admiral

Chester Nimitz dissolved the Mine Force Pacific Fleet

Command. 33 The Mine Force Atlantic Fleet remained. As Admiral

Charles K. Duncan said of the post-war cutbacks, "we were greatly concerned with offensive mining as an anti-submarine device. We were less concerned and had a fairly small force for defensive mining minesweeping." 34

There were no more reductions in strength in 1948 but training became a problem. Due to a shortage of fleet destroyers, the destroyer minesweepers (DMS) were used almost exclusively as destroyers. Most of the auxiliary minesweepers

(AMS) were spread thinly across the Pacific, which hampered training. The only units actively training were the ships in

Japan, which were checking Japanese progress in sweeping the old World War II minefields. 35 The destroyer minesweepers were placed under the control of Commander, Cruiser-Destroyer Force

Pacific Fleet (COMCRUDESPAC), while the regular minesweepers

13 were under Commander, Service Division (COMSERVDIV) after Mine

Force Pacific Fleet was dissolved.

Some attention was still being paid to mine countermeasures during this time. "By 1949 the Bureau of

Ships had produced design characteristics for a new non­ magnetic fleet minesweeper with the operational capabilities of both the converted wooden trawlers and the new steel AMs.

Plans for this new AM were shelved due to lack of funding in fiscal year 1950. " 36

What the budgetary cutbacks left in the Far East in 1950 were "four 180 foot steel-hull, fleet minesweepers (three of them ~n caretaker status), and six wooden auxiliary minesweepers. " 37 The ships were undermanned because 99 percent of the trained U.S. Navy mine personnel from the Pacific war were in the reserves. 38 These were the vessels on hand when the United States went to war in Korea.

Given this background, it is not surprising that the minesweepers encountered difficulties in their attempts to clear mines in Korea. At no time during the Korean War did the available American minesweeping force exceed 27 ships. A fleet one-fifth the size of that which cleared the assault beaches around the tiny island of Okinawa was required to clear and maintain the safety of the entire Korean peninsula.

By June, 1950, the Pacific fleet minesweeping force had been reduced to 10 ships in Japan and 12 Japanese minesweepers under contract, all of which had five years of post-war

14 sweeping behind them. 39 The number of minesweepers available fluctuated with ships rotating in and out of the minesweeping force. Thus, although there were 12 Japanese minesweepers available, the number actually in service fluctuated from a high of 10 to a low of one. In this manner, the minesweeping fleet never rose above 24 active sweepers in the theater, as arriving American ships relieved Japanese, ROKN, and other

American sweepers. There actually were 213 minesweepers of various nationalities in the Pacific at the time.

Unfortunately, about half of them belonged to the Soviet

Union, which for obvious reasons would not use them in Korea.

Of the rest, many were unfit for duty, and, with the exception of the U.S., ROK, and Japanese contract sweepers, none were offered for U.N. service in Korea. 40 The three mine locator ships (AMCU) were unavailable, being then in the Atlantic, and there were no minesweeper tenders left in service as they had been scrapped. 41

The Pacific Fleet stationed all four destroyer minesweepers on the West coast for overhaul, while the three

AMSs were supposed to protect five strategic ports. Pearl

Harbor accounted for another three AMSs, those protecting three ports. Guam's two AMSs protected Agana. Finally, the

19 active ships in Japanese waters were keeping three ports open there. 42 The reserve fleet ships in the Pacific included the 3 AMs in Japan, 5 commissioned reserve vessels, and 72 inactive reserve ships on the west coast. 43

15 The seven minesweepers initially available were listed as inadequate for a combat sweep. Their war diary listed the following deficiencies: ( 1) incapable of pressure minesweeping, (2) no buoys to mark swept areas, (3) a lack of ships, (4) a lack of reserve materials, (5) a lack of nearby degaussing facilities, (6) inadequate intelligence on the enemy's mining capability, (7) no mine disposal personnel, (8)

"no Mine and Counter Mine Technical Unit [MACTU] personnel available ~n Pacific Ocean area," (9) no means of night minesweeping of moored mines, and (10) inadequate sonar to offer safe operation near moored minefields. 44 In short, the forces were insufficient "to keep three ports open to the fleet against a limited mining effort by an alert enemy." 45

Commander, Naval Forces Far East (COMNAVFE) consisted of seven active ships when the war broke out in June, 1950. In addition there were twelve other active United States minesweepers in the Pacific. Of the four AMs in Japan, Pirate

(AM-275) and Incredible (AM-249) were soon ready for duty, but

Mainstay (AM-261) could not join them due to a lack of spare parts. By late July, two of the four destroyer minesweepers

(DMS), Endicott (DMS-35) and Doyle (DMS-34), were dispatched to the theater from the west coast. With the discovery of mines in early September, five AMSs went west, while nine minesweepers in reserve were ordered readied for duty. By

October 2, 1950, the last two DMSs, Thompson (DMS-38) and

16 Carmick (DMS-33), as well as the remaining three AMSs, sailed for Korea. 46

Help was soon on the way. By September 30, 1950, there were 21 active U.S. minesweepers available, with 14 AMS and one AM ordered to report. 47 With these vessels, the losses incurred due to mines could be replaced and ships could be rotated as needed.

The Republic of Korea (ROK) also had a navy which could help. They had one landing ship tank (LST), 15 former

American minesweepers, 10 former Japanese minesweepers, and various other vessels g1. ven them under the Mutual Defense

Assistance Program (MDAP) . 48 They also had not been to a degaussing range in a long time and, more significantly, they lacked gear to sweep moored mines. 49 Nevertheless, they were eager to help defend their seas. The Chief of Naval

Operations authorized the equipping of 10 ROKN YMSs with moored rninesweeping gear, as well as the training of the crews at Sasebo. 50

In mine warfare, the Communists held a tremendous advantage; they had only to lay defensive minefields to delay an amphibious landing until their troops could arrive on the scene. On August 29, 1950, the North Korean Navy's mine expert, Lieutenant Cho Chun Hyon, left Chinnampo to begin the mining of Inchon harbor. 51 The enemy laid mines in most South

Korean ports that carne under their control while United

Nations forces were contained within the Pusan Perimeter. 52

17 Many of the mines were laid by junks and fishing sampans, the smaller sampans carrying only 2 to 4 mines per mission. 53

The North Korean mining effort did not begin until mid-

August, 1950. This delay in beginning mining and even in receiving the mines from their Soviet sponsors indicates the

North Korean decision to mine was a reaction to United

States/United Nations intervention.

The approximately 4, 000 mines laid were Soviet-built.

They were shipped south by rail from Vladivostok beginning in mid-July to Wonsan on the east coast of Korea and Chinnampo on the west coast, from whence they were distributed by truck to the various ports targeted for mining. Although later in the war trains carrying mines were harassed by United Nations aircraft and ships, these first shipments made it through.

Search planes had reported the presence of barges in the enemy held ports, but at the time their presence was not interpreted as an indication of mine laying. 54 By the time U.S. forces moved to close the rail connections, Inchon, Chinnampo, Haeju,

Kunsan, Mokpo, Hungnam, Wonsan, and many lesser ports had already been mined.

The predominant mines were the Russian MKB chemical horn contact mine and the M2 6 inertia contact mine. Magnetic ground mines were also laid. 55 Soviet naval officers went to

North Korea and even to Inchon to assist in training their ally's troops in their use. In Wonsan and Chinnampo schools

18 were established to teach mine assembly. The advisors even helped assemble and lay the mines. 56

The Korean terrain greatly affected minability. The east coast is regular, the 100 fathom curve close inshore, the tidal range small, and the current is slow, ensuring the mines will stay put. The clear water facilitates spotting mines from the air. The west coast, on the other hand, has many estuaries and rivers which are navigable for 100 miles or more. The Yellow Sea is less than 60 fathoms deep and the water is opaque; mines could be sown almost anywhere and would be difficult to spot from the air. The massive tidal range, averaging 21 feet, made mining difficult as at times the moored mines were too far under water to be effective or were completely exposed. The strong currents shifted the mines around considerably and tore them up quickly. 57 Thus, east coast mining was the better option (see Tables 2 and 3) .

United Nations forces first discovered mines on September

4, 1950, off Chinnampo. 58 From then until the end of the month, mines were sighted on 54 occasions. Perhaps more ominously, 25 floaters were also spotted. 59 From October 14 to 19, the number of floaters sighted jumped to 45 in the areas between Chinnampo and Inchon on the west coast and

Hungnam and Yangyang on the east coast. 60 With a predominantly southerly current, the floating mines represented a greater danger than moored mines as their current-driven mobility

19 TABLE 2

COMPARISON OF OCEANGGRAPHIC CO~~ITION ON COASTS OF KOREA

WEST COAST vF KOREA EAST COAST UF KOREA Dottom Character Extensive shoal areas with Narrow shelt with tew islands. numerous islands dissected llottom usually sand or mud by narrow channels. Bottom with isolated rooks near abore. Generally mud, sand and Coast line relatively straight some roCk. Coast deeply with few natural harbors. indented with n\lr.'lero\UI rivers.

Tido Range Spring tide range between Spring tide range very small. 10 o.nd JO ft. with maxima Range for most ot the coast near Inchon and Yalu River. less than one foot.

Tidal Currents Generally strong and Very small. 1\.J particularly so in channels 0 leadirg to principP~ ports (4 to 6 knots).

'riinds liortherly in winter through Northerly in winter througb wasterly to southerly 1n westerly to southerly in summer. In winter o.veraee summer. In winter average force 4. Somewhat weaker force 4. Somewhat weaker in sur.tmor. in summer. ·,'/aves !71th northerly winds waves With northerly and easterly will be loss in protected winds waves may be large in chll."".nels & i.n1,ets. However oxposed bays· and harbor~. ovor shoal areas waves will V/111 generally be ro~Jt!her be steep & will break. Stron~ than west coast. tidnl currents will affect wnves.

Tranpa.rency ~inter turbid due to river run­ Hater generally clear. off Rnd mud disturbed by waves. TABLE 2 CONTINUED

WEST COAST OF K(JRE.A EAST COAST UF KOREA

:i.co River and sea ice sufficient So~e sea ice is carried to impede surface navigation southward by winds ~,d occurs north of nbout JSO t1 currents. Locally produced in cha~~ela and in near shore ice is thin and present for aroo.. only short intervals.

Source: CINCPACFLT Interim Evlauation Report 1, volume 6, 1122.

....t\J TABLI 3

COIQ'4RISON OP' JUNE WARP'ARE OPERATIONS ON COAStS OF IORU

WEST COAST OF KOREA El.ST COAST OF lOW

JUne laying Ditticult due to large tide Ro~ine range, atrong tidal ourrenta and extensive shoal areas and numerous channels.

Nat.u!"al Large due to strong 'U~ Ro~ine Attrition currents combined with b g tides and waves. Detection o! Greater likelihood o! visual Routine J.!oored Uines and raB~ detection at low N tide. Low transparency will N make visual detection o! submerged mines difficult.

Sweeping o! Sater beca".i~e neepera can Routine Jloored Kine~ operate with relative safety at high tide. However dip of cines in strong currents cay limit poriodo of sweeping or require deep drags.

Detection of Tidal currents will produce Routine Floating l.lines. apparently erratic movements.

source: CINCPACFLT Interim Evaluation Report 1, volume 6, 1123. meant they were capable of intruding upon United Nations naval operations over a wide area.

In 1949, the Japanese minesweepers were a part of the

Maritime Safety Board (Kaijo Hoancho), which was increased to

8,000 men. That was all that remained of the former Imperial

Japanese Navy (IJN) . Even though the occupation guidelines demanded the dismantling of the IJN, the Japanese minesweepers were retained to clear the minefields around the Philippines and Japan. These ships as well as American LSTs with Japanese crews, were used in Korea. After the Inchon landing they were hired under contract. In all, 4 6 Japanese ships and 1, 200

Japanese crewmen served in Korea until the Japanese government ordered the units home on December 15, 1950, calling their presence in Korean waters a violation of the Japanese constitution. Two of the ships were lost, one to a mine and the other when it ran aground near Kunsan.

The crews were told they would not be used north of the

38th parallel, that they would not conduct combat sweeps but rather would do check sweeping only, and that they would receive double pay. All these terms were broken. They were not given extra pay, and their regular pay was often late.

And they had to make combat sweeps in Wonsan harbor where MS-

14 was lost to a mine. The crews were also nervous about sweeping for contact mines moored 3 meters below the water's surface in ships with a 3.2 meter draft. These sweep operations were illegal according to Article 25 of the Kaijo

23 Hoancho Law. General Douglas MacAurthur dismissed the matter:

"these vessels were hired and employed, not for combat, but for humanitarian purposes involved in neutralizing infractions of the accepted rules of warfare." 61

Captain Richard T. Spofford, who had an extensive background in mine warfare, assumed command of Mine Squadron

3 and Task Group (TG) 95.6, the minesweeping force, in August

1950. 62 He faced a nightmare landscape for a minesweeper. The currents seized floating mines and carried them down the

Korean coastline in a matter of 15 days; from there they drifted through the shipping lanes, and often fetched up on the shores of Japan. 63 Two days after the war broke out, Vice Admiral C. Turner

Joy was appointed Commander Naval Forces Far East. He then had the needed reservists called to duty. 64 The mine threat forced the naval gunfire support (NGFS) ships to be recalled beyond the 100 fathom curve on the east coast. 65 This, of course, is exactly what the mines were supposed to do.

Task Group 96.5 was ordered to escort ships between

Sasebo and Pusan, to conduct acoustic, magnetic, and moored sweeps of both ports, their approaches, and the convoy routes. 66 Later the list of ports was amended to keep pace with U.N. advances. The task group also assumed control of the Japanese minesweepers (JMS), and the South Korean minesweepers (ROKN YMS) .

24 Minesweepers carried out their work either in conjunction with other minesweepers or in a loose formation. When steaming in echelon formation the ships held a rigid pattern so that the lead ship's gear protected the ships following.

A loose formation offered no such protection, but, in night sweeps especially, echelon formation could be deadly as the floating mines could not be seen clearly and avoided.

Occasionally ships swept mines alone. If sweeping moored mines, a line with wire cutters on it was streamed with the far end attached to a float (kite) and a weight (otter) . As the gear was pulled along, the wire would catch the mine's mooring cable, drawing it taught until a cutter hit it, severed the cable, releasing the mine and revealing it to the - following destructor boat, whose job it was to destroy the mines thus located. Magnetic mine sweeping gear was a modified form of the moored, or "0" (Oropesa), gear. One electrode, called the short leg, was streamed directly behind the minesweeper loosely, while a second electrode, the long leg, was streamed from the stern of the ship to the end of the sweep wire at the otter and kite. With an electrical generator on the minesweeper running power down the wires, it was hoped to generate a magnetic signature similar to that of a larger class ship for the mine to receive thereby prematurely triggering its detonator (see Figure 2) .

On July 15, 1950, the minesweepers sailed to P'ohang- dong, near Pusan (see Figure 3) . Their mission was to clear,

25 Modified moored sweeping gear.

Plan View or ~1ngle 3hip SWoop

...-cutters

Elevation View ot Single ~hip SMeep

~ark 6 la) magnetio awoop l Jig Swoop ).

~Ship

JJ Mark 5 tlagnetio sweep oablo

200 tathom3 ot •o• tno awoep wire Short leg eleotrode

Size ' ""

"0" typo !loa ---Ship' a oourae aiz.e 4 with-. 20 roet pendon 3 rt. or 3 in. sisal line Figure 2. MODIFIED MOORED SWEEPING GEAR AND MAGNETIC SWEEPING GEAR Source: CINCPACFL'l' Interim Evaluation Heport2, volume 11, 14) ~ -1436. 26 c o,...:w t-u.~ z ~~~ ~ 0 :f z !a~~ LLJ ..J C) w C) _J d~~ z 0 ia~ r

0"1 c 0 --~~--...... ,--....,.rr--t----t----r---'0------~_,.___,..,,....-­ l 0"1 c co .c ..0 0..

SWEPT AREAS Figure 3. P'OHANG-DONG SWEEP Source: CINCPACFLT Interim Evaluation Report 3, volume 14, 36

27 in three days, this port situated only 25 miles from the front lines, to enable the 36 United States ships carrying the First

United States Cavalry Division to unload. The North Koreans, however, had been unable to mine P' chang-dong as their advance faltered due to NGFS shelling of enemy troop concentrations along the Pusan perimeter. 67 Such good fortune would not last long for the minesweepers.

