ISO 10972-2:2009

Overview

ISO 10972-2:2009 - Cranes - Requirements for mechanisms - Part 2: Mobile cranes - specifies requirements for the design, arrangement and minimum component characteristics of mobile crane mechanisms, supplementing the general rules in ISO 10972-1. It covers hoisting, boom hoist and telescoping, swing and travel mechanisms, braking and locking devices, and related safety features. Note: rules for proof-of-competence calculations for limit states (yield strength, fatigue, wear) are explicitly excluded.

Key topics and technical requirements

• Hoisting mechanisms (boom and load hoists)

  • Include limiting and indicating devices per ISO 10245‑1/2.
  • Wire‑rope drums or hydraulic cylinders permitted; drums must have sufficient capacity for full boom and load range.
  • Minimum wraps on drums: ≥3 full wraps with wedge anchors, ≥5 full wraps with set‑screw anchors.
  • Drum flange must extend 1 to 1.5× wire rope diameter over top layer during lifting.
  • Brakes/clutches sized for rated loads and thermal capacity; power‑controlled lowering recommended to reduce brake demand.
  • Integrally mounted holding devices (e.g., load check valves) required on hydraulic cylinders to prevent uncontrolled lowering.

• Boom telescoping mechanisms

  • Extension/retraction by hydraulic, mechanical, electrical or manual means.
  • Inspection access for telescoping wire ropes; rope selection per ISO 4308‑2.
  • Powered retract must control any retractable rated load; holding devices required to prevent uncontrolled retraction on hydraulic failure.

• Swing mechanisms

  • Controlled acceleration/deceleration; swing braking with holding power in both directions.
  • Swing locking pawl or equivalent to prevent rotation in transit; must withstand at least 25% above torque from wind and gradient loads.

• Travel and service brakes

  • Travel controls location requirements for single/multi‑station cranes; communication means when operator positions differ.
  • Brakes/locks must hold machine on recommended gradients and remain engaged on loss of power/pressure.
  • Service brake linings must be asbestos‑free and suitable across operating conditions.

• Hydraulic and mechanical safety

  • Multiple boom cylinders hydraulically connected with a safety factor ≥4 against maximum induced pressure; connections must avoid sudden pressure loss and asymmetric overload.

Applications and users

ISO 10972-2:2009 is used by:

• Crane manufacturers and mechanical designers specifying hoists, drums, brakes and hydraulic circuits.
• Safety engineers and maintenance teams implementing inspection, testing and retrofit procedures.
• Certification bodies, regulatory authorities and third‑party inspectors assessing mobile crane conformity.
• Fleet managers and contractors seeking compliance guidance for procurement and safe operation.

Practical uses include component specification, installation checks, operational safety procedures, and design reviews to ensure reliable hoist control, safe boom operation and secure travel/braking systems.

Related standards

• ISO 10972-1 (General requirements)
• ISO 10245-1 / ISO 10245-2 (Limiting and indicating devices)
• ISO 8087 (Drum and sheave sizes)
• ISO 4301-2, ISO 4306-1/2, ISO 4308-2 (classification, vocabulary, wire rope selection)
• Referenced standards for steering/braking: ISO 5010, SAE J1977, IEC 60204-32 (electrical equipment).