General information
In ship design, crabbing (i.e. traversing) is the ability of ships to move sideways while controlling the forward motion. This manoeuvre can be induced by using a combination of main propellers, pods, rudders, lateral thrusters or other dedicated devices. A reduction of berthing-unberthing time, an increase of safety and agility, less need for tug assistance are only few examples of the benefits related to good crabbing abilities.
In ship design, crabbing (i.e. traversing) is the ability of ships to move sideways while controlling the forward motion. This manoeuvre can be induced by using a combination of main propellers, pods, rudders, lateral thrusters or other dedicated devices. A reduction of berthing-unberthing time, an increase of safety and agility, less need for tug assistance are only few examples of the benefits related to good crabbing abilities.
Services & Activities
At the Manoeuvring Department crabbing performances are investigated by means of captive model testing generally performed in the Shallow Water Basin where the water depth can be adjusted to the desired conditions and quays can be modelled with walls or customised structures. Computer tools based on extensive sets of empirical data are available.
The side forces developed by the model are measured and compared with the forces the hull has to withstand (wave impact loads, wind loads, current loads, etc.) High forces and moments must be generated during crabbing to counteract currents, wind and waves. This application is therefore most interesting for ships that benefit from these large forces such as Car and passenger ferries, Cruise vessels, RoRo ships or Work vessels.
At the Manoeuvring Department crabbing performances are investigated by means of captive model testing generally performed in the Shallow Water Basin where the water depth can be adjusted to the desired conditions and quays can be modelled with walls or customised structures. Computer tools based on extensive sets of empirical data are available.
The side forces developed by the model are measured and compared with the forces the hull has to withstand (wave impact loads, wind loads, current loads, etc.) High forces and moments must be generated during crabbing to counteract currents, wind and waves. This application is therefore most interesting for ships that benefit from these large forces such as Car and passenger ferries, Cruise vessels, RoRo ships or Work vessels.
Facilities & Tools
Crabbing studies are carried out in the following MARIN facilities:
Crabbing studies are carried out in the following MARIN facilities:
The following tools are used to study crabbing issues:
CRABSIM: Calculation of harbour manoeuvres
BOTHRUS: Bow thruster forces for manoeuvring
DPCAP: Analysis of thruster capacity in dynamic positioning
SHIPMA: Simulation of ships in ports or fairways (pdf)
BOTHRUS: Bow thruster forces for manoeuvring
DPCAP: Analysis of thruster capacity in dynamic positioning
SHIPMA: Simulation of ships in ports or fairways (pdf)
Software Sales
Some software tools are available for commercial use outside MARIN. A complete overview of these software tools for sale can be found under Software Sales.
Some software tools are available for commercial use outside MARIN. A complete overview of these software tools for sale can be found under Software Sales.
Experience
The list below gives a review of crabbing projects carried out at MARIN:
The list below gives a review of crabbing projects carried out at MARIN:
- USCG WSML National Security Cutter (Northrop Grumman Ship Systems), 2005
- Cruise liner Queen Mary 2 (Chantiers de l'Atlantique), 2002
- NYK Cruise vessel (Chantiers de l'Atlantique), 2002
- RoPax ferry (Hyundai), 2001
- Cruise ships with pods (Fincantieri), 2000
- Cruise vessel Millennium (Chantiers de l'Atlantique), 1999
- Cruise liner New Rotterdam (Fincantieri), 1999
Most recent crabbing papers presented by MARIN
(complete overview of papers can be found under Publications)
(complete overview of papers can be found under Publications)
Hydrodynamics of large motor yachts: Past experience and future developments
Gaillarde, G., Toxopeus, S.L., Verwoest, T.F. and Hooijmans, P.M., ATMA - Association Technique Maritime et Aeronautique, Paris, France, 2004
Manoeuvring of megayachts: performance through model testing
Toxopeus, S.L., The Yacht Report, Issue 49, 2002
Prediction of crabbing in the early design stage
Quadvlieg, F.H.H.A and Toxopeus, S.L., PRADS'98 7th International Symposium on Practical Design of Ships and Mobile Units, 1998
Gaillarde, G., Toxopeus, S.L., Verwoest, T.F. and Hooijmans, P.M., ATMA - Association Technique Maritime et Aeronautique, Paris, France, 2004
Manoeuvring of megayachts: performance through model testing
Toxopeus, S.L., The Yacht Report, Issue 49, 2002
Prediction of crabbing in the early design stage
Quadvlieg, F.H.H.A and Toxopeus, S.L., PRADS'98 7th International Symposium on Practical Design of Ships and Mobile Units, 1998
Most recent crabbing articles written for MARIN Report
(complete overview of articles can be found under Publications)
(complete overview of articles can be found under Publications)
Measuring success
MARIN Report, 2009
Oasis of the Seas
Giedo Loeff, Jaap van Heerd & Reint Dallinga, MARIN report, 2009
Queen of the North Atlantic
Serge Toxopeus, Wim van den Berg & Reint Dallinga, MARIN Report, 2001
MARIN Report, 2009
Oasis of the Seas
Giedo Loeff, Jaap van Heerd & Reint Dallinga, MARIN report, 2009
Queen of the North Atlantic
Serge Toxopeus, Wim van den Berg & Reint Dallinga, MARIN Report, 2001
Contact
For more information on how MARIN can help your organisation with crabbing, please contact the Manoeuvring Department.
For more information on how MARIN can help your organisation with crabbing, please contact the Manoeuvring Department.