Assault sweeps and harbor clearance duty placed a heavy burden on the few available minesweepers. The rest of the

Pacific had been stripped of its mine warfare defenses to strengthen the Korean force, but it was late October before these reinforcements arrived in the theater. 68 To boost the flow of material to the front, Atlantic fleet ships were sent - to the Pacific. Other ships from the reserve fleet were activated and made available. Needed equipment was assembled from American stockpiles and airlifted to Korea. 69

As MacArthur prepared his 5, 000-to-1 gamble at Inchon and hoped for the best, the planners found further cause for concern over the landing force's safety when ROKN PC-703, under Commander Lee Sung Ho, found and destroyed a boat laying mines just north of Inchon harbor. 70 With the possibility of mines in the assault area, caution and verification became critical. Two months after the unobstructed landing at P' chang-dong in July, the minesweepers left for Inchon where MacArthur gambled on a successful landing to outflank the invading NKPA

28 troops, disrupt their flow of supplies flowing through Seoul, and break the North Korean resistance. 71 Nearly 400 ships gathered for the assault. 72 Mines, however, still had the potential to make the operation very costly.

Inchon's tidal range of 33 feet, every inch of which was needed for the deep draft of the overloaded LSTs to reach the designated landing beaches, only came on September 15, October

11, and November 3. The current at the entrance to Inchon,

Flying Fish Channel, had a peak ebb and flow velocity of 5 knots. If a ship of the landing force was sunk by a shore battery or a mine while in the channel, it was possible that all the ships ahead of it would be trapped in the harbor, and those behind blocked from entering, thus dividing the assault force and setting the stage for- disaster. 73 With the muddy waters and extreme tides, Inchon was a perfect place for ground mines; this was an assessment in which Vice Admiral

Arthur D. Struble, Commander Seventh Fleet and Commander of the landing operation, agreed. 74 At 1145 on September 13, 1950, two days before the assault, as Mansfield (DD-728), the lead ship of the pre­ invasion naval gunfire support (NGFS) group, approached Wolmi­ do, lookouts spotted 17 Russian contact mines in Pukchangjaso inlet, below Wolmi-do. DeHaven (DD-727), next in line, commanded by Commander O.B. Lundgren, a mine warfare expert, soon confirmed the report. The three lead ships opened fire with rifles, 20mm, and 40mm guns; destroying the field. The

29 enemy's minefield had not been completed, as they lacked the necessary parts to assemble the rest of the mines. Commander

Lundgren spotted a pile of the unfinished mines at the base of the Wolmi-do causeway. 75

Task Group 96.6, which was the initial designation of the minesweeping force in Korea, was redesignated in August 1950 as Task Group 95. 6, Mine sweeping Force, as a part of the blockade and escort force for Operation Chromite, the Inchon assault. 76 One AMS and one AM guided the landing force of 2

LSDs and 36 LSTs with 12 more LSTs trailing them by 6 miles. 77

Once the NGFS ships discovered the mines, the minesweepers had a far more important mission to perform and so were ordered to abandon escort of the landing force and proceed at best possible speed to Inchon. 78 At Inchon, LCVPs and motor launches were fitted out with minesweeping gear with success. 79 The conversion of LCVPs for minesweeping had never been tried before; its success portended safer sweeping of shallow waters that were hazardous for the larger minesweepers. Henceforth, the use of small minesweeping boats became a major part of minesweeping operations in Korea. When the sweepers arrived at Inchon on

September 15, however, nothing was found and so they retired. 80

The few mines had already been taken care of by the bombarding destroyers. While the destroyers shot mines at low tide, the landing force passed safely over them at high tide. 81 Thus,

30 although a new minesweeping vessel type had been created, it could not be tested in a combat sweep with real mines yet.

The minesweepers' presence proved unnecessary at Inchon due to the North Koreans' failure to sow extensive defensive minefields. Their next area of operations would, however, highlight the importance of the sweepers' mission.

Verification of the presence of mines was difficult as there was no formal plan for reconnaissance; in fact, there were no plans at all. Local initiatives were begun. Single planes roamed the harbors and coasts searching visually for any signs of mines. They flew at 500 to 1,000 feet above the sea with every hatch manned. Most sightings occurred at 1 to

3 miles, although once an APS15 radar equipped aircraft detected a mine a 5.5 miles. 82 Reconnaissance was of little help in the last week of September. Four ships were damaged and one was sunk. When the minesweeper Magpie (AMS-25) sank, a helicopter searched the area looking for survivors. Instead they found a pair of mines off Kokoko. This heavy reliance on aerial searches, dictated by the broad expanse of minable waters and the presence of floating mines, became the hallmark of Korean minesweeping operations. 83 The North Korean sown mines very quickly drew blood from the United Nations forces. The war came home to the navy when in the course of a week five ships were either sunk or badly damaged. From September until November, mines claimed 13 ships as casualties compared to five damaged by bombs and

31 shore battery fire. Of the 13 ships, four ships struck mines in waters below the 38th parallel (see Figure 4) . 84

The destroyer Brush (DD-745) was the first victim. While steaming off Tanchon, 1,000 yards astern of the destroyer

Maddox (DD-731), seeking shore batteries to destroy, Brush hit a mine which tore a five-foot hole in her side. Thirteen men died ~n the explosion and 34 were seriously injured.

Commander Fletcher L. Sheffield, the ship's captain,

"remembered that the destroyer Meredith (DD-726), a ship of the same class similarly damaged during the Normandy assault in 1944, was lost before she could navigate the English

Channel. " 85 The nearest safe port was Sasebo, Japan, over 470 miles away. Escorted by the cruiser Worcester (CL-144), the destroyer DeHaven (DD-727), and the salvage tug Bolster, Brush made it to port on September 30, four days after the explosion. On September 30, in the North Korean harbor of Chosen, 60 miles north of the 38th parallel, the destroyers Lyman K.

Swenson (DD-729) and Mansfield (DD-728) searched for a downed

B-26 pilot. While Swenson stood out at the 50 fathom curve,

Mansfield went in. Having just heard of the fate of the

Brush, one sailor offered odds on whether they also would hit a mine and was taking bets when the sea and Mansfield's bow erupted. The explosion tore a hole in the bow of the ship erasing the numbers 2 and 8 leaving the 7 behind. As Seaman

Glendon Glass put it, "I can't say that it made me feel any

32 z __ ct ~,a. w

z H

33 .n;Y~vr·· ~---~~ ~ ll ...... jt.ln\IIC)) (~~ _,,L ~~ KOREA .,._~. YELLOW Et. ~ 5 aiART OF KNO'Wll Ott ... l(~s.t.ll ~ \ __t.:, lJtmPECTED WIMHIELDS -··:r ~a w -~ ~-- ) ~...,., .. I ... w ~ ~ ,.,...... K.CT::»«D .. -.'" ,.,. ~ .. ~ .,.....,.XTI •U....,...te.U. ~U .._ ~ ••• - .-.ro SECRET /' Oil ~ ., 181(U..~ p? ...JIJIL_ .,_,P ~D 011 .._._ { ..... ,_.. , p (7 IOQ"() ~) MOOI'!(O I. ' loU OOC: TIC --""- ..... ~J · -3 ~ -I Figure 4. CONTINUED Source: CINCPACFLT Interim Evaluation Report 1, volume 6, 1124. more lucky. " 86 Twenty-eight men were injured but no one was killed. Mansfield made it back to port without any further incidents.

The wooden-hulled auxiliary minesweeper Magpie hit a mine shortly after arriving from Guam for her Korean tour. On

October 1, 1950, while sweeping a patrol channel in company with Merganser (AMS-26) two miles off Chuksan, 30 miles North of P'ohang-dong, Magpie hit a floating mine that slipped past the sweep gear. Twelve men of the crew of 33 survived, all of them injured.

On the same day, near Mokpo, ROKN YMS-504 hit a mine with her starboard propeller causing the sympathetic explosion of two nearby mines. With her hull leaking and the engines ruined, they were lucky they had suffered only five casual ties. 87 Unfazed, the captain "radioed that he would

'soon be ready again to kill more Reds.' " 88 Her sister ship, which had hit a mine on September 28, fared much better. ROKN

YMS-509 hit a mine along the south coast, demolishing the bow but not harming the crew or the engines. As a result, the ship made it to the ROK naval base at Chinhae. 89

These heavy losses in such a short time shocked the

Commander, Naval Forces Far East (COMNAVFE) , who promptly ordered the east coast NGFS ships outside the 100 fathom curve. By doing so, the ships were removed from danger, but they were also removed from effective gunfire support range,

35 which diminished their effectiveness and thus helped the North

Koreans. 90

Both Captain Spofford and Admiral Joy pressed repeatedly for an acceleration of the activation of reserve minesweepers.

But as other ships, especially destroyers, were in more demand than minesweepers, their efforts met with little success until

U.N. losses began to mount. All of the vessels lost were destroyer size or smaller. 91

Soon after the Inchon landing, the Canadian Tribal class destroyer Athabaskan (DDE-219) created a new minesweeping method. The reason for this was that there were no minesweepers or minesweeping gear available to clear Kunsan harbor for them. The plan called for a few men to go into the harbor 1n one of the ships' launches at low tide when the mine would be exposed. They would locate each mine, attach a demolition charge with a five minute timer to the mine, and row as fast as possible to get clear of the explosion. In this manner the Athabaskan's crew destroyed five mines. 92

The clearance of Kunsan by minesweepers came on October

2-3, 1950, with a check clearance from October 21 to November

2, 1950. Pledge (AM-277), Mocking Bird (AMS-27), Chatterer

(AMS-40), Kite (AMS-22), and Redhead (AMS-34) cleared a 1,500 yard wide, 22 mile long channel. A total of 49 M26 mines were reported. Seven of the mines were swept and destroyed (see

Figure 5) . 93

36 126• :StJ'I

~ .L9 ,,

•0

•oo·"' w -....] CJaut ~

KuN.511N W£...5T C011...5r KriREA Prriotl • 2-:S Oct; 21 Oct -2 New A-tt .Swttpt : 2.Z "'tJ' clt&Aif~/ Tcv-c:tt~ : U. 3 ~ 6 /I.U_,, 111M ..J~p.- 7 JM:J SECRET Hines r~porl'd : 49 M·26 C:::d ~ Mtnes &w~,Pt : U . .!J. _.,. .Jy-:$(destroy-/

ITliD u..3. t2ZZ1 ..Top. Jrloo,..,rJ M-re# Figure 5. KUNSAN SWEEP »ai"rlic source: CINCPACFLT Interim Evaluation Report 1, volume 6, 1134. CHAPTER III

FORMING OF A NEW STRATEGY

The United Nations forces' Inchon landing threatened the

North Korean supply lines, which ran through Seoul. The enemy had little choice but to withdraw from the Pusan Perimeter and attempt to regroup beyond the South Korean capital. On

September 29, 1950, while in newly liberated Seoul, General

Douglas MacArthur ordered his commanders to prepare for another amphibious assault, designated Operation Tailboard, which he felt would end the war. 94 The hammer was to fall on

North Korea's principal port, the east coast city of Wonsan.

In addition to the port facilities, Wonsan was a transportation center in North Korea second only to the capitol, Pyongyang. The major rail line from the Soviet Union ran along the coast into the city; highways emanated from the port to the major Korean cities, even Seoul.

MacArthur set the landing date at October 20, which left three weeks to plan the assault. Adding to the headache of planning a corps-sized assault landing, the Wonsan area was known to be mined. Although extensive minefields were not expected at Wonsan, Vice Admiral Arthur D. Struble, Commander

Seventh Fleet, warned the ships headed for the port anyway. 95

The army and navy disagreed on how the Wonsan assault should be executed. The argument was unique in that neither force wanted to use the mode of transportation they normally

38 favored. The army, impressed by the effectiveness of the

Inchon landing, desired another amphibious landing. The navy, on the other hand, wished the army would go overland. One reason was that the sea trip to Wonsan from Inchon was 830 miles, much longer than the approximately 110 mile overland route. The army countered that if the X Corps went overland through the mountains half of their heavy equipment would be lost.

Another problem encountered in the planning stage was that outloading the troops from Inchon would hinder the flow of needed supplies to the Eighth Army, which depended upon the same port facilities. A shortage of shipping, amphibious craft, and minesweepers further complicated the situation. Despite these problems, the army pressed to go by sea. As a result, and as a precaution against the possibility of mines

at Wonsan, Vice Admiral Struble, on October 2, ordered all available minesweepers to get underway for Wonsan

immediately. 96 Struble planned on clearing the harbor in five days. If weather was bad, or if influence mines were found, it might take longer. On October 6 he advanced the date for

commencement of sweeping the harbor to ten days before the

landing was to take place. 97 A few days into the operation MacArthur had second thoughts about the landing. In view of the difficulties the navy was encountering clearing the harbor and the fact that

39 the ROK Army was sweeping up from the south, MacArthur was considering shifting the objective of the planned landing north to Hungnam. Vice Admiral C. Turner Joy, Commander, Naval Forces Far East, refused to alter the plans as there was insufficient time to plan the landing and it would divide and diminish the effectiveness of the minesweeping force, which was barely adequate to sweep one harbor. 98

What the United Nations planning staff could not predict was the sheer size of the mine problem that awaited them at

Wonsan. Intelligence was slow to recognize the North Korean mining activity. The Wonsan minefield covered almost 400 square miles. Composed mostly of 1904 vintage Russian contact mines, the field was seeded with magnetic influence mines

"sensitive enough to react to the wooden-ship's engines, making minesweeping by the surface vessels deadly. " 99 The operation was a tragedy waiting to happen. "At Okinawa, for instance, we used 100 sweepers, at Normandy we used 300. At Wonsan we started with 10. " 100 Such a force was inadequate for the task at hand, and therefore was very quickly reinforced. Admiral Joy received the two AMs from Japan that had been in reserve, one AMS from Guam, and two

DMSs from the west coast.They were immediately assigned to the

Wonsan operation along with the high speed transport Diachenko

(APD-213), the repair ship Kermit Roosevelt, and eight

Japanese contract sweepers. In time, four U.N. frigates and

some ROKN YMSs also joined in. 40 Help was also available offshore from the commander of the NGFS ships, Rear Admiral John M. Higgin's, flagship, the cruiser Rochester (CA-124), and several destroyers provided gunfire support. Rochester's helicopter and PBMs operating from the tender Gardiners Bay provided a mine searching force, while aircraft from two fast carriers were available for assistance.

Clearing a path from the 100 fathom curve to the assault beaches at Kalma Pando required the sweeping of an approximately 30 mile long channel and 50 square miles of the harbor in advance of the landing force. 101 Selecting the route had been difficult. Six miles from the assault beaches lay the island of Yo Do, which could be passed to the north or - south; realizing that the Soviets had used the northern channel for their shipping, it was decided to make a direct run south of Yo Do to the beaches (see Figure 6) . To help accomplish the task three ROKN YMSs and eight

Japanese minesweepers, which arrived on October 8 with their commander, Captain Tamura, joined the struggle. On October

10, the first day of the sweeping, Incredible, Chatterer,

Osprey, Pledge, and Mocking Bird swept 18 mines up to the 30 fathom curve . 102 Dan buoys were placed to mark the swept channel as the sweep progressed. 103 Rochester's helicopter aided the force, searching out mines ahead of the sweepers. 104

On the October 10 sweep to the 30 fathom curve, the 28 mile channel cut into a heavily mined area clearing the 18

41 ..... Figure 6. WONSAN APPROACHES

42 .. .'

·.

• --~-· ------·------

~~ C...••~.-K- ~ · ·~· · • ·-~ . =.;:·..:=~..... _...... ,. "'-• " .. ·-·'-...... ·~ ·~.,...., ...... , ... ,-.. .,. ·- . ~ . ,, .. ,.,...... _,... ·- ~ · .._...__ ·- ....., .. ~ · ·~· C) ·- _.,. •• ,_

Figure 6. CONTINUED Source: CINCPACFLT Interim Evaluation Report 1, volume 6, 11 36 .

