How integrated waterjet solutions benefit Balearia’s and Molslinjen’s new fast ferries
High-speed craft ‘remain at the forefront of innovation and technology’, was a key conclusion of Riviera Maritime Media’s Waterjets: balancing speed and efficiency webinar.
Sponsored by Wärtsilä, the webinar was held on 8 April 2021 during Riviera’s Marine Propulsion webinar week. Panellists JG Maritime Solutions Limited managing director John Garner and Wärtsilä global sales manager waterjets David van Luijtelaar discussed themes including the role of waterjets within smart technology solutions including autodocking, within dual-fuel LNG propulsion, their role within vessel safety and the importance of type-rating training for high-speed craft.
Mr Garner, who has maintained and operated many high-speed craft in a shipping career spanning over 40 years, and has previously been a regulator and chair of the high-speed craft advisory group when at MCA, highlighted the benefits of waterjets for high-speed craft: “They are very responsive and can be used on shallow-draft vessels, in shallow water and they are also very quiet. Waterjets are quite simple; their relative lack of complexity supports reliability. The inspection hatch allows in-service inspection.”
Highlighting the link between the waterjets, engines and maintenance, he comments “The engine loading is normally constant… the distance between waterjet and engine is relatively short, so the propulsion system should be under less stress. Due to no turning propellers, vessels have less noise and vibration, which gives customers a comfortable ride. Planned maintenance requirements are kept to a minimum in service with an annual overhaul in a refit and/or drydock period.”
He emphasised the need to train captains, navigators and engineers within high-speed craft who manage waterjets. “The High-Speed Craft Code requires all captains and officers to undergo type-rating training, specific to the craft they will sail on. One of the major differences for captains is to get used to the operational aspects of high-speed craft. These include very quick acceleration and deceleration, which have safety implications for the passengers on board. They need to become familiar with manoeuvring with waterjets. Waterjets are normally controlled by one steerable joystick. Back-up control gives direct control to waterjets independently and captains and navigators are encouraged to use this for training purposes to understand the position of waterjets during manoeuvres.”
Mr Garner said major high-speed craft shipbuilders have a pre-determined joystick strategy which is applied to all vessels they build. “Such a strategy is derived from the rationale of the directional thrust, from the waterjets illustrated as a vector acting from the transom stern.” He explained that this contrasted with mariners used to steering using a steering wheel from the bridge in non-high-speed craft, so the joystick strategy is a “major discussion point”.
He added “On the training of captains, a different philosophy is used, they really need to learn about the position of waterjets during manoeuvres, learn about the combined thrust of the waterjets, and learn about the resulting direction of the craft.”
He underlined the need for ongoing training and development.
Mr Garner also highlighted the role of waterjets within the safety aspects of a ferry. “We recognise that steerable waterjets add to the directional stability of a vessel and contribute to enhanced safety, especially in a heavy seaway with a strong following quarterly sea.”
Next, Wärtsilä’s Mr van Luijtelaar highlighted the role of waterjets within two progressive fast-ferry projects the company is providing integrated solutions for, including the waterjets.
Pioneering fast-ferry newbuilds
Spain’s Astilleros Armon Shipyard is building an LNG dual-fuelled fast ropax ferry for Baleària. Named Eleanor Roosevelt, the Incat Crowther-designed 125-m long catamaran will have capacity for 1,200 passengers and 450 cars. Wärtsilä has engineered, manufactured and installed four dual-fuel 16V31DF engines with 8,800 kW each and four LGX1500SRI steerable reversible hydraulic waterjets. Mr van Luijtelaar said “We have joined forces to make this an eco-efficient ship, and it is a pioneering vessel. On a global scale, LNG for bunkering is becoming more available together with emissions regulation, which is boosting the application of LNG. But up to now we have not seen many LNG-powered high-speed catamarans.”
Speaking about traditional options for high-speed craft, Mr van Luijtelaar said “High-speed engines are more compact but burn more fuel and are very expensive to maintain… lower-speed engines are more fuel efficient, there is longer between maintenance periods and lower emissions levels. The challenge up to now is they traditionally only operate on diesel and cannot take advantage of LNG, but technology is improving, and the engine used here is the best example.”
