DOCSLIB.ORG

Dynamic Positioning During Heavy Lift Operations

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Dynamic Positioning during Heavy Lift Operations Using fuzzy control techniques, Nonlinear Observer and H-Infinity Method Separately to Obtain Stable DP Systems for Heavy Lift Operations J. Ye Thesis for the degree of MSc in Marine Technology in the specialization of DPO – Marine Engineering Dynamic Positioning during Heavy Lift Operations By Jun Ye Performed at RH Marine This thesis (SDPO.16.007.m.) is classified as confidential in accordance with the general conditions for projects performed by the TUDelft. 31.03.2016 Company supervisor Responsible supervisor: E. El Amam Daily Supervisor(s): E. El Amam E-mail: [email protected] Thesis exam committee Chair/Responsible Professor: Prof. ir. J.J. Hopman Staff Member: Dr M. Godjevac Staff Member: Dr. R.R. Negenborn Company Member: E. El Amam Author Details Studynumber: 4274830 Author contact e-mail: [email protected] Summary Dynamic positioning has been developed for over half a century and is now widely used on board. However, the existing dynamic positioning system is not specially made with heavy lift vessels. This report is to solve the dynamic positioning problem during heavy lift operations. To fulfill this goal, the robustness and stability of the solutions are also considered. The solutions mentioned in this report are based on the RH Marine vessel model and the RH Marine dynamic positioning system. First the crane vessel model is reviewed and checked. Then the solutions are chosen and applied. At last the results are presented and analyzed. The stability of each solution is approached and the robustness of each solution is tested in Simulink. There are three solutions in this thesis. Fuzzy controller, nonlinear passive observer and H-infinity controller are implemented to the original system separately. For first two solutions, there’s no theoretical proof that they are robust. For H-infinity controller, it is proven to be robust. All three solutions showed good robustness under tests. This report, as a master thesis, is to present the dynamic positioning problem to the reader and to provide possible solutions to the heavy lift dynamic positioning problem. i Table of Content Summary .................................................................................................................................................. i 1 Introduction ..................................................................................................................................... 1 Crane Vessels ....................................................................................................................... 1 Offshore Heavy Lifting ........................................................................................................ 2 Dynamic Positioning ............................................................................................................ 4 Structure of the Thesis ......................................................................................................... 6 2 Problem of Dynamic Positioning during Heavy Lift Operations and Current Solutions ................ 6 Problem of Dynamic Positioning during Heavy Lift Operations......................................... 7 Current Solutions ............................................................................................................... 10 2.2.1 Current Solutions in Practice .................................................................................. 10 2.2.2 Current Solution in Theory ..................................................................................... 12 Conclusion ......................................................................................................................... 12 3 Modelling of the Vessel and Simulation of the Problem .............................................................. 13 Simulation Model .............................................................................................................. 13 3.1.1 Reference Frames ................................................................................................... 13 3.1.2 Low Frequency Vessel Model ................................................................................ 14 Simulation of the Heavy Lift Mooring Problem ................................................................ 15 3.2.1 Under Seastate 0 ..................................................................................................... 16 3.2.2 Under Seastate 3 ..................................................................................................... 18 3.2.3 With Setpoint Changed ........................................................................................... 19 Conclusion ......................................................................................................................... 21 4 Possible Solutions and Candidate Solutions ................................................................................. 21 Possible Solutions .............................................................................................................. 21 4.1.1 Improve the Observer ............................................................................................. 22 4.1.2 Improve the controller ............................................................................................ 27 4.1.3 Other Solutions ....................................................................................................... 30 Candidate Solutions ........................................................................................................... 32 4.2.1 Load estimator with a fuzzy controller ................................................................... 32 4.2.2 Nonlinear passive observer ..................................................................................... 33 4.2.3 H-infinity controller ................................................................................................ 33 ii 4.2.4 Auxiliary solution: AGC ........................................................................................ 33 Conclusion ......................................................................................................................... 33 5 Implementation of Candidate Solutions ........................................................................................ 34 Fuzzy PID Controller ......................................................................................................... 34 5.1.1 Calculations of mooring stiffness ........................................................................... 34 5.1.2 Load estimator ........................................................................................................ 37 5.1.3 The fuzzy logic ....................................................................................................... 39 5.1.4 Pole Placement Design ........................................................................................... 41 5.1.5 Fuzzy logic ............................................................................................................. 43 Nonlinear Passive Observer ............................................................................................... 45 5.2.1 Observer Model ...................................................................................................... 45 5.2.2 The Tuning of the Nonlinear Passive Observer ...................................................... 46 H-infinity Control Method ................................................................................................. 48 5.3.1 H-infinity Control Method ..................................................................................... 48 5.3.2 H-infinity for crane vessels..................................................................................... 49 5.3.3 Implementation of H-infinity controller ................................................................. 50 6 Results of Implemented Candidate Solutions ............................................................................... 50 Results of the Fuzzy PID Controller .................................................................................. 51 6.1.1 Under Seastate 0 ..................................................................................................... 51 6.1.2 Under Seastate 3 ..................................................................................................... 54 6.1.3 Analyze of the results ............................................................................................. 56 Performance of the Observer ............................................................................................. 56 6.2.1 Performance of Nonlinear Passive Observer in Simulation ................................... 56 6.2.2 Comparing Experiment .......................................................................................... 63 6.2.3 Conclusion of Nonlinear Passive Observer ............................................................ 71 Performance of H-infinity Controller ................................................................................ 71 6.3.1 Under Seastate 0 ..................................................................................................... 71 6.3.2 Under Seastate 3 ..................................................................................................... 73 6.3.3 Analyze of H-infinity Controller ............................................................................ 74 Comparison
Recommended publications
  • Det Norske Veritas