43 mines swept that day. The first warning of the danger came from the helicopter pilot, B.D. Pennington, who spotted five lines of mines inside the 30 fathom curve . 105 When the new mine lines were detected, the ships retired. 106 As a result, the sweep plans were changed to go through the Russian

Hydropac channel, passing between Yo Do and Hwangt' o-do islands. This meant clearing a 34 mile channel, 24 miles from the 100 fathom curve to the outer islands, and 10 miles of inner harbor. 107

On October 11, Underwater Demolition Team (UDT) personnel from Diachenko went out in small boats to help search for mines ahead of the minesweepers. 108 They also searched Yo Do and Ko-to islands for controlled minefields, while overhead a

PBM searched for mines, communicating sightings to the units below. The ships swept around Yo Do and turned toward Kalma

Pando. Pirate led the sweep followed by Pledge and

Incredible. Ahead of them was their helicopter spotter who could communicate with the minesweepers through the DMS

Endicott. At 1122 they entered unswept water. 109 Kite and Redhead followed the group marking the channel with dan buoys.

In all, 16 mines were cut, one of which got stuck in Pirate's

. 1 110 sweep gear and was taken out to sea f or d ~sposa . The urgency to complete the minesweeping operation was removed as Brigadier General Kim Baik Yil's ROK I Corps, whose advance had earlier been slowed by heavy NKPA resistance, seized the city on October 11 while the 1st Marine Division

44 remained embarked in navy amphibious force ships at sea, unable to land until the mine threat was neutralized. 111 The fall of the city removed the threat of shore battery fire, simplifying somewhat the navy's work. 112 Until that time the minesweepers had, of necessity, operated in company with a gunfire support ship.

Disaster befell the minesweeping force on October 12. The same sweep formation as the day before was used with the AMs in lead and the AMSs danning, and Endicott on hand for gunfire support. As the ships swept around Yo Do many mines were cut.

At noon the helicopter spotter reported, and Pirate's sonar confirmed, three mine lines ahead. 113 Moving at eight knots, the ships passed between Yo Do and Ko-to sweeping 12 to 16 m~nes. The helicopter spotter reported the mine lines extending between Yo Do and Ko-to, as well as near Sindo, but gave no precise position or depth. Upon completion of the sweep, the ships moved near Sindo to retire as planned. There they encountered unanticipated trouble:

About 1208, U.S.S. Pirate (AM-275) had many sonar contacts ahead. Pirate changed course to 245 degrees true to avoid the nearest contact. Almost immediately a shallow mine was sighted close aboard the starboard bow and evasive action was taken. At 1209 Pirate struck a mine and began to sink astern. Due to loss of power, attempts to contact the other minesweepers were to no avail. U.S.S. Pledge (AM-277) and U.S.S. Incredible (AM-249) immediately launched their boats and sent them to the rescue of survivors. At about 1210 enemy shore batteries on Sindo island commenced shelling Pirate and her survivors. Also about this time Pirate commenced abandoning ship. At about 1213 Pirate capsized and sank, leaving about 43 feet of the keel forward showing with her stern apparently resting on the bottom. When the Pirate was mined she stopped dead in the water. The Pledge, therefore, was forced to alter course to the left

45 in order to avoid becoming fouled in the Pirate's rninesweeping gear. Enemy shore battery fire was immediately and effectively returned by the Pledge, Incredible, Redhead, and Endicott. Friendly air units gave further assistance. About 1215, Pledge, while in the act of changing course to port struck a mine. Boats from the u.S. S. Diachenko (APD-213), Endicott (DMS-35), and Doyle (DMS-34) immediately carne to the assistance of the survivors. Pledge sank in about 45 minutes. 114

The area was scoured for survivors by small boats, helicopter, PB4 Y, and UDT personnel from Diachenko. Of

Pirate's crew of 77, six men were missing and 43 were injured.

Pledge's crew roster of 74, short two men who were not aboard at the time of the disaster, was reduced by six men, who were missing, and 41 injured. Two visiting Japanese aboard were uninjured. 115 With Admiral Joy's permission, Rear Admiral

Allen E. Smith, the commander of the amphibious task force, starkly summarized the situation for Chief of Naval

Operations, Admiral Sherman: "We have lost control of the seas to a nation without a Navy, using pre-World War I weapons, laid by vessels that were utilized at the time of the birth of

Christ. " 116 One reason for the losses was that on tight turns away from the sweep gear the kite and float broached the surface making them useless until recovered. As a result, tests were run on the Mocking Bird using a depressor to hold the sweep wire below the surface and prevent the gear from broaching.

After a few successful tests the other minesweepers were outfitted with the gear. Faster and tighter turns were made until finally the ships made turns at maximum speed with hard

46 rudder . 117 The tests were successful. Only one other United

States minesweeper was lost during the war, and that loss was no fault of the new sweeping gear.

For the next two days emphasis shifted to searching for the mines. Patrol planes and helicopters searched for and destroyed mines by strafing. UDT personnel also boarded small boats and buoyed mines detected by helicopter and the location of gaps in a mine line where the sweepers could safely pass. 118

Minesweeping boats capable of moving at four knots close inshore in 15 fathoms of water were also used. This group was composed of one 40 foot launch, one landing craft vehicle- personnel (LCVP), and one landing craft mechanized (LCM) . 119

In an attempt to prove the feasibility of aerial . countermining, which had been attempted unsuccessfully in

World War II, 31 ADs (Skyraiders) and 16 F4Us (Cosairs) took off from the carriers Philippine Sea and Leyte on October 12 in an attempt to bomb two five mile strips of water placing the bombs 200 feet apart. The Skyraiders carried three 1,000 pound bombs fused to detonate 25 feet underwater, while the

Corsairs carried one 1,000 pound bomb each. The right column was bombed by 14 ADs and 8 F4Us, the left column by 17 ADs, with 8 F4Us remaining in reserve. Flying at 180 knots at

1,500 feet, they were guided to the drop zone by the ships and search planes which had marked the lines. About 109 1, 000 pound bombs were dropped, but the results proved inconclusive,

47 as it could not be determined if the bombs detonated any mines .12o

A major innovation in the Korean War was the use of patrol aircraft and helicopters to locate and destroy mines.

Beginning on September 29, 1950, Commander, Fleet Air Wing

Japan (COMFAIRJAP) provided Mariner and Sunderland aircraft from Patrol Squadrons 42 and 47, RAF Sunderland Squadron 88, and later RAF Sunderland Squadron 205 based at Iwakuni, Japan.

On October 6, patrols of both coasts of Korea began with the aircraft flying from Chinhae, Korea. At Wonsan aircraft discovered and charted 175 mines, detonating five mines and sinking six others with .50 calibre machinegun fire. They carried overlays of the hydrographic charts used by the sweepers, marked the locations of the mines they spotted, and dropped the charts to the waiting sweepers below . 121

With the UDT frogmen, minesweeping boats, helicopters, and PBMs hunting for mines, the search quickly developed into a competition between the groups to run up their score of mines found. Some crews even ignored fire from the shore batteries in their quest. The search created so much interest among the watching North Korean fishermen that they joined the hunt. One old man kept yelling and gesturing at the water.

When Lieutenant Commander Don DeForest, Captain Spofford's assistant recently transferred from MINELANT, investigated, he discovered that the man had spotted a mine. He rewarded the fellow with a pack of cigarettes and designated him Ko-to

48 Float 1, as Ko-to was the man's horne. Two more boats soon joined in. By nightfall DeForest realized that Ko-to Float 1 was too far out to get horne in the rising seas, so in order to avoid possibly firing on the boat in the night by mistake they towed him horne. The old man apparently reported his treatment by the Americans to the 200 refugees and villagers living on

Ko-to, for the next morning four more fishing boats joined the search. In return the Americans sent as much food as could be spared and a doctor to help the sick and injured. The seven

North Korean boats proved useful in the hunt.

DeForest's adventures were not over yet, though. The next day, while in the bow of an LCVP hunting mines, he watched as a mine popped to the surface less than two feet - from his position. Even as he gave the order to back down the boat struck the mine right below his perch. Amazingly, nothing happened. The LCVP had apparently missed all five horns, contact with any one of which would have destroyed the boat. 122 As he later put it, "I'll never forget the Russian serial on that mine-the numbered part of it that I could read.

I'll remember it after I have forgotten my name. It was number

11825-11825--that will stick with me forever. " 123

By October 23, 16 mines had been discovered by helicopter searches in the line that sank the Pirate and Pledge, alone . 124

More mines had been found elsewhere in the harbor as well.

Such progress notwithstanding, the sweeping was taking too long. As a result, on October 21, one day after the landing

49 had originally been scheduled, General Almond requested that the Marines be offloaded at Kojo, 39 miles south of

Wonsan, where Japanese and ROKN LSTs had run through unswept waters. Admiral Doyle rejected the request as it would have split the landing force and so the sweeping continued at Wonsan . 125

Don DeForest, meanwhile, borrowed an LCVP to cross the unswept waters of Wonsan harbor, where he picked up a jeep and an interpreter-bodyguard from the ROK Army. Searching along the waterfront, he located some fishermen who told him that the mining personnel had been kidnapped or shot and that the mine depot was about 25 miles north of the city. They could not say for certain where it was since it had been heavily guarded.

Leaving the city he travelled along a sniper infested dirt road. Fifteen miles from Wonsan he carne to a village of about 1,000 people. Everyone but a five year old girl ran for cover at his approach. "'It seems incredible that my success or failure rested in the hands of this little girl,' DeForest said. 'But it did. She was my only liaison. Why she remained behind I'll never know because I was worse than a stranger.

I was a foreigner!' " 126

He managed to lure her over with a chocolate bar which soon brought out the other children and their mothers, who followed cautiously. He was soon motioned into a white wooden house where he met the village elder. After he considered

50 DeForest's request for assistance he agreed to cooperate despite the possibility of Communist retribution.

The elder provided him a guide who also knew one of the sampan skippers who planted some of the mines and a North

Korean official who went out in the junks. The guide took him farther into the countryside to where the mines had been assembled. He was shown the bunker where the magnetic mines were assembled and where the North Koreans who had helped in the project had been killed. Thirty Russians had been in town until October 4. When the mines were laid, the Soviets were on the ships. If a mine was laid out of place the pilot was shot and another man was promoted to replace him. Few mistakes were made twice. Having found nothing, DeForest began drawing the diagram of a magnetic mine. When he finished, his guide led him to a pile of straw. It took no time at all to find what he was looking for. On the first try he came up with the search coil for an 1,800 pound mine. Deforest made it back to Wonsan without difficulty. He then found the skipper and the other man, who had worked in the hydrographic office. Both men suddenly became very cooperative after they learned the secret of the magnetic mines was out. The skipper had barely managed to make it out of enemy hands. He knew so much that the

Russians decided to take him and four other men back to

Vladivostok. The skipper slid over the end of the PT boat as it left Wonsan . 127 51 Intelligence turned up shipping manifests. According to

the documents, 4,000 mines had been shipped through Wonsan

between July 10-20. 128 The Soviets set up a mine school for

MKB and M26 mines for 18 men. Soldiers laid the mines off of

sampans towed by junks in the middle of the night. They were

rolled off the end of the boats at 1-1.5 minute intervals.

This way 3, 000 mines had been laid in a period of three weeks. 129

Later the United Nations forces discovered that the

Soviets had provided the North Koreans with torpedoes and

depth charges. On October 16, fourteen twenty-four foot long

torpedoes, as well as 29 300 pound and 40 fifty pound depth

charges, were found in a tunnel near the Wonsan airfield.

With this arsenal were 167 contact mines. U.N. forces found

over 600 mines ashore at Wonsan after the city fell. 130

Nevertheless, losses continued to mount in the Wonsan

minefields. On October 18, the ROKN LST BM SF-673 struck a

mine in the outer harbor when it tried to take a short cut to

the beach through an unswept area. It reported minor damage

and continued on to the shore . 131

The day before, the Japanese minesweeper MS-14 had struck

a mine and sank off the southern shore of Yo Do island. 132

MacArthur ordered a blackout on the news of the sinking, or

even of Japanese involvement in the war, due to the

information's propaganda value to the enemy . 133 The loss of that ship infuriated the Japanese crews, who had been promised

52 double pay, that they would not sweep above the 38th parallel, and that they would not do any combat sweeps. All the promises had been broken. They especially felt used as they were asked to sweep mines at a depth of 3 meters with ships having a draft of 3. 2 meters. As a result, three of the minesweepers left the next day and were dismissed from the minesweeping force. Although the crews of the Japanese ships had been well supplied and repaired by the American Navy, even their reports indicated the troubles they suffered working with the Americans. Among those troubles were language difficulties, a lack of communication equipment to work with the observing ship reduced them to visual signals only, and generally the inability to coordinate with the American mine sweeping effort. 134 De.spi te these difficulties, they still managed to do a good job. Another ship was lost on October 19. While sweeping the moored mine line between Tae Do and Hwangt'o Do, the third ship in the formation accidentally triggered an influence mine with its kite and float. The explosion triggered a second explosion 150 yards south of the first one. At that all the ships stopped their machinery, cut their gear, and headed out at one-third speed on one engine. The ships made it away safely but, due to poor communications, they could not warn a formation of ROKN ships headed right for the mine fields. 135

Commander Sihak Hyun had wanted YMS-516 in the lead of the formation to be followed by his flagship, PC-704, YMS-510

53 ~n third place, and the six power boats on hand to bring up the rear. After repeated orders for YMS-516 to proceed 40 without any action taken by that vessel, he began to worry.

The other captain, Lieutenant Commander Jun Churl Ung, had been his classmate at the Chinhae Naval Academy. Hyun knew the loss of a minesweeper would cause him to lose face but he couldn't risk the valuable PC, which, in the diminished scale of the fledgling ROKN, they thought of as a cruiser. Hyun was forced to take the lead as his friend refused to obey his orders. A powerboat took second place and YMS-516 the third position. Moving at one-third speed on one engine, Hyun saw the explosions set off by the American minesweepers. Two minutes later, he felt another explosion. YMS-516, whose commander had refused to perform his duty for fear of risking his ship, most ironically had struck a mine and was sinking.

Four men were killed instantly and 13 men were missing. 136

Over a year later, on December 26, 1951, Commander Hyun's humiliation over losing YMS-516 was compounded when his ship,

PC-704, struck a mine off Yo Do island and sank with all hands. Wonsan harbor's mines claimed another victim on November

16, 1950. Army tug LT-236 was towing a crane barge when it struck a mine at the entrance to the harbor. Its sinking marked the greatest loss of life yet, 30 of the 40 crew aboard died . 137 The harbor minefield had claimed five ships and injured one other. 54 On October 25, after fifteen days of work by a motley crew, a channel into the assault beaches at Wonsan was declared clear. 138 The enemy minefields had delayed the

landing of the amphibious force since October 19, when the 7th division arrived off Wonsan. Forced to back and fill while

the minesweepers went about their dangerous mission, the

amphibious force first sailed south for twelve hours then

north arriving back off the port only to be ordered to head

south again. Dubbed Operation Yo-Yo by the men aboard the

ships, problems almost as serious as mines arose. Food ran

short and dysentery flared up on the MSTS transport Phoenix

affecting 700 of the 2,000 men aboard. After six days, from

October 19 to October 25, at sea outside, the wait was over as . the assault ships descended upon the beaches at 1500 hours,

October 25 (see Figure 7) . 139

The landing proved anti-climactic. Fifty-thousand men

hit the beaches only to be welcomed by banners set up by the

ROK troops who had liberated the town over a week before.

Another sign, this one set up by Mine Squadron 3, let the

Marines know who had cleared the beach for them. Perhaps more

humiliating for the ever proud Marines was that Army Major

General Edward M. Almond and Comedian Bob Hope, who was in

town performing with his USO group, were on hand to welcome

them ashore . 140 Nine days after the capture of Wonsan, the North Korean

capital of Pyongyang fell to United States and ROK forces

55 ~ (Kat-to);w ...

rOiffiHIINfi-MAN

GR IDIRON

11!111•-o-.-....., ...... _ ·

Figure 7. WONSAN Source: Cagle and Manson, The Sea War in Korea, 601.

56 advancing north along Korea' s west coast . The supplies flowing into Inchon for this front were too far from the combat zone. The increasing distance from the front and the relatively small capacity of the Inchon port facilities made it obvious to United Nations commanders that a new port, nearer the front lines, was needed. Attention focused on the next significant port in North Korea, Chinnampo.

Admiral Joy obtained the services of Commander Donald

Clay and Mine Force Atlantic Fleet's Commander Stephen Archer.

He placed Clay in charge of intelligence in Chinnampo and sent Archer off to Sasebo to commandeer any ships he could. 141

Commander Archer's experience in mine warfare was . . ~mpress~ve. He had been an observer on a British minelayer from 1940 to 1941. From June, 1941, until April, 1943, he attended the Mine Disposal School at the Washington Navy Yard.

