Anti-Heeling & Propulsion SystemsMarine/Products

This system is designed for automatic and manual control of the ship's list during loading and unloading. It is to rebalance the ship automatically with the feedback from the inclinometer by pumping ballast water from starboard to port or vice versa.

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 starts only if it get the signal that both resp. valves (BW170V and BW173V, or BW171V and BW172V) are open. These valves will be controlled by means of master PLC or thru Central Vessel Management System / 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 the automatic mode the pump and valves are automatically controlled to shift the water Athwart ships in order to counteract the vessel's heel. If the angle has reach a selectable limit angle call 'Starting Angle'. The Starting Angle is selectable in the range of ±0.5o - ±2o. After crossing the starting angle, the system will start the heeling pump and activates the relevant control valve. In case of a systems with a nonreversible heeling pump and four controlled valve there will be a interlock between the control of the valves and the pump.

After the ship is rebalanced to 0°, the heeling pump will not be shut down immediately. For a time delay the pump will run further more, waiting a new rebalancing procedure. The valves are opened during the time delay for bypass operation. That means the water into the relevant heeling tank will be pumped around a permanent circle.

(Example: BW170V & BW172V valves opened and BW171V & BW173V valve closed.)

Manual Operation
This mode is a standalone direct operation independent of the Touchscreen/PLC
If the 'MAN' mode is selected, the pump running can be simply activated/deactivated by pressing/ stop pressing of the relevant direction push button:   

Emergency Stop
When this button is depressed, the pump stops and all the valves will be closed.

Fault Reactions

• Heeling angle exceeded 4 deg :
  - Valve relevant to the max list direction are temporary disabled to operate and it is only possible to operate in the opposite direction when switch to manual mode. Switch the mode to manual to operate the system.
  The reaching of max. HEELING-ANGLE will be indicated at mimic (touchscreen) diagram red warning light: PUMP STOP MAX. LIST
• One or more float sensor low level alarm is activated :
  - The system shutdown and all valves / pump are closed / support.
  Low water level are indicated at mimic(touchscreen) diagram by red warning light: PUMP STOP LOW LEVEL

Independently Emergency-Stop Device

Heeling angle exceeded 4.5 deg :
Independ Inclinometer is used to detect exceeded HEELING-ANGLE. If HEELING-ANGLE of ±4.5° is exceeded, the system shutdown will activate and all valve / pump will close immediately.
Switch to manual mode to operate the valve and pump, the valves relevant to the max list direction are temporary disabled to operate and it can only be carried out in the opposite direction when switch to manual mode.

Bi Direction Anti–Heeling System

General System Function And Working Principle – Bi- Directional  Pump Design 
The application of the Single Pump with 2 valve is of Bi-Directional Pump design. Systems wise is basically the same 

In terms of operation. The angle of the vessel must be within the limits designed. 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 usually not as large as single direction pumps.

Disadvantages:

• - Reversible motor required which translates to possibility of shorter motor life
  - Usage of VFD is unlikely as cost of VFD is high including harmonics filtration.
  - Braking and reversing cause delays which in some cases is not so welcomed.
  - 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. 

There is no such system as the best system. There is always a give and take process involved.

MOWE PROPULSION SYSTEM

From switchboards, motor control centre to propulsion system, MOWE has come a long way indeed in the arena of power.

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

Advantages:

• - Produce less pollution compared to conventional marine propulsion system, which involves burning of heavy 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 allowed Mowe to supply MV/LV systems, MCC and Propulsion systems. Performed needed designs, harmonics control and braking control functions in 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.