ISO INTERNATIONAL STANDARD 21711 First edition 2019-04 Marine structures Mobile offshore units Chain wheels Structures maritimes - Unites mobiles au large - Pignons a chaine Reference number IS0 21711:2019(E) so @ IS0 2019 IS0 21711:2019(E) COPYRIGHTPROTECTEDDOCUMENT @ ISO 2019 All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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 copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +4122 749 0111 Fax: +41 22 749 09 47 Email: [email protected] Website: www.iso.org Published in Switzerland ii @ IS0 2019 - All rights reserved IS0 21711:2019(E) Contents Page Foreword ..iv 1 Scope .1 2 Normative references. 3 Terms and definitions. 4 Classification ..2 4.1 Types of the chain wheels .2 4.2 Designation. 7 5 Requirements 5.1 Geometric tolerance and dimensional tolerance .7 5.2 Materials... ..8 6 Inspection ..8 6.1 Dimensional and geometric inspection. .8 6.2 Visual inspection for surface quality. ..8 6.3 Inspection of tooth surface hardness .8 6.4 Material inspection. ..8 Bibliography 9 @ IS0 2019 - All rights reserved ii