In July, 1950, he commanded Mine Division 4. On October 4,

1950, he reported for duty in Korea as the head of the underwater reconnaissance effort at Wonsan. 142 Archer had to scrape together a force to sweep Chinnampo.

This was a challenging assignment, as there were no ships, men, or plans available. 143 Among his first "volunteers" were the destroyer Forrest Royal (DD-872), DMSs Thompson (DMS-38) and Carmick (DMS-33), AMSs Pelican (AMS-32), Gull (AMS-16), and Swallow (AMS-36) out of Pearl Harbor, ROKN YMSs 502, 306,

513, and 503, a helicopter, SCAJAP LST Q007 to give the helicopter a place to land, Horace A. Bass (APD-124) with UDT

57 One, Catamount (LSD-1 7) with 14 minesweeping boats, and

Bolster (ARS-38) Later he received 13 Japanese minesweepers with their own mother ship and the Japanese guinea pig ship Soei-Maru (SS/MV-32) .

Mine clearing operations began on October 29 when

Thompson and Carmick started sweeping in the Yellow Sea, 39 miles from the area in which mines were expected. Most of the ships arrived for duty by November 2, with the exception of

Catamount which arrived three days later with her LCVPs rigged for moored and magnetic sweeping . 144

Acting on hard lessons learned at Wonsan, the Eighth Army was ordered to seize all ship logs, hydrographic charts, mine plans, boat captains, and minelaying personnel in Chinnampo.

Unlike Wonsan, the water in Chinnampo was shallow, muddy, and fast. The tidal range was 12 feet and a five knot current prevailed during ebb and flow. There were two channels approaching the port. The southern channel was a mere 15 feet deep at high tide while the other one was twice that (see

Figure 8) . 145

Chinnampo was chosen for opening because of its location along the Taedong estuary near Pyongyang, similar to Inchon in relation Seoul. Mud banks line the shores and islands dot the approach. After Wonsan was opened, the PBMs shifted back to hunting along the west coast. Three days searching garnered

34 mine sightings and 16 mines sunk by strafing. 146

58 THE CHINNAMPO SWEEP Oct 29th to Nov 20th 1950

Figure 8. CHINNAMPO SWEEP Source: Karig et al. ,354.

59 Minehunting preceded the sweepers. PBM and helicopter patrols and surface searches by rninesweeping boats and the UDT personnel helped clear the way into the harbor. An LST was used to good effect as a helicopter base and a supply depot for the force. The operation needed all the help it could get as it sought to clear 200 square miles of water between them and the port. 147

As the entire Yellow Sea is minable, the sweep began 39 miles from the channel entrance, which put them 69 miles from the port. Commander Clay and Lieutenant (junior grade) Hong,

ROKN, discovered the details of the minefield. The information carne from a North Korean river pilot called simply "Shorty," who had helped lay the mines and knew the location of them all. The field consisted of 217 moored and 25 magnetic mines placed in five lines north of Sok-to and one line to the south of it. Searching before they swept an area, the minesweepers and MSBs maneuvered to avoid the mines rather than actually sweeping them. As the minesweepers were few in number and late in arriving, the task of clearing the channels fell to the MSBs. In addition, Martin Mariners with the seaplane tender Gardiners Bay began working after October 2 8. RAF

Sunderlands joined shortly afterward. In six weeks the patrol planes accounted for 340 mine sightings alone . 148 By November

3 the shallow southern channel was opened to small ships and the minesweepers turned to the deeper channel, which would be needed to get the larger LSTs through (see Figure 9) . 149

60 SECRET

CHINNANPO APPROAC ES

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Figure 9. CHINNAMPO APPROACHES

61 8111&11 CUT

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Figure 9. CONTINUED SWEPT AREAS Source: CINCPACFLT Interim Evaluation Report 3, volume 14, 42. Winter proved a dangerous enemy of the minesweepers, for it brought heavy seas and chilling conditions that reduced the effectiveness of mine sweeping crews working in open mine sweeping boats. The MSBs, themselves, had difficulties in the mid-winter operation as their engines needed to be thawed every morning. Similarly, the helicopter crew removed the lube-oil from the helicopter every night to keep it warm.

The weather also affected the mines. Four mines broke their moorings in rough seas over a 24 hour period. This presented another danger to the ships as the floating mines could drift right into their anchorages. The minesweepers, therefore, had to remain alert for the floaters.

Four of the LCVPs were rigged for moored minesweeping and another four for magnetic sweeping . 150 Two 40 foot launches from the carrier Boxer had also been fitted with minesweeping gear as MSBs. The effort proved a total failure at Chinnampo, however, as the fast current quickly burned out the boats' engines when the gear was streamed. 151

Planes from the British carrier Theseus sank a barge in the Chinnampo area believed to be laying mines. Later the sunken barge was found with 15 mines still aboard. 152 Those mines, at least, never troubled anyone. Theseus also provided fighter cover to protect the minesweeping operation from harassing aerial interference as well as shore batteries. 153

In the meantime Catamount was used as a mine school for ROKN

63 officers and men. Six full crews were trained for Korean minesweepers being fitted out at Sasebo, Japan.

From October 29 to December 3, 1950, eighty mines had been cleared at Chinnampo, 36 by PBMs, 27 by UDT frogmen, 12 by storms, and five by the minesweepers . 154 In addition to the

8 0 M-2 6 mines swept, 4 magnetic mines were destroyed (see Figure 10) . 155

The day Wonsan was opened, October 25, 1950, Chinese troops engaged ROK II Corps troops at Unsan, near Sinanju.

Four days later, ROK I Corps attacked enemy positions near the Changjin (Chosin) Reservoir.

With the nearest supply point on the east coast at

Wonsan, and that still being cleared, the need to open Hungnam became paramount (see Figure 11) . From there United Nations troops could be better supplied for the drive to the Yalu River.

Fortunately, naval intelligence paid off. Kim Tae Lee, the captain of the lead ship during the mining operations at

Hungnam, was located and proved more than willing to cooperate. Kim had helped plant two lines of mines: the inner line was laid by two ships carrying 18 mines each, while the outer line was laid by three ships, two carrying 18 mines and one carrying 20. The minefield thus numbered 92 mines. Kim was uncertain whether magnetic mines had been laid. He informed the intelligence officer of how he and the Russian navigator had laid the mines, and he volunteered to pilot

64 ...... 0 Ill ~ z z H ::X:: u

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Figure 10. CONTINUED------L--L------~ Source: CINCPACFLT Interim Evaluation Report 1, volume 6, 1135. ..SIC. RET

• • • ... . . • 0 0. IJIIA•I o • s.;,.ru • .. 0 , ''"''I ......

Figure 11. HUNGNAM source: CINCPACFLT Interim Evaluation Report 1, volume 6 , 114 0 .

67 CCUJr KouA

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Figure 11. CONTINUED

68 United Nations ships in the area . 156 From November 6 to

November 11, Doyle (DMS-34) and seven AMSs cleared a 28 mile

long, 1600 yard wide channel. 157

The opening of the port was very important as the Chinese

"volunteers" stepped up their attacks. The day the sweep

began, United Nations troops held off assaults along the

Ch'ongch'ong bridgehead near Sinanju after the loss of Unsan.

Marines from Wonsan relieved the ROK troops fighting around

the Changj in Reservoir on November 2. The U.N. advance in the

face of heavy resistance was slow. By November 26 the Marines

were nearing the southern end of the reservoir itself. The

next day, as U.N. troops advanced on Samsu, near the Yalu

River, 100,000 Chinese troops descended upon the Marines.

Fortunately, Hungnam provided a nearby logistical base for

operations. The overwhelming power of the Chinese formations began to

take its toll, however, and the Marines began a gradual

fighting withdrawal on December 2, 1950. The naval gunfire

support ships in Hungnam harbor provided supporting fire to

the Marines around Hungnam. By December 10 the Marines had

completed their epic withdrawal from "frozen Chosin" to

Hungnam where they were protected from enemy attack by the

NGFS ships' barrages. They then were loaded on board

transports and redeployed to Pusan. In two weeks 200,000 men,

350,000 tons of equipment, and 17,500 vehicles were shipped

from Hungnam, while the enemy was kept at bay by intense and

69 accurate naval gunfire. Unlike retreating army units, which tended to leave equipment that proved difficult to move, the

Marines took everything with them, even the airlifted bridge they used to cross into Hungnam.

While these units left Hungnam, troops were outloaded from Wonsan beginning December 3. For the next week the troops were shipped from the port to Pusan. On December 5, troopships entered Chinnampo to begin evacuating the men to

Inchon and Pusan. That same day troops began to withdraw from

Inchon. 158 Under the intense pressure of the massive Chinese

Communist intervention, the United Nations withdrew southward rapidly. This development had the effect of overextending the advancing Communist forces' supply lines.

In March, 1951, U.N. forces launched Operation Ripper, a counterattack against the weakened North Korean and Chinese troops. With their lengthy supply lines under air attack by

United Nations forces, the enemy slowly started to fall back.

By the end of the month, Seoul and Inchon had been retaken.

The front stabilized after July, 1951, when Chinese resistance stiffened. The new line would be held with only minor changes until the end of the war . 159 Rear Admiral John M. Higgins was appointed Commander of the newly activated Mine sweeping Force Western Pacific on

November 11, 1951 . 160 The mission of this force was to make check sweeps of Wonsan, Hungnam, Songjin, the coastal area from Songjin to Kosong, the area from Sok-to to the Han

70 estuary, Cho-Do, Sok-to, and Haeju, all of which were in enemy hands. In all, this totalled 270 square miles of harbors and

300 miles of coastal channels to be kept clear. These fire support, bombardment, and patrol channels were kept open by an on-paper force of 6 AM and 14 AMS of which only half could be effectively maintained on station. 161 Routine patrol and the blockade of the Korean coast constituted the major naval activity for the rest of the war . 162

In the Kansong-Kosong-Sokcho Ri coastal region, Comstock

(LSD-19), 7 LCVPs, Mainstay (AM-261), Partridge (AMS-31),

Redhead (AMS-34), and Swallow (AMS-36) swept 13 mines on

February 2, 1951. Partridge experienced engine trouble during the operation and was swept by rough weather into a mine that - somehow was in waters that had been well swept, and sunk. 163

From December 13 to 16, 1951, Curlew (AMS-8), and Swallow

(AMS-36) cleared 19 mines from Songjin harbor. Dextrous (AM-

341) Murrelet (AM-372), and LST-799 aided in the search on the last two days. 164 In an unusual event that has become known as the "Nootka incident," a Canadian Tribal class destroyer captured a minelayer. On September 22, 1952, late at night near Chinnampo they unsuccessfully chased a minelayer. The ship disappeared back up a coastal waterway. Shortly after midnight, September 22/23, the Nootka discovered a second vessel leaving the Taedong estuary. Moving in at high speed they caught the ship after firing several shots at it. The

71 minelayer's crew had abandoned the vessel in an attempt to escape in small boats. When challenged by small boats from the Nootka, a brief firefight ensued. Although the majority of the crew escaped to the shore, two lieutenants, three chief petty officers, and a few crewmen were captured. The men cooperated and outlined the recently laid minefields in the area . 165

In addition to besieging North Korean cities, bombarding enemy troop positions, and sweeping fire support channels and assault beach areas, the navy also participated in diversionary amphibious assaults designed to cause the enemy concern about the real possibility of such assaults. The idea was to compel the enemy to shore up defenses along the coast by drawing troops away from the front lines. The first such feint was targeted at Chinnampo and the Taedong estuary. On

February 27, 1951, Carmick (DMS-33) and two ROKN YMSs began a two day job clearing the approaches. The amphibious group arrived on March 3 . They ran in near the shore before retiring to the south. 166

In a more daring and costly effort, the army, air force, and navy coordinated for a feint at Kojo. The difference this time was that only the top commanders knew this was not a real assault. D-Day was set for October 15, 1952. The minesweepers arrived and began sweeping in close to the shore.

Shore bombardment and fighter activity increased. They hoped to draw nearby enemy units into the open so that regular army

72 units with naval gunfire support could eliminate them. The

187th Regimental Combat Team prepared for an airborne assault, while the 1st Cavalry Division would move by sea. In the end the operation failed to draw the enemy out due to the speed of our actions and the slow reaction of the North Koreans, who, lacking motorized transport, could reach the area only on foot. Enemy shore batteries, however, made the feint costly for the United States as they took a toll on the minesweepers. 167 Osprey (AMS-2 8) sustained damage from a near miss by a 76mrn shore gun. Four crewmen were injured by the blast.

Until the end of the war, the West Coast Island Defense

Unit (WCIDU) and its east coast counterpart ECIDU reported on the enemy mining activities. When the war ended the withdrawing U.S. troops took the villagers on the occupied islands with them to protect them from reprisals . 168

With the end of the war, the navy issued orders to prevent the enemy from having any excuse to accuse the U.S. of violating the Armistice. They were issued to CTF 95 as follows: a. ROKN vessels were confined to areas south of the demarcation lines and after 15 August all U.N. patrols were restricted to South of the demarcation line. b. No visiting or searching of suspicious craft was permitted. c. Patrols were required to remain outside the three mile limit when north of the demarcation line. d. Patrols were directed to take evasive action when subjected to enemy fire, rather than return fire.

73 Fortunately no violations of the Armistice occurred and hostilities came to an end. 169

The last two-and-a-half years of the war were spent primarily check sweeping (see Figures 12 and 13) . Only two major incidents had to be dealt with: the ongoing siege of

Wonsan and the floating mine problem.

74 ' I '"

~ 0 a

LEGEND

AIICA CHCLOHO llr SOLIO LIHCS SWfi'T IT OWS'e TOll IIOOIICO TO 10 TT. JAH : Ill.

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fHCLOSUIIf I SE'CRIT AI'I'CHOI/t I "'.- ',./ Figure 12. EAST COAST COASTAL SWEEP FROM YANGYANG TO SUWON DAN Source: CINCPACFLT Interim Evaluation Report 2, volume 11, 1426.

75 ,, .... _., ·' / I f•. / ~ /. ~· . -Y . _____ ._ ..... ___----~~-/___ . . · ,r·:--·-· / /" /~/ · // 't" v .,. ,' . • • ..t/ .

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..... M HYDROPAC 8 IHSHOAE SWEEP LINES [AST C.OUT Of I(X)Hf.l Ul NOV£WB( R Ill :U

- ·- H'ft)ll()fW; L IH( • • • •• IIOHOH£ ,.((1' LIN£ - Mt(llf tfY~ LJN( 6 'W((I'LJH( COIHOOf. Figure 13.EAST COAST COASTAL SWEEP FROM SUWON DAN TO SONGJIN AREA Source: CINCPACFLT Interim Evaluation Report 5, volume 7, 47. 76 CHAPTER IV THE SIEGE OF WONSAN AND THE FLOATING MINE THREAT

After the Chinese intervention and subsequent winter offensive the North Koreans regained control of Wonsan from the retreating allies. Once ~n possession, remining, necessary in view of the American amphibious ability, began in earnest with Soviet mines and technical help . 170

With the Chinese "intervention" in mid-November 1950, United Nations forces began a fighting withdrawal. On the west coast, the Communists pressed forward, while in the east the Marine withdrawal slowed the enemy advance considerably. The Marines withdrew by sea from Hungnam under the protection of NGFS ships, which kept the Communist forces out of the city.

At Wonsan the defenders held firm. Shortly after the harbor was officially declared completely clear of mines on December 4, 1950, the United Nations forces withdrew to the next line of defense farther south.

In an effort to restrict enemy junk traffic and minelaying and to tie down as many enemy troops as possible,

United Nations forces made a bid to seize Wonsan harbor's outer islands. The navy, with the aid of South Korean

Marines, seized Yo Do and Ko-to islands, which control harbor traffic quite effectively. The lack of a reaction among the 77 North Korean forces holding the city caused United Nations forces to quickly seize islands further in. Plans were laid to begin the siege in early February 1951. Foul weather, however, hindered bombardment for 13 days . 171 The siege, begun on February 16, 1951, was the longest continuous siege in naval history.

Wonsan was not the only city held under siege, but it was the most important. The port of Songjin, north of Hungnam, was also placed under siege in March, 1951. 172 Wonsan was the second most important city in North Korea next to the capitol,

Pyongyang, and the largest seaport. Like Pyongyang, Wonsan was a center of the national rail and road transportation network. It had connections to almost every major city on the peninsula. It also had a direct rail link to Vladivostok. By holding the islands in the harbor, U.N. forces prevented resupply by sea and forced the enemy to divert troops and material away from the front to defend the city from attack.

