MEG4: The new standards of mooring ropes and the solution of 3 steps

The updated MEG4 represents the output of a multi-discipline working group representing members of various shipping trade organizations, mooring line manufacturers, shipyards, and OCIMF members. In previous guidelines of MEG requirements there was no specific jurisdiction of industry guidance on condition-based monitoring of mooring lines and tails. The new MEG requirements have strived to provide guidance and clarity on the condition-monitoring of mooring lines. Below is a list of some new terms that will be introduced in MEG4.

New terminology during the revision of MEG4

Ship Design Minimum Breaking Load – SDMBL. The minimum breaking load of new, dry mooring lines for which a ship’s mooring system is designed, to meet OCIMF standard environmental criteria restraint requirements. The SDMBL is the main parameter against which all the other components of a ship’s mooring system are sized and designed with defined tolerances.
Line Design Break Force – LDBF. LDBF is the minimum force that a new, dry, spliced mooring line will break at when tested according to appendix B. This is for all mooring line and tail materials except those manufactured from nylon which is tested wet and spliced. This value is declared by the manufacturer on each line’s mooring line certificate (see appendix B) and it is stated on a manufacturer’s line data sheet. As outlined in appendix B, when selecting lines, the LDBF of a line shall be 100%–105% of the SDMBL.

Line Design Break Force – LDBF.

LDBF is the minimum force that a new, dry, spliced mooring line will break at when tested according to appendix B. This is for all mooring line and tail materials except those manufactured from nylon which is tested wet and spliced. This value is declared by the manufacturer on each line’s mooring line certificate (see appendix B) and it is stated on a manufacturer’s line data sheet. As outlined in appendix B, when selecting lines, the LDBF of a line shall be 100%–105% of the SDMBL.

Tail Design Break Force – TDBF.

TDBF is the minimum force that a new, dry, spliced mooring tail will break at when tested according to appendix B. This is for all mooring line and tail materials except those manufactured from nylon which is tested wet and spliced. This value is declared by the manufacturer on each line’s mooring line certificate (see appendix B) and it is stated on a manufacturer’s line data sheet. As outlined in appendix B, when selecting lines, the TDBF of a line shall be 125%–130% of the SDMBL. The TDBF for nylon mooring lines should be specified as break tested wet because nylon tails change strength characteristics once exposed to water.

Working Load Limit – WLL (instead SWL).

The maximum load that a mooring line should be subjected to in an operational service, calculated from the standard environmental criteria. The WLL is expressed as a percentage of ship design MBL and should be used as a limiting value in both ship design and operational mooring analysis. During operation, the WLL should not be exceeded.

  • Steel wire ropes have a WLL of 55% of the SDMBL
  • Cordage (synthetic) ropes have a WLL of 50% of the SDMBL

Line Management Plan – LMP.

LMP is used to manage the operation and retirement of mooring lines and tails. The LMP also documents the requirements, assumptions and evaluation methods which used in determining the line retirement criteria. The LMP is specific to an operator, ship type, mooring line type and trade route.

Mooring System Management Plan – MSMP.

The MSMP which will complement the ship’s SMS. Through a ‘goal-based’ approach core elements of the mooring system are identified, against which high level ‘goals’ are established supported by more detailed ‘functional requirements’.

New standards for purchasing mooring line during of OCIMF

AIM: For the selecting right mooring line

During MEG3, only
• Length
• Diameter
• MBL

During MEG4, furthermore
• Load bearing linear tenacity
• Type of Vessel, frequency and type of mooring.
• Line tenacity
• Axial compression resistance
• Temperature conditions
• Specifications of vessel’s mooring equipment
• Material (no brand’s name)
• The replacement reason of mooring line

and more

New philosophy of inspection and monitoring of mooring lines during the revision of MEG4

AIM: To minimize the risk of failure of mooring lines and increase crew safety

New standards of inspection-monitoring
i)Environmental criteria
• Direction & force of wind and current
• Temperature
• Swell of sea
• Humidity
ii) Other criteria
• Type of work of line (ex. spring, head, breast, stern etc.)
• Hours of working operations
• Type of mooring operation (ex. STS, Open sea port etc.)
• Type of mooring equipment (ex. chock, fairlead, rollers and other deck fittings.)
• Protection of mooring lines (ex. chafe sleeves, protectors etc.)
• Construction & specification of mooring line or tail from the manufacturer
and more

The solution of 3 steps

First step: Planning

Support for optimal mooring line selection and LMP according to MEG4. Expert rope makers will be assigned to your project and will work closely with your managers. The support offered includes conference calls, on-site visits from the assigned sales account manager as well as from an expert Engineer. Furthermore, we will follow up whenever changes in specifications or production schedules are applied, in order to fully serve your project’s specific requirements.

Second step: Training

Training courses from expert rope makers can train your crew and executives in safety, maintenance, inspection and management of your mooring lines according to OCIMF MEG4, IMO & ISO/CI standards. The training courses are designed to provide you with increased crew safety and improved management of your mooring ropes. The training courses include instructional videos and presentations, easy-to-fill checklists for on board procedures and online technical support.

Third step: Monitoring

Makers of ropes must help you assess the condition of your mooring lines worldwide, at any time. Technicians of ropes can perform on board visual quality inspections and audit your mooring operation. After the inspection, you will receive a comprehensive official inspection report about the condition of your mooring lines and recommendations for your mooring operation. Also monitoring software from makers of ropes can be used to track line usage & condition in order to reliably prevision the replacement of your mooring lines & tails according to MEG4. Last but not least makers of ropes must evaluate precisely the remaining operational life of your mooring lines. All testing will be done according to the latest OCIMF & ISO/CI standards. Your mooring lines & mooring tails must be replaced with strength not less than 75% of SDMBL strength.

Results

• Reduce your operational costs by improving the working life of mooring lines
• Reduce mooring operation risks by preventing incidents
• Improve your safety by trusting the monitoring of your lines to the experts

 

Capt. Vasilis Giannopoulos
Marine Mooring Consultant
COO at Black Rope