He Baoxin, Zhu Yuexing

In the 2023 Nor Shipping, the 175,000 m3 A-BOX?large LNG carrier design jointly developed by CSSC SDARI and Norway LNT Marine officially winning the AiP of ABS certificate triggered a great attention.

This is the world's first large LNG carrier with LNT A-BOX?cargo containment system, which not only breaks the long-term technology monopoly in the field, but also has an important milestone significance for enriching the product chain of large LNG carriers and promoting differentiated market competition.

We learn the ship is a large LNG carrier jointly developed by SDARI,LNT MARINE and ABS, using LNT A-BOX?as the cargo containment system, and another LNG carrier jointly developed by SDARI using the A-BOX?cargo containment system in the wake of the previous design of the 80,000 m3 and 40,000 m3 A-BOX?LNG carrier granted with AiP. This enables the institute to enrich and consumate the LNG carrier lineage of the A-BOX?cargo containment system,and highlight its strong heritage and strength in LNG high-end ship R&D and design while officially entering the R&D and design field of A-BOX?large LNG carrier.

According to the exclusive interview of “China Shipbuilding News＂ reporters, featuring an overall length of 294.8 m, a molded breadth of 45.8 m, a design draft of 11.5 m, a hold capacity of 175,000 m3, a service speed of 19.5 knots; the ship applies separate cargo tank form, made of aluminum alloy, adapt to the hull form characteristics, without any loading restrictions; 4 cargo tanks with uniform capacity can effectively improve the cargo handling efficiency.

This ship installs insulation on the hull wall, resulting in better insulation performance, the evaporation rate is only 0.08%, lower than its pals. The ship adopts double engines and double propellers, and body lines fully match the twin-skeg and cargo tank form,with low oil and gas consumption and better economy. The ship is equipped with two pumps for each tank, with a maximum handling capacity of 14,400 cubic meters per hour. Meanwhile, it has partial re-liquefaction function,effectively meeting the operational needs of large LNG carriers.

The R&D of 175,000 m3 A-BOX?large LNG carrier was the key R&D project of the SDARI in 2022. Through repeated optimization and analysis with the help of CFD technology,SDARI conquered the twin-skeg lines technology suitable for A-BOX?cargo containment, and as verified by the ship model trial, tperformance index reaches the international first-class level. By the comparative analysis of the structural forms of different materials, key technologies such as aluminum alloy separate tank and hull structure of large carriers, which,on the premise of ensuring structural safety, considerably optimizes the structure weight and ensures the overall performanc advance. For the characteristics of 175,000 m3 LNG carriers, SDARI developed a bubble lubrication drag reduction system for large LNG carriers, significantly reducing the navigation drag, and further improving the energy efficiency of the hull form under R&D.

The LNG cargo containment system is the core technology of the LNG carrier. After decades of development, NO96 and MARK III are the two types of the LNG cargo containment system. Both systems are developed by French giant GTT, with a market share of more than 90%.

In recent years, in order to break the technological monopoly,shipyards and institutes in China and South Korea and other countries are trying to promote the R&D of the LNG cargo containment system. Under the leadership of CSSC, the SDARI has always taken leading the development of shipbuilding technology as its own responsibility. By cooperating with LNT Marine and ABS to develop a series of LNG carriers with LNT A-BOX?as the cargo containment system, the institute innovated and enriched the storage tank forms of LNG carriers, and provided more choices for ship owners and the market.

At present, the SDARI has a professional technical team engaged in the R&D and design of liquefied gas tanker related hull forms. Most of its team members have participated in the R&D of liquefied gas tankers for more than 10 years and have accumulated rich experience. The institute has liquefied gas related product design capability of A, B, C and membrane type whole series of cargo containment form, able to independently complete liquefied gas related elementary calculations and analysis of load and sway, thermal load and temperature field, full ship finite element, piping stress andmooring force calculation,the product spectrum covers small,medium and large liquefied gas carriers, and the hospital has become an important force in the design field.

LNT Marine said that the 175,000 m3 A-BOX?large LNG carrier obtained AiP also shows that LNT A-BOX?cargo containment system has strong applicability and competitiveness in the application of large LNG carriers, which can help more shipyards build large LNG carriers, thus promoting the development of LNG shipping industry.

It is reported that in March 2021, CSSC Shanghai Waigaoqiao Shipbuilding signed a cooperation agreement with Qatar Petroleum,ABS, LNT Marine to jointly develop medium and large LNG carriers based on LNT-BOX?technology for the LNG cargo containment system; the China merchants Heavy Industries (Jiangsu)Co., Ltd., the shipyard which built and delivered the global first 45,000 m3 LNG carrier “Saga Dawn” with the LNT-BOX?cargo containment system officially entered the large LNG carrier building market last year. There are signs that more Chinese shipyards are about to compete in the future shipbuilding market of large LNG carriers.