ISO 21125:2019

Overview

ISO 21125:2019 - Ships and marine technology - Marine cranes - Manufacturing requirements - defines the general technical manufacturing requirements for metal marine cranes intended for harbour conditions. Published in 2019, the standard targets deck cranes, floating/barge-mounted cranes, engine-room and provision cranes used on ships (including floating docks). It complements related ISO crane standards and focuses on fabrication, assembly, corrosion protection, testing and documentation.

Key topics and technical requirements

The standard covers practical manufacturing controls and inspection practices, including:

• Scope & exclusions

  • Applicable to metal marine cranes for harbour operations.
  • Not applicable to operation below −20 °C or above +45 °C, multi-crane lifts, emergency rescue, shore-side cargo cranes, lifeboat/launching appliances and certain other specified uses.

• Materials & traceability

  • Requirements for material selection and maintaining test/inspection certificates and records.

• Fabrication & welding

  • Rules for welded connections between plates of differing thickness, allowable mismatches, clearance between weld seams, and dimensional tolerances for assemblies.

• Machining & dimensional control

  • Inspection records for critical mating surfaces (shafts, holes, flanges, sheaves) and planarity checks during shipboard installation.

• Anticorrosion & oil sealing

  • Surface preparation, rust removal and continuous oil-sealing procedures before storage or installation.

• Mechanical, hydraulic and electrical assembly

  • Field/ workshop requirements, component identification and records, bolt-torque and assembly sequence guidance, hydraulic port marking, pipe tracing, and electrical cable lay/installation principles.

• Tests, markings & documentation

  • Requirements for keeping test records, marking plates and traceability for inspection by ship classification or inspection institutions.

Applications and who uses it

ISO 21125:2019 is intended for practical use by:

• Marine crane manufacturers - to define production, welding, machining, assembly and QA processes.
• Shipbuilders and offshore fabricators - for integrating cranes during shipboard installation and verifying flange planarity and mounting tolerances.
• Classification societies and inspection bodies - for conformity checks and review of material/test certificates.
• Ship operators, fleet maintenance and OEM service providers - to guide maintenance, replacement part manufacture and safe reassembly.

Related standards

Key linked documents referenced by ISO 21125:2019:

• ISO 19354 (Marine cranes - General requirements)
• ISO 19355 (Structural requirements)
• ISO 19356 (Test specifications)
• ISO 19360 (Rigging applications)
• ISO 3828 and ISO 4306‑1 (vocabulary and symbols)

Using ISO 21125:2019 helps ensure robust, traceable manufacturing and safer marine crane installation and operation in harbour environments.