The 1999 Station Keeping Seminar - the eighth in the series - proved a great success. More than 150 participants from around the world gathered to hear and discuss cutting edge developments in DP operations. The event was organised in collaboration with the prestigious French industry association GEP - Groupement des Entreprises Parapétrolières et Paragazières - at the Maison de la Mécanique in the La Défense area of Paris. The first day was chaired by Hervé Lomenech of Elf and the second day by Christian Plé of TotalFina.

The first day was dominated by power management questions and the frequency of problems on existing vessels. However from incident data it appears that thruster problems are more likely to cause a position loss than power management. The second day revisited the ionospheric interference problem raised dramatically last year at the Rio seminar.

The presentation in Paris from Owen Goodman on Combating Ionospheric Interference with DGPS provided insights into Fugro's approach to mitigating but not eliminating the problem. Angus Cooper of Racal Survey spoke from the floor on the action his company was taking and both participated in the Position Reference workshop.

The loss of the GPS signal for up to four hours at a time forces the rigs to rely on acoustic positioning reference systems and/or riser inclination measurements. A clear need was seen for an additional deep water reference system during such periods when GPS is not available.

The potential to use inertial navitation for position fixes was explained by Jeff Burns of Nauticos, again with useful inputs from the floor from Keith Vickery of Sonardyne. As with any inertial navigation system, the certainty of the fix deteriorates with time but these systems clearly show promise for meeting the need. In both instances the presence of the key manufacturers and system users on the platform and in the audience made for lively debates.

Graeme Gardner gave a good insight into a DP FPSO with a non-DP offtake, and Bob Bishop and Joe Hughes presented the work of Intertanko with respect to tanker offtake and outlined the proposed future activities of the Independent Tanker Owners Association in this area and the interaction envisaged with the OCIMF and IMCA guidance.

Seminar Papers

• Trends in DP Incidents
  Chris Jenman - Global Maritime
• IMCA Power Management Study
  Peter Napier and Steven Cargill - Poseidon Maritime
• Simulation of Electrical Power Problems
  Bjørn Bungum - Unitech
• Successful DP Class 3 Drillship Construction
  D Y Moon - Samsung Heavy Industries
• Electrical Installation on a DP Class 3 Semi-submersible
  Gilbert Beraud and M Gautier - Groupe SNEF
• Converting the 450ft Derrick Lay Barge Polaris to DP Class 3
  Charles Magloire - ETPM
• Practical Experience of FPSO and Offtake Tanker Station Keeping
  Graeme Gardner - Northern Marine Management
• DP Model Testing: Purpose, Experience and Limitations
  Radboud van Dijk - MARIN
• The Work of Intertanko with Respect to Tanker Offtake
  Robert Bishop and Joe Hughes - Intertanko
• Combating the Ionospheric Interference of DGPS
  Owen Goodman - Fugro NV
• Potential of Inertial Navigation for DP
  Jeff Burns - Nauticos
• An Alternative Acoustic System
  Frédéric Rybicki - Thomson Marconi Sonar

Workshops

A number of workshops were also held, summarised in this fascinating document, on the following subjects:

• The Purpose and Practice of Annual DP Trials on DP Vessels
• QA Systems for Software on DP Vessels
• Delegates' Choice: Class 2 vs. Class 3/Networks
• DP and Position Reference Training
• Contingency Planning for Y2K
• Delegates' Choice: Position Reference Systems