Rolls-Royce Installs mtu Gas Engines on LNG Tug, JMS Sunshine

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The JMS Sunshine, owned and operated by Seatrium, is equipped with two 16-cylinder mtu Series 4000M55RN gas engines and a gas regulating unit (GRU).

Seatrium Ltd.’s 65-ton bollard pull tug, JMS Sunshine, has been in regular service in the Port of Singapore since mid-May 2024, and is powered by a hybrid system with mtu gas engines from Rolls-Royce. The JMS Sunshine’s hybrid system consists of two V16 mtu Series 4000M55RM gas engines and a gas regulating unit (GRU). The use of mtu gas engines aligns with the Port of Singapore’s Maritime R&D Roadmap 2030, operating below the limit values of current emission guidelines prior to exhaust gas aftertreatment. These gas engines also have a particulate mass below the detection limit and emit minuscule quantities of NOx.

“We are proud that we were able to contribute to Seatrium’s innovative project with our gas engines. The workboat market is one of our strategic business areas,” said Chew Xiang Yu, Head of Rolls-Royce Power Systems' Civil Marine business in Asia. “The mtu engines were selected because they meet the demanding requirements of harbor tug operations - in terms of reliability, ease of operation, dynamic engine behavior and low emissions.”

The hybrid propulsion system is suited for the load profile of Seatrium’s harbor tug, as it allows precise maneuvering and a strong bollard pull during full-power operation. Maximum thrust is enabled by the total power of two azimuth stern thrusters at 4,000 kW. The mtu gas engines each provide 1,492 kW and each shaft contains an electric motor with 500 kW of power—JMS Sunshine is also equipped with a battery capacity of 904 KWh. This battery power is used to absorb peak loads during acceleration, for example, and to electrically maneuver in port and supply the ship with electricity on board.


The Power Systems division at Rolls-Royce received orders for mtu gas engine-powered propulsion systems and on-board gensets for 11 ships worldwide, including ferries, tugs, and government vessels. Currently, two catamarans owned by the Doeksen shipping company are operating with mtu gas engines in the North Sea’s Wadden Sea nature reserve since 2021. Also, the Richmond ferry has been using the engines for commuter service on the Lake Constance drinking water reservoir in southern Germany since 2023.

In terms of recent mtu engine development and deployment, Rolls-Royce introduced new mtu Series 4000 biogas gensets for power and heat generation in October 2023. The initial Series 4000 model is being installed at starch producer in Thailand, supplying the Tongjit factory with electricity and hot steam access.

mtu biogas gensets generate their own electricity and offer a stable power supply in the event of a power outage. The development of the new series was aided by operating experience gained with the previous models: L32 for biogas and L64FNER for natural gas. Currently, Rolls-Royce has deployed Series 4000 gensets in several gas sectors in the global market, including natural gas and biogas.

The 12-cylinder variant is the only model to have been publicly released thus far, although Rolls-Royce plans to release 8-V, 16-V, and 20-V cylinder configurations for delivery in 2024. Rolls-Royce’s 12 V genset has an electrical output of 1,521 kWe, peak electrical efficiency of 44.1%, and overall efficiency of more than 90%. In comparison to the Series 4000 L32FB model, output has risen 30%. The system has a compact design that enables increased power density, evidenced by the equivalent power output of the current 12V model and the predecessor 16V L32 model.