ISO 13742:2020

Ships and marine technology - Ship's mooring and towing fittings - Universal fairleads without upper roller

This document specifies the types, nominal sizes, dimensions and materials, as well as construction, manufacturing and marking requirements, for universal fairleads without upper roller(s) installed to lead the mooring rope of a ship.

Navires et technologie maritime — Corps-morts et ferrures de remorquage de navires — Chaumards universels sans rouleau supérieur

General Information

• Status: Published
• Publication Date: 27-Aug-2020
• 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 4 - Ship's mooring and towing fittings
• Current Stage: 9060 - Close of review
• Completion Date: 04-Mar-2031

Relations

• Revises: ISO 13742:2012 - Ships and marine technology - Ship's mooring and towing fittings - Universal fairleads without upper roller
• Effective Date: 30-Sep-2017

Overview

ISO 13742:2020 - Ships and marine technology - Ship's mooring and towing fittings - Universal fairleads without upper roller - specifies types, nominal sizes, dimensions, materials, construction, manufacturing, inspection and marking requirements for universal fairleads installed to lead a ship’s mooring rope. The standard covers fairleads without upper roller(s) (used where the mooring deck level is higher than the quay) and includes dimension tables, assembly figures and a normative annex on strength assessment.

Key topics and technical requirements

• Types and classification
  • Four types are defined: 3R, 4RL, 4RR, 5R (single or double rope-pass openings, with optional side guide rollers).
• Nominal sizes
  • Specified nominal roller diameters: 140, 160, 180, 200, 250, 300A, 300B, 400A, 400B, 400C (dimensions and SWL referenced in tabulated data).
• Materials and mechanical properties
  • Frame/plates: weldable steel (yield ≥ 235 N/mm²; for 400A/B/C frames ≥ 315 N/mm²).
  • Rollers: weldable steel plates or equivalent tubes (same yield point rules).
  • Axles: carbon steel (yield ≥ 345 N/mm²).
  • Bushes: brass, bronze or equivalent.
• Construction
  • Rollers from steel tubes or plate; foundation and welding details to ensure load transmission to hull without plastic deformation or cracks.
  • Guidance on D/d ratio (roller diameter D vs rope diameter d) to reduce strength loss by bend radius; tensile strength reduction per rope manufacturer guidelines.
• Manufacturing and inspection
  • All surfaces (including welded surfaces) free of visible flaws; rope-contact surfaces free of roughness that could abrade ropes.
  • External anti‑corrosion coating required; rotating parts greased.
• Marking and documentation
  • Safe working load (SWL) must be recorded in the ship’s towing and mooring plan (IMO MSC/Circ.1175) and marked on the fitting (weld bead or equivalent), expressed in tonnes. SWL values in the standard’s tables are for reference and may be adjusted based on actual foundation/reinforcement.

Practical applications and users

• Intended for shipbuilders, marine equipment manufacturers, naval architects, ship outfitters, classification societies and ship operators.
• Used for design, procurement, fabrication, inspection, installation and maintenance of ship mooring and towing fittings (universal fairleads without upper roller).
• Supports specification of fittings for new-builds, retrofits and in-service replacement to ensure compatibility with mooring plans and rope manufacturer guidance.

Related standards and references

• Normative reference: IMO Circular MSC/Circ.1175 (Guidance on shipboard towing and mooring equipment).
• Developed by ISO/TC 8 (Ships and marine technology), Subcommittee SC 4 (Outfitting and deck machinery).

Keywords: ISO 13742:2020, universal fairleads, mooring fittings, ship mooring, SWL, D/d ratio, marine hardware standard, ship outfitting.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 13742
Second edition
2020-08
Ships and marine technology —
Ship's mooring and towing fittings
— Universal fairleads without upper
roller
Navires et technologie maritime — Corps-morts et ferrures de
remorquage de navires — Chaumards universels sans rouleau
supérieur
Reference number
©
ISO 2020
© 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
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Phone: [phone]
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Published in Switzerland
ii © ISO 2020 – All rights reserved

