ABB’s Azipod technology was developed 30 years ago for a groundbreaking Finnish ice breaker, but the electric-drive propulsion systems are now finding wider uses as shipping seeks to decarbonise.
Capable of cutting fuel consumption by 20%, the Azipod’s real breakthrough came about 25 years ago when two units were ordered for and fitted to the 70,367-gt Carnival Elation (built 1998), according to ABB Marine & Ports president Juha Koskela.
Since then, the hull-mounted electric motors have been installed on some of the largest cruiseships built and have saved that sector about 1m tonnes of fuel.
“The rest is history,” said Koskela in an interview.
Some 700 Azipod units were delivered to nearly 300 vessels across 25 specialist ship types, also including offshore support and wind turbine installation vessels, LNG carriers, ferries and yachts.
But it is not just history. The benefits of greater manoeuvrability, fuel efficiency, lower noise and vibration are spreading the Azipod’s potential, as sustainability becomes an overriding issue for shipping. And the propulsion units have promise for bulkers and possibly even boxships.
In mid-2019, ABB filled the gap between its low and high-power range of Azipod propulsors with the launch of a new series in the 7.5 MW to 14.5 MW output range. The full range now goes from 1 MW to 22 MW.
ABB said the mid-power range was specifically applicable to dual-fuel or battery electric ferries and ropax vessels, as well as larger offshore construction vessels, midsize cruiseships and shuttle tankers.
Mounting the gearless and rotatable propulsion units under the hull allows for maximisation of deck space in small ferries, helping fast turnaround of vehicle loading while cutting emissions.
An independent study by ship design firm Deltamarin showed average annual savings in fuel and energy equivalent to $1.7m for a twin 10-MW Azipod-equipped ropax over a conventional vessel with shaftline propulsion. That lower fuel consumption equated to a cut in CO2 emissions of about 10,000 tonnes per year.
A first delivery of pods for a P&O Ferries’ vessel that will operate in the English Channel will be made this year.
And in late 2019, Germany’s Oldendorff Carriers opted for what will be the Azipod debut on bulkers when it selected them for two self-unloading 21,500-dwt ships due for delivery this year from China’s Chengxi Shipyard.
Koskela said greater flexibility of manoeuvring in shallow waters under variable loads and speeds was a factor for adding the technology to the transshipment vessels.
The ability to save time and cost using tugs to manoeuvre in ports could be a major boon for containership operators too.
“Electric propulsion is applicable to container vessels and Azipod could be a no-brainer for the increasing size of the vessel type,” Koskela said.
ABB Marine & Ports senior vice president Antti Ruohonen, who heads up its propulsion solutions business line, added that greater control in strong winds would also be a factor for boxships.
“In Suez, it would have helped,” he said in reference to the 23 March grounding of the 20,388-teu containership Ever Given (built 2018) in the Egyptian canal.
Koskela said ABB has previously had discussions with container lines and is interested in doing so again, but he admitted liner operators may not yet be looking to shift from mechanical to electrical propulsion.
Ruohonen said increased safety includes the Azipod’s capability to stop a ship in half the time it takes for a conventional vessel, as well as being able to steer while braking. Engine redundancy is also a factor where two units are installed.
History is coming full circle, with exploration cruise vessels one of the latest growth markets for Azipod propulsion for all the same reasons of safety, manoeuvrability, ice capability and sustainability, particularly where ships are operating in Arctic or Antarctic regions.
And the early driver of enhanced ice-breaking capabilities has also been built into the Arc7 LNG carriers — the first to navigate the Arctic Northern Sea Route this January. Previously, the route had been closed to large merchant vessels from December to July.
An Azipod was damaged when the 172,600-cbm Nikolay Yevgenov (built 2019) took the Arctic route this year, but Ruohonen said the LNG carrier was able to continue operating after the problem and the unit was quickly repaired when the ship was docked.
Electrification of passenger ferries has led to the development of a demonstration zero-emissions fuel-cell-based hybrid power train for Finnish research vessel Aranda as part of the European Union-funded Maranda project.
ABB Marine & Ports provided a 165-kW fuel-cell generation system to power the Aranda’s dynamic positioning and electrical equipment during measurements when the research vessel turns off its main engine to minimise noise, vibrations and air pollution that could interfere with readings.
The three-year, €3.77m ($4.6m) project has raised issues for the consortium involved in the tests as to how difficult it could be to get approval for a ship propelled by hydrogen and fuel cells, according to an interim report.
A fire protection system to prevent and detect leakage was recommended, as were swappable fuel tanks due to the current shortage of hydrogen-fuelling infrastructure.
It was also pointed out that plastics should be limited as a flammable mass aboard, but that proton exchange membrane fuel cells that use hydrogen are generally made of plastic.
President Juha Koskela said ABB is now close to delivering a 1-MW fuel-cell system for a small passenger vessel, with the ship likely to be in operation within about three years.