Amphibious assault, or the threat of it, compelled the enemy to deploy thousands of troops to protect this important hub. Along with the influx of troops, the civilians were cleared out for protection. With mining again under way, U.N. minesweepers had to clear the harbor and its approaches once more. The minesweepers cleared 54 square miles of space for the gunfire support and bombardment ships . 173

The North Koreans responded to these U.N. efforts by building up their artillery and garrison forces to oppose the

78 bombardment, and by remining the harbor. The enemy placed

200 new mines in Wonsan harbor from March 25-30, 1951. 174 Of the 28 mines swept from Korean waters in March, 1951, 20 came from Wonsan. The minesweepers were frequently taken under fire by enemy shore batteries, on which occasions, accompanying gunfire support ships provided counter battery fire. 175 The struggle between the opposing sides, the enemy wishing to retain control of Wonsan and the U.N. forces endeavoring to tie down enemy troops and gain a better bargaining position at the peace table, lasted an incredible

861 days without any give by either side . 176

When the sweepers first began the job of clearing Wonsan harbor for the siege, they went about their task unmolested by the enemy shore batteries. In fact, it was so peaceful that when the pilot of the helicopter spotting mines for the minesweepers had to use the restroom, he landed at the city airfield and used their facilities. The North Koreans were so surprised by his visit they did not even try to stop him.

Once the destroyers arrived and began their bombardment, the enemy batteries opened up on the minesweepers, for the minesweepers cleared the way for the bombarding ships to fire into the city and the troops, trains, and supply vehicles that pas sed through it . 177 In addition to the sea-going minesweepers were the minesweeping boats (MSBs) . The MSBs were converted 40 foot launches and LCVPs. They were slow, had a shallow draft, and

79 had a low magnetic signature. These boats were especially useful for clearing the shallow waters near shore, usually operating directly beneath the enemy guns . 178 Obviously, the naval gunfire support ships did not need to go inshore, but such clearance, which was carried out in clearing Wonsan for the landing, gave credence to the fear of an amphibious assault.

Sweeping was done by a group of five ships, with four sweepers and one destructor vessel carrying an EOD team.

Moored mines located and cut free by the minesweepers were the targets of the destructor boat's hostility. 179 Sinking the floaters, all of which had to be eliminated, was a very trying job at Wonsan. There were not only those moored mines cut adrift by minesweepers, but also floaters that broke loose from their moorings, or were deliberately set adrift.

The minesweepers were not the only units to destroy mines. On March 1, 1951, the navy was informed by Korean agents that a trainload of Russian mines was being unloaded at

Kalma Gak. On the 7th of March the light cruiser Manchester

(CL-83) sailed into the Wonsan harbor swept bombardment channel and pounded the rail area with her 6" guns until a massive explosion marked the end of at least one boxcar of the offending mines, after which it left. 180 The work of the minesweepers eased a bit when LST 799 arrived at Wonsan. She had been converted to a badly needed helicopter base and a minesweeper tender. 181 This one vessel

80 enabled the minesweepers to remain on station without returning to Sasebo for routine repairs and replenishment.

In the face of the U.N.'s overwhelming naval strength, the enemy developed new methods of mining the harbor. Sampans often went out at night. Fishing boats carried mines tied to their bottoms, which they planted by simply cutting the connecting lines. Extensive use of floaters also harassed

U.N. operations. 182 The enemy used a new Russian self-planting mechanism, which used a hook attached to an oil drum, log, or other floating object to carry the mine. When a water soluble restraining washer dissolved, the mine was released. This resulted in the creation of irregular minefields, which were harder to clear, and they afforded a no-risk method to mine already cleared areas which were under U.N. surveillance. The

MYaM ground magnetic induction mine could also be affixed to the mechanism resulting in the planting of these shallow water ground mines. MSBs discovered an MYaM type mine in the

Hatchery area of Wonsan harbor and had to declare it offlimits to shipping. 183 Life had been eased somewhat by the ROK Marines, who had seized Yo Do island on February 14, two days before the siege began removing the threat of enemy fire from there for the minesweepers clearing the harbor for the bombarding ships that would arrive in two more days . 184 The minesweepers often worked at night under the harsh glare of starshells and

81 parachute flares, as working at night offered some protection from shore batteries. 185

On March 30, 1951, 15 new M26 mines were swept, confirming the unidentified radar contacts from the previous nights . 186 Five months later two floating objects believed to be fish or submarine type mines were sunk but confirmation of what type of mine they were was not forthcoming . 187

From May 1 to December 31, 1951, 317 moored contact mines and 8 magnetic mines were swept at Wonsan alone. 188 The majority of the mines swept after 1950 came from Wonsan harbor. From January 1 to June 30, 1952, of the 197 mines encountered, 141 were at Wonsan. 189

The current, slower here than on the west coast, caused mines to continue to "creep" along the harbor floor among the areas cleared by the minesweepers as the minesweeper Gladiator

(AM-319) discovered. Early in 1953, while anchored in the outer harbor waiting out heavy seas, their anchor dragged and eventually caught, holding them fast. In the morning, as they weighed, a mine came up attached to the anchor. Before the crew could react one of the mine's horns smashed against the ship's bow. When the mine failed to detonate, the crew quickly veered the chain. After dropping the anchor to the harbor bottom then hauling it in partially, then repeating the dangerous process several times, Gladiator finally managed to dislodge its unwelcome guest . 190

82 On occasion the minesweeping force got a break, such as when ROK intelligence questioned a defector from the North

Korean Navy based at Kojo, a town 39 miles south of Wonsan, who revealed that anti-landing craft mines had been sown ~n the harbor as protection against an amphibious assault . 191 The news was welcome as it averted a possible disaster, for the

MSBs were mostly converted landing craft.

Shore battery fire was the minesweepers' worst enemy.

The only way to avoid it was to sweep at night, an operation for which the sweepers were ill-equipped. Without an effective radar unit or mine locating sonar, night sweeping operations were hazardous as the minesweeper might run into a mine or run aground, as sometimes happened. As a result, most of the damage inflicted on minesweepers during the war came from the shore, not the sea. Destroyers often followed behind the little ships to provide counterbattery fire when an enemy battery attempted to engage them. Sometimes the minesweepers were overlooked by the shore batteries. One minesweeper kept sweeping while nearby shore batteries pounded a friendly island; to have made smoke and zigzagged out of the area would have only drawn attention to the ship and made it a target . 192

All ships conducting nighttime sweeps had to meet the following criteria: (a) daytime helicopter reconnaissance; (b) moonlight to get visual bearings; (c) no magnetic sweeping by

MSBs; (d) only one pass without echelon formation so no one

83 runs into a cut mine; and (e) smooth ocean for spotting cut mines . 193

In May, 1951, shore batteries were moved to Ilari Point on Kalma Gak. On the 17th, the batteries opened fire on the minesweepers' nighttime anchorage around Yo Do island. 194 With the safety of the anchorage compromised, the ships were forced to move.

From February 1953. until the end of the war in July, 13

U.N. vessels were fired on by the North Korean guns. 195

Fortunately during this period, few hits were achieved and no major casualties sustained. The threat of significant damage, like that sustained on October 20, 1952, at Songjin, by

Thompson (DMS-38), which had been taken under fire by enemy shore batteries, was ever-present. That day the ship sustained five hits from 105mm or 155mrn guns causing extensive damage to the ship and killing 3 men, while wounding eight.

During the Korean War, shore batteries scored hits on 21 U.S. and 4 ROKN ships killing 11 men and wounding 35.

By no means were these the only duties of the tiny minesweeping force. On occasion the minesweeper's crew would give up much needed rest in order to catch the minelayers in the act. In Operation Flycatcher, a recurring operation, the minesweepers would wait at night looking for any sign of enemy

. 1 196 minelaying and then descend upon and destroy t h e m~ne ayers.

They also participated on occasion in repelling sampans massing to attack friendly islands. 1 n A vessel of the

84 minesweeping force, Hitchiti (ATF-103), helped refloat ROKN

PC-704 after she ran aground on May 11, 1951. 198

Not all missions ended happily. One of the reconnaissance pilots, a lieutenant (junior grade), was on a rescue mission when his helicopter capsized in the sea resulting ~n its loss. He pushed the people aboard his aircraft into the two remaining helicopters, refusing to leave until everyone else was rescued. When the overloaded helicopters deposited their passengers and returned to search for him, the heroic pilot could not be found. 199

The Floating Mine Threat

During and after the Russo-Japanese War of 1904-05, unmoored floating mines had been found far from the war zone, usually with explosive results. Due to the threat they posed to neutral shipping, the Hague Conference of 1907 banned their use. The Korean War era threat from floating mines stemmed from the fact that neither the Soviet Union nor North Korea had ever signed the Hague Convention. The Russian mines provided to the North Koreans therefore lacked sterilizers, and they posed a grave danger to neutral as well as U.N. shipping. 200 The currents along the Korean peninsula run north to south and thence across the shipping lanes to Japan; the full scope of the danger posed by floating mines thus can easily be

85 201 seen. Floaters required only fifteen days to complete the transit from North Korean waters down the southern coast.

They could easily be launched from junks and sampans. 202 on

September 7, 1950, HMS Jamaica and Charity sighted and destroyed the first two floaters of the war at Changsangot, near Chinnarnpo. 203 From then until September 30, 25 floaters were spotted. 204

One reason for the initial landing at Wonsan, and later for the long siege, was that the many estuaries in the area provided good launch vehicles for floaters. Continuous attention was given this port to curb the flow of these menaces and thus protect shipping. 205

The number of drifting mines continued undiminished early in the war. From September 29 to October 23, 1950, 45 floaters were encountered on both coasts (see Figures 14 through 18) . From then until November 15, 35 more floaters were sighted in the Chinnarnpo area alone. Many of these mines were destroyed by Mariner and Sunderland flying patrol boats using . 50 calibre machine guns on strafing runs. 206

With the Russian mines remaining armed after being turned loose, floating mine sightings began corning in from the Sea of

Japan and the North Pacific. In June 1951, the destroyer

Walke (DD-723), which was stationed 60 miles offshore with the carrier task force, ran into a floater, suffered serious damage to the port side aft, and lost 25 men. 207 By October of

86 .. • .. • ~ 4 • I~ r.~~ I -. •"' I• • • •• • 0 • /- ~~ • ...... • • I • z 0 ' H I • J • '\ • 8 .. • . u • <,. I ::J • ~ • • 8 l ~ U) .. ~ • Q t a ~

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S£CRET Figure 15. MINES SIGHTED AND SWEPT, 1950-51 Source: CINCPACFLT Interim Evaluation Heport 2, volume 11, 1421.

89 ~o· ~

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ALAS ItA S · I 8 (A I A I I !CIIJIOC S[A UHIOH or SOVI(T SO(IA~IST IICPVBliCS I SEA or I OKHOTSK I ...... ~ 1.0 I N I I NOATH PACirlt; OC [AN

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Figure 18. MINE SIGHTINGS, 1951 Source: CINCPACLFT Interim Evaluation Report 3, volume 14, 44.

93 1951, over 300 Russian mines had washed up on the shores of

Japan. 2oa

As the war dragged on and the blockading ships moved farther offshore, the number of mines encountered in the fire support channels dropped. This is partly due to increased patrolling. · The percentage of the mines encountered that were floaters naturally increased. In April, 1952, 13 of the 33 mines encountered were drifters. 209

Some of the floaters were legitimately torn loose from their moorings by bad weather. In mid-August, 1952, Typhoon Karen swept through Korean waters resulting in 37 floaters. 210

One of these mines was struck by the fleet ocean tug Sarsi

(ATF-111) . The 37 floaters comprised most of the 54 mines

encountered that month. 211 September saw over 40 floaters sunk in the Sea of Japan.

One of the drifting terrors floated 90 miles east of Wonsan

where the destroyer Barton (DD-722) struck it on September 16.

"Just before his ship hit the mine, Conunander H.B. Seim had

read a report stating that a ship making more than ten knots

was safe from floating mines as the bow wave pushed them

aside. Barton's 15 knot bow wave didn't push quite far

enough . " 212 Barton survived with a five foot hole in her

side. 213 In February, 1953, 10 of the 12 mines sighted and sunk

were floaters. 214 April caused serious concern as "not since

August 1952, when a typhoon swept the Korean area, have so

94 many mines been encountered. " 215 Even when the war ended in late July, 1953, the majority of the mines were floaters, comprising 11 of the 13 mines encountered. 216 From February until July 1953, 93 mines were encountered, 81 of which were floaters. All of them were on the east coast (see Table 4) . 211

TABLE 4

NUMBER OF FLOATING MINES SIGHTED

Date Mines September 4-September 31, 1950 25 September 29-0ctober 23, 1950 45 October 23-November 15, 1950 35 March, 1951 7 May 1-December 31, 1951 11 January, 1952 14 February, 1952 23 March, 1952 24 April, 1952 13 June, 1952 5 August 16-September 30, 1952 37 February, 1953 10 March, 1953 14 April, 1953 21 May, 1953 9 June, 1953 19 July, 1953 11

Note: The table is incomplete as some documents pertaining to the Korean War are still classified.

Source: Cagle and Manson, "Wonsan: The Battle of the Mines," CINCPACFLT Interim Reports, MINRON 3 War Diary, Action Report Serial 0119, and COMNAVFE Command and Historical Reports.

There can be little doubt that the floating mines were anything other than a deliberate use of a deadly weapon outlawed by the Hague Convention. Storms accounted for some of them but in most cases there were no storms to produce the

95 many floating mines detected. Some authorities still believe that all of the drifting mines sighted were the result of natural causes as anything else would be a violation of the

1907 Hague Convention and the Soviets deneid they were doing it. 218 The fallacy of this position is immediately obvious from an investigation of the records. Eighty-one floating mines were encountered during the last six months of the war.

According to naval records, from the end of the war "to 1

January 1954, there had been only one mine encountered. This was an old floater estimated to have been in the water for about two years. " 219 Thus the number of floaters sighted during the six months prior to the end of the war was 81, and the number sighted in the six months after the war was one.

These figures offer irrefutable evidence that many of the

floaters earlier encountered by United Nations forces had been

deliberately launched.

96 CHAPTER V

AFTERMATH AND CONCLUSION

The initial response to the losses at Wonsan was to outfit landing craft with mine locating sonar so they could be used in that function. The World War II UOL MK4 short-pulse, high-frequency sonic imaging device had by 1950 evolved into the AN/UQS-1 mine locator. Tests were run in Korea using these units, but they performed poorly in the colder seas.

Similar experimentation in radar produced the SO and su types, which proved to be of great value to night mine sweeping operations. 220

There were also some wooden-hulled minesweepers built as a result of the discovery of magnetic mines. 221 The Bureau of

Ships turned to Philip L. Rhodes, who had designed minesweepers in the Second World War, for a new ship design.

The result was the 172 foot Aggressive class fleet ocean minesweeper, designated MSO. It used a Packard or General

Motors non-magnetic engine, controllable pitch propellers, wooden-hulled construction, and an improved minehunting sonar.

The 780 ton Acme class and 750 ton Agile class MSOs were also built. The ships of the Aggressive class represented the epitome of 1950s mine warfare ship construction. Sixty-five of these ships were built for the United States Navy. Many ships were converted, and 159 coastal minesweepers, MSCs, were also built. These ships were equipped with controllable

97 pitch propellers and separate engines to generate power for magnetic rninesweeping. All but 20 of the MSCs were turned over to our allies under the Military Defense Assistance

Program (MDAP) . The recipients included South Korea, Mexico,

Norway, Peru, Philippines, Taiwan, Uruguay, Burma, and the

Dominican Republic. 222 One new rninehunter, Bittern (MHC-43) , was also built. Perhaps most indicative of the mine warfare lessons of the Korean War, and Wonsan in particular, was the decision to specially produce 36 foot rninesweeping boats (MSBs) to replace the converted LCVPs.

In a truly revolutionary move, the Navy began testing a helicopter-towed rninesweeping array. The idea formed during the Korean War when helicopters proved their worth to rninehunting efforts as reconnaissance units. The towed arrays were tested at the mine countermeasures station at Panama

City, Florida, but with little progress due to unreliable funding. 223 The idea carne to fruition years later, and the systems were used during Operation End Sweep in Haiphong harbor at the end of the Vietnam War. The new MSOs and MSCs were equipped with automatic degaussing systems, as well as other features to defeat mines of types not even encountered in Korea, such as acoustic and pressure mines. And in a step in the other direction, Liberty ships were converted into guinea pig vessels for use in check sweeping, after the effectiveness of the Japanese ship Soei­

Maru was proved. 224 The Soei-Maru did check sweeping

98 operations at ports below the 38th parallel during the Korean

War. The successful use of this vessel lightened the burden on United States minesweepers for the important combat sweep operations.