    Det Norske Veritas

    DET NORSKE VERITAS Report Heavy fuel in the Arctic (Phase 1) PAME-Skrifstofan á Íslandi Report No./DNV Reg No.: 2011-0053/ 12RJ7IW-4 Rev 00, 2011-01-18 DET NORSKE VERITAS Report for PAME-Skrifstofan á Íslandi Heavy fuel in the Arctic (Phase 1) MANAGING RISK Table of Contents SUMMARY............................................................................................................................... 1 1 INTRODUCTION ............................................................................................................. 3 2 PHASE 1 OBJECTIVE..................................................................................................... 3 3 METHODOLOGY ............................................................................................................ 3 3.1 General ....................................................................................................................... 3 3.2 Arctic waters delimitation .......................................................................................... 3 3.3 Heavy fuel oil definition and fuel descriptions .......................................................... 4 3.4 Application of AIS data.............................................................................................. 5 3.5 Identifying the vessels within the Arctic.................................................................... 6 3.6 Identifying the vessels using HFO as fuel.................................................................. 7 4 TECHNICAL AND PRACTICAL ASPECTS OF USING HFO
  • Problems of Handling Ships Equipped with Azipod Propulsion Systems

    Problems of Handling Ships Equipped with Azipod Propulsion Systems

    PRACE NAUKOWE POLITECHNIKI WARSZAWSKIEJ z. 95 Transport 2013 Lech Kobyliski Foundation for Safety of Navigation and Environment Protection PROBLEMS OF HANDLING SHIPS EQUIPPED WITH AZIPOD PROPULSION SYSTEMS The manuscript delivered, March 2013 Abstract: Large ships, mainly large cruise vessels, built during last two decades are quite often equipped with revolutionary propulsion devices known under the name AZIPODs. There are many reasons for choosing AZIPODs as main propulsion units, the main reason being excellent manoeuvring characteristics achieved. However in case of large propulsion units, having power of 15-25 MW, used for propulsion there are also some disadvantages and limitations, the last mainly related to operational factors. Handling of ships equipped with AZIPODS is different from handling conventional ships and in certain manoeuvring situations safety of the ship and of the propulsion units might be endangered.. Therefore some limitations imposed on handling procedures are necessary and it is essential that pilots and masters of ships fitted with AZIPODs must be specially trained. Keywords: ship manoeuvrability, podded propulsion, handling of ships with Azipods 1. INTRODUCTION During recent times the new type of vessel has been introduced to the world shipping fleet in large numbers. This type is passenger cruise vessel. Statistics of ships in operation and on order reveals that more than 750 ships of different size that could be defined as cruise ships are recently in operation, more than about 50 of them are large ships of more than 250 metres in length and carrying sometimes as much as 6000 passengers. According to the definition cruise ship is usually a very large passenger ship that makes a roundtrip with several en route stops and takes passengers only at the port where trip begins and ends.
  • Optimal Thrust Allocation Methods for Dynamic Positioning of Ships

