Hybrid tug brings sunshine to Singapore
Joining Singapore’s list of ‘green vessel firsts’, which includes the 2022-launched all-electric cargo vessel Hydromover and all-electric patrol boat MPA Guardian, the new hybrid tug JMS Sunshine is being hailed as Singapore’s first vessel to incorporate a pure LNG engine.
Built domestically by Sembcorp Marine for its Jurong Marine Services (JMS) vessel operator subsidiary, the tug is the forerunner in a series of 12 battery-LNG hybrids to be constructed at the group’s Tuas Boulevard Yard facility. The concept for JMS Sunshine was first mooted in 2018, when JMS announced plans to “progressively replace” its existing diesel-powered tug fleet. Its design was supplied by naval architect LMG Marin (another Sembcorp Marine subsidiary) and has been certified by class society ABS.
When delivered at the end of March, JMS Sunshine will be used for ship manoeuvring, mooring and unmooring operations at the builder’s yards, as well as to escort various vessels within Singapore port limits. Speaking after the tug’s christening ceremony, hosted in late January, Simon Kuik, Sembcorp Marine head of R&D, said: “Emission regulations for marine vessels are getting more stringent every year. The ultimate goal is to cut the group’s greenhouse gas emissions by at least 50% by 2050 compared to 2008.”
JMS Sunshine features a length of 30m, a breadth of 12m and a depth of 4.9m, and is laid out for eight crew members. The tug’s onboard LNG supply is contained inside a 50m3-capacity Type C tank, and the LNG engines comprise twin MTU models, rated 1,492kW apiece. Additionally, the tug carries a pair of 442kWh lithium-ion (Li-ion) batteries, supplied by Spear Power Systems, for peak shaving, acceleration, boost and slow-speed operations. Sembcorp Marine explains: “JMS Sunshine runs on pure LNG, with a sizeable energy storage system based on lithium-ion battery power. This system allows emission-free operation of the tug during idling and low speed transits.
“It is capable of taking over the energy needs if a spike in power is warranted, and comes equipped with a ‘take-me-home’ reserve capacity to ensure safe return of the tug in the event of engine failure.” Ultimately, the builder calculates that this hybrid arrangement will result in emission savings of 251 tonnes of CO2 equivalent (tCO2e) each year.
The tug has been fitted with Schottel’s Sydrive-E azimuthal hybrid drive system, comprising two SRP 430-type Schottel Rudderpropellers, each with a power intake capacity of approximately 2,000kW. Fed by the electric motors and/or the LNG main engines, the SRPs are 360°-steerable, granting the crew optimal manoeuvrability ahead, astern and sideways, and enabling a bollard pull of 65tonnes. Schottel comments: “In terms of thruster integration, each upper gearbox offers two power input positions with an offset angle of +/- 90° for two power sources. An option with a +/- 135° offset angle is also available allowing even more design flexibility.”
JMS Sunshine has also been awarded the Cyber Secure 1 notation, which recognises efforts to implement cybersecurity into existing operational procedures and onboard systems.