An unusual experimental effort was the XMAP (Experimental

Magnetic, Acoustic, and Pressure Sweep) towed array project.

It was a 250 foot long, 2, 880 ton steel cylinder that was supposed to counter all influence mine types in one pass.

After large cost overruns and poor performance, the project was finally allowed to die a humble death.

The disaster at Wonsan compelled the nation to rebuild the mine warfare force to the state in which it should have been maintained following World War II. With the conversions and new construction, including 65 MSOs, 22 MSCs, and one minehunting vessel, the United States Navy possessed a total of 333 mine warfare ships. An impressive array of 180 new ships had been added to the fleet, which boasted 93 active minesweepers. 225 One of the more important changes for the mine forces was the reestablishment of the Mine Force Pacific Fleet (MINEPAC) in January, 1951, which signalled a continuing commitment to mine warfare. 226 Joining in on the scientific front was the

Mine Advisory Committee (MAC}, established in 1951 with some of the faculty of the Catholic University, and later moved to the National Academy of Sciences. They were responsible for

99 conducting a systematic study of mine warfare technology; many pioneering technical studies resulted from their efforts. 227

Naval intelligence, especially that obtained from helicopter spotters, was very important during the war. The reports from air and surface forces helped assess the mine threat during the war. With good intelligence, minefields such as the ones at Wonsan, Chinnampo, and Hungnam, could be cleared with relative ease. The harbor and river pilots who cooperated with U.N. forces helped outline the fields. In some cases, intelligence about shipments of mines caused their destruction before they reached their destination.

The enemy used the MKB chemical horn contact mine, the

M26 inertia contact mine, and the MYaM ground magnetic induction mine. Several other types were also in limited use.

The liberal use of floating contact and magnetic mines also complicated operations. 228

Fortunately for the u.s., experienced Japanese minesweeper crews, who had spent the years since the end of

World War II sweeping the waters around Japan, were on hand to take up the slack until reinforcements could arrive, although the method of their contracting was questionable. Their efficiency in the use of the guinea pig ship Soei-Maru in check sweeping operations prompted U.S. interest in keeping

. t 229 some guinea pig vessels in every strateg~c por .

Despite the lack of vessels, parts, and trained men, the minesweeping force (TG 95.6) did a remarkable job. They swept

100 the assault beaches, the bombardment channels, and gunfire support channels, all of which were maintained until the end of the war. They faced determined remining and intense shore battery fire. Mine countermeasures changed dramatically during the war. A lack of ships forced many innovations.

Indeed, innovations ~n minesweeping gear, mine hunting tactics, and mine disposal were earmarks of this war.

Admiral C. Turner Joy felt that neglecting mine warfare was a foolish mistake as any alert enemy who could use mines

intelligently could stop or hinder u.S. naval operations. 230

The North Koreans, with Soviet aid and assistance, did so,

and, for the expenditure of 3,000 obsolete mines sank five

ships, held off a 250 ship armada for five days, and

indirectly caused the United States to spend millions of

dollars on increased research and construction that otherwise

would have been unnecessary. For the enemy, the decision to

mine was a simple one. 231 The greatest problem is that such a

tragedy might occur again. As Admiral Duncan said, "we don't

seem to learn though, historically the Navy especially, never

pays much attention in peacetime to the passive or less

glamorous weapon systems. " 232 If a mine force exists, it

should not be reduced as Secretary of Defense Louis Johnson

reduced the u.S. Navy by 1950. 233 On the other hand, the U.S.

should not have fallen prey to the exaggerated psychological

impact mine warfare tends to produce in its victim. The

101 victim often views the threat as being vastly more significant than it is. 234

After the initial shock of the losses was over, funding for increased mine countermeasures slowly dried up after

235 1958. Many of our old vessels were retained even up until

the 1970s. The last of the Auk and Admirable class ships, built in World War II and used extensively in Korea, were

removed from service on July 1, 1972. They were soon transferred to foreign navies like the rest of their predecessors. The Acme class MSO, commissioned in 1957 and

1958 were eliminated in 1976. The last three active Agile class MSO, commissioned from 1952 to 1956, remained in service in 1979 for research purposes in Panama City. Twenty more were in the Naval Reserve Force and 10 were mothballed. 236

Although during the crisis the U.S. Navy built up a large mine sweeping fleet, many of the vessels were subsequently mothballed or sold.

In 1987, during the Iran-Iraq war, reflagged Kuwaiti tankers faced a threat from mines laid by Iran in the Persian

Gulf. This threat was intensified by the fact that these supertankers were restricted to the deep water channel close to the Iranian coast. Complicating the United States pledge to protect these ships was the total lack of minesweepers in the Gulf area. On July 24, 1987, the tanker Bridgeton became the first victim of an Iranian mine. Within a short period, six minesweepers and a few minesweeping helicopters arrived in

102 the Persian Gulf, proving once again the unfortunate fact that resolute action in mine warfare could only be undertaken after losses had been sustained. By year's end, 13 minesweepers were at work. With the old Korean War-era minesweepers' state of the art equipment, the U.S. Navy was still unprepared to counter World War I vintage mines. 237

Visions of ships like the frigate Samuel B. Roberts (FFG-

58), which hit a mine on April 14, 1988, ~n the Persian Gulf and had a 20 foot hole torn ~n the hull, as well as a broken keel and other damage, were still recent memories when the

United States again became involved in the area during Desert

Shield and Desert Storm. On February 18, 1991, the amphibious carrier Tripoli (LPH-10) hit a mine 50 miles off Kuwait,

suffering a 16 by 25 foot hole in her hull. The ship managed

to stay on station to continue supporting the minesweeping and

amphibious assault operations. Soon afterwards a mine

detonated under the keel of the guided missile cruiser

Princeton (CG-59) cracking the hull. In 1989-1990, the United States Navy's entire mine

countermeasures force totalled 20 Korean War-era MSOs in

active and reserve fleets, 21 RH-53D helicopters, and 7

MSBs. 238 Even with an expanded construction program planned

after Desert Storm, recent budget cuts are almost certain to

result in a reduction of the construction program to preserve

active ships.

103 In the early phases of the Korean War, the United States was totally unprepared to undertake mine clearance due to the

cutbacks of previous years. There were far too few ships trying desperately to cover all the gaps. As a result the enemy succeeded in delaying amphibious operations and shore bombardments. The United Nations naval forces suffered heavy

casual ties, the loss of several small vessels, and severe

damage to many larger ships.

America's neglect and subsequent rush to compensate for

that neglect in the late 1980s and early 1990s, only to

sacrifice such mine warfare advances as were made during this

latest crisis period, repeats with remarkable consistency the

sad cycle of neglect, accelerated attention, and gradual

neglect which characterized the Korean War years just four

decades ago. No need could be more clear in the 1990s; yet

the lesson, it seems, will be less heeded.

104 ENDNOTES

1 The Reminiscences of Admiral Charles K. Duncan, USN (Ret.), 4 vol. (Annapolis: U.S. Naval Institute Oral History Interview, Operational Archives, Naval Histo~ical Center, Washington, D.C.), 346-347 (hereafter cited as Admiral Duncan) .

2Harry K. Griffin, "The Navy in Korean Waters," Army Information Digest 12 (1951): 13.

3 Ibid., 18.

4 Ibid., 12.

5C.W. Saar, "Offensive Mining as a Soviet Strategy," U.S. Naval Institute Proceedings 90 (August 1964): 45.

6Cornrnander In Chief Pacific Fleet Interim Evaluation Report 1, vol. 6 (Wilmington, Delaware: Scholarly Resources Inc., 1978), 1088 (hereafter cited as CINCPACFLT Interim Report 1) .

7Gregory K. Hartmann, Weapons That Wait: Mine Warfare in the U.S. Navy (Annapolis: Naval Institute Press, 1979), 78.

8 Cornrnander In Chief Pacific Fleet Interim Evaluation Report 6, vol. 1 (Operational Archives, Naval Historical Center, Washington, D.C.), 9 (hereafter cited as CINCPACFLT Interim Report 6) .

9Malcolm w. Cagle and Frank A. Manson, "Wonsan: The Battle of the Mines, " U.S. Naval Institute Proceedings 8 3 (June 1957) : 611. 10Arnold s. Lott, Most Dangerous Sea: A History of Mine Warfare (Annapolis: Naval Institute Press, 1954), 268, 269.

11 Ibid., 270.

12 Ibid., 277.

13Ibid., 285.

l 4Harry w. Edwards, "A Naval Lesson of the Korean War," U.S. Naval Institute Proceedings 80 (December 1954): 1338.

15Andrew Patterson, Jr., "Mining: A Naval Strategy'" Naval War College Review 97 (May 1971): 54.

105 16 Howard S. Levie, Mine Warfare and International Law (N.p., 1972), 100.

17 Ibid., 113.

18Patterson, 54-55.

19Tamara Moser Melia, "Damn the Torperdoes:" A Short History of U.S. Naval Mine Countermeasures, 1777-1991 (Washington: Naval Historical Center, 1991), 72.

20Malcolm W. Cagle and Frank A. Manson, The Sea War in Korea (Annapolis: U.S. Naval Institute Press, 1957), 124.

21Cagle and Manson, "Wonsan: The Battle of the Mines," 599.

22 CINCPACFLT Interim Report 6, 1: 9.

23 CINCPACFLT Interim Report 1, 2: 102.

24 Cagle and Manson, The Sea War in Korea , 125.

25Me 1 i a , 57 , 61 .

26 Griffin, 12.

27 Lot t, 2 6 9 .

28Melia, 69.

29 CINCPACFLT Interim Report 1, 6: 1091.

30Melia, 69. 31James A. Field, A History of United States Naval operations: Korea (Washington: Department of the Navy, 1962), 231. 32Cagle and Manson, The Sea War in Korea, 127.

33 Ibid., 126.

34Admiral Duncan, 345.

35CINCPACFLT Interim Report 1, 6: 1091-1092.

36Melia, 68. 37 Cagle and Manson, The Sea War in Korea, 125.

106 38 Ibid.

39 Cagle and Manson, "Wonsan: The Battle of the Mines," 601.

4°Field, 232.

41Cagle and Manson, The Sea War in Korea, 126.

42CINCPACFLT Interim Report 1, 6: 1092.

43 Ibid., 1095.

44War Diary, Commander Mine Squadron 3(1), August, 1950- August, 1951, Operational Archives, Naval Historical Center, Washington, D.C., August, 1950, 2 (hereafter cited as MINRON 3 War Diary) .

45Commander Naval Forces Far East, Command and Historical Report, June 26-August 31, 1950, Post 1 January 1946 Command File, Operational Arhcives, Naval Historical Center, Washington, D.C., chapter 2, 14 (hereafter cited as COMNAVFE Command and Historical Report) .

46Field, 231.

47CINCPACFLT Interim Report 1, 6: 10 95.

48Walter Karig, Malcolm W. Cagle, and Frank A. Manson, Battle Report: The War in Korea (New York: Rinehart and Company, Inc., 1952), 67.

49CINCPACFLT Interim Report 1, 6: 1149.

50 Ibid., 6: 1097.

51Karig et al., 172.

52COMNAVFE, Command and Historical Report, September­ November 1950, chapter 2, 9-10.

53Cagle and Manson, The Sea War in Korea, 131.

54CINCPACFLT Interim Report 1, 3: 361.

55Ibid., 6: 1088, 1089.

56Field, 183.

57CINCPACFLT Interim Report 1, 6: 1088.

58 Ibid. , 1 : 9 · 107 sgcagle and Manson, The Sea War in Korea, 131.

6oCINCPACFLT Interim Report 1 r 3 : 3 62. 61J . ames Cotton and Jan Neary, eds., The Korean war in H~story (Atlantic Highlands N J . -:-H:-----7'. ...;;;t;..:."-=;.:_....:..:...:==-----=.:..:. I t · r • • • uman~ ~es Press n ernat~onal, Inc., 1989), 127, 129, 130.

62R· h ~c ard T. Spofford, Officer Biographies, Operational Archives, Naval Historical Center, Washington, D.C., 1. 63 Cagle and Manson, "Wonsan: The Battle of the Mines, " 599.

64Griffin, 13, 22. 65 CINCPACFLT Interim Report 1, 1: 9. 66 b. I ~d. , 6: 10 9 6.

67 Lott, 268.

68Field, 231-232.

69Admiral Duncan, 345, 346.

7°Karig et al. , 195.

71Lott, 270.

72Griffin, 12.

73Lott, 271.

74Edwards, 1340.

75Robert Debs Heinl, Jr., Victory at High Tide (New York: J.B. Lippincott Company, 1968), 27, 81, 82, 83.

76MINRON 3 War Diary, September, 1950, 5.

77 Lynn Montross and Nicholas A. Canzona, The Inchon-Seoul Campaign, U.S. Marine Operations in Korea, 1950-1953, vol. 2 (Washington: Historical Branch, G-3, Headquarters, U.S. Marine Corps, 1955), 83.

78Heinl, 85.

79Action Report, Commander Mine Squadron 3, Serial 0119, March 10, 1951, Operational Archives, Naval Historical Center, Washington, D.C., 9.

108 80Lott, 271.

81Melia, 73.

82 CINCPACFLT Interim Report 1, 3: 365. 83Melia, 73.

84 COMNAVFE Command an d H~storical· Report, September- November, 1950, chapter 2, 9-10, 12.

85Karig et al., 281-283.

86 Ibid.

87 Ibid., 284.

88Lot t , 2 7 3 .

89 Ibid., 272-273.

9°Field, 217.

91CINCPACFLT Interim Report 1, 1: 9.

82Karig et al. , 342.

93CINCPACFLT Interim Report 1, 6: 1133-1134; MINRON 3 War Diary, October, 1950, 2-3.

94Cagle and Manson, "Wonsan: The Battle of the Mines, " 598; Karig et. al, 298.

95Melia, 73.

96Lott, 272.

97Field, 233.

98James F. Schnabel, Policy and Direction: The First Year, United States Army in the Korean War (Washington: Office of the chief of Military History, Department of the Army, 1972), 205-206.

99Melia, 77.

10°Karig et al., 315.

101Field, 232.

109 102 Lynn Montross and Nicholas A. Canzona The Chosin Reservoir Campaign, United States Marine Operations in Korea, 1950-1953, vel. 3 (Washington: Historical Branch, G-3, H7adquarters, United States Marine Corps, 1957), 27; war D~ary, October, 1950, 4.

103Cagle and Manson, The Sea War in Korea, 134.

104 Field, 233.

105Cagle and Manson, The Sea War in Korea, 135.

106Resurne Report-Tailboard, Commander Mine Squadron 3, Serial 024, November 27, 1950, Operational Archives, Naval Historical Center, Washington, D.C., 1.

107Roy E. Appleman, South to the Naktonq, North to the Yalu, United States Army in the Korean War (Washington: Office of the Chief of Military History, Department of the Army, 1961), 633.

108Cagle and Manson, The Sea War in Korea, 136.

109Field, 233.

110MINRON 3 War Diary, October, 1950, 5.

111Karig et al., 305; Andrew Geer, The New Breed (New York: Harper adn Brothers Publishers, 1952), 192, other sources list different dates for the fall of Wonsan to ROK I Corps troops, this date was chosen as most of the sources agreed on this point.

112Appleman, 634.

113Field, 235.

114MINRON 3 war Diary, October, 1950, 5-6·

115Action Report, Mine Squadron 3, Serial 0204, Operational Archives, Naval Historical Center, Washington, D.C., 3.

116Melia, 7 6. 117Lieutenant Commander D' Arcy v. Shouldice to the Chief of Naval Operations, February 11, 1953, Po~t 1 ~anuary 1946 Command File, Operational Archives, Naval H~sto:~cal Center, Washington, D.C., 3, (hereafter cited as Should~ce) ·

118CINCPACFLT Interim Report 1, 5: 7 32 ·

110 11 ~Action Report, Small Boat Minesweepers, Mine Squadron 3,. Ser~al. 01, November 30, 1950, Operational Archives ' Naval H~stor~cal Center, Washington, D.C., cover, 1.

