Overview
ISO 11661:2022 specifies a standardized presentation and format for mobile crane rated capacity charts. Applicable to mobile cranes fitted with boom and boom/jib combinations (as defined in ISO 4306-2), the standard defines what must be included in a crane rating manual and how rated capacity data, working range and stability information should be published so that operators and personnel can quickly and safely determine lifting capacities.
Key Topics
The standard sets minimum content, format and publication requirements for rated capacity charts and crane rating manuals. Key technical topics include:
- Crane rating manual requirements: must be supplied with each crane and be available at the operator controls; may be electronic or physical and include an alternative access method if electronic systems fail.
- Mandatory content in the manual:
- Boom extend modes and boom/jib configurations
- Counterweight configuration and identification
- Auxiliary equipment mass table and instructions for capacity deductions
- Working range diagrams (side elevation showing heights and radii)
- Working area diagram (plan/top view showing 360°/over-side/over-front limits)
- Forward and backward stability limits and warnings
- Notes subdivided into informational data, warnings (general, set‑up, operational) and definitions
- Maximum outrigger reaction
- Rated capacity chart data requirements: manufacturer model, required counterweights, boom/jib combination, support configuration (crawlers, outriggers, tires) with outrigger base dimensions if variable, slew area, special restrictions, and boom extend mode.
- Presentation rules: ratings with at least three significant figures; units in kilograms, pounds or tonnes; indicate minimum boom angle and maximum boom length for unloaded conditions and note hook block mass where applicable.
- Publication and durability: legibility and durability for physical manuals (resistance to water, oil, temperatures −40 °C to 60 °C), provisions for electronic manuals, and language competence for translations.
- Annex A: examples of data presentation formats.
Applications and Users
ISO 11661:2022 is essential for:
- Crane manufacturers - to produce compliant crane rating manuals and charts.
- Crane operators and riggers - to reliably read rated capacity charts and understand stability and setup limits.
- Site safety managers and inspectors - to verify correct documentation and safe lifting practices.
- Rental companies and fleet managers - to ensure charts match configurations and attachments.
- Regulators and certifiers - for conformity assessments and safety audits.
Using ISO 11661 helps reduce operator confusion, improve lifting safety, and ensure consistent presentation of rated capacities across mobile crane models.
Related Standards
- ISO 4306 (all parts) - Cranes - Vocabulary, Part 2: Mobile cranes (defines boom/jib terminology referenced by ISO 11661).