MAN B&W Auxiliary Propulsion System. Propulsion redundancy
Another stamp of quality
It is expected that an increasing number of shipowners in future will specify their new vessels on the basis of high quality and ‘green images’ like crew safety and environmental safety – rather than exclusively on short-term economic efficiency. With MAN B&W AP System including:
- two-stroke propulsion engine
- CP Propeller & control system
- Tunnel gear with two steps
- Alpha clutcher
- ship designers, yards, owners and operators can obtain a specific class notation for redundant propulsion and manoeuvring capability.
The following table is a brief overview of the present class rules for redundancy, some of them are provisional only:
Service speed in auxiliary propulsion mode
Calculations and practical experience show – as an input to evaluation of the engine power needed, that an electrical shaft alternator/motor corresponding to 20% of the main engine output is recommended in connection with two-step gearing in the tunnel gear.
Competing clutch systems are available in the market, at almost twice the price of the alpha clutcher concept. These systems are also more complex and more expensive to install.