    Optimal Thrust Allocation Methods for Dynamic Positioning of Ships

    Delft University of Technology Faculty of Electrical Engineering, Mathematics and Computer Science Delft Institute of Applied Mathematics Optimal Thrust Allocation Methods for Dynamic Positioning of Ships A thesis submitted to the Delft Institute of Applied Mathematics in partial fulfillment of the requirements for the degree MASTER OF SCIENCE in APPLIED MATHEMATICS by CHRISTIAAN DE WIT Delft, the Netherlands July 2009 Copyright © 2009 by Christiaan de Wit. All rights reserved. MSc THESIS APPLIED MATHEMATICS “Optimal Thrust Allocation Methods for Dynamic Positioning of Ships” CHRISTIAAN DE WIT Delft University of Technology Daily supervisor Responsible professor Dr. J.W. van der Woude Prof. dr. K.I. Aardal Other thesis committee members M. Gachet, Ingenieur ENSTA Dr. R.J. Fokkink July 2009 Delft, the Netherlands Optimal Thrust Allocation Methods for Dynamic Positioning of Ships Christiaan de Wit July 2009 Environment from Abstract The first Dynamic Positioning (DP) systems emerged in the 1960’s from the need for deep water drilling by the offshore oil and gas industry, as conventional mooring systems, like a jack-up barge or an anchored rig, can only be used in shallow waters. GustoMSC has been developing DP drill ships since the early 1970’s and it is still one of their core businesses. DP systems automatically control the position and heading of a ship subjected to environmental and external forces, using its own actuators. The thrust allocator of a DP system is responsible for the thrust distribution over the actuators of the ship. Apart from minimizing the power consumption an ideal thrust allocator can also take other aspects into account, such as forbidden/spoil zones and thruster relations.
  • Integrating INS and GNSS Sensors to Provide Reliable Surface Positioning

    Integrating INS and GNSS Sensors to Provide Reliable Surface Positioning

    Author’s Name Name of the Paper Session DYNAMIC POSITIONING CONFERENCE October 9-10, 2012 SENSORS I SESSION Integrating INS and GNSS Sensors to Provide Reliable Surface Positioning By David Russell VERIPOS David Russell, VERIPOS Integrating INS and GNSS Sensors to Provide Reliable Surface Positioning ABSTRACT The ideal surface positioning system will provide a constant, stable, accurate and repeatable position in real-time which is essential to safe and productive operations. In perfect conditions, GNSS along with augmentation data can deliver this performance and with the modernization of existing constellations and the imminent arrival of new satellite constellations the performance and availability of GNSS should improve. However, while additional observations will be available, the satellite signals are still susceptible to effects of ionosphere scintillation and interference whether intentional or un-intentional plus signal blockage can occur when working close to platforms and this will result in degraded positioning. Inertial Navigation involves determining a position through dead reckoning using gyros and accelerometers to calculate changes in position, velocity and attitude. Inertial Navigation Systems (INS) are completely self contained and inherently robust providing output with exceptional good short term accuracy but the position accuracy will drift with time. INS and GNSS are complementary sensors and when combined can deliver constant, stable, accurate and repeatable positioning. The integration of GNSS and inertial technologies exploits the long term accuracy and precision characteristics of GNSS positioning with the continuous availability and fast update rate of inertial sensors. The resulting integrated system can bridge GNSS disruptions (e.g. ionospheric scintillation, physical obstructions, etc.) as well as detecting position outliers due to common mode failures which can affect vessel GNSS systems simultaneously which is particularly advantageous for DP operations.
  • DYNAMIC POSITIONING ACCREDITATION and CERTIFICATION SCHEME STANDARD January 2017