12 °CINCPACFLT Interim Report 1, 3: 366.

121 Ibid., 1: 9, 3:362,365.

122Karig et al., 324.

123Ibid., 322-323.

124MINRON 3 War Diary, October, 1950, 11.

125Schnabel, 217.

126Karig et. al, 327.

127Ibid., 327-330.

128Cagle and Manson, The Sea War in Korea, 145.

129CINCPACFLT Interim Report 1, 6: 1089.

13°Cagle and Manson, "Wonsan: The Battle of the Mines," 610.

131MINRON 3 War Diary, October, 1950, 9.

132Field, 235; Action Report, Mine Squadron 3, Serial 0121, March 10, 1951, Operational Archives, Naval Historical Center, Washington, D.C., H.O. 6515.

133Schnabel, 2 0 9.

134CINCPACFLT Interim Report 1, 6: 1098, 1154-1155 ·

135Shouldice, 1-2.

136Karig et al., 324-325.

137Appleman, 634.

138Karig et al. , 332.

139Field, 243.

140Melia, 7 8.

141Lott, 27 8.

111 1420fficer B · h · ~ogra:p ~es, Stephen M. Archer, Operational Archves, Naval H~stor~cal Center, Washington, D.C., 1_ 2 _ 143 Cagle an d Manson, The Sea War in Korea, 153. 144Lott, 27 9.

l4SKarig e t a 1 ., 358 , 359.

146Field, 237-238.

147Melia, 81.

148Lott, 27 9.

149Field, 240.

15°Karig et al., 361.

151 Ibid. , 3 62. 152 Cagle and Manson, The Sea War ~n Korea, 159.

153Karig et al. , 35 9.

154Lot t, 2 8 0 .

155CINCPACFLT Interim Report 1, 6: 1132. 156 Action Report, Mine Squadron 3, Serial 0019, November 3, 1950, Operational Archives, Naval Historical Center, Washington, D.C., 1-2.

157CINCPACFLT Interim Report 1, 6: 1137; Field, 249.

158Lot t , 2 81 .

159Billy C. Mossman, Ebb and Flow, November 1950-July 1951, United States Army in the Korean War (Washington: Center of Military History, United States Army, 1990), 155, 165, 210.

160MINRON 3 War Diary, November, 1950, 2-3.

161COMNAVFE, Command and Historical Report, October­ November, 1952, chapter 2, 25-26; Comander in Chief Pacific Fleet Interim Evaluation Report 5, vol. 7, (Wilmington, Delaware: Scholarly Resources Inc., 1978), 1 (hereafter cited as CINCPACFLT Interim Report 5) .

162Walter G. Hermes, Truce Tent and Fighting Front, United States Army in the Korean War (Washington: Office of the Chief of Military History, United States Army, 1966), 328.

112 163 A c t.~on R eport , M~ne . Squadron 3, Serial 0124 March 10 1951, Operational Archives, Naval Historical Center' Washington, D.C., 2-3. '

164A t. R . c ~on eport, M~ne Squadron 1, Serial 044, Operational Archives, Naval Historical Center, Washington, D.C., 1, 3.

165Cagle and Manson, The Sea War in Korea, 204-206.

166Field, 330.

167Robert F. Futrell, The United States Air Force in Korea, 1950-1953 (New York: Duell, Sloan and Pearce, 1961), 494-496; Melia, 82.

168Pat Meid and James M. Yingling, Operations in West Korea, United States Marine Operations in Korea, 1950-1953, vol. 5 (Washington: Historical Division, Headquarters, United States Marine Corps, 1972), 359.

169CINCPACFLT Interim Report 6, 8: 28-29.

17°F ield, 32 6.

171Sheldon Kinney, "All Quiet at Wonsan," United States Navla Institute Proceedings 80 (August 1954): 861.

172Field, 331.

173CINCPACFLT Interim Report 5, 7: 44.

174Commander in Chief Pacific Fleet Interim Evaluaiton Report 2 (Wilmington, Delaware: Scholarly Resour~es Inc·, 1978), 1770., (hereafter cited as CINCPACFLT Inter~rn Report 2) .

175Field, 331.

176Kinney, 85 9.

177 Ibid., 861.

178Richard B. Phillips, "T h e s e~ge· of Wonsan," Army Information Digest 8 (November 1953): 42.

179Ibid., 43.

18°Field, 331.

181Ibid. , 345.

182Kinney, 8 62. 113 183 Commander 1.n Chief Pacific Fleet Interim Evaluation Report 4, vol. 8 (Wilmington, Delaware: Scholarly Resources Inc., 1978), 17 (hereafter cited as CINCPACFLT Interim Report 4) .

184Phillips, 45.

18 ~INRON 3 War Diary, February, 1951, 5. 186 Ibid. , March, 1951, 7-8. 187 Ibid., August, 1951, 13. 188 Commander in Chief Pacific Fleet Interim Evaluation Report 3, vol. 14 (Wilmington, Delaware: Scholarly Resources Inc., 1978), 23 (hereafter cited as CINCPACFLT Interim Report 3) •

189CINCPACFLT Interim Report 4, 8: 14.

190Phillips, 43.

191CINCPACFLT Interim Report 6, 8: 2 6.

192p. w. Rairden, Jr., "The Junior Officer in Mine Warfare," United States Naval Institute Proceedings 79 (September 1953): 978.

193CINCPACLFT Interm Report 4, 8: 27.

194MINRON 3 War Diary, May, 1951, 8.

195CINCPACFLT Interim Report 6, 8: 41.

196Kinney, 8 62.

197Phillips, 45-4 6.

198MINRON 3 War Diary, May, 1951, 6.

199 Ibid., March, 1951, 8.

200Cagle and Manson, The Sea War in Korea, 131.

2mcagle and Manson, "Wonsan·. The Battle of the Mines," 599.

202 CINCPACFLT Interim Report 1, 6: 1088.

2o3Cagle and Manson, The Sea War in Korea, 130.

204 Ibid., 131.

114 205Phillips, 41.

206CINCPACFLT Interim Report 1, 3: 363, 365.

2 ~Field, 358-359.

208CINCPACFLT Interim Report 3, 14: 12-13.

209COMANVFE Command and Historical Report, April, 1952, chapter 2, 11.

21°COMNAVFE Command and Historical Report, August-Septem­ ber 1952, chapter 2, 11.

211CINCPACFLT Interim Report 5, 7: 5.

212Lott, 284.

213Commander in Chief Pacific Fleet Interim Evaluation Report 5, 7: 22.

214COMNAVFE Command and Historical Report, January­ February, 1953, chapter 2, 18.

215COMNAVFE Command and Historical Report, March-April, 1953, chapter 2, 25.

216COMNAVFE Command and Historical Report, July, 1953, chapter 2, 18.

217CINCPACFLT Interim Report 6, 8: 1, 9.

218Levie, 143.

219CINCPACFLT Interim Report 6, 8: 2 9.

220Hartmann, 135; CINCPACFLT Interim Evaluation Report 6, 8: 3.

221Lott, 4 02.

222Hartmann, 141 .

223Melia, 85.

224 Ibid. , 83, 85.

225 Ibid. , 85, 87.

226Ibid., 83.

227Hartmann, 81.

115 228 C INCPACFLT Interim Report 6, 1: 9.

229 C INCPACFLT Interim Report 1, 6: 1147.

23 °Cagle and Manson, "Wonsan: The Battle of the Mines," 611.

231Patterson, 56.

232Duncan, 34 7.

233Lott, 277.

234Patterson, 62.

235Melia, 8 6.

236Hartmann, 141 .

237Michael A. Palmer, On Course to Desert Storm (Washing­ ton: Naval Historical Center, 1992), 122, 123, 124, 129.

238Melia, 127, 128, 131.

116 BIBLIOGRAPHY

Unpublished Government Documents

OPERATIONAL ARCHIVES, NAVAL HISTORICAL CENTER, WASHINGTON, D.C.

Action Reports

Commander Mine Squadron 1. Serial 044. December 26, 1951.

Commander Mine Squadron 3, Serial 0119. March 10, 1951.

Commander Mine Squadron 3. Serial 0124. March 10, 1951.

Mine Squadron 3. Serial 0019. November 3, 1950.

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Mine Squadron 3. Serial 0204.

Small Boat Minesweepers. Mine Squadron 3. Serial 01. November 30, 1950.

Command and Historical Reports (COMMANDER NAVAL FORCES FAR EAST) POST 1 JANUARY 1946 COMMAND FILE

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January-February, 1953.

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July, 1953.

Interim Evaluation Report (COMMANDER IN CHIEF, PACIFIC FLEET) Report 6.

Officer Biographies

Richard T. Spofford

Stephen M. Archer

Oral History

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Lieutenant Commander D'Arcy V. Shouldice to the Chief of Naval Operations. February 11, 1953. Post 1 January 1946 Command File.

Resume Report-Tailboard. Commander Mine Squadron 3. Serial 024. November 27, 1950.

War Diary. Commander Mine Squadron 3. August, 1950-August, 1951.

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Interim Evaluation Reports (COMMANDER IN CHIEF, PACIFIC FLEET)

Report 1, Wilmington, Delaware: Scholarly Resources Inc., 1978.

Report 2, Wilmington, Delaware: Scholarly Resources Inc., 1978.

Report 3, Wilmington, Delaware: Scholarly Resources Inc., 1978.

118 Report 4, Wilmington, Delaware: Scholarly Resources I 1978. nc.,

Report 5, Wilmington, Delaware: Scholarly Resources I 1978. nc.,

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Applema~, Roy E. South to the Naktong, North to the Yalu. Un1. ted St?-tes Arm.y ~n the Korean War. Washington: Office of the Ch1.ef of M1.l1.tary History. Department of the Army 1961. .

Blackman, Raymond V.B. and Francis E. McMurtie eds. Jane's Fighting Ships, 1949-1950. New York: McG;aw Hill Book Company Inc., 1949.

Blackman, Raymond V.B., ed. Jane's Fighting Ships, 1950-1951. New York: McGraw Hill Book Company Inc., 1951.

Jane's Fighting Ships, 1951-1952. London: Sampson Low, Marston & Co. Ltd., 1952.

______. Jane's Fighting Ships, 1952-1953. London: Sampson Low, Marston & Co. Ltd., 1953.

------:--· Jane's Fighting Ships, 1953-1954. New York: McGraw Hill Book Company Inc., 1954.

Cagle, Malcolm W. and Frank A. Manson. The Sea War in Korea. Annapolis: United States Naval Institute Press, 1957.

Cotton, James and Jan Neary, eds. The Korean War in History. Atlantic Highlands, N.J.: Humanities Press Int~tion­ al, Inc., 1989.

Field, James A., Jr. A History of United States Naval Operations: Korea. Washington: Department of the Navy, 1962.

Futrell, Robert F. The United States Air Force in Korea, 1950- 1953. New York: Duell, Sloan, and Pearce, 1961.

Geer, Andrew. The New Breed. New York: Harper and Brothers Publishers, 1952.

Hartmann, Gregory K. Weapons That Wait: Mine Warfare in the United States Navy. Annapolis: Naval Institute Press, 1979.

Heinl, Robert Debs, Jr. Victory At High Tide. New York: JB Lippincott Company, 1968.

119 Hermes, Wa~ter G. Truce Tent and Fighting Front. United states Army ~n the Korean War. Washington: Office of the Chief of Military History, United States Army, 1966.

Karig, Walter, Malcolm W. Cagle and Frank A. Manson. Battle Report: The War in Korea. New York: Rinehart and Company Inc., 1952.

Levie, Howard S. Mine Warfare and International Law. N.p. 1972. '

Lott, ArnoldS. Most Dangerous Sea: A History of Mine Warfare. Annapolis: Naval Institute Press, 1954.

Meid, Pat and James M. Yingling. Operations in West Korea. United States Marine Operations in Korea, 1950-1953. vol. 5. Washington: Historical Division, Headquarters, United States Marine Corps, 1972.

Melia, Tamara Moser. "Damn the Torpedoes:" A Short History of United States Naval Mine Countermeasures, 1777-1991. Washington: Naval Historical Center, 1991.

Montross, Lynn and Nicholas A. Can zona. The Inchon-Seoul Campaign. United States Marine Operations in Korea, 1950-1953. vol. 2. Washington: Historical Branch, G-3, Headquarters, United States Marine Corps, 1995.

The Chosin Reservoir Campaiqn. United States Marine Operations in Korea, 1950-1953. vol. 3. Washington: Historical Branch, G-3, Headquarters, Ullted States Marine Corps, 1957. Palmer, Michael A. On Course to Desert Storm. Washington: Naval Historical Center, 1992. Schnabel James F. Policy and Direction: The First Year. United States Army in the Korean War. Washington: Office of the Chief of Military History, Department of the Army, 1972. Articles Cagle, Malcolm w. and Frank A. Manson. "Wonsan: The Battle of the Mines." United States Naval Institute Proceedings 83 (June 1957): 598-611. Dempewolff, Richard F. "Mother of the Minesweepers." Popular Mechanics Magazine 97 (February 1952): 97-104.

120 Edwards, Harry W. "A Naval Lesson of the Korean Conflict." United States Naval Institute Proceedings 80 (December 1954) : 1337-1340.

Griffin, Harry K. "The Navy in Korean Waters." Army Information Digest 12 (1951): 12-22.

Kinney, Sheldon. "All Quiet at Wonsan." United States Naval Institute Proceedings 80 (August 1954): 858-867.

Patterson, Andrew, Jr. "Mining: A Naval Strategy." Naval War College Review 97 (May 1971): 52-66.

Phillips, Richard B. "The Siege of Wonsan." Army Information Digest 8 (November 1953): 39-47.

Rairden, P. W., Jr. "The Junior Officer in Mine Warfare." United States Naval Institute Proceedings 79 (September 1953) : 977-979.

Saar, C.W. "Offensive Mining as a Soviet Strategy." United States Naval Institute Proceedings 90 (August 1964) : 42- 51.

121 APPENDIX A

UNITS ASSIGNED TO CTG 95.6 MINESWEEPING FORCE DURING THE KOREAN WAR NAME DESIGNATION CLASS MINESWEEPER (AM) Chief AM-315 AUK Competent AM-336 AUK Defense AM-317 AUK Devastator AM-318 AUK Dextrous AM-341 AUK Impeccable AM-320 AUK Incredible AM-249 ADMIRABLE Gladiator AM-319 AUK Mainstay AM-261 ADMIRABLE Murre let AM-372 AUK Pirate AM-275 ADMIRABLE Pledge AM-277 ADMIRABLE Ptarmigan AM-376 AUK Redstart AM-373 AUK Ruddy AM-380 AUK Shoveler AM-382 AUK Surfbird AM-383 AUK Swift AM-122 AUK Symbol AM-123 AUK Toucan AM-387 AUK Waxwing AM-389 AUK Zeal AM-131 AUK AUXILIARY MINESWEEPER (AMS) Chatterer AMS-40 ALBATROSS Condor AMS-5 ALBATROSS Curlew AMS-8 ALBATROSS Firecrest AMS-10 ALBATROSS Gull AMS-16 ALBATROSS Heron AMS-18 ALBATROSS Kite AMS-22 ALBATROSS Magpie AMS-25 ALBATROSS Merganser AMS-26 ALBATROSS Mocking Bird AMS-27 ALBATROSS Osprey AMS-28 ALBATROSS Partridge AMS-31 ALBATROSS Pelican AMS-32 ALBATROSS Redhead AMS-34 ALBATROSS Swallow AMS-36 ALBATROSS Waxbill AMS-39 ALBATROSS DESTROYER MINESWEEPER (DMS) Carmick DMS-33 ELLYSON Doyle DMS-34 ELLYSON Endicott DMS-35 ELLYSON Thompson DMS-38 ELLYSON 122 AUXILIARY SHIPS NET LAYING SHIP (AN) Mulberry AN-27 TREE DEGAUSSING SHIP (ADG) ADG-11 GASOLINE TANKER Genesee AOG-8 PATAPSCO HIGH SPEED TRANSPORT (APD) Diachenko APD-213 Horace A. Bass APD-124 SALVAGE SHIP (ARS) Bolster ARS-38 BOLSTER Conserver ARS-39 BOLSTER Current ARS-22 BOLSTER Deliverer ARS-23 BOLSTER Grapple ARS-7 BOLSTER Grasp ARS-24 BOLSTER Reclaimer ARS-42 BOLSTER Safeguard ARS-25 BOLSTER FLEET OCEAN TUG (ATF) Abnaki ATF-96 ABNAKI Apache ATF-67 ABNAKI Arikara ATF-98 ABNAKI Chickasaw ATF-83 ABNAKI Hitchiti ATF-103 ABNAKI Moctobi ATF-105 ABNAKI Molal a ATF-106 ABNAKI Quapaw ATF-110 ABNAKI Sarsi ATF-111 ABNAKI Takelma ATF-113 ABNAKI Tawas a ATF-92 ABNAKI Tawakoni ATF-114 ABNAKI Ute ATF-76 ABNAKI Yuma ATF-94 ABNAKI LANDING CRAFT/SHIP UTILITY (LCU/LSU) LCU-1124 501-1465 SERIES LCU-1363 501-1465 SERIES LANDING SHIP DOCK (LSD) Cabildo LSD-16 CABILDO Catamount LSD-17 CABILDO Colonial LSD-18 CABILDO Comstock LSD-19 CABILDO Epping Forest LSD-4 ASHLAND Fort Marian LSD-22 CABILDO Gunston Hall LSD-5 ASHLAND Tortuga LSD-32 CABILDO Whetstone LSD-27 CABILDO LANDING SHIP TANK (LST) LST-692 511-1152 SERIES LST-735 511-1152 SERIES LST-772 511-1152 SERIES

