Owner is working with naval architects, shipyards, engine manufacturers and technology providers to reduce emissions from harbour towage
Tug owners are central to decarbonising marine services in ports, providing solutions to environmental challenges through investment in green tugs. The towage industry is incorporating revolutionary technology in newbuild tugs, with electric-powered tugs and those ready for alternative fuels entering service in the next three years.
Tugs are being designed to be compact, with high power and low emissions with excellent stability, safety and manoeuvrability. Vessels ordered for 2025 and 2026 deliveries could use methanol as an alternative to diesel, with dual-fuel engines and selective catalytic reduction (SCR) units to remove NOx from exhausts.
Svitzer is a global leader in introducing efficient, low-emissions tugs into its regional fleets worldwide. It is at the forefront of many technical and operational innovations to reduce the environmental footprint of port services, while maintaining its focus on safety and sustainability.
It has designed a multipurpose tug with better performance and flexibility than azimuth stern drive (ASD) tugboats, implemented low-carbon biofuels on up to 70 vessels in one country and is working with manufacturers to develop and trial methanol dual-fuel engines.
Svitzer global chief operating officer Kasper Karlsen is positive about decarbonising tugboats and port operations in a sustainable way. The Danish shipowner is implementing various innovations to reach these goals, he tells Riviera Maritime Media.
It is rolling out biofuels across the UK towage fleet, designing more efficient and powerful tugs, installing mechanical hybrid propulsion, preparing to build electric tugs and to use future fuels, such as methanol.
Transverse plans
Svitzer worked with Robert Allan Ltd to design the TRAnsverse tug concept and has a memorandum of understanding with MAN Energy Solutions and Caterpillar to develop and trial methanol dual-fuel engines on tug newbuilds.
Mr Karlsen expects the first TRAnsverse tug to enter service and two more to be completed this year.
“The TRAnsverse tug was developed based on our operational knowledge and information from masters and engineers, using joint expertise from the engineroom and wheelhouse,” says Mr Karlsen. “Then we partnered with Robert Allan and came up with the staple design, which means we can have a range of many more positions around assisted vessels to deliver stronger pull forces than an ASD tug.”
Thrusters are positioned along the centre line of the hull, which was optimised during the design, while the towage points and arrangements with the staple “provide in combination superior and enhanced pull forces, especially beneficial for escorting ships,” says Mr Karlsen. “We tested this in simulations and tank tests, while the first tug has undertaken sea trials.”
Sanmar Shipyards built the first of these 26-m TRAnsverse tugs, and it was tested Q4 2023. Unfortunately, its delivery has been delayed until later in 2024.
“The first TRAnsverse tug will be going to Amsterdam,” he adds. “We are happy with the result of initial sea trials as these confirmed our expectations, which were high.”
Uzmar Shipyard is building two larger version TRAnsverse tugs, at 32-m, for Svitzer’s towage operations in Newcastle, Australia, for delivery by the end of this year.
Also in Australia, Svitzer is applying mechanical-hybrid propulsion and Caterpillar engines on harbour tugs built for a major Western Australian port. Cheoy Lee Shipyards is close to finishing four harbour tugs for Svitzer’s contract with mining conglomerate BHP.
“We have taken delivery of the first two tugs already and expect the next two to come within the next months,” says Mr Karlsen. “A fifth tug for the same operations will follow from Med Marine shipyard in Turkey, later in the year.
Each have Schottel Sydrive, which Svitzer helped to develop, enabling two thrusters to be powered by one engine, with the second engine resting.
“With Sydrive, we can clutch in the drive between the thrusters, raising the load on one engine to more favourable levels and saving on the engine not in use,” says Mr Karlsen.
“During transits and mobilisations, this saves fuel, emissions and the total cost of ownership. On tugs with Sydrive, we are seeing lower fuel consumption. This is a solution to partially decarbonise.”
Fuel developments
Svitzer is committed to trialling fuels with low carbon emissions and offering net-zero operations in ports, starting with the mass use of hydrogenated vegetable oil (HVO) biofuel on up to 70 tugs operating in the UK during 2023. “Drop-in fuels are good to maintain viable and sustainable operations. We are offering our customers Ecotow for tank-to-wake carbon-neutral towage at a premium, this decreases the scope 2 emissions for our customers,” Mr Karlsen explains.
“We adapted to challenges on pricing and availability, and tested with OEMs to ensure HVO fits with engine maintenance regimes. We have not seen any unexpected behaviour or surprises with HVO. It has been a good success for us,” he continues.
Svitzer has also tested using B20 biodiesel on a tug in the Middle East and plans to extend this to more tugs operating in the terminal.
“We are looking at different drop-in fuels, but other biofuels may generate other challenges,” says Mr Karlsen. “We are developing green solutions and new products, while working with ports to decarbonise. We are front runners in these products.”
For the longer term, methanol has been selected as one of the future fuels of choice for lowering tug emissions. Svitzer expects its MoUs with MAN and Caterpillar will result in trialling dual-fuel engines on newbuild tugs within the next 18 months.
