The genuine propulsion package

MAN B&W Auxiliary Propulsion System. The genuine propulsion package

The Genuine Propulsion Package 
Since 1989, MAN B&W Diesel’s works in  Frederikshavn, Denmark have manufactured and supplied two-stroke engines of the successful MC-series, today up to the 8S50MC-C engine.  
The MAN B&W CP propeller programme has been developed to efficiently match the MC-engine series up to the 70MC versions.
The Alpha Clutcher is an integrated part of those propeller systems which are designed, manufactured and supplied by one company taking full responsibility for functionality, order handling, commissioning, warranty and after-sales service of the complete propulsion system.

Significant advantages

MAN B&W Auxiliary Propulsion System. Significant advantages

The Auxiliary Propulsion System with Alpha Clutcher means:

  1. cost-efficient propulsion redundancy
  2. simple, reliable and proven technology
  3. safe operation and quick change of propulsion mode
  4. full integration with the CP Propeller system
  5. easy handling and installation at shipyards
  6. no separate thrust transmitting foundation required
  7. no static hydraulic or electric power consumption
  8. maintenance free
  9. no practical wear
  10. free of back-lash

Remote control system

MAN B&W Auxiliary Propulsion System. Remote control system

The el-motor/alternator and clutch control system is integrated with the CP Propeller and main engine system.
The automatic PTI start-up sequence includes, eg interlocks for ‘main engine stopped’, ‘Clutcher in clutched-out position’, ‘el-motor/alternator clutched out’, gearing in the tunnel gear ‘changed to the PTI step-down ratio’, ‘propeller pitch adjusted to zero-position’. And then follows the transformer-start of the el-motor and the clutching in at the tunnel gear. In auxiliary propulsion mode the power absorption of the CP Propeller is controlled to stay within the load range of the el-motor. All electrical circuits of the control system are monitored by the alarm system.

Operating manuals, tests and trials

MAN B&W Auxiliary Propulsion System. Operating manuals, tests and trials

Operating manuals
An operating manual will provide the operating crew with a clear guidance on the redundancy features of the system. The manuals cover all details including a general description of the complete propulsion system, operating instructions and procedures for dealing with the situations identified in the class required Failure Mode and Effect Analysis, FMEA-report.

Installations and alignment

MAN B&W Auxiliary Propulsion System. Installations and alignment

Easy installation
The clutcher is easily installed with a traditional hydraulic shrink-fitted coupling to the fore end of the intermediate shaft through the tunnel gear. 
The connection to the intermediate shaft at the engine side is made by hydraulically operated fit and tie bolts.

Ordinary propulsion mode

MAN B&W Auxiliary Propulsion System. Ordinary propulsion mode

When operating in ordinary propulsion mode, the main engine delivers the propulsion power directly to the propeller shaft via the clutched-in Alpha Clutcher. PTO-power is delivered from the shaft via flexible coupling to the tunnel gearbox and the shaft alternator. 
When switching from auxiliary propulsion mode, ordinary operation mode is re-established in five minutes. The main engine and the shaft alternator have to be stopped, when the Alpha Clutcher is activated for clutching in.

Auxiliary propulsion mode

MAN B&W Auxiliary Propulsion System. Auxiliary propulsion mode

Clutching out the Alpha Clutcher is done remotely from the bridge. Auxiliary propulsion mode is established in less than two minutes. When clutching in, the Clutcher is remotely controlled from a panel in the engine room.
When operating in auxiliary propulsion mode, the shaft alternator is used as electric motor. This motor delivers power via the tunnel gear to the propeller shaft. When the Alpha Clutcher is clutched out, the main engine is disconnected from the propeller shaft and stopped. In this mode, however, the Alpha Clutcher will transmit the propeller thrust to the trust bearing of the main engine.

Propulsion redundancy

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:

  1. two-stroke propulsion engine
  2. CP Propeller & control system
  3. Tunnel gear with two steps
  4. El-motor/alternator
  5. Alpha clutcher

Alpha Clutcher characteristics

MAN B&W Auxiliary Propulsion System. Alpha Clutcher characteristics

The MAN B&W AP System is based on the “Power Take-in” principle including the Alpha Clutcher, for the clutching out the main engine from the propeller shaft in PTI-mode.
The prototype of the Alpha Clutcher was produced in the spring of ’99. The clutch function is controlled by hydraulic oil added through an oil distributor ring similar to that of the CP Propellers.

Maintainability and increased propulsion availability

MAN B&W Auxiliary Propulsion System. Maintainability and increased propulsion availability

Reduce the maintenance-stress at sort stay in harbour
Punctuality, short stays in harbour and scheduled maintenance of the main engine must form a synthesis with the ship’s charter. During the stay at quayside, overhaul and maintenance work can be carried out without delaying the scheduled departure.

Advantageous auxiliary propulsion power

MAN B&W Auxiliary Propulsion System. Advantageous auxiliary propulsion power

Increase the safety for the crew as well as for the ship
In case of a failure causing loss of main propulsion power, the MAN B&W AP System secures the course and manoeuvring as well as safe navigation at reduced speed to the nearest harbour. From the bridge panel the main engine is stopped and the Alpha Clutcher is clutched out enabling the propeller to be driven by the PTI-motor on the tunnel gear. Propulsion power is retained and the ship has regained its steering capability at a service speed of at least seven knots. Under adverse weather conditions the ship can maintain its position until the weather conditions improve or assistance has arrived.

Proven elements

MAN B&W Auxiliary Propulsion System. Proven elements

The low-speed two-stroke engine itself is unique in its simplicity and efficiency always securing safe operation.
The long lasting know-how and practical experience from a vast number of different ship types and propulsion applications form the basis for the very high mechanical quality of B&W CP propellers.
The supply of a large numbers of complete propulsion packages including tunnel gear and shaft alternator has accumulated good long-term service experience.

Safety of highest priority

MAN B&W Auxiliary Propulsion System. Safety of highest priority

Propulsion redundancy
In recent years focus has been set on redundancy of propulsion machinery as well as on requirements for arrangements necessary to restoring and maintaining availability of the ships’ propulsion power and manoeuvring capability.
In order to meet this demand, MAN B&W have developed a new Auxiliary Propulsion System consisting of:

  1. Two-stroke propulsion engine
  2. CP propeller & control system
  3. Tunnel gear with two steps
  4. El-motor/alternator and the Alpha Clutcher.

Therefore Safety first

MAN B&W Auxiliary Propulsion System. Therefore Safety first

Extra margins of safety are dictated by the transportation and handling of volatile and flammable liquids and gases, corrosive chemicals, and similar hazardous cargoes which may harm the personnel and the environment.
Safety precautions on board ships have constantly been improved throughout shipping history. Accidents at sea give rise to such improvements in order to secure the best possible safety for the crew, the ship, other vessels and installations at sea, the environment and the business as a whole.

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