    DYNAMIC POSITIONING ACCREDITATION and CERTIFICATION SCHEME STANDARD January 2017

    DYNAMIC POSITIONING ACCREDITATION AND CERTIFICATION SCHEME STANDARD Effective Date 1st January 2017 DISCLAIMER While every effort has been made to ensure that all the information in this document is updated and correct, The Nautical Institute cannot be held responsible for any loss, financial or otherwise, direct or indirect, resulting from use of this information. Likewise, The Nautical Institute cannot be held responsible for any damage to property, trainers or operators while following these guidelines. This information is produced in good faith, but we cannot guarantee the accuracy and/or completeness of the information which is produced for guidance purposes only. DYNAMIC POSITIONING ACCREDITATION AND CERTIFICATION SCHEME STANDARD January 2017 © The Nautical Institute 2016 202 Lambeth Road, London, SE1 7LQ - United Kingdom Tel: +44 (0) 207 928 1351 Fax: (0) 207 401 2817 www.nautinst.org www.nialexisplatform.org DPACCSTD-v1.1-Jan 2017 CONTENTS 1. INTRODUCTION TO THE DYNAMIC POSITIONING OPERATOR TRAINING STANDARD ........................... 2 2. OFFSHORE TRAINING SCHEME ............................................................................................................ 6 3. SHUTTLE TANKER TRAINING SCHEME ................................................................................................ 10 4. ACCREDITATION ................................................................................................................................ 13 APPENDIX A - MINIMUM QUALIFICATION REQUIREMENT ............................................................................
  • Saipem Constellation Ultra-Deep Water Rigid & Flexible Pipelay, Heavy Lift, Construction Dp 3 Vessel Saipem Constellation

    Saipem Constellation Ultra-Deep Water Rigid & Flexible Pipelay, Heavy Lift, Construction Dp 3 Vessel Saipem Constellation

    VESSEL SAIPEM CONSTELLATION ULTRA-DEEP WATER RIGID & FLEXIBLE PIPELAY, HEAVY LIFT, CONSTRUCTION DP 3 VESSEL SAIPEM CONSTELLATION ULTRA-DEEP WATER RIGID & FLEXIBLE PIPELAY, HEAVY LIFT, CONSTRUCTION DP 3 VESSEL VERSATILITY CAPABILITY RELIABILITY HIGH MANOEUVRABILITY ULTRA-DEEP WATER RIGID DP 3, ICE CLASS, HELIDECK AND TRANSIT SPEED REELED/ FLEXIBLE PIPELAY, HEAVY LIFT AND CONSTRUCTION TECHNICAL SPECIFICATIONS* MAIN FEATURES DYNAMIC POSITIONING PIPELAY EQUIPMENT Length overall: 178 m DP 3 system: Kongsberg K-Pos DP Type: combined pipelay tower for reel Moulded breadth: 46 m Position Reference Interface lay and flex lay over a moon pool Moulded depth: 15 m Taut Wire Tensioners: 2 x 400 t (rigid) Draft max.: 10.5 m summer draft 3 DGPS or 2 x 260 t Pipelay type: rigid and flex systems, 1 x Radius Hang-off module: 900 t through moon pool 1 x Spot Track Pipe storage: 8 x 1,200 t reels Pipelay capacity: rigid: 4” - 16” OD Acoustic Reference: 2 for rigid pipe (4 onboard – 4 ashore) flexible: 4” - 24” OD Gyro: 3 2 x 1,250 t under-deck carousels Anemometer: 3 for flexible pipe CLASSIFICATION VRU: 3 A&R system: 2 x 600 t traction winches Det Norske Veritas single or tandem use through moonpool DNV 1A1 Ship Shaped Pipelaying Vessel, POWER GENERATION single through STBD AHC Fairlead Dynpos Autro, ICE-1A, Clean Design 37 MW through 12 gensets (removable) IMO: 9629756 in 4 engine rooms Steel wire rope capacity: 2 x 4,500 m Call sign: C6DW9 Flag: Bahamas CARGO DECK ROVs Deck area: 4,200 m2 (without reels) 2 x Schilling HD work class systems, DESIGN 150 HP, launchable from ROV hangars Held-SH, Crane, EC0, BIS, COMF ACCOMMODATIONS with dedicated moon pools (V3, C3), NAUT-OSV (A) Berth/Cabin: 239 x 1 berth cabin LARS: 2 x launch and recovery systems Total: 239 persons inside the ROV hangars, water depth PROPULSION / DP 4,000 m Stern azimuth thruster aft onboard: DECK EQUIPMENT 2 x Rolls Royce Aquamaster, 6,000 kW ea.
  • Assessment of Vessel Requirements for the U.S. Offshore Wind Sector