Future deliveries
“We are building a hybrid methanol-fuelled tug for the Port of Gothenburg, Sweden. Originally, we also planned for fuel-cell technology on this tug,” says Mr Karlsen.
“However, we reviewed the technology and liaised with vendors of fuel cells. Although the technology is something we keep a close eye on, we believe it is for the future, and technology is not mature enough yet for the intended application in these types of vessels.”
This is why the project is now aiming at having dual-fuel methanol, hybrid-electric propulsion with onboard batteries and generator sets working on methanol.
“There is no silver bullet for decarbonisation, and it is a race for the right technology, which will depend on what infrastructure is available,” says Mr Karlsen. “It depends on access to shore power, green sustainable fuels and what can be applied in tugboats.”
Also, on the operational profile of tugs and performance from their propulsion, which can be complex with variations on power requirements throughout daily operations. “Average engine loads are relatively low, and then we need the bollard pull when required,” he explains. “Tugs spend time between jobs alongside, so batteries will be part of the future. But we also need back-up and boosting, as we would not want flat batteries during jobs or transits.”
Tug owners will need to work with ports in a collaborative effort to decarbonise the sector. While all new tugs have efficient hullforms and engines, lowering carbon intensity in port operations, to go further, future tugs operated by Svitzer are expected to have hybrid propulsion, methanol-ready engines and exhaust aftertreatment systems to minimise emissions.
Shipbuilder journey
Tug builders are at the centre of producing vessels with low emissions and zero-carbon exhaust to help owners reduce their environmental footprints in ports. They are building tugboats with innovations, electric technology and ready to use alternative fuels such as methanol and LNG.
A select few shipyards have built tugs with all-electric propulsion incorporating batteries to provide power for harbour operations and generator sets to provide back-up and range extension.
Sanmar Shipyards, a sponsor of the International Tug & Salvage Convention, Exhibition & Awards 2024, is a leader in the field of environmentally friendly tugboats.
It has been a decade of innovation, with a promise of much more to come from the Turkish shipbuilder and tug owner. Sanmar has produced the most battery-powered, zero-emissions tugs, six to date, and several tugs using LNG fuel, including the world’s first in 2014, plus it is building the first methanol-diesel dual-fuel escort tugs.
An electric future
Robert Allan Ltd provides exclusive designs to Sanmar including the ElectRA series of battery-powered tugs and those for dual-fuel vessels. Sanmar chairman of the board Ali Gürün says the sixth of these ElectRA tugs, BB Electra, was delivered to its owner Norway’s Buksér og Berging in March 2024. Five others have already left the shipyard and arrived in British Columbia, Canada.
“We have delivered three electric tugs and two LNG dual-fuel escort tugs to HaiSea Marine and two ElectRA tugs to SAAM Towage,” says Mr Gürün. “Apart from these, we have delivered and we are still building almost a dozen other tugs to owners around the world.”
Sanmar launched the first ElectRA tug for its own fleet operating in Turkey in February and started constructing two methanol-fuelled escort tugs for Kotug Canada, a partnership between Kotug International and Canada’s Horizon Maritime Services.
Mr Gürün says the shipbuilder has garnered more interest for electric tugs and already has five more ElectRA tugs in the orderbook for delivery in 2025.
“Sanmar is leading this move to greener, cleaner, sustainable operations with a new generation of emissions-free tugs such as the ElectRA series of harbour tugs and our joint project to build the world’s first methanol-fuelled tugboats.”
Methanol project
Sanmar Shipyards cut steel on the first of these methanol-fuelled tugboats in February 2024, to be named SD Aisemaht and SD Qwii-Aan’c Sarah, and will build them based on Robert Allan’s RAsalvor 4400 DFM design.
Kotug Canada has partnered with the Sc’ianew First Nation to provide ship escort and emergency response services from Beecher Bay, which is strategically located along the shipping route to the Trans Mountain pipeline’s Westridge Marine Terminal for crude oil exports. These tugs will have an overall length of 44 m and a bollard pull of 115 tonnes to escort tankers from the Port of Vancouver to the open Pacific Ocean through the commercial shipping lanes of the Salish Sea.
They will be equipped with the latest Schottel Sydrive azimuth thrusters to enable a single engine to drive two thrusters, significantly reducing fuel consumption, plus firefighting and spill response capabilities.
Their hulls will have Graphite Innovation Technologies’ graphene paint applied to reduce biofouling and enhance the vessels’ hull smoothness, which also reduces underwater radiant noise and makes the vessels more fuel efficient.
During the 27th ITS Convention, Sanmar Shipyards director of research and development Tamer Geçkin will present the latest decarbonisation technologies and fuels, including energy storage solutions, LNG, methanol, ammonia and hydrogen. He will consider risk management for alternate fuels and battery systems, automation and autonomous technology familiarisation, requirements for crew training and the need for human intervention and improvisation.
The 27th International Tug & Salvage Convention, Exhibition & Awards will be held in association with Caterpillar in Dubai, UAE, 21-23 May 2024. Use this link for more details of this industry event and the associated social and networking opportunities; and this link to book your ticket for the exhibition, social gatherings and awards night.
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