123 LST-799 511-1152 SERIES LST-802 511-1152 SERIES LST-819 511-1152 SERIES LST-855 511-1152 SERIES LST-901 511-1152 SERIES LST-975 511-1152 SERIES LST-1077 511-1152 SERIES LST-1138 511-1152 SERIES LST-1141 511-1152 SERIES SCAJAP LST-Q007 511-1152 SERIES SCAJAP LST-Q008 511-1152 SERIES SCAJAP LST-QO 12 511-1152 SERIES SCAJAP LST-Q092 511-1152 SERIES MISCELLANEOUS AUXILIARY (YAG) GUINEA PIG SHIP YAG-36 LIBERTY SHIP YAG-37 LIBERTY SHIP YAG-38 LIBERTY SHIP JAPANESE MINESWEEPERS MS01-17, 57, 81-86 MS18-30 MS31 HEADQUARTERS SHIP Soei-Maru SS/MV MS32 MS33-39, 41-42, 50, 54-56, 58-62, 66-72, 75, 77, 80 PS02, 04, 08 43 SOUTH KOREAN MINESWEEPERS (YMS) JMS-302 JMS-306 Kanggyong YMS-510 Kangjin YMS-501 Kangkae YMS-506 Kangnung YMS-507 Kimchon YMS-513 Kimhae YMS-505 Kuwalsan YMS-512 Kwangju YMS-503 Kyongju YMS-502 Ue Nan YMS-515 LANDING SHIP INFANTRY, LARGE (LSIL) Chung Jin LSIL-105 LANDING SHIP SUPPORT, LARGE (LSSL) LSSL-107 LSSL-108 LSSL-109 LSSL-110 LANDING SHIP TANK (LST) An dong LST-803 Chongho LST-801 LST-805 LST-806 Ulsan LST-802

124 NOTE: Many of the auxiliary vessels were assigned for one mission only and so served for less than one month before being rotated out. The DMSs were paired up and transferred out to replace one another. LST-799 and LST-735 were also exchanged for one another regularly.

SOURCE: Cagle and Manson, Sea War in Korea, CINCPACLFT Interim Reports 1-6, and COMNAVFE Command and Historical Reports.

125 APPENDIX B

SHIP STATISTICS

MINESWEEPERS

AM AUK Class Minesweeper (AM): 890 tons, 215', 1-3", 2 to 4-40nun AA, 3 to 5-20mm AA, 18kts., 105 crew.

ADMIRABLE Class Minesweeper (AM): 650 tons, 180', 1-3", 4-40nun AA, 15kts., 104 crew.

AMS ALBATROSS Class Auxiliary Minesweeper (AMS): 270 tons, 136', 1-3", 2-20nun AA, 15kts., 50 crew.

DMS ELLYSON Class Destroyer Minesweeper (DMS): 1630 tons, 341', 3- 5", 38 cal., 4-40nun AA, 3 to 5-2nun AA, 37kts., 250 crew.

MSBs: 30 tons, 57', 10knts., 6 crew.

AUXILIARY SHIPS

TREE Classs Net Laying Ship (AN): 560 tons, 146', 1-3"AA, 13kts., 48 crew.

PATAPSCO Class Gasoline Tanker (AOG): 1850 tons, 292', 4-3", 50 cal., 14 kts., 124 crew.

High Speed Transport (APD) : 1400 tons, 300', 1-5", 38 cal., 6- 40mm AA, 23.6kts., 214 crew.

BOLSTER Class Salvage Ship (ARS) : 1360 tons, 207', 4-40nun AA, 14kts., 85 crew.

ABNAKI Class Fleet Ocean Tug (ATF) : 1235 tons, 195', 1-3", 4- 40mm AA, 2-20mm AA, 16.5kts., 85 crew.

AMPHIBIOUS SHIPS

501-1465 SERIES Landing Craft Utility (LCU): 143 tons, 120', lOkts., 150 tons cargo capacity.

CABILDO Class Landing Ship Dock (LSD): 4032 tons, 454'' 1~5"' 38 cal., 12-40mm AA, 15.4kts., 240 crew, 14 LCMs carr1ed.

126 ASHLAND Class Landing Ship Dock (LSD) : 4500 tons, 454', 1-5", 4-40rnm AA, 16-20rnm AA, 17kts., 18LCMs carried.

511-1152 SERIES Landing Ship Tank (LST): 1653 tons, 316', 7- 40rnm AA, 2-20rnm AA, 11kts., 211 crew.

JAPANESE MINESWEEPERS

MS01-17, 57, 81-86: 135 tons, 11kts., unarmed wooden ex­ auxiliary submarine chaser.

Minesweeper Headquarters Ship: MS31-6,888 tons, 13kts. MS32- 2,850 tons, 11.5kts., ex-wartime 2TM tanker used as a guinea pig.

MS33-39, 41-42, 50, 54-56, 58-62, 66-72, 75, 77, 80: varyig tonnages up to 350 tons, auxiliary minesweepers, MS62 (SCAP Y071) mother ship to MSs.

PS02, 04, 08, 43: destrucotr ships following the minesweepers to sink swept mines. PS43 barracks ship in Korea and Japan.

ROKN MINESWEEPERS

ROKN YMS: 270 tons, 136', 1-3", 50 cal., 2-20mm AA, 15kts., 50 crew, wooden ex-U.S. auxiliary minesweepers.

ROKN LST: ex-U.S. LSTs. Source: Raymond V.B. Blackman, ed. Jane's Fighting Ships, 1949-1954.

127 APPENDIX C

TASK ORGANIZATIONS FOR THE INCHON, WONSAN, AND CHINNAMPO SWEEPS INCHON Screening and Protective Group, Captain Richard T. Spofford Rowan Southerland 2DD Bayonne Newport Evansville HMS Mounts Bay HMS Whitesand Bay HMNZS Tutira FS La Grandiere 7PF MINRON 3, Captain Spofford Pledge lAM Kite Mocking Bird Partridge Osprey Chatterer Redhead 6AMS WON SAN Minesweeping and Protective Group, Captain Richard T. Spofford Collet lDD Diachenko lAPD Doyle Endicott 2DMS Pledge Incredible 2AM Kite Merganser Mocking Bird Osprey Partridge (assigned later for Iwon) Redhead Chatterer 7AMS HMS Mounts Bav HMNZS Pukaki HMNZS Tutira FS La Grandiere 4PF 8 Japanese minesweepers 4 Japanese mine destruction and danning vessels 1 ROK FS Plus other units assigned

128 CHINNAMPO Task Element 95.69, Commander Stephen M. Archer Horace A. Bass 1APD Bolster 1ARS Thompson Carmick 2DMS Gull Pelican Swallow 3AMS Catamount 1LSD MSBs 12LCVP work boats 2 40' motor launches LST Q007 1LST Japanese Minesweepers PS-56 PS-62 2PS MS-03 MS-06 MS-08 MS-09 MS-10 MS-12 MS-13 MS-15 MS-21 MS-22 MS-23 MS-57 12MS ROKN Minesweepers JMS-306 YMS-502 YMS-503 YMS-513 4ROKN YMS Source: CINCPACFLT Interim Report 1, 5: 740-745; Karig, 357- 358.

129 APPENDIX D

AVAILABLE MINESWEEPERS IN THE FAR EAST

Country Number Location Status Australia 32 in reserve Canada 9 4 operational French Indochina 22 operational Great Britain 7 6 Singapore activating 1 Hong Kong unknown India 6 4 operational Indonesia 4 lack training Nationalist China lSAM Formosa operational 8AMS operational Netherlands 9 Indonesia operational Philippine Republic 2AM poor condition South Korea lOYMS no gear Thailand lAM unknown 3AMS unknown 3CMC unknown U.S.S.R. 33AM Petropavlovsk operational SOAMS Kosakov operational (ex-US) Olga Sovetskaya Vladivostok Nadhodka TOTAL 213

Source: CINCPACFLT Interim Report 1, 6: 1094.

130 APPENDIX E

MINES SWEPT

DISPOSITION OF MINES ENCOUNTERED BY MONTHS MONTH SWEPT SWEPT FLOATER FLOATER RECOVERED TOTAL DEST. NOT SIGHTED SIGHTED DEST. DEST. NOT DEST. 1950 August NA NA NA NA NA 4 1951 September NA NA NA NA NA 216 November- December NA NA NA NA NA 173 1952 January 1 0 13 1 0 15 February 4 0 15 7 1 27 March 40 5 24 2 5 76 April 15 1 13 0 4 33 May 15 5 7 5 1 33 June 7 0 3 0 3 13 July NA NA NA NA NA 6 August NA NA NA NA NA 54 September NA NA NA NA NA 32 October NA NA NA NA NA 10 November NA NA NA NA NA 17 December NA NA NA NA NA 6 1953 NA NA NA NA NA 13 January 13 February 3 0 10 0 0 1 0 9 0 1 11 March 23 April 1 1 19 2 0 0 14 May 3 0 11 0 1 15 1 0 18 June 1 14 1 0 13 0 0 July 15 1088 TOTAL 92 13 152 18 ENCOUNTERED BY MONTHS MINE TYPES UNIDENT. TOTAL MONTH MKB M26 MY aM PLT 1952 4 15 January 5 6 0 0 0 3 27 February 14 10 0 46 0 5 76 March 16 9 33 11 2 0 4 April 16 7 33 4 17 5 0 May 0 0 13 June 0 5 8 6 1 2 1 0 July 2 16 54 8 22 8 0 August 2 6 32 September 4 19 1 3 0 10 October 5 1 1

131 MONTH MKB M26 MY aM PLT UNIDENT. November 2 14 TOTAL 0 0 1 17 December 0 2 4 1953 0 0 6 January 3 4 3 0 3 February 3 13 3 4 0 3 March 2 13 2 6 0 1 April 1 11 15 2 1 4 May 3 23 7 0 0 4 14 June 7 5 4 0 July 2 18 5 5 3 0 1 TOTAL 100 14 158 99 7 64 428 DISPOSITION OF MINES ENCOUNTERED TYPES SWEPT SWEPT FLOATER FLOATER RECOVERED TOTAL DEST. NOT SIGHTED SIGHTED DEST. DEST. NOT DEST. January-June, 1952 MKB 23 0 27 1 4 55 M26 17 6 29 2 4 58 MYaM 41 2 11 1 6 61 Unident. 1 3 8 11 0 23 July, 1952-January, 1953 MKB 1 0 21 1 1 24 M26 13 0 50 0 0 63 MYaM 0 0 17 0 2 19 PLT 6 0 0 0 0 6 Unident. 3 0 14 9 0 26 February-July, 1953 MKB 0 1 20 0 0 21 M26 7 0 30 0 0 37 MYaM 0 0 17 1 1 19 PLT 0 1 0 0 0 1 Unident. 2 1 10 2 0 15 TOTAL 114 14 254 28 18 428 Note: The tables are incomplete as some documents pertaining to the Korean War are still classified. Many of the available documents differed on the number of mines swept, even conflicting with the text attached to the documents. Emphasis has been placed on the CINCPACFLT Interim Evaluation Reports as they are the most precise.

Source: CINCPACFLT InterimReport 2, 11: 1751-1763, 1769-1773, CINCPACFLT Interim Report 4, 8: 3 9-4 0, CINCPACFLT Interim Report 5, 7: 50, CINCPACFLT Interim Report 6, 8: 45, COMNAVFE Command and Historical Reports.

132 APPENDIX F

UNITED NATIONS SHIPS SUNK AND DAMAGED IN KOREAN WATERS SHIPS SUNK BY MINES NAME DATE NOTES

Magpie (AMS-25) September 29, 1950 12WIA, 21MIA Pirate (AM-275) October 12, 1950 Wonsan Pledge (AM-277) October 12, 1950 Wonsan Japanese MS-14 October 17, 1950 Wonsan ROKN YMS-516 October 19, 1950 Wonsan, 4KIA, 13MIA LT-236 November 15, 1950 Wonsan, buoy 3 Partridge (AMS-31) February 2, 1951 4KIA, 7WIA, 4MIA ROKN JMS-306 May 5, 1951 Chinnampo, 6KIA, 18WIA ROKN PC-704 December 26, 1951 Wonsan, all hands lost Sarsi (ATF-111) August 27, 1952 2KIA, 4WIA, 3MIA

SHIPS DAMAGED BY MINES

NAME DATE NOTES Brush (DD-745) September 26, 1950 Tanchon, 9KIA, 10WIA ROKN YMS-509 September 28, 1950 1KIA, 5WIA, 25MIA Mansfield (DD-728) September 30, 1950 48WIA, 5MIA ROKN YMS-504 October 1, 1950 Mokpo ROKN BM FS-673 October 18, 1950 Wonsan Suzen-Maru (S-152) December 6, 1950 Hungnam EG Small (DD-838) October 7, 1951 Hungnam, 9KIA, 8WIA Kite (AMS-22) November 9, 1951 Won san

MINESWEEPERS DAMAGED IN KOREA DUE TO OTHER CAUSES (SHORE BATTERY FIRE UNLESS SPECIFIED DIFFERENTLY)

NAME DATE NOTES

ROKN YMS-510 March 16, 1951 Wonsan, 3KIA, 8WIA Carmick (DMS-33) March 27, 1951 Collision, Songjin Thompson (DMS-38) June 14, 1951 3KIA, 4WIA Dextrous (AM-341) August 11, 1951 superficial damage Redstart (AM-373) September 10, 1951 minor damage Heron (AMS-18) September 10, 1951 superficial damage Firecrest (AMS-10) October 5, 1951 hull damage Osprey (AMS-28) October 29, 1951 1WIA Dextrous (AM-341) January 11, 1952 Wonsan, 3WIA Endicott (DMS-35) February 4, 1952 Songjin, minor damage ROKN JMS-301 March 1, 1952 sunwi-do, 1KIA

133 Endicott (DMS-35) April 7, 1952 Chongjin Endicott (DMS-35) April 19, 1952 Chongjin, minor damage Osprey (AMS-28) April 24, 1952 Songjin, minor damage Murrelet (AM-372) May 26, 1952 Songjin, 1KIA, 2WIA Swallow (AMS-36) May 26, 1952 Songjin, slight damage Firecrest (AMS-10) May 29, 1952 minor damage Thompson (DMS-38) August 20, 1952 Songjin, 3KIA, 8WIA Competent (AM-336) August 27, 1952 minor damage Osprey (AMS-28) October 13, 1952 Kojo, 4WIA, near miss Kite (AMS-22) November 19, 1952 Wonsan, 5WIA Thompson (DMS-38) November 20, 1952 Wonsan, hull damage ROKN YMS-506 March 9, 1953 no details given ROKN YMS-510 March 9, 1953 no details given ~ (AMS-16) March 16, 1953 no details given ROKN YMS-506 May 15, 1953 no details given Swift (AM-122) May 29, 1953 no details given

Source: CINCPACFLT Interim Report 1, 6: 1141, CINCPACFLT Interim Report 3, 1: 33-35, CINCPACFLT Interim Report 4, 1: 23-24, CINCPACFLT Interim Report 5, 7: 22, CINCPACFLT Interim Report 6, 1: 30-35., COMNAVFE, Command and Historical Report, September-November 1950, chapter 2, 13.

134