The Korean Register of Shipping (KR) and STX Offshore & Shipbuilding (STX O&S) have signed a memorandum of understanding (MOU) covering the joint development of designs for LNG-powered bulk carriers and their fuel gas supply systems.
The preliminary agreement builds on similar arrangements that KR has with other Korean shipyards and shipowners promoting dual-fuel bulk carrier designs.
KR and STX O&S will explore design options for an optimal LNG bunker tank, installation locations, LNG-powered engines, fuel preparation rooms and fuel gas supply systems. The work will take into consideration the impact of variables such as expected routes and bunkering arrangements, while minimising the loss of cargo space will be a primary focus.
The LNG-fuelled bulk carrier designs that will be developed through this joint project will not require any additional exhaust gas treatment equipment in order to meet IMO regulations governing sulphur oxide (SOx) and nitrogen oxide (NOx) emissions.
KR and Lloyd’s Register (LR) jointly classed Green Iris, the LNG-fuelled 50,000 dwt bulk carrier delivered to Ilshin Logistics by Hyundai Mipo Dockyard (HMD) in February 2018. The ship, the largest of only a handful of dual-fuel bulk carriers in operation, is utilised in the carriage of limestone between Korean ports.
Green Iris is powered by one of MAN Energy Solutions’ M-type, electronically controlled, gas-injection (ME-GI) engines, more specifically a MAN B&W 6G50ME-C9.5-GI unit with an output of 7,550 KW.
The bulk carrier has also been provided with a 500 m3 Type C LNG bunker tank made of austenitic, high-manganese steel and positioned on the aft mooring deck. Developed by POSCO, the Korean steel conglomerate, the cryogenic steel has a manganese content of approximately 26%. The properties and characteristics of the material, as well as the required welding technology and fuel tank design, have been proven suitable for LNG service.
Testing by KR helped verify the merits of the new POSCO steel and its use is likely to be a favoured option in the class society’s new collaboration with STX O&S. The high-manganese steel has shown superiority over many existing cryogenic materials in terms of ultimate tensile strength and elongation, and has a relatively low thermal expansion coefficient.
Another advantage offered by the material is its economic feasibility. The continuing rise in demand for LNG bunker and storage tanks has resulted in a shortage of nickel, a traditional constituent of cryogenic steels. POSCO’s manganese-based steel does not contain any nickel, and the steel maker points out that manganese is not currently under the upward price pressures being encountered by nickel.
© 2023 Riviera Maritime Media Ltd.