General information
A Spar is a vertical floating platform which is moored with a semi-taut or taut mooring system. There are different riser options to provide the flow from the seabed to the Spar, from Top Tensioned Risers (TTRs) to Steel Catenary Risers (SCRs). The Spar is able to support drilling as well as production activities at the same time. The family of Spars consists of Classical Spars (completely cylindrical), Truss Spars (cylindrical at the top, truss frame at the bottom) and Cell Spars (A number of vertical cylinders).

Services & Activities
The Offshore Department has performed a lot of tests on Spars in recent years. The in-place behaviour during hurricanes was investigated to study wave run up and green water problems.

During tests of the horizontal tow of the platform to the field the wave loads on the heave plates in the truss were the main subject of investigations.

Finally the Vortex Induced Motions (VIM) of Spars has been the subject of a lto of investigations of towing tests in the Depressurised Towing Tank. This is an important problem for Spars in the loop current in the Gulf of Mexico. For testing Vortex Induced Motions (VIM), this tank is specially suited due to its long tow length and large cross section (main dimensions: 240 x 18 x 8 m). Uniform current flow is simulated by towing the Spar model in calm water. During these tests the effectivity of VIM reduction devices such as helical strakes is detemrined and optimised.

The Trials & Monitoring Department can be involved in full-scale measurements on Spar platforms. Spar motions and mooring line loads can be measured and analysed.

Facilities & Tools
Spars are tested in the following MARIN facilities :

The behaviour of spars is simulated with the following tools: (DIFFRAC, DRIFTP and DYNFORC for MARIN internal use only)

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 record
The list below gives a review of spar model tests carried out at MARIN :

  • Perdido Regional Host Spar (Technip/Shell, 2006)
  • Tahiti Spar (Technip/Chevron, 2004)
  • Genesis Spar (Technip/Chevron, 2003)
  • Mad Dog Spar (Technip/BP, 2002)
  • Holstein Spar (Technip/BP, 2002)
  • Murphy Medusa Spar (McDermott/Murphy, 2001)
  • King Spar (BP Amoco, 1999)
Most recent papers on spars presented by MARIN
(complete overview of papers can be found under Publications)

A Study on Simplified Loading Models for Vertical Wave-in-deck Loading
Jule Scharnke, Wim Lafeber , ISOPE 26th International Ocean and Polar Engineering Conference, Rhodes, Greece, 2016

Scaling Methodology for Floating Wind Turbines
S├ębastien Gueydon (MARIN), Gerson Fernandes (MARIN Academy), EWEA, 2013

The Dynamic Response Of An Offshore Wind Turbine With Realistic Flexibility To Breaking Wave Impact
Erik Jan de Ridder, Pieter Aalberts Joris van den Berg, Bas Buchner (MARIN), Johan Peeringa (ECN), 30th International Conference on Ocean, Offshore and Arctic Engineering (OMAE), Rotterdam, The Netherlands, 2011

Floating wind turbine motion assessment; Numerical simulation results compared to model test measurements
S├ębastien Gueydon (MARIN), Wei Xu (MARIN-USA), OCEANS, 2011

Flow Induced Motions of Multi Column Floaters
Olaf J.Waals (MARIN), Amal C. Phadke (ConocoPhillips) and Stephen Bultema (Bultema Marine), OMAE Conference, San Diego, 2007

Most recent Spar articles written for MARIN Report
(complete overview of articles can be found under Publications)

Aasta Hansteen - Bridging engineering to operations
MARIN Report, 2015

New SCR capable Disconnectable Mooring System tested for SBM Atlantia
Remmelt van der Wal & Arjan Voogt, MARIN Report, 2008

MARIN conducts Thunder Hawk VIM testing
Remmelt van der Wal, MARIN Report, 2007

A valuable sparring partner for Spars
Olaf Waals, MARIN Report, 2006

Spar Vortex Induced Motion in current and waves towing tank
Radboud van Dijk, MARIN Report, 2005

For more information on how MARIN can help your organisation with spars, please contact:

For model test and simulation activities: Offshore Department
For full scale measurements: Trials and Monitoring Department

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