[Militech] USNS Yukon Maintenance Site Revealed for the First Time... Even the US Is Impressed [Yang Nakgyu's Defence Club]

A Visit to Hanwha Ocean's Okpo Shipyard
Second US Navy Vessel MRO After Wally Shirra

US Secretary of the Navy John P. Phelan is reportedly planning to visit South Korea as early as this week, with a scheduled stop at Hanwha Ocean. There is also speculation that Donald Trump Jr., the eldest son of former US President Donald Trump, who will be visiting South Korea around the same time, may join the itinerary. Against the backdrop of the United States' increasing interest in Korean shipbuilding since the start of the Trump administration's second term, Secretary Phelan’s visit signals a direct inspection of domestic special ship facilities.

In August of last year, Hanwha Ocean became the first Korean shipyard to win a maintenance, repair, and overhaul (MRO) contract for a US Navy logistics support ship, the Wally Shirra. Three months later, the company secured an additional MRO contract for the USNS Yukon, a replenishment oiler belonging to the US Navy 7th Fleet. The Wally Shirra completed six months of maintenance and departed from Hanwha Ocean’s Okpo Shipyard in March. The Yukon is scheduled to be repaired and delivered to the US Navy by next month. To observe the Yukon’s maintenance process, which was disclosed to Korean media for the first time, we visited Hanwha Ocean’s Okpo Shipyard.

Kim Daesik, Executive Director of Hanwha Ocean Special Ship MRO Business TFT, is explaining internal maintenance in front of the Yukon ship. Executive Director Kim said, "The US Navy requested about 80 maintenance items, but more than 120 maintenance items emerged during the internal maintenance process," adding, "We had to visit more than 20 domestic companies to find substitutes." Hanwha Ocean

The Yukon is the sixth ship in the Henry J. Kaiser-class of large replenishment oilers. It was built by Avondale Shipyard in New Orleans, Louisiana. Commissioned in March 1994, it was deployed to the US Pacific Fleet and is operated by the US Navy’s Military Sealift Command (MSC). At the shipyard dock?where ships are constructed and maintained?maintenance work on the Yukon was underway. Ship maintenance is divided into three stages: voyage repair (VR, annual, two weeks), mid-term availability (MTA, every 18 months, 1.5 months), and overhaul (every 5 to 7 years, three months). This is the first time a Korean shipyard has been entrusted with the overhaul of a US Navy vessel, signifying US recognition of the Korean shipbuilding industry’s technological capabilities.

Armed Personnel Stand Guard 24 Hours Inside the Under-Repair Yukon

To see the Yukon up close, one must endure intense scrutiny. The interior of the Yukon is considered US territory. There are guard posts outside the ship, and armed US Navy personnel stand watch inside 24 hours a day.

Approaching the Yukon, its sheer size is overwhelming. The ship measures 206 meters in length. The Yukon carries up to 160,000 barrels of fuel for resupplying other vessels, as well as 31,200 tons of various cargo. Its full load displacement alone reaches 42,382 tons. At the stern, there is a deck for helicopter takeoff and landing.

First High-Pressure Washing Robot Introduced at a Korean Shipyard

Hanwha Ocean employees lifted the Yukon and began cleaning the ship’s exterior. For the first time at a Korean shipyard, a high-pressure washing robot was deployed. Previously, workers would blast the ship’s surface with metal grit to remove foreign substances, resulting in severe dust. In contrast, the high-pressure washing robot uses water jets to strip away debris and vacuums it up. This process alone takes two weeks. The areas cleaned by the robot were visibly free of contaminants, as if wiped with a cloth. Unlike container ships, which have flat bottoms to maximize cargo space, the Yukon must maintain the same speed as a US aircraft carrier. Using two massive diesel engines and propeller shafts, it reaches speeds of 20 knots (37 km/h). Due to its streamlined, curved surfaces, some areas must still be cleaned manually rather than by robot.

Expanded US Navy Maintenance List Also Addressed

Internal maintenance is even more challenging. As the vessel is over 30 years old, the US Navy requested 82 maintenance items. However, after four months of internal work, the list grew even longer, with more than 120 additional maintenance items identified. The repair period was also extended, ending up one month behind the original schedule. Technicians from various foreign parts manufacturers had to be called in. Within a month of the Yukon arriving at the Geoje shipyard for maintenance, technicians from over 40 companies across 10 countries?including Japan, the United States, and Germany?entered Korea. Some parts manufacturers had gone out of business or discontinued certain components. Hanwha Ocean provided solutions by visiting more than 20 domestic companies with experience supplying naval vessels and locating each necessary part individually.

Kim Daesik, Executive Director of Hanwha Ocean Special Ship MRO Business TFT, said, "The US Navy pays more attention to the operation of equipment for mission performance than to the exterior surface of the ship," adding, "While repairing parts is important, the US Navy is more satisfied with finding substitutes." Hanwha Ocean

Kim Daesik, Executive Director of Hanwha Ocean Special Ship MRO Business TFT, said, "The US Navy pays more attention to the operation of equipment for mission performance than to the exterior surface of the ship," adding, "While repairing parts is important, the US Navy is more satisfied with finding substitutes." According to those involved, there were even more difficulties than with the Wally Shirra, which was built 15 years ago.

Previously, the Yukon had undergone maintenance at shipyards in Southeast Asia, including Singapore and Thailand. The US military was not satisfied. When Steve Koehler, Commander of the US Pacific Fleet, visited Hanwha Ocean in October last year, he stated, "I am relieved that Korean shipyards are handling US Navy MRO," reflecting this sentiment.

Goal: Preempting the 20 Trillion Won US MRO Market

After signing the Master Ship Repair Agreement (MSRA) with the US last July, Hanwha Ocean won the Wally Shirra MRO contract as its first project. Through this, Hanwha Ocean plans to establish Korean shipyards as strategic hubs in the global naval MRO market. The initial target market is the United States, where the annual scale of naval MRO projects alone reaches 20 trillion won. The US is strengthening its naval power to counter China. Notably, most of China’s major warships have been built since 2010, meaning they are largely state-of-the-art. Chinese state-owned shipyards built over 80 warships in just eight years at an unprecedented pace. As of March 2021, the Chinese Navy had 360 warships, surpassing the US Navy’s 297. The US Navy is also rushing to complete maintenance. Since the end of the US-Soviet Cold War, defense budget cuts have limited investment in maintenance facilities, resulting in only about 40% of scheduled warship maintenance being completed on time.

In September last year, US Chief of Naval Operations Lisa Franchetti announced "Project-33," a plan to strengthen naval power in response to China’s military threat. The plan’s top priority is to address delays in the maintenance of ships, submarines, and aircraft. The core objective is to maximize the operational availability of all warships through such initiatives. Hanwha Ocean plans to expand its MRO business beyond the US to Asia, the Middle East, and Europe. The global naval MRO market is valued at approximately $8 billion (11.6304 trillion won).