Liberty Lines launches high-speed ferry with Rolls-Royce mtu hybrid system
Italian shipping company Liberty Lines has launched a hybrid fast ferry in Trapani, Sicily, powered by a mtu hybrid propulsion system from Rolls-Royce.
Vittorio Morace
The Vittorio Morace, built by the Spanish shipyard Astilleros Armon and designed by Incat Crowther, is said to be the world’s first IMO high-speed craft (HSC) hybrid fast ferry of this size and has been classified as a Green Plus ship by the Italian classification society RINA. The 39.5m ship has a capacity of 251 passengers and reaches a speed of over 30kts.
The new member of the fleet, named after the founder of the shipping company, is the first of nine ferries that will operate between Sicily and the neighboring Aeolian and Egadi islands as well as between the Italian mainland, Croatia and Slovenia.
The 31 ferries in the Liberty Lines fleet operate all year round, transporting more than three and a half million passengers on routes of up to 100 nautical miles. They not only serve as tourist excursion ships but are above all an important lifeline for many residents of the islands who have to commute regularly. The best known are the Aeolian Islands of Panarea, Stromboli, Vulcano, Alicudi, Filicudi, Lipari and Salina, which are UNESCO World Heritage Sites.
The battery-electric part of the drive is used for locally emission-free driving in the harbor area and as a booster. CO2 emissions are reduced by the particularly efficient mtu Series 4000 diesel engines which can also run on renewable hydrotreated vegetable oil (HVO). Its use can lower the CO2 footprint by up to 90%. Furthermore, the comparatively low overall weight of both the engines and the hybrid drive system contributes to high vessel propulsion efficiency, thereby reducing fuel consumption and emissions.
Rolls-Royce’s mtu hybrid propulsion packs
When entering and leaving the port areas, the batteries ensure silent and emission-free maneuvering. They supply power to all the ship’s electrical equipment and the bow thrusters. When the ship leaves the harbor and increases speed, the mtu combustion engines are used. They drive the propellers directly, enabling the ship to travel at speeds of up to 30kts. At the same time, they drive the hybrid electric motors via the gearboxes to charge the batteries and supply the electrical consumers on board without having to operate generator sets (gensets). The generators on board are available as a backup. When the ship is in the harbor, the batteries are used for the entire electrical supply on board during shorter stopovers, also silently and emission-free without power generators. During longer stopovers, shore power can be connected to recharge the batteries.
The mtu hybrid propulsion packs for Liberty Lines ferries consist of two mtu 16V4000 M65L combustion engines, each rated at 2560kW/1800 rpm. With mtu SCR exhaust after-treatment systems, these engines meet IMO Tier III and US EPA Tier 4 emission standards. The gearboxes are Reintjes WVSA-1542 hybrid-capable, featuring clutchable PTO/PTIs for interfacing with electric machines. The electric machines on board are two Danfoss Editron EM-PMI375 T1100-2900 permanent magnet e-machines. These e-machines provide approximately 130kW each of propulsion power, and in charging mode, they can deliver up to about 260kW each. By using variable-speed electric motors, the system enables the use of simple fixed-pitch propellers on the vessel.
Additionally, there are two 100kWe variable-speed gensets operating between 1000rpm and 2400rpm, equipped with lightweight PM generators. The battery setup includes 3 x 11 EST Green Orca 1050 Battery Packs (totaling 346kWh installed). The system also features DC switchboards (including DC power converters, circuit breakers, filters, and protection equipment), an electrical power management system, and the mtu NautIQ Blue Vision NG_Hybrid Control and Monitoring System. The latter controls and monitors both the hybrid propulsion system and other main ship systems, such as tanks, bilge alarms and gensets.
Gennaro Carlo Cotella, CEO of Liberty Lines, said, “We chose mtu hybrid systems because we want to minimize the environmental impact of our new fleet while not compromising on the high speed and range of our vessels. As we have trusted mtu products for decades, we have also opted for this partnership for our major fleet renewal.”
Denise Kurtulus, vice president of global marine at Rolls-Royce Power Systems, added, “Liberty Lines is the ideal partner to demonstrate the progress that can be made toward environmentally and climate-friendly ship operation: We have used all possibilities and combined highly efficient combustion engines with exhaust gas after-treatment, batteries and electric motors with an intelligent electronic control system to create an emission-optimized system. Together with Liberty Lines, Armon and Incat Crowther, we have developed a passenger ferry that will set new standards in this category of shipbuilding. We are proud of this. Our goal is to help this technology achieve a breakthrough.”
Automation and monitoring
All components are coordinated by the mtu NautIQ Blue Vision NG control and monitoring system. The complete propulsion systems of the first two ships will be monitored by the mtu NautIQ Foresight equipment health monitoring system. It collects data on the technical condition and analyses and stores it in order to improve the operational availability of the ship, reduce maintenance costs and lower fuel consumption and thus CO2 emissions.
In related news, the world’s first LNG tug powered by a hybrid system has gone into operation at the port of Singapore with mtu gas engines from Rolls-Royce. Click here to read the full story.
