Lloyd’s Register, CoolCo, and HD HMS deliver sub-coolers for LNG boil-off reliquefaction retrofit

The retrofit, carried out by HD Hyundai Marine Solution as turnkey provider at Yiu Lian Dockyard (Shekou) in China, is designed to manage efficiently the boil-off gas (BOG), a challenge that has long impacted LNG carriers.

By integrating the ALaT TBF 1800 sub cooling reliquefaction system, with a capacity of 2.1 tph, the Kool Glacier can now condense this BOG and return back into liquid form, improving operational efficiency and environmental performance. In particular, this sub-cooler technology reduces BOG generated during both maritime transportation and during waiting periods at terminals, with positive impacts on both operational costs and the vessel’s carbon footprint.

The retrofit commissioning and cold test were completed ahead of schedule, with the vessel departing on 16 March 2025. Subsequently, the vessel completed gas trials during a laden voyage from Papua New Guinea to Thailand in early May 2025.

Throughout the project, LR provided comprehensive technical oversight and flexible classification support, including the expedited notation for the reliquefaction unit installation, ensuring the ship's delivery remained on schedule.

This achievement represents the second reliquefaction retrofit in CoolCo’s fleet, following the completion of similar work on the Kool Husky, with two more vessels scheduled for upgrade. CoolCo will upgrade in total five vessels with sub-coolers. As regulatory pressure increases and fuel efficiency becomes ever more vital, demand for similar retrofits is expected to grow.

Jose Navarro, Global Gas Technology Director at LR, said: “This achievement demonstrates LR’s reputation as a trusted partner for LNG operators looking to future-proof their fleets. By enabling CoolCo to meet its efficiency and sustainability ambitions, LR continues to lead the way in supporting the transition to a lower-carbon maritime industry.

“LR’s proactive, solution-driven approach brings together global expertise and local responsiveness to deliver complex retrofits on time, and with lasting value to clients and the environment alike.”

Richard Tyrrell, CEO of CoolCo, added: “LR's flexible approach and technical expertise proved invaluable throughout this complex retrofit project. Their ability to deliver timely solutions, particularly regarding notation assignment exemptions for the reliquefaction unit, ensured we met our scheduling requirements. CoolCo is midway through the upgrade sub-cooler upgrade programme with two more LR-classed vessels to come. LR’s partnership through this process is enabling us to cost-effectively and efficiently deploy technology to materially enhance our fleet’s operational efficiency and competitiveness in the market.”

Kidong Lee, CEO at HD Hyundai Marine Solution, concluded: “By successfully completing the retrofit not only for the first vessel but for the subsequent one, HD HMS has further reinforced its standing as a reliable technology partner in the maritime industry’s transition toward sustainability.

“In particular, by completing both the commissioning and cold testing ahead of schedule, HD HMS was able to achieve outstanding performance while simultaneously shortened the overall project timeline.”

Read the article online at: https://www.lngindustry.com/liquefaction/02062025/lloyds-register-coolco-and-hd-hms-deliver-sub-coolers-for-lng-boil-off-reliquefaction-retrofit/