Overview
ISO 11660-4:2012 specifies the particular requirements for access, guards and restraints for jib cranes (as defined in ISO 4306-1). It complements the general provisions in ISO 11660-1 by addressing design and safety measures specific to jib crane structures, walkways and components used during normal operation, inspection, maintenance, erection and dismantling. The standard is intended to reduce risks from moving parts, falling objects and fall hazards on or near jib cranes.
Key topics and technical requirements
- Access design
- Access to control stations and other crane areas must be provided by walkways, stairs, ladders, landings or mobile ground-mounted facilities.
- Design must comply with the relevant clauses of ISO 11660-1 with jib-specific additions from ISO 11660-4.
- Crushing hazard controls
- For frequently used access (type 1), transfer points with crushing risk must have interlocked gates that disable the relevant motion.
- For less frequent access (type 2), maintain a safety distance of at least 0.5 m; where not possible, apply warning labels and motion-disabling devices.
- Stairs and ladders
- Recommended stair step dimensions: rise 200 mm, clear width 500 mm.
- Rung ladders: first flight ≤ 10 m; rest landings at least every 10 m of vertical climb.
- Manholes and hatch apertures
- Minimum effective hatch sizes where larger dimensions cannot be provided: type 1: 0.5 m × 0.5 m; type 2: 0.5 m × 0.4 m.
- Walkway along inclined jib
- When the jib cannot be lowered, a walkway with side protection or personal fall-protection device is required.
- Walkway width should follow ISO 11660-1 (Table 6, type 2 access).
- Toe boards: minimum height 0.03 m; may be required on one or both sides depending on clearance (1.8 m threshold).
- Guards and restraints
- Moving parts must be guarded by safety distances per ISO 13852 or by fixed/removable guards; warnings where guarding is not practicable.
- Open gears, chain drives and similar transmissions in permanent access zones shall be guarded unless drawing-in points are sufficiently remote.
- Covers and access closures must be hinged or retained to prevent falling. External slewing gears require covers or devices to prevent falling if rupture/jamming occurs.
- Use of multi-part hook block designs is recommended to minimize hand-drawing-in risks.
Applications and who uses it
ISO 11660-4 is used by:
- Crane manufacturers and designers specifying safe access and guarding for jib cranes
- Health & safety officers, maintenance teams and inspectors conducting risk assessments and safety audits
- Employers and site managers developing procedures for inspection, maintenance and safe access
- Regulators and procurement teams referencing standards in specifications and compliance checks
Practical benefits include improved crane safety, clearer maintenance access design, reduced falling-object risk and harmonized requirements for jib-crane installations.
Related standards
- ISO 11660-1:2008 - Cranes: Access, guards and restraints - Part 1: General
- ISO 4306-1 - Cranes: Vocabulary (definitions for jib cranes)
- ISO 13852 - Safety distances to prevent reaching danger zones
Keywords: ISO 11660-4, jib cranes, crane safety, access guards restraints, walkway design, rung ladder requirements, guard for moving parts.