VESSEL REVIEW | Meta 7 – Hybrid electric tug to serve South Korea's Busan Port

A new harbour tug fitted with a hybrid electric propulsion system has begun operational sailings at one of South Korea's largest ports in Busan.

As the Port of Busan is known for its poor air quality, which is largely due to emissions from ships and other sources, the use of electric tugs can help to mitigate this problem by reducing emissions of harmful pollutants. The recently delivered Meta 7 (메타7호) is therefore one of three tugs to be built for operation in South Korean ports to prove the viability of battery-hybrid tugs in reducing emissions. Operation of the new tug is the responsibility of local company Meta Tug.

In addition to Meta 7 in Busan, a tug from the Sunjin project has started commercial operation in Ulsan Port, and the World Marine project in Gunsan Port will be commissioned soon. All three tugs will feature hybrid systems and propulsion supplied by Kongsberg Maritime.

Meta 7 tug measures 37 by 11 metres (120 by 36 feet) and is fitted with a hybrid propulsion arrangement consisting of a main diesel engine, batteries, and fixed-pitch propellers housed in two azimuthing thrusters and connected to 400kW electric induction motors.

Flexible propulsion arrangement

The diesel engine will be used primarily to generate electricity, which is then stored in the batteries. The two electric motors can be used to propel the vessel independently or in conjunction with the diesel engine.

Kongsberg also equipped the tug with a DC electrical system with an energy storage capacity of 646 kWh, a transformer, an automation and control system, and a shore charging connection for the battery.

When operating in electric mode, Meta 7 produces zero emissions, offering a significant advantage over traditional diesel-powered tugs that emit large volumes of pollutants. By reducing its reliance on diesel fuel, the new tug can help improve air quality in Busan Port and nearby residential areas.

The tug is designed to operate on full electric power for most of its tasks, including berthing and unberthing operations. This is made possible by the vessel's advanced battery system, which can store enough energy to power the electric motor for extended periods. For instance, the tug can operate for up to one hour in electric mode following a single full charge of the batteries for normal speed transit operations.

Built for ease of use and maintenance

While the tug’s diesel engine remains in use and automatic hybrid mode conversion is not yet applied, the PTI mode helps lower fuel consumption and ensure ease of maintenance due to the reduced operating time of any rotating machinery.

Construction of Meta 7 was undertaken by South Korea's DongSung Shipyard.