Risto PAKASTE1, Matti LEHTI2
ABSTRACT
The second part concentrates on development work and experiences from currently operating ships equipped with the Azipod propulsion system.
The third part presents the Contra Rotating Propeller concept applying a podded drive in place of a rudder of a conventional propulsion system. The concept is an alternative to mechanical propulsion systems where a twin shaftline design is chosen.
1. INTRODUCTION
In the marine industry it takes several years before a new innovation is accepted to enter the market. Therefore systematic development work is required before a product or a system can be released to the commercial vessel market. The Azipod concept was studied for the first time some 13 years ago for an ice-breaker and only later came other vessel applications such as tankers, cruise liners and roro-vessels. Certain design steps and early projects were studied and necessary experience was gained for further enhancement of the system. The following are examples of such projects:
The first Azipod unit (1500 kW/2040 HP) installation on the waterway service vessel Seili proved the concept and idea to be sound and demonstrated the installation process.
The first high power (11400 kW/15500 HP) installation for a commercial vessel, the arctic tanker Uikku, proved the concept's superior capabilities in maneuvering both in open water and in the most difficult ice conditions. The mechanical construction has also experienced extreme loads and given confidence in the strength and durability of the design.
The first pulling Azipod units were installed onboard the icebreaker Rothelstein in 1995. The comparison to pushing types was made and some very useful conclusions were drawn.
The above projects have been essential to be able to reach today's level of performance and reliability.
At the same time the tools for dimensioning and simulating the function of the electrical net work have been developed. It is possible to use commercially available simulation packages as simulation platform in this kind of development, but quite an amount of own R&D effort is required to build efficient and reliable design tools for daily use.
Affiliations:
1 Risto Pakaste
ABB Azipod Oy Laivanrakentajantie 2 00980 Helsinki, Finland
Tel: +358 1022 26020
Fax: +358 1022 26060
E-mail: risto.pakaste@fi.abb.com
2 Matti Lehti
ABB Industry Oy
2. POWER GENERATION AND PROPULSION DRIVE SYSTEM
2.1 Power generation and distribution
Selection power plant concept is made based on total installed power, operating modes, flexibility-, redundancy requirements and total cost. Availability of suitable components, e.g. switchboards, generating sets and cables, act as limiting factor.
Number and rating of power generating sets must be optimized to achieve desired flexibility of plant, service factor and fuel economy of prime movers for the selected service profile.
