ISO 4301-4:2025

International
Standard
ISO 4301-4
Second edition
Cranes — Classification —
2025-11
Part 4:
Jib cranes
Grues — Classification —
Partie 4: Grues à flèche
Reference number
© ISO 2025
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: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
Contents  Page
Foreword .iv
Introduction .v
1  Scope . 1
2  Normative references . 1
3  Terms and definitions . 1
4  Symbols . 1
5  Classification . 2
5.1 Classification of jib cranes .2
5.2 Classification of components and mechanisms .4
5.2.1 Classes of utilization and load spectrum factor .4
5.2.2 Group classification .5
5.2.3 Average displacements .6
Annex A (informative)  Calculation method for transforming a time-based classification into a
cycle-based classification . 8
Bibliography .11

iii
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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 96, Cranes, Subcommittee SC 8, Jib cranes.
This second edition cancels and replaces the first edition (ISO 4301- 4:1989), which has been technically
revised.
The main changes are as follows:
— updated normative references;
— new approach for the classification of jib cranes and its components has been introduced, based on
ISO 4301-1:2016;
— new Annex A for transforming a time-based classification (ISO 4301-1:1986) into a cycle-based
classification (ISO 4301-1:2016).
A list of all parts in the ISO 4301 series can be found on the ISO website.
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
Introduction
Jib cranes are designed for a duty that can be expressed in number of work cycles, load spectrum factor and
average displacements. However, there can be wide variations in their duty. The design of jib cranes takes
into account the specified duty in order to reach an appropriate level of safety and useful design life, which
is in line with the purchaser's requirements.
Classification serves as a reference framework between purchaser and manufacturer, by which a particular
jib crane can be matched to the intended service. It is also the system used to provide a means of establishing
rational bases for the design of jib crane structure and mechanisms.

v
International Standard ISO 4301-4:2025(en)
Cranes — Classification —
Part 4:
Jib cranes
1  Scope
This document establishes a general classification of jib cranes and their mechanisms based on the service
conditions, expressed by the following:
— the total number of working cycles to be carried out during the specified design life of the jib crane;
— the load spectrum factor which represents the relative frequencies of loads to be handled;
— the average displacements.
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 4301-1:2016, Cranes — Classification — Part 1: General
ISO 4306-1, Cranes — Vocabulary — Part 1: General
ISO 4306-4, Cranes — Vocabulary — Part 4: Jib cranes
3  Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4301-1, ISO 4306-1 and
ISO 4306-4 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 https:// www .electropedia .org/
4  Symbols
For the purposes of this document, the main symbols used in this document are given in Table 1.

