ISO INTERNATIONAL STANDARD 19901-1 Second edition 2015-10-15 Petroleum and natural gas industries Specific requirements for offshore structures - Part 1: Metocean design and operating considerations Industries du pétrole et du gaz naturel - Exigences speécifiques relatives aux structures en mer Partie 1: Dispositions océano-météorologiques pour la conception et l'exploitation Reference number IS0 19901-1:2015(E) SO International Organization for Standardization @ IS0 2015 dardization5956617 ed without license from IHS IS0 19901-1:2015(E) COPYRIGHTPROTECTEDDOCUMENT IS02015,PublishedinSwitzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISO copyrightoffice Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 [email protected] www.iso.org PrganizationforStandardization Not for Resale, 2015/11/30 07:17:22 etworking permitted without license from IHS IS0 19901-1:2015(E) Contents Page Foreword ..V Introduction. ..vii 1 Scope. 2 Normative references 3 Terms and definitions 4 Symbols and abbreviated terms 4.1 Symbols .9 4.2 Abbreviated terms .12 5 Determining the relevant metocean parameters .12 5.1 General. .12 5.2 Expert development of metocean criteria .13 5.3 Selecting appropriate parameters for determining design actions and action effects. .13 5.4 The metocean database.. 14 5.5 Storm types in a region. .14 5.6 Directionality .14 5.7 Extrapolation to extreme and abnormal conditions .15 5.8 Metocean parameters for fatigue assessments .15 5.9 Metocean parameters for short-term activities. .16 5.10 Metocean parameters for medium-term activities ..17 6 Water depth, tides and storm surges .17 6.1 General .17 6.2 Tides.. ..17 6.3 Storm surges ..18 6.4 Extreme water level. ..18 7 Wind .19 7.1 General. .19 7.2 Wind actions and action effects .20 7.3 Wind profile and time-averaged wind speed. .21 7.4 Wind spectra. .21 8 Waves. 21 8.1 General .21 8.2 Wave actions and action effects 22 8.3 Seastates- Spectralwaves 23 8.3.1 Wave spectrum. 23 8.3.2 Directional spreading 23 8.3.3 Wave periods. 23 8.3.4 Wave kinematics - Velocities and accelerations 23 8.4 Regular (periodic) waves 24 8.4.1 General. 24 8.4.2 Wave period 24 8.4.3 Wave kinematics - - Velocities and accelerations. 24 8.4.4 Intrinsic, apparent and encounter wave periods. .24 8.5 Maximum height of an individual wave for long return periods 25 8.6 Linear wave models. 25 8.7 Wave crest elevation 25 9 Currents .26 9.1 General 26 9.2 Current velocities. 26 9.3 Current profile. .27 9.4 Current profile stretching .27 9.5 Current blockage .27 ntemaonalganizatin5All rights reserved iii iseeZhejang Insttute of Standardization 5956617 ovided byIHS under license with ISO vithoutlicense from IHS Not for Resale, 2015/11/30 07:17:22 IS0 19901-1:2015(E) 10 Other environmental factors .27 10.1 Marine growth 27 10.2 Tsunamis. 28 10.3 Seiches 28 10.4 Sea ice and icebergs. 28 10.5 Snow and ice accretion 28 10.6 Miscellaneous. 29 11 Collection of metocean data. 29 11.1 General. 29 11.2 Common requirements 30 11.2.1 General. 30 11.2.2 Instrumentation 30 11.3 Meteorology 30 11.3.1 General 30 11.3.2 Weather observation and reporting for helicopter operations. 30 11.3.3 Weather observation and reporting for weather forecasting services 31 11.3.4 Weather observation and reporting for climatological purposes 31 11.4 Oceanography 31 11.4.1 General 31 11.4.2 Measurements and observations. 32 11.5 Data quality control 32 12 Information concerning the annexes 32 12.1 Information concerning Annex A 32 12.2 Information concerning the regional annexes 32 Annex A (informative) Additional information and guidanc