ISO 21711:2019

Marine structures — Mobile offshore units — Chain wheels

This document specifies the requirements for the profiles, dimensions, tolerances, materials and inspection of chain wheels for chains on mobile offshore units. Chain wheels meeting the requirements of this document can be used with offshore mooring chains conforming to ISO 20438.

Structures maritimes — Unités mobiles au large — Pignons à chaîne

General Information

• Status: Published
• Publication Date: 23-Apr-2019
• ICS: 47.020.50 - Deck equipment and installations
• Technical Committee: ISO/TC 8/SC 4 - Outfitting and deck machinery
• Drafting Committee: ISO/TC 8/SC 4/WG 2 - Deck machinery
• Parallel Committee: ISO/TC 4 - Rolling bearings
• Current Stage: 6060 - International Standard published
• Due Date: 22-Aug-2019
• Completion Date: 24-Apr-2019

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 21711
First edition
2019-04
Marine structures — Mobile offshore
units — Chain wheels
Structures maritimes — Unités mobiles au large — Pignons à chaîne
Reference number
ISO 21711:2019(E)
©
ISO 2019

---------------------- Page: 1 ----------------------
ISO 21711:2019(E)

COPYRIGHT PROTECTED DOCUMENT
© 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: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 21711:2019(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification . 2
4.1 Types of the chain wheels . 2
4.2 Designation . 7
5 Requirements . 7
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
© ISO 2019 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 21711:2019(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 technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take Part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www .iso .org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 8, Ships and marine technology,
Subcommittee SC 4, Outfitting and deck machinery.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
iv © ISO 2019 – All rights reserved

---------------------- Page: 4 ----------------------
INTERNATIONAL STANDARD ISO 21711:2019(E)
Marine structures — Mobile offshore units — Chain wheels
1 Scope
This document specifies the requirements for the profiles, dimensions, tolerances, materials and
inspection of chain wheels for chains on mobile offshore units.
Chain wheels meeting the requirements of this document can be used with offshore mooring chains
conforming to ISO 20438.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3828, Shipbuilding and marine structures — Deck machinery — Vocabulary and symbols
ISO 6506-1, Metallic materials — Brinell hardness test — Part 1: Test method
ISO 8062-3, Geometrical product specifications (GPS) — Dimensional and geometrical tolerances for
moulded parts — Part 3: General dimensional and geometrical tolerances and machining allowances for
castings
1)
ISO 11971:— , Steel and iron castings — Visual examination of surface quality
ISO 16859-1, Metallic materials — Leeb hardness test — Part 1: Test method
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 3828 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
pitch diameter
D
p
circumscribed circle diameter of the regular polygon formed by the centerline of the stud-link anchor
chain where the anchor chain is engaged with the chain wheel
Note 1 to entry: Pitch diameter is used to calculate the maximum torque of the anchor chain during operation.
3.2
speed calculation diameter
D
v
diameter of the moving line of the stud-link anchor chain when anchoring with power
1) Under preparation. Stage at the time of publication: ISO/DIS 11971:2018.
© ISO 2019 – All rights reserved 1

---------------------- Page: 5 ----------------------
ISO 21711:2019(E)

4 Classification
4.1 Types of the chain wheels
a) Type A — 5-tooth chain wheel, see Figure 1 for the tooth profile structure. The nominal dimensions
are given in Table 1.

It is not recommended to select values in the shaded area.
Figure 1 — Tooth profile structure of type A chain wheel
2 © ISO 2019 – All rights reserved

---------------------- Page: 6 ----------------------
ISO 21711:2019(E)

b) Type B — 6-tooth chain wheel, see Figure 2 for the tooth profile structure. The nominal dimensions
are given in Table 1.

It is not recommended to select values in the shaded area.
Figure 2 — Tooth profile structure of type B chain wheel
© ISO 2019 – All rights reserved 3

---------------------- Page: 7 ----------------------
ISO 21711:2019(E)

c) Type C — 7-tooth chain wheel, see Figure 3 for the tooth profile structure. The nominal dimensions
are given in Table 1.
It is not recommended to select values in the shaded
...