Nor-Shipping: raft of gas ship and LNG carrier tank designs green-lighted

Three-tank LNG carrier design

KR also signed an MoU with Samsung Heavy Industries (SHI) on 4 June at Nor-Shipping 2025 in Oslo to jointly develop a 174,000-m³ LNG carrier featuring three cargo tanks.

"Despite the ongoing trend toward larger vessels across all ship types, the 174,000-m³ LNG carrier remains the standard design in the global LNG shipbuilding market, with dozens of orders placed annually," KR said.

KR and SHI say they plan to introduce a revised cargo tank configuration – reducing the number of tanks from four to three – while ensuring both economic efficiency and structural safety.

"Reducing the number of tanks is expected to lighten the hull, thereby improving fuel efficiency and decreasing natural boil-off and vaporisation of LNG, ultimately reducing operating costs. Fewer tanks also mean fewer onboard pumping systems, which simplifies maintenance and reduces long-term operational expenses," the companies said.

However, larger individual tank sizes can lead to more pronounced liquid movement – known as sloshing – within the tank. This motion can exert repeated pressure loads on the tank walls and internal structures, potentially affecting the vessel’s structural integrity. KR said it will conduct a thorough review to ensure the vessel’s compliance with applicable classification rules and international regulations, and plans to grant an AIP once structural safety and conformity have been verified.

ECA techniques for IMO Type-C gas carrier cargo tank designs

In another LNG carrier tank-related agreement, KR signed an MoU with HD Hyundai Mipo and HD Korean Shipbuilding & Offshore Engineering (HD KSOE) that focuses on applying engineering critical assessment (ECA) techniques to the design of Type-C cargo tanks for liquefied gas carriers to ensure their structural safety.

"With the maritime industry accelerating its transition toward decarbonisation, demand is growing for ships powered by alternative fuels such as LNG, ammonia and hydrogen. These fuels are typically stored and transported in high-pressure, cryogenic liquefied form, requiring advanced safety measures for onboard containment systems. Therefore, ensuring the structural integrity of cargo tanks has become a critical element in next-generation, environmentally sustainable ship design," the companies said. "This MoU represents a proactive response to these evolving needs. The three parties aim to improve the structural safety and design reliability of IMO Type-C independent tanks – one of the most widely adopted containment systems for low-emissions vessels. Type-C tanks are commonly used on small to mid-sized gas carriers and bunkering vessels due to their structural independence and ability to store high-pressure cargo, and therefore require precise structural analysis to ensure safety."

To tackle these technical challenges, the partners say they will apply an ECA – a fracture mechanics-based structural analysis method – from the early stages of design. ECA techniques simulate potential crack propagation in metallic structures, and assess whether the structures can safely withstand real-world operating conditions. The methodology is particularly well-suited for high-pressure, low-temperature environments such as those found in liquefied gas storage. 

Under the agreement, HD Hyundai Mipo will conduct structural strength and fatigue assessments of the tanks, and HD KSOE will lead tank design and perform ECA-based structural evaluations. KR will review safety and compliance of the design in accordance with its classification rules and the international convention (IGC Code), with the goal of issuing an AIP.

Korean Register has also signed a memorandum of understanding HD Hyundai Heavy Industries to jointly develop a next-generation very large ethane carrier.

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