Mooreast MA7 Anchor: Development Process Of A New … TechEvent-MooringInd/Mooreast … · Mooreast MA7 Anchor: Development Process ... • Simple fabrication . ... top right, Øyvind

Mooreast MA7 Anchor: Development Process Of A New Anchor For The Offshore Mooring

Industry

Roderick Ruinen Mooreast Asia Pte Ltd

Contents Presentation • Introduction • Review of existing anchors and patents • Testing of scale models • Prototype testing • Structural verification

24/11/2015 2 SNAMES Technical Talk, November 2015

Introduction


Floating Oil & Gas


Floating Renewable Energy


Drag anchor development

24/11/2015

6

SNAMES Technical Talk, November 2015


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• Anchor holding capacity (HC) increased over time: – Stone HC = 1 * Wanchor

– Stock anchor HC = 2 * Wanchor

– Flipper Delate / Stevin anchor HC = 20 * Wanchor

– FFTS / Stevpris HC = 50 to 100 * Wanchor

– Denla / Stevmanta (plate) HC = 100 to 175 * Wanchor



Anchor design process I. Define the requirements

– Review of existing anchors – Review (anchor) patents – Feedback from industry

II. Define different anchor models III. Test scale models and compare results IV. Proceed with model? Else back to step II. V. Build prototype model for testing VI. Offshore testing of prototype VII. Proceed with prototype? Else back to step II. VIII. Structural analysis of final design


Commercial offshore anchors Review of existing anchors


11

Holding capacity Ultimate Holding Capacity (UHC)

12 mT MAG 12 mT Stevpris Mk5 12 mT Stevpris Mk6

very soft clay 484 mT 393 mT 512 mT

medium clay - 551 mT 716 mT

hard clay / sand 874 mT 708 mT 921 mT

Ultimate Holding Capacity (UHC)

12 mT MAG 12 mT Bruce FFTS Mk4 12 mT Bruce FFTS PM

very soft clay 484 mT 393 mT 562 mT

medium clay - - -

hard clay / sand 874 mT 485 mT 630 mT

24/11/2015 SNAMES Technical Talk, November 2015

Commercial anchors


Commercial anchors


Commercial anchors


Commercial yacht anchors Review of existing anchors


Yacht Anchors

16 24/11/2015 SNAMES Technical Talk, November 2015

17

Yacht anchors


18

Yacht Anchors


Review of (anchor) patents


Patents

• Review of valid patents (technology can’t be used)

• Review of expired patents (technology can be used)

• Review of patent applications


Patents


Patents


Requirements


Requirements new anchor • Good penetration in hard soil, i.e. medium to dense sand and hard clays • Holding capacity similar (or higher) than that of the commercial anchors • Suitable for handling with a chaser • Stable on deck (when upside down) • Suitable for use in permanent and mobile moorings • Simple fabrication


Definition and testing of scale models


Models


Reference model


Test bed


Testing


0

100

200

300

400

500

600

700

800

900

1000

0 500 1000 1500 2000 2500 3000

Load

ach

ieve

d (k

g)

Drag Distance (mm)

Fluke Design #2

Fluke #2

Test results

Design Holding capacity [kg] Efficiency MA7#1 320 57.1 MA7#2 440 78.6 MA7#3 310 55.4 MA5P 250 41.7


Wear pattern after testing


Prototype selection


Prototype selection


Offshore Testing


Prototype anchor

• Fabrication of ± 1500 kg prototype testing

• Testing offshore Singapore

• Test with AHV


Location


Procedure


Sensor data


Testing


Testing


Test results


Structural design

DESIGN OF DRAG EMBEDMENT ANCHORS


Anchor handling

• Modern AHVs are extremely powerfull: – High bollard pull applied

during anchor installation

– Large winches used during anchor recovery

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Anchor handling

• Mobile moorings: – Anchors deployed and

recovered using chaser system

– Mooring line in contact with anchor during recovery

– Over lifetime multiple installations

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44


Anchor handling

• Permanent moorings: – Anchors generally placed

carefully on seabed – Single installation during

lifetime – High installation loads

possible

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Structural design


• The structural design must be sufficient to withstand: – The maximum holding capacity in the seabed (UPC) – Forces due to normal anchor handling, installation / recovery – Accidental situations, for example:

• Anchor stuck behind seabed obstruction • Pulling sidewards on the anchor • Dropping of the anchor

Structural design

• Carefull consideration must be given to the accidental loading conditions.

• It is not possible to predict all situations that will occur.

• It is not possible to design for all.


Final steps • Structural analysis of MA7 anchor to be completed resulting in selection of

plate thicknesses • Final relationship between anchor size (weight) and holding capacity to be

defined • Documentation to be submitted for type approval. Before that time on a

case by case basis.


The End

Questions?


References • All pictures Mooreast Asia Pte Ltd / Mooreast Europe BV unless as stated below. • Page 4, top left, http://maritime-connector.com/wiki/platforms/ • Page 4, top right, http://maritime-connector.com/wiki/platforms/ • Page 4, bottom left, http://www.sci-chain.com/?page_id=234 • Page 4, bottom right, www.maritimeconnector.com • Page 5, top left, https://en.wikipedia.org/wiki/Floating_wind_turbine#/media/File:Agucadoura_WindFloat_Prototype.jpg • Page 5, top right, Øyvind Hagen - Statoil AS • Page 5, bottom left, http://www.cenews.in/pelamis-wave-power/ • Page 5, bottom right, http://www.emec.org.uk/?attachment_id=5720 • Page 6, top left, http://nauticalarch.org/images2/gallery/main/photo_gallery1_31.jpg • Page 6, top right, Mojo Maritime Ltd • Page 6, bottom left, http://www.kolumbustours.com/images/Unterwater%20Museum/replica_of_16th_centurry_stock_anchor.JPG • Page 6, bottom right, http://www.cruisersforum.com/forums/f118/open-source-anchor-project-113732-16.html • Page 12, top left, http://www.sbmoffshore.com/wp-content/uploads/2013/09/SBMO-Glossary-_Original_2045.pdf • Page 12, top right, http://dcl-usa.com/category/product-line/anchors/ • Page 12, bottom left, www.bruceanchor.co.uk • Page 13, left, http://vryhof.com/products/anchor_data_acquisition.html • Page 13, right, http://www.bruceanchor.co.uk/products/ffts-gp/ • Page 14, top left, www.bruceanchor.co.uk • Page 14, top right, www.vryhof.com • Page 14, bottom left, www.bruceanchor.co.uk • Page 14, bottom right, www.vryhof.com • Page 16, http://billspringer.blogspot.nl/2011/03/which-anchor-holds-best-14-anchors-are.html?m=1 • Page 17, http://www.rocna.com/sites/default/files/RocnaBrochure2014.pdf • Page 18, http://www.anchorright.com.au/ • Page 43, http://www.marineinsight.com/wp-content/uploads/2013/03/Anchor-Handling-Tug-Supply-Vessel.jpg?dc5353 • Page 44, https://www.flickr.com/photos/31540804@N08/2947414642 • Page 45, Christian Romberg • Page 47, http://www.gwec.co.uk/ports-and-terminals/139/buoy-moorings


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Mooreast MA7 Anchor: Development Process Of A New … TechEvent-MooringInd/Mooreast … · Mooreast MA7 Anchor: Development Process ... • Simple fabrication . ... top right, Øyvind