The “Vision of the Fjords” is a futuristic sightseeing catamaran in carbon construction by the Norwegian shipyard Brødrene Aa AS. It received the “Ship of the year Award” from the Norwegian ship magazine “Skipsrevyen” at the fair SMM 2016 in Hamburg. Its parallel hybrid drive turns out to be particularly groundbreaking, as both the electric and diesel engines can be operated independently of each other. A world first in a marine application when presented at SMM is the arrangement and design of the drive train components as well as the advanced monitoring system. The basis of the parallel hybrid drive is a 12-cylinder diesel engine from MAN Engines in each of the two drive units.
The drive train was developed and designed by MANCRAFT AS, another Norwegian supplier of marine propulsion systems. “We have chosen a highly solid and proven product – a diesel engine from MAN Engines – as the basis for our innovative driveline,” says owner and managing director Øyvind Alvern, who has been working exclusively with the engine manufacturer from Nuremberg since 1997. Each MAN engine type D2862 LE422 is equipped with a third-generation common rail injection system and delivers an output of 749 kW (1,019 HP) at 2,100 rpm.
This power is transmitted by a CENTA electromagnetic coupling to an Oswald electric motor via a CENTALINK cardan shaft. The subsequent contactless and inductive torque measurement allows the power of both motors to be selected and controlled in an advanced manner. The converted energy is transferred to the ZF transmission via another CENTALINK shaft. The diesel engine and the electric engine can drive the propellers together or independently of each other, thereby creating system redundancy. In the case of diesel operation, its full power can be fed through the electric engine to the ZF transmission and the CP propeller.
The MAN D2862 LE422 diesel engine of the “Vision of the Fjords” is already designed for maximum emission efficiency. With the third-generation common rail system, the MAN engine is inherently designed for low exhaust emissions. For trips in the harbour or sightseeing, however, the “Vision of the Fjords” can also be powered purely by the two Oswald electric engines, allowing a quiet and emission-free journey for up to three hours. The separate damping and insulation of all individual components of the drive ensures additional vibration-free operation and safety.
The batteries are recharged electrically in port or en route at the optimum operating point by the excess energy of the diesel engine, which is generated at high speed. The water-cooled electric engine is a permanent magnet synchronous motor (PMSM) that is operated as a generator or electric engine, depending on the operating mode. The energy collected in the batteries can thus be used as the sole source of energy, as the diesel engine can be put into stop mode at any time.
The complete propulsion system as well as the monitoring system were submitted to the classification society by MANCRAFT and tested and approved in accordance with DNV GL’s “high speed light craft” guideline for fast, light boats. The modular design of the new parallel hybrid drive makes it transferable and applicable to countless other systems.
|Ship name||Vision of the Fjords (Project name: Seasight)|
|Material||Composite carbon fibre|
|Classification||DNV GL high speed light craft|
|Main drive||2 x MAN D2862 LE422, each with 749 kW (1,019 HP) at 2,100 rpm|
|Electric engine||2 x Oswald permanent magnet electric motor 150 kW, as generator 200 kW|