ISO 23113:2020

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 23113
ISO/TC 8/SC 4
Ships and marine technology — Ship's
Secretariat: SAC
mooring and towing fittings — Seats
Voting begins on:
2020­05­27 for closed chocks
Voting terminates on:
2020­07­22
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/FDIS 23113:2020(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN­
DARDS TO WHICH REFERENCE MAY BE MADE IN
©
NATIONAL REGULATIONS. ISO 2020

---------------------- Page: 1 ----------------------
ISO/FDIS 23113:2020(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
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
CH­1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/FDIS 23113:2020(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification . 1
4.1 Type . 1
4.2 Nominal sizes . 1
5 Dimensions . 2
6 Materials . 2
7 Construction . 2
8 Manufacturing and inspection . 2
9 Marking . 2
Annex A (normative) Basis for strength assessment of the seats for closed chocks .9
Bibliography .13
© ISO 2020 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO/FDIS 23113:2020(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 non­governmental, 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 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 2020 – All rights reserved

---------------------- Page: 4 ----------------------
ISO/FDIS 23113:2020(E)

Introduction
The seat for closed chocks is a seat type of ship’s mooring and towing fitting installed on the shipside to
lead the mooring and towing rope from the ship’s inboard to outboard.
© ISO 2020 – All rights reserved v

---------------------- Page: 5 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 23113:2020(E)
Ships and marine technology — Ship's mooring and towing
fittings — Seats for closed chocks
1 Scope
This document specifies the types, nominal sizes, dimensions and materials, as well as construction,
manufacturing and marking requirements, for the seats for closed chocks installed to lead the mooring
and towing rope of a ship,
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.
IMO Circular MSC/Circ.1175, Guidance on shipboard towing and mooring equipment
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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
safe working load
SWL
safe load limit (maximum permissible load) of the fittings used for mooring and towing
4 Classification
4.1 Type
The seat for closed chocks shall be classified by its installation site as belonging to one of the
following types:
a) Type A: seat for deck-mounted closed chock;
b) Type B: seat for deck and side shell-mounted closed chock;
c) Type C: brackets for bulwark-mounted closed chock.
4.2 Nominal sizes
The nominal sizes of seats for closed chocks are denoted by reference to the same nominal sizes of closed
chocks (ISO 13729). For the seats for closed chocks having the same size, the letter of the alphabet, i.e.
A, B or C, is followed by the nominal size for the different safe working loads (SWL).
The nominal sizes are:
© ISO 2020 – All rights reserved 1

---------------------- Page: 6 ----------------------
ISO/FDIS 23113:2020(E)

250 × 200 × 214, 300 × 250 × 286, 350 × 250 × 333, 400 × 250 × 381, 450 × 250 × 381, 500 × 250 × 381,
400 × 250 × 428, 450 × 250 × 428, 500 × 250 × 428, 500 × 400 × 428, 500 × 250 × 525A, 500 × 400 ×
525A, 500 × 250 × 525B, 500 × 400 × 525B
5 Dimensions
The seats for closed chocks shall have dimensions and particulars in accordance with Tables 1, 2 and 3,
and Figures 1, 2 and 3.
6 Materials
2
Weldable steel plates having a yield point of not less than 235 N/mm shall be used for manufacturing
the seats for closed chocks.
7 Construction
The foundation of the closed chocks shall be determined by considering the actual load direction. The
foundation and welding connections to the hull shall guarantee a reliable transmission of the maximum
loading of the closed chocks to the hull construction without any plastic deformation or cracks.
8 Manufacturing and inspection
8.1 All surfaces of the seats for closed chocks, including welded surfaces, shall be free from any visible
flaws or imperfections.
8.2 All surfaces in contact with the ropes shall be free from surface roughness or irregularities likely to
cause damage to the ropes by abrasion.
8.3 The seats for closed chocks shall be coated externally with an anti-corrosion protective finish.
9 Marking
9.1 The SWL for the intended use of the s
...