ISO INTERNATIONAL STANDARD 19901-7 Second edition 2013-05-01 Petroleum and natural gas industries - Specific requirements for offshore structures Part 7: Stationkeeping systems for floating offshore structures and mobile offshore units Industries du pétrole et du gaz naturel Exigences spécifiques relativesauxstructuresenmer Partie 7: Systemes de maintien en position des structures en mer flottantes et des unites mobiles en mer Reference number ISO 19901-7:2013(E) ISO 2013 THS unde Not for Resale ISO 19901-7:2013(E) COPYRIGHTPROTECTEDDOCUMENT @ISO2013 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either Iso at the address below or ISO's member body in the country of the requester. ISO copyright office Case postale 56. CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.org Published in Switzerland @ ISO 2013 - All rights reserved Not for Resale ISO 19901-7:2013(E) Contents Page Foreword Introduction. ..vii 1 Scope 2 Normative references.. 3 Terms and definitions 2 4 Symbols and abbreviated terms 4.1 Symbols.. 4.2 Abbreviated terms. 5 Overall considerations.. .9 5.1 Functional requirements.... .9 5.2 Safety requirements.. .9 5.3 Planning requirements. 5.4 Inspection and maintenance requirements 10 5.5 Analytical tools....... 6 Design requirements... 6.1 Exposure levels. 10 6.2 Limit states.. 6.3 Defining design situations 6.4 Design situations. 12 7 Actions. 14 7.1 General 14 7.2 14 7.3 7.4 Indirect actions ... .16 8: Mooring analysis . .18 8.1 Basic considerations 18 8.2 Floating structure offset...... 8.3 Floating structure response.... .20 8.4 Mooring line response .. 25 8.5 Linetension... 26 8.6 Line length and geometry constraints 8.7 Anchorforces.. 27 8.8 Typical mooring configuration analysis and assessment.. 27 8.9 Thruster-assisted moorings....... .28 8.10 Transient analysis of floating structure motions.... .29 9 Fatigue analysis.... 9.1 Basic considerations. .30 9.2 Fatigue resistance. 30 9.3 Fatigue analysis procedure.... 10 Design criteria. 37 10.1 Floating structure offset 37 10.2 Line tension limit. 38 10.3 Grounded line length .38 10.4 Anchoring systems..... 10.5 Fatigue safety factor 41 10.6 Corrosion and wear.. 41 10.7 .42 ili Copyright International Organization for Standardizalon ghts reserved se from IHS Not for Resale ISO 19901-7:2013(E) 10.8 Supporting structures. 11 Mooring hardware... ..42 11.1 Mooring line components, 11.2 Winching equipment 11.3 Monitoring equipment. .43 12 In-service inspection, monitoring and maintenance. ..44 12.1 General.... 12.2 Mobile moorings . 12.3 Permanent moorings.. 13 Dynamic positioning system.. .46 13.1 Basic considerations. 13.2 Design and analysis . 47 13.3 Design, test and maintenance .48 13.4 Operating personnel. .48 13.5 Determination of stationkeeping capability ..48 14 Synthetic fibre rope mooring.... 14.1 Basicconsiderations.. ..48 14.2 Fibre rope mooring analysis... 14.3 Fatigue analysis.. ..50 14.4 Creep analysis... ..50 14.5 Design criteria.. ..50 14.6 Model testing. .51 Annex A (informative) Additional information and guidance ... ..52 Annex B (informative) Regional information 169 Bibliography. 176 @ISO2013-All rights reserved ational Organization for Standardization from IHS Not for Resale ISO 19901-7:2013(E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (isO member bodies). The work of preparing International Standards is normally carried out through isO established has the right to be represented on that committee. International organizations, governmental and International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Dire