    Assessment of Vessel Requirements for the U.S. Offshore Wind Sector

    Assessment of Vessel Requirements for the U.S. Offshore Wind Sector Prepared for the Department of Energy as subtopic 5.2 of the U.S. Offshore Wind: Removing Market Barriers Grant Opportunity 24th September 2013 Disclaimer This Report is being disseminated by the Department of Energy. As such, the document was prepared in compliance with Section 515 of the Treasury and General Government Appropriations Act for Fiscal Year 2001 (Public Law 106-554) and information quality guidelines issued by the Department of Energy. Though this Report does not constitute “influential” information, as that term is defined in DOE’s information quality guidelines or the Office of Management and Budget's Information Quality Bulletin for Peer Review (Bulletin), the study was reviewed both internally and externally prior to publication. For purposes of external review, the study and this final Report benefited from the advice and comments of offshore wind industry stakeholders. A series of project-specific workshops at which study findings were presented for critical review included qualified representatives from private corporations, national laboratories, and universities. Acknowledgements Preparing a report of this scope represented a year-long effort with the assistance of many people from government, the consulting sector, the offshore wind industry and our own consortium members. We would like to thank our friends and colleagues at Navigant and Garrad Hassan for their collaboration and input into our thinking and modeling. We would especially like to thank the team at the National Renewable Energy Laboratory (NREL) who prepared many of the detailed, technical analyses which underpinned much of our own subsequent modeling.
  • Guidelines for the Selection and Operation of Jack-Ups in the Marine Renewable Energy Industry

    Guidelines for the Selection and Operation of Jack-Ups in the Marine Renewable Energy Industry

    www.RenewableUK.com Guidelines for the Selection and Operation of Jack-ups in the Marine Renewable Energy Industry Issue 2: 2013 RUK13-019-02 2 Industry guidance aimed at jack-up owners operators, developers and contractors engaged in site-investigation, construction, operation and maintenance of offshore wind and marine energy installations. Acknowledgements RenewableUK acknowledges the time, effort, experience and expertise of all those who have contributed to this document. This Issue 2 of these guidelines was prepared for RenewableUK by London Offshore Consultants. This was in consultation with key consultees listed at the end of this document, RenewableUK members and key industry stakeholders. Status of this Document RenewableUK Health and Safety Guidelines are intended to provide information on particular technical, legal or policy issues relevant to the core membership base of RenewableUK. Their objective is to provide industry-specific guidance, for example where current information could be considered absent or incomplete. Health and Safety Guidelines are likely to be subject to review and updating, and so the latest version of the guidelines must be referred to. Attention is also drawn to the disclaimer below. Disclaimer The contents of these guidelines are intended for information and general guidance only, and do not constitute advice, are not exhaustive and do not indicate any specific course of action. Detailed professional advice should be obtained before taking or refraining from action in relation to any of the contents of this guide, or the relevance or applicability of the information herein. RenewableUK is not responsible for the content of external websites included in these guidelines and, where applicable, the inclusion of a link to an external website should not be understood to be an endorsement of that website or the site’s owners (or its products/services).
  • Dynamic Positioning Nonlinear Control System of the Dredger Based on Profinet IO

