National foreword

This British Standard is the UK implementation of ISO 4301‑4:2025.

The UK participation in its preparation was entrusted to Technical Committee MHE/3/3, Bridge, gantry and slewing jib cranes.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 November 2025.

Foreword

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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).

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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

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.

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

3 Terms and definitions

4 Symbols

5 Classification

5.1 Classification of jib cranes

5.2 Classification of components and mechanisms

Bibliography

BS ISO 4301-4:2025

Cranes — Classification - Jib cranes

Current

Published:

30 Nov 2025