General information
In heavy storms, the waves and ship motions can become so large that water flows onto the deck of a ship. This problem is known as ‘shipping of water’, ‘deck wetness’ or ‘green water loading’. The term ‘green water’ is used to distinguish between the spray (small amounts of water and foam) flying around and the real solid seawater on the deck. Because seawater is rather green than blue, the term ‘green water’ is widely used. Beside FPSOs, the green water problem is nowadays considered to be a problem for other offshore structures such as TLPs, SPARs and semi-submersibles.
In heavy storms, the waves and ship motions can become so large that water flows onto the deck of a ship. This problem is known as ‘shipping of water’, ‘deck wetness’ or ‘green water loading’. The term ‘green water’ is used to distinguish between the spray (small amounts of water and foam) flying around and the real solid seawater on the deck. Because seawater is rather green than blue, the term ‘green water’ is widely used. Beside FPSOs, the green water problem is nowadays considered to be a problem for other offshore structures such as TLPs, SPARs and semi-submersibles.
Services & Activities
The Offshore Department has a lot of expertise in the field of green water loading on FPSOs. As these should be able to survive the most critical environmental conditions occurring, green water can cause damage to their equipment and superstructure. This green water can occur at the bow, side and stern of the FPSOs and needs carefully to be taken into account in the design.
The Seakeeping Knowledge group is involved in investigations into the greenwater problems of naval vessels and merchant ships with forward speed. It contributed strongly to the investigations related to the sinking of the bulk carrier Derbyshire.
The Offshore Department has a lot of expertise in the field of green water loading on FPSOs. As these should be able to survive the most critical environmental conditions occurring, green water can cause damage to their equipment and superstructure. This green water can occur at the bow, side and stern of the FPSOs and needs carefully to be taken into account in the design.
The Seakeeping Knowledge group is involved in investigations into the greenwater problems of naval vessels and merchant ships with forward speed. It contributed strongly to the investigations related to the sinking of the bulk carrier Derbyshire.
Facilities & Tools
Green water model tests are carried out in the following MARIN facilities :
Green water model tests are carried out in the following MARIN facilities :
- Offshore Basin: DP model tests in combined current, waves and wind
- Seakeeping and Manoeuvring Basin: model tests in waves
The following tools are used to study green water loads:
Experience
The list below gives a review of green water projects carried out at MARIN:
The list below gives a review of green water projects carried out at MARIN:
- Erha FPSO (ExxonMobil/Saipem) 2001
- Jotun FPSO (Esso/Bluewater/Kvaerner) 1997
- Varg Field FPSO (SAGA/FELS) 1997
- Curlew North Sea FPSO (Maersk/AMEC/SBM) 1996
- MacCulloch FPSO (Amstrong Technology Associates/Bluewater) 1996
The list below gives a review of green water JIPs carried out at MARIN:
- CresT: Co-operative Research on Extreme Seas and their impacT
- SAFE-FLOW (2000-2004)
- FPSO Green water loading (1996-1997)
Most recent green water papers presented by MARIN
(complete overview of papers can be found under Publications)
(complete overview of papers can be found under Publications)
Calculation method to include water on deck effects
Carette, van Walree, 11th International Ship Stability Workshop ISSW, 2010
Pilot Model Tests on the ‘Green Water Concept’ for Wave Energy Conversion with Model Scale Power Take Off (PTO) Modelling
Buchner, B., Van der Schaaf, H., and Hoefakker, C.M., (MARIN), OMAE Conference, Shanghai, 2010
Model Tests and Simulations on a Wave Energy Converter Based on Inverse Offshore Engineering
B. Buchner (MARIN), Offshore Technology Conference, Houston, Texas, USA 2010, 2010
‘Inverse’ Concept: Wave Energy Generation by Motion and Green Water Maximisation
Bas Buchner and Frederick Jaouen (MARIN), OMAE Conference, Honolulu, 2009
Prediction of Extreme Wave Loads in Focused Wave Groups
Tim Bunnik (MARIN), Arthur Veldman (University of Groningen), Peter Wellens (Delft University of Technology), ISOPE Conference, Vancouver, 2008
Carette, van Walree, 11th International Ship Stability Workshop ISSW, 2010
Pilot Model Tests on the ‘Green Water Concept’ for Wave Energy Conversion with Model Scale Power Take Off (PTO) Modelling
Buchner, B., Van der Schaaf, H., and Hoefakker, C.M., (MARIN), OMAE Conference, Shanghai, 2010
Model Tests and Simulations on a Wave Energy Converter Based on Inverse Offshore Engineering
B. Buchner (MARIN), Offshore Technology Conference, Houston, Texas, USA 2010, 2010
‘Inverse’ Concept: Wave Energy Generation by Motion and Green Water Maximisation
Bas Buchner and Frederick Jaouen (MARIN), OMAE Conference, Honolulu, 2009
Prediction of Extreme Wave Loads in Focused Wave Groups
Tim Bunnik (MARIN), Arthur Veldman (University of Groningen), Peter Wellens (Delft University of Technology), ISOPE Conference, Vancouver, 2008
Other scientific publications on green water
(complete overview of theses can be found under Publications)
(complete overview of theses can be found under Publications)
Green Water on Ship-type Offshore Structures
B. Buchner, PhD-thesis Delft University of Technology, 2002
B. Buchner, PhD-thesis Delft University of Technology, 2002
Most recent green water articles written for MARIN Report
(complete overview of articles can be found under Publications)
(complete overview of articles can be found under Publications)
MARIN set to open its new Depressurised Wave Basin
MARIN Report, 2011
World’s deepest TLP becomes MARIN’s 9,000th test model!
Bas Buchner, MARIN Report, 2010
Measuring success
MARIN Report, 2009
Oasis of the Seas
Giedo Loeff, Jaap van Heerd & Reint Dallinga, MARIN report, 2009
ComFLOW used for green water assessment Ningaloo Vision FPSO
Robert Heerink, MARIN Report, 2009
MARIN Report, 2011
World’s deepest TLP becomes MARIN’s 9,000th test model!
Bas Buchner, MARIN Report, 2010
Measuring success
MARIN Report, 2009
Oasis of the Seas
Giedo Loeff, Jaap van Heerd & Reint Dallinga, MARIN report, 2009
ComFLOW used for green water assessment Ningaloo Vision FPSO
Robert Heerink, MARIN Report, 2009
Contact
For more information on how MARIN can help your organisation with green water, please contact the Offshore Department for offshore structures or the Ships Seakeeping knowledge group .
For more information on how MARIN can help your organisation with green water, please contact the Offshore Department for offshore structures or the Ships Seakeeping knowledge group .