Anti-Heeling & Propulsion SystemsMarine/Products

This system is designed for both automatic and manual control of a vessel's list during loading and unloading operations. The system automatically rebalances the vessel using feedback from the inclinometer by transferring ballast water from starboard to port, or vice versa.

Typical Applications

• - Container Vessels
• - Tankers
• - FPSO and FSO Units
• - Offshore Support Vessels (OSV)
• - Naval Vessels
• - Passenger Ferries
• - Heavy Lift and Cargo Ships

General Anti-Heeling System Function And Working Principle - SINGLE DIRECTION PUMP DESIGN

The Anti-Heeling systems operates with reversible or non reversible pumps and corresponding Remote Controlled Valves.

The complete systems includes:

• - Anti-Heeling Control Panel
• - Pump Starter Panel
• - Inclinometer Box
• - Heeling Pump
• - Heeling Valves
• - Level Transmitter
• - Level Switch

The Anti-Heeling System AH2000 & AH2000i can work in conjunction with the stability control system and the valve remote control system for bilge and ballast valve control, the precision heeling sensor, mounted athwart to the ship's direction and supplies the heeling angle signal to the master PLC.

The master CPU is housed in a flush mounting box (600 X 600 X 300mm). The front panel of the anti- heeling system includes hardwired selector switch for mode selection and lamp test for manual operation and a mimic panel.

The ballast pump will start only upon receiving a confirmation signal that both corresponding valves (BW170V and BW173V, or BW171V and BW172V) are open. These valves are controlled by the Master PLC or through the Central Vessel Management System (CVMS) / ICSS.

By pumping from:

• - Starboard to Portside - Valve BW170V and BW173V is Open. Valve BW171V and BW172V is Close.
  - Portside to Starboard - Valve BW171V and BW172V is Open. Valve BW170V and BW173V is Close.
  - Anti-heeling control system is only "Enabled" when the pump starter is in "Operation mode “.
  - Failure of such will render the system "Not operational"

Automatic Operation

In automatic mode, the pump and valves are automatically controlled to transfer water athwart ships in order to counteract the vessel’s heel. If the heel angle reaches the preset “Starting Angle” (adjustable between ±0.5° and ±2°), the system will automatically start the heeling pump and activate the relevant control valve. For systems equipped with a non-reversible heeling pump and four control valves, an interlock is provided between the valves and the pump operation.

After the vessel is rebalanced to 0°, the heeling pump will not shut down immediately. The pump will continue running for a preset time delay while waiting for any further rebalancing requirements. During this period, the valves remain open for bypass operation, allowing water to circulate continuously through the relevant heeling tank in a closed loop.

(Example: BW170V and BW172V are open, while BW171V and BW173V are closed.)

Manual Operation
This mode provides standalone direct operation independent of the Touchscreen/PLC. When ‘MAN’ mode is selected, the pump can be activated or stopped by operating the corresponding direction push button.

Emergency Stop
When the Emergency Stop button is activated, the pump will stop immediately and all valves will be closed.

Fault Reactions

• Heeling angle exceeds 4°:
  - The valves associated with the maximum list direction will be temporarily disabled. System operation can only be performed in the opposite direction when switched to Manual Mode.
  The maximum heeling angle condition will be indicated on the touchscreen mimic diagram by the red warning light: PUMP STOP MAX. LIST.
• One or more float sensor low-level alarms are activated:
  - The system will shut down and all valves and pumps will be stopped.
  A low water level condition will be indicated on the touchscreen mimic diagram by the red warning light: PUMP STOP LOW LEVEL.

Independently Emergency-Stop Device

Heeling angle exceeded 4.5°:
An independent inclinometer is used to detect excessive heel angles. If the heel angle exceeds ±4.5°, the emergency shutdown function will be activated and all valves and pumps will be closed immediately.
To operate the system, switch to Manual Mode. The valves associated with the maximum list direction will be temporarily disabled, and operation can only be carried out in the opposite direction.

Bi Direction Anti–Heeling System

General System Function And Working Principle – Bi-Directional Pump Design
The Single Pump with 2 Valves configuration is based on a bi-directional pump design. System operation is generally similar to the single-direction pump arrangement.

Key Benefits

• - Automatic vessel stability correction.
• - Improved vessel safety during loading and unloading operations.
• - Reduced heel angle and cargo shifting risks.
• - Lower crew intervention requirements.
• - Seamless integration with PLC, ICSS and Vessel Management Systems.
• - Reliable operation for offshore and marine environments.

In operation, the vessel heel angle must remain within the designed operating limits. The following are the advantages  and disadvantages of the Single Pump design.

Advantages:

• - Less components translate to less areas of failure
  - Lower design cost both for the System itself and for the vessel
  - Occupies less space on board the vessel.
  - Pump sizes are generally smaller compared to single-direction pumps systems.

Disadvantages:

• - A reversible motor is required, which may result in a shorter motor service life
  - Usage of VFD is unlikely as cost of VFD is high including harmonics filtration.
  - Braking and reversing operation may introduce delays that are not desirable in certain applications.
  - Water hammer to pumps may be possible due to sudden stop / start applications and resulting in more costly pumps and designs.
  - Every system has its pros and cons and designers of systems will have to decide carefully on the application. 

No single system is suitable for every application. Systems selection should be based on operational requirements, performance expectations and project constraints.

MOWE PROPULSION SYSTEM

From switchboards and motor control centres to complete propulsion systems, MOWE has established extensive experience in power and propulsion solutions.

Electrical Propulsion is a system used in most modern ships to generate thrust through propellers driven by two-stroke or four-stroke diesel engines, outboard motors, and gas turbine engines.

Advantages:

• - Produce lower emission compared to conventional marine propulsion systems that rely on heavy fuel oil.
  

The propeller shaft of the ship is connected to large motors, which can be D.C or A.C driven and are known as propulsion motors. Power for propulsion motor is supplied by the ship’s generator and prime mover assembly.

Years of experience have enabled MOWE to supply MV/LV systems, MCC and Propulsion systems while performing the necessary design, harmonic control and braking control functions for various applications to meet client needs.

Application of high end products, developing the best solution for clients, working with the best partners in the industry. ABB, Siemens, MG, Schneider are just a few.

We always place our clients’ needs seriously and perform required safety recommendations.

Contact us at This email address is being protected from spambots. You need JavaScript enabled to view it.  for more in depth design and analysis.