Here's What You Need to Know: The amphibious landing at Wonsan never took place as it would be overrun by U.N. troops advancing on land. But just a few weeks later Wonsan fell to a massive Chinese-North Korean counterattack. Beginning in February 1951, the port was subject to a U.N. naval blockade that would become the longest in modern history. During the 861-day long blockade, three more small boats were sunk by mines, and over two dozen more ships were damaged by them and coastal gunfire.

At noon sharp on October 12, 1950, the minesweeper USS Pirate had just completed a busy but productive morning off the North Korean port of Wonsan when everything went wrong at once. 

Hours earlier, the small, 625-ton vessel had led the five ships of Mine Division 32 based in Sasebo, Japan through two belts of contact mines laid in a channel just one mile wide, and fourteen miles long leading into Wonsan Harbor in North Korea. 

At the time U.N. troops were on the offensive following a successful amphibious landing at Inchon on the western coast of the Korean peninsula. Therefore, a second landing called Operation Tailboard at Wonsan on the eastern coastline was planned. But that meant the minefields barring access to Wonsan had to be cleared first. 

This was no piece of cake, as North Korean boats had laid over 3,000 Soviet-supplied contact and magnetic mines in the 400 island-congested square miles surrounding the port.

Knowing the division was entering dangerous waters, skipper Lt. Cornelius McMullen ordered all non-essential personnel on deck with life jackets to minimize the number that might be trapped below should things go wrong. Cornelius’s superior, Lt. Commander Bruce Hyatt, was also aboard to coordinate the actions of the five-ship division.

But for the first few hours things went swimmingly. Pirate’s crew detected and disabled six mines spaced 50 meters apart using the vessel’s mechanical “sweep” that fanned the water behind it, cutting the cables connecting mines to the seafloor. The mines then floated to the surface where they could be blasted by the ship’s gunners. Fellow Admirable-class minesweepers Pledge and Incredible located another string of four.

But at a minute past noon, a Navy helicopter orbiting overhead reported a third, dense ‘cabbage patch’ of mines near Pirate’s position. At the same time, Pirate’s sonar operator reported multiple contacts all about her hull.

Then eight minutes later a lookout spotted a large spiky contact mine straight before the Pirate.

Pirate’s sweep was designed to disable mines behind her, but her current trajectory meant she was bound for a deadly collision.

McMullen faced a terrible choice, as turning risked triggering the mine as well.

Crew member Earl Richard, at the time manning an anti-aircraft gun close to the bridge, recalled what happened next to the CNO’s Naval History Division:

“The skipper called for a hard left rudder to try and turn away from the mine, but we were so close that by the time the ship began its turn, the port side of the ship came right on to the mine and it stuck the back quarter of the ship on the port side. The hole was wider than a two-car garage.

Everyone on the bridge was blown in different directions. Some were blown over the side, and I was blown to the main deck. I can only remember being showered by what smelled like diesel oil and tons of dust and debris.”

Her back broken in two, the Pirate’s separate halves rapidly sank. 

Richard recounted the horrifying four minutes:

“When I finally realized what had happened, I was picking myself up from the main deck and heard a shipmate yelling, only to find he was trapped under several hundred feet of 2 inch diameter mooring line that had been coiled on top of ventilating unit. When the ship listed the line slid off and trapped his legs. One other shipmate and myself were able to get him out from under at the same time the ship was going down. It had listed to the starboard side and when it came back to the port side, we slid off into the water. With the other guy and myself we were able to drag the injured guy away from the ship before it went completely under water which was in about four minutes.

I remember the water was very cold and at first most of the crew began swimming towards the shore until the beach guns opened fire and began blowing guys out of the water.”

The three coastal batteries were situated upon Sin Do island three miles to the southwest. Another battery of smaller, rapid-fire guns opened fire from Ryo-Do island to the southeast. This map shows the positioning of the minefield belts and the two islands here.

Fellow minesweepers Pledge, Incredible and Kite began dueling the battery with their single 3” deck guns. But the most effective fire came from beefier 1,600-ton USS Endicott, with her four 5” gun turrets. 

Six years earlier during World War II, the Gleaves-class destroyer had sunk two German corvettes in a swashbuckling action off southern France. Since then she had been converted into a “fast minesweeper,” but had not lost her fighting spirit (nor her guns).

Meanwhile, Pledge surged towards the Pirate’s position in an effort to rescue the scattered survivors but was bracketed by accurate shellfire.

Just ten minutes into the engagement, a second huge explosion announced that Pledge too struck a mine while engaged in a hard turn attempting to dodge shellfire.

For 45 minutes, skipper Lt. Richard Young led a frantic effort to save his wounded ship as water poured into her ruptured hull. But the North Korean shore gunners zeroed in on the floundering minesweeper.

Finally, Young too had to give the order to abandon ship.

It was the turn of the even smaller 320-ton USS Redhead—named after the duck, not gingers—to come to the rescue.

The YMS-1 class boat managed to weave around the numerous mines in the channel, but was repeatedly battered by North Korean shells as she trawled for thirty minutes picking up survivors, all the while her smaller 3” deck gun returned fire at her tormentors.

The Incredible too helped rescue twenty-seven sailors before her engines seized up and she had to disengage.

Soon, Corsair fighter bombers from the carrier USS Leyte came howling overhead, blasting gun positions with napalm, rockets and bombs. Meanwhile, a paunchy PBM5 Marine flying boat from Navy squadron VP-47 flew overhead to help the Endicott’s and Redhead’s shellfire.

Together, shells from Endicott and Redhead managed to silence all three North Korea batteries. Navy divers belonging the Underwater Demolition Teams swam and boats launched from the Endicott recovered additional sailors.

The four-hour rescue effort saved 170 crew from Pledge and Pirate—though a dozen crew from Pirate and Pledge would never make it back home. 

The following day, Navy divers swam to the sunken Pledge and Pirate and recovered their sensitive encryption systems, before demolishing the wrecks. The ships and their commanders would all be decorated for their valor in action.

The amphibious landing at Wonsan never took place as it would be overrun by U.N. troops advancing on land. But just a few weeks later Wonsan fell to a massive Chinese-North Korean counterattack. Beginning in February 1951, the port was subject to a U.N. naval blockade that would become the longest in modern history. During the 861-day long blockade, three more small boats were sunk by mines, and over two dozen more ships were damaged by them and coastal gunfire.

Two years after the traumatic incident, the Pirate’s skipper McMullen received a mysterious package in the mail: the Pirate’s flag, recovered by an anonymous benefactor.

Sébastien Roblin holds a master’s degree in conflict resolution from Georgetown University and served as a university instructor for the Peace Corps in China. He has also worked in education, editing, and refugee resettlement in France and the United States. He currently writes on security and military history for War Is Boring.

This article first appeared in September 2019.

Image: Flickr.