[Report] SK Ocean Plant Building the World's Largest Offshore Wind Facility, the Size of 220 Soccer Fields

Goseong First Yard in South Gyeongsang: Producing Substructures Using Thick-Walled Pipes
Construction of New Yard Began in 2022, Phase 1 Now 95% Complete
Main Quay Wall Extends 1.2km... Poised to Become the World's Largest Upon Completion
Dedicated to Floating Offshore Wind Power... Capable of Integrating Upper Structures

The world's largest offshore wind foundation structure manufactured by SK Ocean Plant. SK Ocean Plant

Driving along the scenic coastline of Goseong, South Gyeongsang Province, you can spot a massive crane in the distance emblazoned with 'SK Ocean Plant.' Upon arriving at the site, its sheer size is overwhelming. This piece of equipment is a 'Goliath Crane' capable of lifting up to 800 tons.

On July 4, at the SK Ocean Plant's First Yard in Goseong, South Gyeongsang, production was in full swing for offshore wind substructures destined for a Taiwanese client. Inside the three-sectioned production facility, thick steel plates were being bent into large-diameter steel pipes. Outside on the quay, several steel structures assembled from these pipes were lying on their sides. The Goliath Crane is used to lift these structures for assembly into offshore wind substructures.

These large-diameter steel pipes are extra-large industrial pipes made by bending thick steel plates. They are mainly used for natural gas facilities and oil pipelines. The maximum diameter reaches 10 meters, and the thickness can be up to 15 millimeters.

Since 2019, SK Ocean Plant has been manufacturing offshore wind substructures using these large-diameter pipes and exporting them to Taiwan. As of last year, the company held a 44% share of the Taiwanese offshore wind market, emerging as Asia's largest offshore wind substructure manufacturer. To date, SK Ocean Plant has supplied about 190 substructures to Taiwan's offshore wind sector, representing a total power generation capacity of 2GW.

A view of offshore wind substructures being manufactured at the SK Ocean Plant yard. SK Ocean Plant

Offshore wind substructures serve to support the upper structures such as towers, turbines, and blades beneath the sea. Depending on the design, a single-legged structure is called a monopile, while structures with multiple legs are classified as jackets. SK Ocean Plant specializes in the jacket type.

A jacket is largely divided into three components: the leg, the X-brace, and the transition piece. The transition piece, which sits at the very top of the jacket, is especially critical as it bears the weight and vibration of the upper structure. Client specifications for this component are demanding, and the design varies from project to project, making expertise and technical know-how essential. SK Ocean Plant is recognized as having world-class technology in manufacturing transition pieces.

An offshore wind substructure manufactured by SK Ocean Plant installed at the offshore wind farm in Changhua County, western Taiwan. Photo by SK Ocean Plant

At the nearby Second Yard of SK Ocean Plant, even larger jackets are produced. These can reach up to 94 meters in height, equivalent to a 35-story apartment building, and weigh as much as 2,200 tons. The Second Yard covers an area of 510,000 square meters, which is larger than the First Yard's 419,000 square meters. Upper jacket sections fabricated at the First Yard are transported by barge to the Second Yard, where they are finally connected to the lower jacket sections. The completed jackets are then loaded onto ships and delivered to clients. SK Ocean Plant is also equipped with a Jacket Lift Tool (JCT) capable of lifting up to 2,500 tons.

The First and Second Yards together can produce 40 offshore wind substructures annually. According to Jung Jinyeop, head of the sales team at SK Ocean Plant, "It takes about 11 to 12 months to complete an offshore wind substructure," and "with a continuous production system, we can produce one finished unit every 10 days."

SK Ocean Plant New Yard (Goseong Yangchon Yongjeong District) construction site. As of July 2025, the first phase of the reclamation work has reached a progress rate of 95%. SK Ocean Plant

SK Ocean Plant is also in the midst of constructing its Third Yard (New Yard), located about 10 minutes by car from the First Yard. During the visit, dump trucks were busy transporting soil at the New Yard. This was to fill the empty spaces after building the quay wall with caissons, which are large hollow concrete structures.

As of July, the first phase of the reclamation work at the New Yard is 95% complete. Once this phase is finished, full-scale construction of the upper production facilities will begin. Construction, which started in 2022, is scheduled for final completion in 2028.

Upon completion, the New Yard will span approximately 1,574,300 square meters?the size of 220 soccer fields?making it the world's largest offshore wind substructure production facility. The main quay wall alone will stretch 1.2 kilometers, allowing ships to dock.

SK Ocean Plant plans to develop the New Yard as a dedicated facility for floating offshore wind substructures. A company representative explained, "We will be able to produce 40 floating substructures annually," and "based on 15MW turbines, we can handle floating offshore wind projects with a total capacity of 600MW." This is aimed at the floating offshore wind project currently underway off the coast of Ulsan.

A bird's-eye view of the offshore wind foundation new yard being developed by SK Ocean Plant. It is designed to be loaded onto ships with the superstructure attached. SK Ocean Plant

Notably, the New Yard is designed to allow for the assembly of upper structures such as towers, blades, and nacelles onto the substructures after production. This means that floating offshore wind turbines can be fully assembled at the quay and then shipped out, requiring only installation at the destination.

Bolstered by the success of its Taiwanese projects, SK Ocean Plant continues to secure new contracts. The company recently won a 383.4 billion won contract for the Anma Offshore Wind Substructure project in Korea, as well as a 200 billion won offshore wind project in the Asia-Pacific region. With these consecutive orders, SK Ocean Plant expects to achieve annual sales in the 1 trillion won range this year. The company recorded sales of 925 billion won in 2023 and 662 billion won last year.