Communication between Dynamic Positioning System and Power Management System What is needed? DOCUMENT HISTORY Revision Index Chapter Description of changes Prepared Checked Approved Date 01 Document first issue KH/HMA 2012-04-25 02 Updated KH/HMA 2013-02-02
INDEX 1 INTRODUCTION...3 1.1 INTENTION AND SCOPE...3 1.2 NOTICE...3 1.3 ABBREVIATIONS AND DEFINITIONS...3 1.4 RELATED DOCUMENTS...3 2 GENERAL...5 2.1.1 The redundancy aspect...6 2.1.2 List of HMA vessels not having communication between DP and PMS...8 2.1.3 Contact details...9 Page 2/9
1 Introduction 1.1 Intention and scope The intention of this document is to emphasize and support the fact that DP systems and the PMS systems should be independent from each other rather than connected together. This document further describes in text and pictures the use of a non-existing communication between the DP system and the PMS. At last but not least there is a list of vessels showing the vessels delivered with HMA PMS that do not have any communication what so ever, between the DP and PMS. These systems are working independently. 1.2 Notice The information in this document is subject to change without notice and should not be construed as a commitment by Høglund Marine Automation AS. HMA will not and cannot be held responsible for any changes that might occur. Copyright 2012 Høglund Marine Automation AS. 1.3 Abbreviations and definitions HMA DP PMS DP MTBF Høglund Marine Automation AS Dynamic positioning System Power Management System Dynamic Positioning Mean Time Between Failure 1.4 Related documents Document identity Title Page 3/9
ANY INTERFACE REQUIERED? Page 4/9
2 General Due to the fact that some companies want to mystify this subject in order to deliver an integrated DP-PMS- ICAS solution, a demand for this clarification document has risen. There is a huge misunderstanding in this subject to day. Many engineers among ship owners and yards believe that a communication between the DP and the PMS is crucial for a safe operation of the vessel. This is mainly caused by lack of detailed knowledge and experience in this field. The truth is: NO INTERFACE FROM PMS TO DP IS NEEDED AT ALL! How is this possible? The only signals needed by the DP, is the power signals from each generator. In a systems with a bus tie breaker, a connected signal from bus tie is also needed. For many decades there have been delivered systems with the demand for generator power information. It became a common practice to install several power transducers in the switchboard for this information. The reason for this is that in the early days, it was each consumer that had to limit its own power and protect the generators from overload. Typically this have been done for propellers (pitch controlled) compressors, pumps, drilling drives, and other large consumers. All this consumers would get an own generator power signal for load control. This was also the case with the first DP systems as diesel electric propulsion become more common. The DP system got its own power converter for each generator, and in some cases also the connect signal from the breaker. The connect signal from the breaker is not necessary, as the power signal will give a clear indication on the status of the generator breaker, because the power signal will be above zero KW when it is connected. There are other PMS information that might be sent from the PMS to the DP, however most of the installed DP systems do not need such information for operating. This information must be understood as nice to have only. Page 5/9
2.1.1 The redundancy aspect The DP system is 100% dependent of the load status of the generators in order to operate. If this information is sent to the DP system from the PMS, the total operation of the vessel is dependent on a fully operational PMS. Any failure of the PMS or any PMS component will be crucial for the DP, as the generator power load situation will be uncertain. MTBF figures for the DP will drop significantly due to the dependency of a fully operating PMS. Page 6/9
