Two South Korean-owned LNG carriers have been out of action for over four years as the battle to find a repair solution for their cargo tank containment systems continues — but one has recently loaded test volumes of product.

The 174,100-cbm SK Serenity and sistership SK Spica (both built 2018), which were both constructed with South Korea’s home-designed KC-1 LNG containment system, have spent the bulk of their time since delivery anchored off the South Korean coast near Samsung Heavy Industries’ Geoje Island facility, or in the yard undergoing repair work.

South Korean brokers said the vessels featured in domestic news reports at the start of the year. One from KBS news mentions that one of the ship’s tanks had undergone repairs on four occasions.

But Kpler data shows that on 30 December the SK Serenity was loaded with LNG at South Korea’s Samcheok LNG terminal.

Since then, tracking data shows the vessel making a long out-and-back voyage to the north of the Japanese archipelago, returning close to its departure point near its sistership on 22 January.

The SK Spica remains in ballast and at anchor.

Sources told TradeWinds that legal action over the ships is ongoing among KC LNG Tech — the Kogas-controlled designer of the vessel’s cargo containment system — shipbuilder SHI and owner SK Shipping.

TradeWinds has contacted KC LNG Tech for an update on the repairs.

The problems on the two Kogas-chartered vessels — the only full-size LNG carriers to have been fitted with KC-1 systems — were identified shortly after their deliveries in 2018.

The SK Serenity lifted two cargoes from the US before ­icing was found on its hull, suggesting a possible cargo leak, and the ship was pulled from service. The SK Spica never loaded a shipment.

Difficult discussions

Repairs started on the SK Serenity in late 2019 after long and difficult discussions between the parties.

In February 2021, KC LNG Tech said repair work had been completed on the SK Serenity’s No 2 tank. At the time, the company said it was waiting for the work to be signed off before tackling similar jobs in the ship’s remaining tanks.

Company officials said the SK Serenity was due to be returned to service in the second half of 2021, with its sistership to follow in 2022.

At the time, work had yet to start on the SK Spica. Those following the ships said it had proved more complicated for the parties involved to agree on what was wrong with the vessel and how to fix it.

The KC-1 containment system was to be South Korea’s rival to GTT’s widely adopted Mark III membrane option.

Two small-scale, 7,500-cbm LNG carriers have been successfully fitted with the KC-1 system. These vessels are chartered to Kogas, and ship cargoes from South Korea’s Tongyeong LNG terminal to the southern resort destination of Jeju Island.

KC LNG Tech has previously spoken about developing a new system, dubbed KC-2.