South Korean shipbuilding major HD Korea Shipbuilding & Offshore Engineering (HD KSOE), in collaboration with ship designer Robert Allan, has received approval in principle (AiP) from classification society ABS for an escort tug with methanol dual-fuel (DF) hybrid propulsion system.
The AiP certification was awarded for the RAstar 3500-W escort tug developed by HD KSOE and Robert Allan as part of their joint project that includes three different types of tugboats.
Specifically, the development project includes a harbor tug (AmpRA 2800) with a 6,000 kWh battery for pure electric propulsion and two escort tugs (RAstar 3200-W with electric propulsion powered by a HiMSEN methanol DF generation set and the RAstar 3500-W with hybrid propulsion using HiMSEN methanol DF propulsion engine).
The RAstar 3500-W tugboat certified by ABS measures 34.75 meters in length and has a lightship weight of approximately 833 tons. Its propulsion system includes two HiMSEN methanol DF engines (9H22CDFP-LM), supplied by HD KSOE as part of a propulsion package.
According to the shipbuilder, the tug achieves a bollard pull of around 69 tons when operating solely on the main engines. With the electric motor boost, this figure can increase to a maximum of 82 tons, offering strong towing capability and operational flexibility.
Robert Allan has also designed the RAsalvor 4400-DFM dual-fuel methanol escort tugs being built for KOTUG Canada, a partnership between KOTUG International and Canada’s Horizon Maritime, at at Sanmar Shipyard in Türkiye.
The keel-laying ceremony for two dual-fuel methanol escort tugs that will service the Trans Mountain Expansion Project (TMEP) was held in May 2024.