The only way to maintain safe DP operation independent of PMS, is with total separation of the signal interface, In addition to the necessary power information there are additional information that might be sent between the PMS and the DP: PMS to DP Number of available generators in the system Critical failures in a running generator Any load limitations on the connected generators Status of other essential consumers requesting power DP to PMS DP out of position Requested power Force preference trip All this information is optional and rarely used, and may be sent via standard I/O signals, or a simple NMEA or Modbus line. Page 7/9
2.1.2 List of HMA vessels not having communication between DP and PMS There are hundreds of vessels in operation to day, where there is no communication between the DP and the PMS. The following list just shows some of this vessels where HMA has been involved in delivering the PMS. None of the following vessels have any communication between DP and PMS. Vessel Shipyard Owner Type Crystal Sea (BW Carmen) Aker Langsten DOF (BW Offshore) FPSO Sea Launch Rig Kværner Rosenberg Kværner Launch Rig Sea Launch Ship Kværner Rosenberg Kværner Launch Support Vessel Fresnel Ulstein Verft Diesel Electric Cable Layer Crystal Ocean Kvaerner Govan Brøvig Diesel Electric Offshore Vessel Bideford Dolphin Harland Wolf Fred Olsen Energy Drilling Rig Normand Cutter Ulstein Verft Solstad Offshore Cable layer Yatzy Boelverf, Belgium Dimond Drilling Oil Rig Skandi Carla Aker Aukra DOF ROV IRM Normand Clipper Ulstein Verft Solstad Offshore Cable layer Stril Poseidon Aker Langsten Møkster Standby Vessel Tulpar Ulstein Verft BUE Marine UK Ice Supply Seaway Petrel Aker Yards, Brattvaag Uksnøy Petrel AS Diesel Electric Offshore Vessel Skandi Sotra Myklebust DOF Diesel Electric Offshore Vessel Viking Avant Aker Langsten Eidesvik Supply Bibby Sapphire Aker Langsten Volstad Diesel electric ROV Vessel Strilmøy Aker Langsten Møkster Diesel Electric Supply Havila Harmony Havyard Havila Diesel electric Supply Vessel Siem Louisa Aker Aukra Siem Offshore Supply Siem Danis Aker Aukra Siem Offshore Supply SBS Typhoon Aker Aukra SBS Marine Supply Pacific Endurance Aker Langsten Prisco Swire Offshore Diesel Electric Ice supply Pacific Enterprise Aker Langsten Prisco Swire Offshore Diesel Electric Ice supply Siem Sophie Aker Langsten Siem Offshore Supply Stril Odin Aker Langsten Møkster Diesel Electric Supply Far Swan (prev Sical Torino) Aker Langsten Siem Offshore Supply Pacific Endeavour Aker Yards, Langsten Prisco Swire Offshore Diesel Electric Ice supply Lewek Atlas (ex Siem Mollie) Aker Aukra Siem Offshore Supply Siem Hanne Aker Aukra Siem Offshore Supply Ocean Protector (Skandi Bergen) Aker Aukra DOF ROV Skandi Commander Fitjar Mekaniske Verksted DOF Diesel electric Supply Vessel Bibby Topaz Fosen Mekaniske Verksted Volstad Diesel Electric Offshore Vessel Volstad Supplier Aker Yards, brattvåg Volstad Diesel electric Supply Vessel Skandi Acergy Søviknes Verft DOF Offshore Construction Volstad Princess Aker Brattvaag Volstad Shipping Offshore Vessel Skandi Salvador Aker Promar DOF Offshore Vessel Skandi Brazil Aker Promar DOF Offshore Vessel B129 Aker Søviknes DOF Offshore Vessel Page 8/9
Seabed Worker Fjellstrand Multipurpose vessel Skandi Arctic STX Søviknes Doftech DA Diving vessel Skandi Salvatore Fittjar Mek DOF Offshore Vessel Skandi Flora Aker Aukra DOF Offshore Vessel Skandi Vitoria Aker Promar DOF Offshore Vessel Atlantis Dweller WestCon Møkster ROV/Diving Lewik Atria (Trico Star) Tebma Shipyard, India Emas Offshore VS470 MK2 Supply Abyss Dweller WestCon Møkster VS470 MK2 Tebma Shipyard, India Trico Marine VS470 MK2 Supply West Epsilon Seadrill Upgrade IAS-F&G-ESD Stril Merkur Astilleros Gondan Simon Møkster Shipping VS-482.II FSV Stril Orion STX Søviknes Simon Møkster Shipping PSV Stril Polar STX Søviknes Simon Møkster Shipping PSV SCI Pawan Cochin AHTS Skandi Sotra Bergen DOF Uppgrade IAS-PMS SCI Kundan Cochin AHTS BW Athena BW Offshore FPSO - Upgrade Cargo Control VS470 MK2 Tebma Shipyard, India Trico Marine VS470 MK2 Supply 2.1.3 Contact details Høglund Marine Automasjon AS Carl XV`s gate 19 N-3150 Tolvsrød Norway Telephone: +47 33 41 41 50 Page 9/9