İstanbul, Türkiye-headquartered Navtek Naval Technologies has made huge progress building the world’s first fleet of electric tugboats with three in operation, and the first of a new series launched at the end of March 2023.
Three of the zero-emissions tugboats were built to its ZeeTug30 design with 30 tonnes of bollard pull and on 28 March, it launched the first ZeeTug45 design with 45 tonnes of bollard pull.
These are all destined to support ship movements into and out of quaysides and shipyards for Gisas Port, which has become the world’s first harbour with a zero-emissions tugboat fleet.
Navtek technical deputy general manager Murat Avinal explains why these zero-emissions tugboats are “game-changers for ports” and that other zero-emissions projects are on the way.
“The first ZeeTug30, Gisas Power, is a proven vessel, affirming our commitment to true zero-emissions in shipbuilding,” he says.
“We have recently launched two new sister tugs and a larger ZeeTug45 to join the world’s first true-zero-emissions tugboat fleet.”
Navtek launched Gisas Power II in November 2022 and brought it into service in January 2023, when it also launched Gisas Power III. ZeeTug30s have an overall length of 19 m, beam of 7 m, depth of around 5 m and a draught of almost 4 m. Corvus energy storage systems drive two propulsion motors connected to azimuth thrusters. They have more than 30 tonnes of bollard pull and speeds of around 10 knots all from battery power.
For Gisas Power, Navtek collaborated with Turkish power systems integrator BMA Technology and drive and converter supplier ABB. For safety, it has two redundant battery rooms, one fore and one aft, that are maintained at a constant temperature by a cooling system. It can be charged in less than an hour through a quayside charging station.
Mr Avinal notes that during the first 1,010 days of service, Gisas Power completed 2,749 jobs with more than 4,241 motor running hours and accumulative charging of around 788,162 kWh.
“A remarkable 560.6 tonnes of CO2 and 1.6 tonnes of NOx emissions were avoided after 1,010 days,” he says. “Furthermore, public health impacts of particulate matter pollution and significant marine noise pollution have also been avoided.”
The ZeeTug45, Gisas Power IV, has azimuth stern drive with two thrusters using total power of 2,900 kW from electric drives connected to batteries rooms.
“We are determined to be the world’s best example and first fully decarbonised port with operations from a fleet of four all-electric zero-emissions ZeeTugs from Q2 2023, contributing to waterborne transport decarbonisation efforts,” says Mr Avinal. “Sea trials and class approvals will be completed very soon.”
There are plans for larger electric-powered, zero-emissions tugs with higher bollard pulls and power capabilities for more varied towage activities. “Designs for much larger ZeeTugs with up to 80 tonnes of bollard pull are now finalised,” says Mr Avinal.
“A new feature added to all our ZeeTugs is to regenerate energy while manoeuvring large ships,” he adds.
Onshore charging and workboats
To accompany these electric tugs, Navtek designed a patent-pending onshore quick-charging station (QCS) with two 600-kW charge units with fast plugin and charging.
“The QCS can fully charge a ZeeTug with Corvus-supplied lithium-ion batteries on board in less than an hour,” says Mr Avinal.
This enables these electric tugs to complete multiple ship-handling jobs each day without needing lengthy recharging.
Navtek has also designed smaller all-electric workboats with a tugboat notation for support work in shipyards and harbours. The first ZeeBoat05, with just 6.5 tonnes of bollard pull is ready for production at a Turkish facility, Mr Avinal adds.
One of the key challenges with battery-powered tugs is their limited operating areas, being confined by their distance from a QCS. But Navtek has developed design and technology to provide range extension and power boosts when these are required.
Its latest design is a hydrogen-battery hybrid tugboat, H2ydroTug60, which is scheduled to be constructed in Türkiye this year, with new power-generating technology on board.
“A recent technological breakthrough, low-pressure solid-state hydrogen storage systems and fuel cells will be integrated into existing proven ZeeTug infrastructure to gain longer distances and greater operation capabilities for a new generation of tugboats,” says Mr Avinal.
Green ports and shipping
All these tugs could be operating in a ZeePort, a Navtek concept for zero-emissions harbours and marine terminals where integrated transport could be all electric.
“Our unique port-decarbonisation project has been fully developed and several international funding opportunities are now being considered,” says Mr Avinal.
Navtek has applied for a Norwegian government grant to further develop its EcoBarge concept with collaboration from other companies, and Navtek is helping the Port of Gothenburg to prepare a decarbonisation feasibility study.
“We firmly believe decarbonisation in waterborne transport is an integrated route that requires close collaboration and partnership at all levels of stakeholders in the sector and we are committed to making this dream a real one,” says Mr Avinal.
In Q4 2023, Navtek signed a memorandum of understanding with e1 Marine to design hydrogen-powered tugboats and car carriers to reduce emissions during European port operations.
Navtek has also formed a partnership with Toronto-based Oppsense Inc to promote its holistic approach to maritime decarbonisation, ZeeTug and ZeePort, in the Canadian market.
Other designs from Navtek include a combination bulk carrier with wind-turbine sails, batteries, solar panels and hydrogen fuel cells and generator sets for back up; Blue Bird leisure yachts with batteries and solar panels; and an all-electric passenger ferry for use in Türkiye.
“We have also designed the ZeeVMax a Volga river low-emissions cargo vessel with seagoing capabilities,” says Mr Avinal
“Furthermore, we are working on several projects for retrofitting fossil-fuelled vessels, such as passenger ferries, car carriers, roro vessels, icebreakers, offshore support and multipurpose vessels, aiming to convert them to zero emissions or into low-emissions vessels.”
Navtek is working in close collaboration with Netherlands-based Seawind Ocean Technology to design deepsea floating foundations for 6, 12 and 18-MW wind turbines to produce green hydrogen.
Source : Rivieramm