Experiments by Invited Researchers


Arctic Production and Tandem Offloading Terminal - ATOT

Project acronym: HyIII-HSVA-01
Name of Group Leader: Prof. Sveinung Løset, Norwegian University of Scie
User-Project Title: Arctic Production and Tandem Offloading Terminal - ATOT
Facility: Large Ice Model Basin (LIMB)
Proceedings TA Project: Ice basin testing of a moored offloading icebreaker in variable ice drift: innovations and new findings
Data Management Report: There is no Data Management Report available for this project

User-Project Objectives


The experiments were carried out in June/July 2007 in the Large Ice Model Basin at HSVA ARCTECLAB.
The model testing in a scale at 1:24 showed that the Offloading Icebreaker (OIB):

  • stayed on moored in all level ice conditions and ridges
  • operates in tight ice conditions and rubble fields
  • was challenged with heading keeping and stability in severe ice ridges

Arctic shuttle tanker and OIB penetrating into a ridgeFurther, the model testing showed:

  • The tandem mooring loads were higher in ridges than in level ice when
    the ice drift was straight.
  • The capacity of the winches was overloaded once, due to large tandem
    mooring forces induced by interaction between the tanker and a ridge.
  • The OIB pitched significantly in the ridges and the effects of the reamers
    were reduced. This caused high tandem mooring forces during ridge interaction.
  • The model of the full scale tandem mooring system did not work well
    with respect to mooring loads when there was relative yaw between the
  • The ice-vaning of the tanker was efficiently when there was a slow change of ice drift
    direction, but over steered the OIB before OIB and tanker aligned.

In short term the results from this project will benefit the work of one post doc, one student in his doctoral
studies and two master students. In longer term the work will contribute to a safer and more cost-effective
export of hydrocarbons from cold waters. In this way the applicability of these results extend far beyond the
present user group.

Three papers have been published in the Proceedings of the 19th IAHR International Symposium on Ice , 6-11 July 2008, Vancouver, Canada