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 . 3
Annex A (normative) Basis for strength assessment of universal fairleads .14
Bibliography .19
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
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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
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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.
This second edition cancels and replaces the first edition (ISO 13742:2012), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— technical guidelines have been added in 7.3 and 7.4;
— the definition of SWL (3.1) has been reworded;
— the object lines and key numbers in Figures 1, 2, 3 and 4 have been amended;
— the values of “t” for the lower horizontal roller in Table 5 (former Table 3) have been amended;
— the thickness of the bushes and washers have been added in Table 5 (former Table 3);
— the numbering of A.2.2, A.3 and A.4 have been corrected;
— the dimension line (θ ) in Figure A.2 has been amended;
— the descriptions in Clause A.3 have been amended;
— technical information on FEM and strength calculation have been added in A.3.2 and A.3.3.
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

Introduction
The universal fairlead is a type of ship’s mooring fitting installed on board to lead the mooring rope
from the ship’s inboard to outboard.
A universal fairlead without upper roller is used for vessels in which the mooring deck level is higher
than quay side.
INTERNATIONAL STANDARD ISO 13742:2020(E)
Ships and marine technology — Ship's mooring and towing
fittings — Universal fairleads without upper roller
1 Scope
This document specifies the types, nominal sizes, dimensions and materials, as well as construction,
manufacturing and marking requirements, for universal fairleads without upper roller(s) installed to
lead the mooring 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
Depending on the construction, universal fairleads shall be classified as belonging to one of the
following four types:
a) Type 3R: with one rope-passing opening;
b) Type 4RL: with one rope-passing opening with an additional guide roller on the left side;
c) Type 4RR: with one rope-passing opening with an additional guide roller on the right side;
d) Type 5R: with two rope-passing openings.
4.2 Nominal sizes
The nominal sizes, D , of universal fairleads are denoted by reference to the outside diameter of the
n
main roller, in millimetres, in terms of the nearest number drawn from a basic series of preferred
numbers. For the universal fairleads having the same roller diameter, the code, i.e. 3R, 4RL, 4RR or 5R,
is followed by the nominal size for the different SWLs.
The nominal sizes are:
140, 160, 180, 200, 250, 300A, 300B, 400A, 400B and 400C.
5 Dimensions
Universal fairleads shall have dimensions and particulars in accordance with Tables 1, 2, 3, 4, 5 and 6,
and Figures 1, 2, 3, 4 and 5.
6 Materials
The following materials shall be used for manufacturing the components of universal fairleads.
a) Frame and other plates: weldable steel plates having a yield point of not less than 235 N/mm ,
except for the frames with a rope guide for nominal sizes 400A, 400B and 400C, which shall be
made of weldable steel plates having a yield point of not less than 315 N/mm .
b) Roller: weldable steel plates having a yield point of not less than 235 N/mm , except for the rollers
for nominal sizes 400A, 400B and 400C, which shall be made of weldable steel plates having a yield
point of not less than 315 N/mm , or equivalent steel tubes.
c) Axle: carbon steel having a yield point of not less than 345 N/mm .
d) Bush: brass or bronze or equivalent.
7 Construction
7.1 The rollers of the universal fairleads shall be constructed from steel tubes or formed from plate.
7.2 The foundation of the universal fairleads shall be determined by the manufacturer. The foundation
and welding connections to the hull shall guarantee a reliable transmission of the maximum loading of
the universal fairleads to the hull construction without any plastic deformation or cracks.
7.3 The selection of ship’s mooring fittings and mooring lines should take into account the diameter, D,
of surfaces of mooring fittings that are in contact with the mooring line diameter, d, (D/d ratio) to reduce
or mitigate bend ross of strength.
7.4 The tensile strength of mooring rope may be reduced depending on bend radius (D/d ratio)
through the mooring fittings, in accordance with the rope manufacturer’s guidelines.
8 Manufacturing and inspection
8.1 All surfaces of the universal fairleads, 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 universal fairleads shall be coated externally with an anti-corrosion protective finish.
8.4 All rotating parts shall be greased.
2 © ISO 2020 – All rights reserved

9 Marking
9.1 The safe working load (SWL) for the intended use of the universal fairleads shall be noted in the
towing and mooring plan available on board for the guidance of the shipmaster as specified in IMO
circular MSC/Circ.1175.
9.2 The actual SWL on board shall be determined by considering the foundation and under deck
reinforcement, and it shall be marked on the towing and mooring plan. The actual SWL shall not be over
the SWL indicated in this document.
9.3 The universal fairleads shall be clearly marked with their SWL by weld bead or equivalent. The
SWL shall be expressed in tonnes (symbol 't') and be placed so that it is not obscure
...