Kvaerner Masa-Yards and ABB made an agreement in 1992 to develop and market the unit jointly. In 1993 the name Azipod was registered. After the order of the conversion of the M/T Lunni in 1994, the Kvaerner Masa-Azipod unit was founded.
Finally, on October 1, 1997 ABB, Fincantieri and Kvaerner Masa-Yards founded ABB Azipod Oy to market, design and produce Azipod propulsion systems.
3.1 Different installations and experiences of the Azipod systems
M/S Seili
The first joint R&D project was the conversion of Seili, a waterway service vessel owned by the Finnish Maritime Administration, into the first Azipod ship in the world. This took place in 1991. The Seili continues to operate today, and its 1.5 MW unit has operated faultlessly since the conversion.
M/T Uikku and M/T Lunni
The next ship to be equipped with Azipod was a 16 000 DWT product tanker, the M/T Uikku, built in 1978 in Germany. The conversion work of Uikku was done in 1993. The power of Uikku's Azipod unit is 11,4 MW. The ship was built to ice class 1A Super and the Azipod to Dn V ice 10 class. In 1995, Uikku's sister ship the M/T Lunni was similarly converted. Both ships have been in heavy commercial use since conversion. Their combined operating hours total well over 40,000. Of these, about 1 5,000 hours were on ice-infested waters.
In 1997 Uikku became the first western cargo ship to navigate through the North-East Sea route. Uikku started its journey in Murmansk in western Russia in the beginning of September. Twelve days later Uikku arrived in Providenya, located in eastern Siberia south of the Bering Strait. The Uikku and The Lunni demonstrate the soundness of the basic design and construction chosen for the Azipod. The Azipod propulsion is the only way to make North-East Sea route economically viable because the ships can operate very safely without icebreaker assistance
The icebreaking concept of going astern with pulling Azipod units demonstrates an icebreaking capability that surpasses all other technologies. It has also been tested with the Lunni. The tests showed that although the Lunni was not designed to operate stern first in heavy ice, it was able to operate in the toughest conditions found in Finnish waters without icebreaker assistance. Model and full scale test confirm that only 60% Of the power needed when attacking the ice bow first is needed for this mode of icebreaking.
M/S Elation and Paradise
The good results and reliable operation of the Uikku and the Lunni enabled CCL (Carnival Cruise Lines) to choose Azipod for the Elation and the Paradise in the autumn of 1995. The power of each of the two units is 14 MW. This order actually set off the change of propulsor type for big cruise ships. The CCL Fantacy series actually started the electrical propulsion era for cruise ships. When Elation and Paradise belongs to that series we can say that no other series of passenger ships has affected so much the propulsion concept of cruise ships.
The VOYAGER Class
The next Azipod system order carne over a year later. It was placed for RCI (Royal Caribbean International). The biggest cruise ships ever ordered will be equipped with two 14 MW (19 000 HP) Azipod units and one 14 MW Fixipod, a non-rotating Azipod unit. The first ship will sail in the autumn of 2000. It is also one of the first cruise ships equipped with a DP-system. With the Azipod propulsion system and 3 x 4 MW (5 440 HP) bow thrusters, this system will be so powerful that the giant ship will be able to stay on its designated place in winds, from any direction, of up to 18 m/second.
The MSV Botnica
In February 1997 Finnyards Oy ordered two 5 000 kW (6 800 HP) Azipod units for the multipurpose icebreaker Botnica it had on order for The Finnish Maritime Administration. The ship will operate in the Gulf of Finland in winter and in the North Sea oil fields for the rest of the year. To accomplish its offshore duties, the ship is equipped with a DnV Autro dp-class. The ship entered service at the North Sea in the summer of 1998. Excellent sea-trial experiences proved the system to make the ship very well suitable for the offshore work.
The Botnica is the first ship equipped with Azipod units and used in the offshore market and will provide a good reference for future applications.
Supply ships Arcticaborg and Antarcticaborg
In November 1997 Kvaerner Masa-Yards received an order for two small icebreaking supply ships powered by two 1620 kW (2200 HP) Azipod units. The ship's operation pattern in the Caspian Sea is made possible by the use of Azipod propulsion units. The ice conditions in the northern Caspian Sea are very severe, so the Azipod units will operate as ice lathes.
Other Azipod propulsion concepts
As the Podded propulsion has become standard solution on cruise ships ABB has secured orders in power classes from 6,6 to 19,5 MW. The total number of built or on order or Azipod units are to-day, 30.5.2000 55 units.
The concept has been used also on separate project such as product tankers, RoPax ships but not by us.
The first cost of the diesel electric propulsion compared to direct diesel driven shaft line prevents the use of electric propulsion in normal merchant ships. The last part of this paper describes a concept, CRP; that can change the situation.
3.2 Design Aspects of the Azipod Propulsion System for ELATION and PARADISE
In the following the different aspects are described. I use the Elation and Paradise conversion as an example because the difference with normal shaft line is quite clearly seen.
Several aspects have to be taken into consideration when applying the Azipod concept: hull form, Azipod location, motor design parameters, propeller design and strength, hydrodynamic details, structural strength, vibration design and tuning, steering logic and operation modes, ship characteristics like course stability and heeling, behavior in black-out situation and redundancy.
