MODU Moorings
Design, verification, feasibility studies, installation procedures, quantitative and qualitative risk assessments
+61 447 460 808
mmseng.com
marine, mechanical & structural engineering services based in Perth, Western Australia
Marine engineering
Marine & Mooring Services
contact us to discuss
MODU Moorings
Inshore Moorings
Design of cyclone and storm rated moorings. Support for procurement and installation.
Mooring Analyses
Calculation of vessel environmental loads and feasibility study of vessel and mooring coupling
Vessel Hydrodynamics
Calculation of the dynamic characteristics of the moored vessel to perform motion studies
General Arrangement Drawings
Detailed CAD drawings of mooring systems and connection details
Inspections Reviews
and Sign-offs
Pilbara Port Authority Naval Architecture review and sign-offs on annual mooring inspections
MODU moorings
MMS ENG
Mooring systems for MODUs are typically analysed and designed following the recommendations of API-2SK, DNVGL-OS-E301or similar Industry Standards.
The design / verification process starts by checking that maximum loads are within the code prescribed allowable values in the different conditions: operational & survival; with all mooring lines intact & with one ore more line failures.
The mooring lines can be made of one or combination of components: chain, steel wires or fibre ropes. Can also feature buoys or clump weights to adjust their response. Different characteristics of the components have to be correctly accounted for in the calculations. Some rigs may also have a thruster system to assist the mooring.
The mooring system should:
maintain the rig in location under extreme survival conditions with maximum loads on the mooring lines and anchors within the allowable;
limit the offsets in under the design conditions of the drilling equipment while operating;
maintain sufficient clearance from subsea and other floating assets;
allow kedging or skidding to different well locations if required;
be installable and reliable.
Other aspects should be considered as well when evaluating a MODU mooring system such as (but not limited to): reliability of the components, type and size of anchors, assessment of the risks, availability of the components, etc.
MMS ENG will be more than happy to discuss more in detail any aspect of a MODU mooring project. We have experience in all the phases of the project from screening studies to detailed design.
Additionally we can write or review the offshore installation procedures for all the different phases: prelay, hookup, conventional deployment, recovery, etc. and travel offshore to support you mooring project.
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Inshore moorings
MMS ENG
Clump weight with single riser, crow feet arrangement, admiral type swing mooring, spread mooring systems and other configurations for: day mooring, over night, stand-by, diving, work over, storm, cyclones, transhipment operations, quay side, ...
MMS ENG engineers have designed and deployed dozens of these mooring systems across Australia and APAC for a variety of different vessels: Anchor Handlers, Tugs, Barges, Bulk Carriers, Diving Vessels, Fishing Boats, Patrol Boats, Tankers, Drilling Platforms, Ferries, etc.
We can verify the suitability of your design or re-design your mooring system to suit your requirements. We have real word expertise and our designs will consider the availability of the mooring components to come out with the most efficient and cost effective solution.
Do not hesitate to contact us via email or over the phone to discuss your mooring requirements for any size of vessel, location or environmental condition.
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Mooring Analyses
MMS ENG
A mooring analysis study is carried out to verify the suitability of a mooring system to keep a vessel in location under the prescribed environmental conditions. A mooring analysis report may be required for the following, but not limited to, reasons:
a different vessel is to be moored to a existing mooring system;
some of the mooring components have been replaced or are degraded;
the environmental conditions have changed or have been reassessed.
The mooring analysis study will calculate the maximum loads and offsets of the moored vessel under the design environment.
MMS ENG can quickly assess the suitability of a given mooring system for the operational requirements.
MMS ENG engineers have carried out dozens of mooring analyses any type of vessels all over Australia and in the APAC area.
Contact us to discuss and we will go through the available options for your project.
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Vessel Hydrodynamics
MMS ENG
The hydrodynamic characteristics of a vessel are required in order to calculate its response, for instance the motions, in a given environment.
A vessel hydrodynamic study provides the quantities required to perform these calculations: response amplitude operators RAOs, load RAOs, quadratic transfer functions QTFs, current and wind coefficients, etc.
MMS ENG time domain analysis approach is then used to assess the operational limits to perform a given activity; for instance lifting, transfer, drilling, diving, etc.
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General Arrangement Drawings
MMS ENG
Technical general arrangement drawings – GAs – of a mooring system are used to illustrate the required details with clarity and precision to clients, operators, for record keeping, insurance purposes.
MMS ENG GAs are produced typically for: complete mooring systems assemblies, component details, hawser configurations, plan view of anchor locations, preliminary sketching, connection details, etc.
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Inspections Reviews and Sign-offs
MMS ENG
During their operating life mooring systems are inspected regularly by divers or ROVs to assess their conditions and the wear of the components. The inspection report will provide measurements and general comments on their status.
The inspection report observations are reviewed by the engineer that then provide his recommendations to the mooring owner: for instance what type of maintenance, if required and what are the current capabilities of the mooring system.
Each year MMS ENG engineers review the inspections of tens of different mooring systems already installed.
MMS ENG inspection review is more than just ticking the box, we will keep an historical record of your mooring, year by year, with updated drawings and maintenance interventions.
For the mooring systems installed in the areas managed by the Pilbara Port Authority, from the Port of Ashburton near Onslow in the south, to the Port of Port Hedland in the north, including Dampier, this is a compulsory requirement, for which MMS ENG is accredited to perform the review and sign-off in their Klein mooring management system [LINK] prior to the beginning of the cyclone season (typically before October you mooring should be signed off).
Chances are that if you own a mooring system in the Pilbara we have already reviewed it.
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Phone & Email
+61 447 460 808