Hanwha Ocean (formerly Daewoo Shipbuilding & Marine Engineering) recently announced the delivery of a 24,000 TEU ultra-large container ship “Singapore Express” to German liner giant Hapag-Lloyd.
The container ship is equipped with Type-B high manganese steel-based liquefied natural gas (LNG) fuel tanks, which is the first time in the world that high manganese steel LNG fuel tank is applied to a 24,000 TEU container ship.
The Type-B high manganese steel LNG fuel tank for the Singapore Express was jointly developed by Hanwha Ocean and POSCO. The two companies conducted a Joint Development Program (JDP) in 2010 to study the feasibility of high manganese steel materials. The JDP, which was completed in 2013, involved five major classification societies: ABS, BV, DNV, KR and LR.
It is reported that traditional LNG fuel tanks, which need to loading LNG at a low temperature of -163°C, are mainly made of 9% nickel steel, stainless steel and aluminum alloy, which have the shortcomings of high cost, high process requirement and low strength, etc.
In contrast, high manganese steel material is easy to process, with high productivity, high wear resistance and high strength, etc., while its price is lower than that of 9% nickel steel, which has a obvious advantage in the production cost.
With this advantage, high manganese steel material is recognized by the International Maritime Organization (IMO) in 2022 as a material that can be used as a fabrication material for carrying cryogenic cargo and fuel tanks. In order to prevent ship safety accidents, IMO stipulates that ships using cryogenic fuels must be equipped with fuel tanks made of materials that meet certain standards.
Hanwha Ocean said that if large-scale production of high manganese steel LNG fuel tanks is possible in the future, Korea’s shipbuilding industry will have a significant price competition advantage, and its competitiveness in the industry will be further strengthened through the localization of the LNG liquid cargo tank technology.
To date, Hanwha Ocean has received orders for 36 vessels equipped with high manganese steel fuel tanks, including 22 container ships and 14 Very Large Crude Carriers (VLCCs). Among them, 5 container ships and 14 VLCCs, including the latest delivery of “Singapore Express”, have been delivered to their owners, while the remaining 17 ships are under construction.