    Dynamic Positioning Nonlinear Control System of the Dredger Based on Profinet IO

    JOURNAL OF COMPUTERS, VOL. 8, NO. 2, FEBRUARY 2013 455 Dynamic Positioning Nonlinear Control System of the Dredger Based on Profinet IO Yu-hua Zhang1, 2 1Key Lab of Control of Power Transmission and Transformation, Ministry of Education, Shanghai Jiaotong University, Shanghai, China 2School of Electrical Engineering and Automation, Henan Polytechnic University, Jaozuo, China Email: [email protected] Jian-guo Jiang and Yan-jun Jiang Key Lab of Control of Power Transmission and Transformation, Ministry of Education, Shanghai Jiaotong University, Shanghai, China Email: [email protected], [email protected] Abstract— A dredger’s dynamic positioning system (DPS) is 1st-order wave motions from the low frequency (LF) designed with real-time Profinet IO structure and nonlinear positions while reconstructing LF velocities [4, 5]. All control algorithm. Real-time industrial Ethernet is used in these have been realized by using linear Kalman filter. this system to improve the real-time performance. Unfortunately, the results of Kalman filter are only valid Noise-free estimates of the position and the velocity are locally. This motivates the research on nonlinear ship produced by the observer, and the adaptive dynamic surface control. Backstepping method is the first attempt towards control (ADSC) algorithm is adopted to solve the special problem of the dredger with strong disturbances. nonlinear output feedback control of dynamic positioning Disturbances can be estimated and compensated by system. And a passive nonlinear observer is proposed in adaptive arithmetic. This work solves the contradiction Ref. [6]. between the real-time control requirement and complex Dynamic surface control technique is an improved control algorithms well.
  • Part I - Updated Estimate Of

    Part I - Updated Estimate Of

    Part I - Updated Estimate of Fair Market Value of the S.S. Keewatin in September 2018 05 October 2018 Part I INDEX PART I S.S. KEEWATIN – ESTIMATE OF FAIR MARKET VALUE SEPTEMBER 2018 SCHEDULE A – UPDATED MUSEUM SHIPS SCHEDULE B – UPDATED COMPASS MARITIME SERVICES DESKTOP VALUATION CERTIFICATE SCHEDULE C – UPDATED VALUATION REPORT ON MACHINERY, EQUIPMENT AND RELATED ASSETS SCHEDULE D – LETTER FROM BELLEHOLME MANAGEMENT INC. PART II S.S. KEEWATIN – ESTIMATE OF FAIR MARKET VALUE NOVEMBER 2017 SCHEDULE 1 – SHIPS LAUNCHED IN 1907 SCHEDULE 2 – MUSEUM SHIPS APPENDIX 1 – JUSTIFICATION FOR OUTSTANDING SIGNIFICANCE & NATIONAL IMPORTANCE OF S.S. KEEWATIN 1907 APPENDIX 2 – THE NORTH AMERICAN MARINE, INC. REPORT OF INSPECTION APPENDIX 3 – COMPASS MARITIME SERVICES INDEPENDENT VALUATION REPORT APPENDIX 4 – CULTURAL PERSONAL PROPERTY VALUATION REPORT APPENDIX 5 – BELLEHOME MANAGEMENT INC. 5 October 2018 The RJ and Diane Peterson Keewatin Foundation 311 Talbot Street PO Box 189 Port McNicoll, ON L0K 1R0 Ladies & Gentlemen We are pleased to enclose an Updated Valuation Report, setting out, at September 2018, our Estimate of Fair Market Value of the Museum Ship S.S. Keewatin, which its owner, Skyline (Port McNicoll) Development Inc., intends to donate to the RJ and Diane Peterson Keewatin Foundation (the “Foundation”). It is prepared to accompany an application by the Foundation for the Canadian Cultural Property Export Review Board. This Updated Valuation Report, for the reasons set out in it, estimates the Fair Market Value of a proposed donation of the S.S. Keewatin to the Foundation at FORTY-EIGHT MILLION FOUR HUNDRED AND SEVENTY-FIVE THOUSAND DOLLARS ($48,475,000) and the effective date is the date of this Report.
  • Dp Operations Guidance