Table 1 — Main symbols
Symbols Description
A Classes for group classification
A Classes for group classification of components and mechanisms
c
C Total number of working cycles
D Classes for average displacements
D Classes for average angular displacements
a
K Load spectrum factor
p
K Load effect spectrum factor of components
cp
M Classes for group classification of mechanisms (see ISO 4301-1:1986)
P Individual load magnitudes (i.e. load levels)
Q Classes Q of load spectrum factors K
p p
Q Classes Q of load spectrum factors K
cp cp
t Total duration of use for full load cycles (i.e. K = 1,0)
T-f cp
U Classes of total numbers of working cycles C
5  Classification
5.1  Classification of jib cranes
For the purpose of classification, a jib crane working cycle is a sequence of movements which commences
when the jib crane is ready to hoist the load and ends when the jib crane is ready to hoist the next load
within the same task. A task can be characterized by a specific combination of crane configuration and a
sequence of intended movements.
The range of the total number of jib crane working cycles, C, shall be determined in accordance with
ISO 4301-1:2016, Table 2.
The load spectrum factor, K , is one of the parameters used to specify the duty of the jib crane by describing
p
the different net loads to be handled during the working movements. It takes into account the number of
times a load of a particular magnitude, in relation to the rated capacity of the jib crane, is lifted. The load
spectrum factor, K , shall be determined in accordance with ISO 4301-1:2016, Table 3.
p
Having determined the class of utilization (see ISO 4301-1:2016, Table 2) and the state of loading (see
ISO 4301-1:2016, Table 3), they can be combined into a single group classification A for the jib crane as a
whole. The group classification of jib cranes shall be in accordance with ISO 4301-1:2016, Table 4.
The minimum group classifications A of jib crane as a whole, class of utilization and state of loading are
given in Table 2.
Table 2 — Minimum group classification of jib crane as a whole, including class of utilization and
state of loading
Group clas-
Type of
Type of jib  Operation  sification of  Class of utili- State of
No. lifting at- Service condition
crane condition jib crane as a  zation loading
tachment
whole
Regular light use with
Hook A4 U4 Q 3
p
moderate loads
Irregular intensive
A6 U5 Q 4
p
use with heavy loads
Grab or
Storage yard magnet
Intensive use with
A8 U7 Q 4
p
heavy loads
Irregular intensive
Container
use with moderate A6 U6 Q 3
p
spreader
loads
Regular light use with
A3 U4 Q 2
p
light loads
Regular intermittent
Hook A6 U5 Q 4
p
use with heavy loads
Irregular intensive
A7 U6 Q 4
p
Portal
use with heavy loads
slewing
Irregular intensive
crane and A7 U6 Q 4
p
1 use with heavy loads
Semi-por- Harbour
Grab or
Irregular intensive
tal slewing
magnet
use with close to the A8 U6 Q 5
crane
p
rated load
Irregular intensive
use with moderate A6 U6 Q 3
p
Container
loads
spreader
Irregular intensive
A7 U6 Q 4
p
use with heavy loads
Regular light use with
Shipbuilding Hook A4 U4 Q 3
p
moderate loads
Regular light use with
Erection Hook A4 U4 Q 3
p
moderate loads
Regular light use with
Water re-
A4 U4 Q 3
p
moderate loads
sources and
Hook
electric power
Irregular intensive
A7 U6 Q 4
p
construction
use with heavy loads
Regular intermittent
use with moderate A5 U5 Q 3
p
loads
Hook
Regular intermittent
A6 U5 Q 4
p
use with heavy loads
Irregular intensive
A7 U6 Q 4
p
use with heavy loads
Fixed-base Grab or
2 Harbour
Irregular intensive
jib crane magnet
use with close to the A8 U6 Q 5
p
rated load
Irregular intensive
use with moderate A6 U6 Q 3
p
Container
loads
spreader
Irregular intensive
A7 U6 Q 4
p
use with heavy loads
TTabablele 2 2 ((ccoonnttiinnueuedd))
Group clas-
Type of
Type of jib  Operation  sification of  Class of utili- State of
No. lifting at- Service condition
crane condition jib crane as a  zation loading
tachment
whole
Irregular use with
A3 U1 Q 5
p
close to the rated load
Hook
Regular intermittent
A6 U5 Q 4
p
with heavy loads
Regular intermittent
use with close to the A7 U5 Q 5
p
High mast
rated load
3 Harbour Grab
crane
Intensive use with
A8 U7 Q 4
p
heavy loads
Regular intermittent
A6 U5 Q 4
p
use with heavy loads
Container
spreader
Irregular intensive
A7 U6 Q 4
p
use with heavy loads
Irregular use with
Erection Hook A2 U2 Q 3
p
moderate loads
Regular light use with
Storage yard Hook A4 U4 Q 3
p
moderate loads
Irregular use with
A2 U0 Q 5
p
Derrick close to the rated load
crane
Heavy lifting Hook
Regular intermittent
use with close to the A5 U5 Q 3
p
rated load
Irregular intensive
Harbour Hook use with moderate A6 U6 Q 3
p
loads
Manual opera- Irregular use with
Hook A1 U2 Q 2
p
tion light loads
Cantilever
crane
Workshop as- Irregular use with
Hook A2 U2 Q 3
p
sembly duties moderate loads
5.2  Classification of components and mechanisms
5.2.1  Classes of utilization and load spectrum factor
Classification can be specified for design of hois
...