Overview
ISO 16856:2013 - Ships and marine technology - Loose gear of lifting appliances on ships - Hooks - defines types, basic parameters and technical requirements for hooks used as loose gear on shipboard lifting appliances. The standard applies to manufacturing, testing, marking, storage, transportation, use and maintenance of hooks fitted to ship lifting gear and complements general loose-gear requirements for maritime lifting equipment.
Key topics and technical requirements
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Hook types and designation
- Covers common shapes (S-shaped shank hook with point, D-shaped shank ramshorn hook, C-hook) and E-shaped variants. Example designation: “Hook ISO 16856 H‑S20” for a 20 t SWL hook.
- Requires automatic locking devices for various hook types.
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Materials and metallurgy
- Specifies preferred steel production routes (Martin, electric, oxygen converters) and recommends electroslag remelting for improved quality.
- Gives chemical composition ranges for carbon and carbon‑manganese steels (e.g., C 0.17–0.24 %, Si 0.17–0.35 %, Mn up to ~1.50 %, P/S limits ≤0.035 %).
- Mechanical property ranges (tensile strength and impact requirements) are specified; low‑temperature impact behaviour is addressed for designs below −10 °C.
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Manufacture and heat treatment
- Forging ratios: ≥3 for ingot-based forgings, ≥1.5 for billet.
- Heat treatment required after forging, with a maximum of three cycles.
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Surface/internal quality
- Hooks must be free from burrs, cracks, burns or folding. Internal defects are constrained (single defect ≤5 mm; scattered defects ≤3 mm diameter and ≤30 mm total length).
- Rewelding of defects is not permitted.
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Testing and inspection
- Every hook requires a proof test (duration ≥5 minutes). Proof load formula: for SWL ≤245 kN use 2×SWL; for SWL >245 kN use 1.22×SWL + 196 kN.
- Post‑test inspection for deformation, cracks and free rotation of moving parts. Manufacturers must provide certification for passing hooks.
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Marking, storage and transport
- Mandatory permanent marks: SWL (t), test load (kN), test date, hook number and manufacturer/test unit stamp.
- Anti‑rust treatment for stored hooks and secure packaging for transport.
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Use and maintenance
- Pre‑use checks: wear, moving parts, lubrication, looseness, cracks, heat damage or welding marks.
- Hooks must be repaired only by qualified personnel; scrap criteria include cracks, heat damage or wear exceeding 10% of moving part dimension.
Applications and users
ISO 16856 is used by:
- Shipbuilders, naval architects and rigging designers specifying shipboard lifting systems
- Hook manufacturers and foundries producing forged maritime hooks
- Classification societies, port operators and ship operators for procurement and inspection
- Maritime maintenance teams and safety officers applying inspection, testing and scrapping rules
Practical uses include specifying hook selection by SWL and shape, setting acceptance criteria for incoming hooks, defining proof test procedures, and establishing maintenance/marking protocols to enhance maritime lifting safety.
Related standards
- ISO 1837 - Lifting hooks - Nomenclature
- ISO 16855 - Ships and marine technology - Loose gear of lifting appliances on ships - General requirements
Keywords: ISO 16856, ship hooks, marine lifting gear, loose gear, lifting appliances on ships, proof load, SWL, hook marking, forging, hook inspection.