    Dp Operations Guidance

    DP OPERATIONS GUIDANCE DP OPERATIONS GUIDANCE PREPARED THROUGH THE DYNAMIC POSITIONING COMMITTEE OF THE MARINE TECHNOLOGY SOCIETY TO AID IN THE SAFE AND EFFECTIVE MANAGEMENT OF DP OPERATIONS PART 2 APPENDIX 1 - DP MODUS APRIL 2021 DP OPERATIONS GUIDANCE - PART 2 - APP 1 (Rev3 - Apr21) MODU 1 DP OPERATIONS GUIDANCE This Dynamic Positioning Guidance was created by the Dynamic Positioning Committee of the Marine Technology Society. The guidelines have been developed from regulations, codes, guidance and industry practice existing at the time of publication, and their purpose is to aid in the safe management of DP operations. This publication was designed and intended as a resource for dynamic positioning professionals. For any other use beyond personal, research or educational purposes, please contact the Marine Technology Society. All rights reserved © Marine Technology Society. 2 DP OPERATIONS GUIDANCE - PART 2 - APP 1 (Rev3 - Apr21) MODU DP OPERATIONS GUIDANCE DISCLAIMER AND LIMITATION OF LIABILITY The information presented in this publication of the Dynamic Positioning Committee of the Marine Technology Society (“DP Committee”) is made available for general information purposes without charge. The DP Committee does not warrant the accuracy, completeness, or usefulness of this information. Any reliance you place on this publication is strictly at your own risk. We disclaim all liability and responsibility arising from any reliance placed on this publication by you or anyone who may be informed of its contents. IN NO EVENT WILL THE DP
  • The International Marine Contractors Association ~Yf, F-J F ,‘I’ Y;

    The International Marine Contractors Association ~Yf, F-J F ,‘I’ Y;

    .Ly ;y!--)!~ -“I 1 MCA The International Marine Contractors Association ~yf, f-J F ,‘I’ y;. r*:*t:;pQ~p$Tjo)j Represents offshore, marine and underwa er~~rne~r~--qQ~an~es.a.-& __.. i+...,,r 21 September 1998 Docket Management Facility (USCG-1998-37861) - 3 7 US Department of Transportation Room PL-40 1 400 Seventh Street SW Washington DC 20590-00 1 USA Attn: Joseph J Angelo Dear Sir Commercial Diving Operations I art-r responding to the invitation to respond to the Advance notice of proposed rule- making. IMCA, as was its forerunner the Association of Offshore Diving Contractors (AODC), is an international industry association representing offshore Diving and offshore Construction Contractors operating in 30-plus countries. It issues guidance to its members on safe diving practices and safe operation of DP vessels. This guidance is based on 20-plus years’ diving experience from 50-plus diving support vessels. The notice addressed two issues on which IMCA members have considerable expertise: i> diving from dynamically positioned vessels ii) diving supervisors. The enclosed copy of IMCA Guidance document DO10 - ‘Diving Operations from vessels operating in dynamic positioning mode’ - relates to the first. This is the third version of our guidance on this topic - the most recent revision was prompted by a fatal accident on the UK Continental Shelf. The US Coastguard might like to consider the advice contained therein should it decide to regulate in this area. cant/.... Carlyle House, 235 Vauxhall Bridge Road, London, UK, SWlV 1EJ Tel: t44 (0)171-931 8171 Fax: t44 (0)171-931 8935 E-mail: imcaeimca-int.com Inmwmratinrr AON! nnri IIPVOA -2- A copy of the IMCA offshore diving supervisor and life support technician schemes is also enclosed.