He said Wärtsilä’s 31 model engine, available in diesel and dual-fuel versions, is the world’s most efficient four-stroke diesel engine in the Guinness book of records, and “gives the best of both worlds”. In comparison with standard diesel engines in high-speed craft, this engine consumes 15-20 grams per kilowatt hour less fuel, leading to over a €1M savings per year for companies with two vessels operating at 10 hours a day.
Balearia’s new catamaran will be able to travel 400 nautical miles without refuelling. “We believe this ferry will shape the future of the supply of high-speed gas-powered catamaran vessels,” Mr van Luijtelaar commented.
In a second case study, Wärtsilä will supply the drive train propulsion package for Molslinjen’s new 150-m high-speed ferry under construction at Austal Philippines, which will carry 1,600 passengers and operate at 37 knots service speed in Denmark. This ferry will use Wärtsilä’s 16V31DF four stroke engines – which can be upgraded to LNG in future – combined with Wartsila’s new generation WXJ waterjets. Mr van Luijtelaar explained that the company introduced these waterjets in 2019, which have 3% more efficiency. He said “This has resulted in lower fuel consumption and it is the jet with the lowest size to weight ratio in the market; this is very important when sailing high-speed craft.”
Mr van Luijtelaar commented that the vessel “will be another milestone for Austal Philippines and Wärtsilä, it is the largest ferry by volume ever built in the Austal Philippines shipyard; it is powerful, economical and environmentally friendly.”
An innovative feature about the ferry is that Wärtsilä is applying smart technology to it and so it will have the world’s first auto docking system available in a fast ferry. Mr van Luijtelaar said “This is a nice example of safety, by automating all kinds of docking procedures, and preventing human errors, as captains have to perform technical manoeuvres many times a day, especially for a commuter ferry which has to enter tight docking space and small harbours.
“The captain selects the destination with a click of a button, the smart docking system takes over and the vessel leaves the dock, manoeuvres out of harbour, sails to the next point of call and docks alongside the quay, all without human intervention. This is an interesting development of smart technology that improves the efficiency and safety of high-speed craft.”
Mr Garner commented “Auto docking is really interesting. For commuter ferries, it takes operational testing and also establishing a level of confidence that captains need to gain in autodocking, as the captain remains responsible at all times for the craft.”
On both ferries, Wärtsilä is installing its data collection unit, collecting sensor data via secured connections from its waterjets, engines and even from third-party assets via the data collection box. This data will be collected in a cloud-based environment for remote monitoring.
Mr van Luijtelaar highlighted the integrated waterjet solutions Wärtsilä is providing in both ferry projects.
Mr Garner commented on this aspect. “Many operators prefer using a systems integrator who takes full responsibility for all systems and that can have a lot of benefits.”
Mr van Luijtelaar said an integrated solution reduced risk and increased performance, with options for a fuel-flexible solution and smart technologies that can improve safety.
The importance of efficiency of the powertrain can be seen by the webinar audience’s response to a poll asking them: What is the most important to you when selecting vessel solutions?
In order of preference: efficiency of the powertrain; environmental impact; ease of integration; local support and service, was top with 35% of votes.
In joint second place were: efficiency of the powertrain; environmental impact; ease of integration; local support and service; and local support and service; efficiency of the powertrain; environmental impact; ease of integration, with 25% of votes, respectively.
Some 20% voted for ease of integration; local support and service; efficiency of the powertrain; environmental impact.
Interestingly there were no votes for the order of environmental impact; ease of integration; local support and service; efficiency of the powertrain.
Mr Garner summed up “I am really impressed with high-speed craft remaining at the forefront of innovation and technology.”
On the ferry case studies presented in the webinar, he said they were “moving forward and pushing barriers but also taking care of environmental concerns at the same time.
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Riviera’s Waterjets: balancing speed and efficiency webinar panellists were, from left to right: Wärtsilä global sales manager waterjets David van Luijtelaar and JG Maritime Solutions Limited managing director John Garner