Overview
ISO 24061:2021 - "Ships and marine technology - High holding power balance anchors" defines design, production, testing, marking and inspection-certificate requirements for high holding power balance (HHPB) anchors. Applicable to the design, selection, production and acceptance of these anchors, the standard provides manufacturers, shipbuilders and Class/inspection bodies with a consistent technical baseline for anchor design, manufacturing controls and conformance testing.
Key topics and technical requirements
- Scope and definitions: establishes terminology for HHPB anchors (rotatory fluke that restores upright by gravity and has ≥2× holding power vs. ordinary stockless anchor of the same mass).
- Design and structure: typical components include shank, fluke, head pin, lateral pin, shackles (Annex A provides structure/dimensions). Anchors are classified by theoretical mass with corresponding basic dimensions.
- Materials and mechanical properties: chemical composition and minimum mechanical property requirements are specified for shank, fluke, shackles and pins (see tables for tensile strength, yield strength, elongation, impact energy).
- Production controls:
- Surface and internal defect criteria for cast/forged components.
- Welding, heat treatment: welding materials must match parent metal; normalizing and tempering required with tempering temperature ≥600 °C.
- Surface finish: rotary parts ground to Ra 25 μm; non-processed parts ≤ Ra 100 μm.
- Mass tolerance: +7 % / −3 %; balance requirement that flukes restore upright automatically when fully hung.
- Dimensional & geometric tolerances: typical tolerance ±4 % (max ±20 mm); straightness ≤3 mm per 1 m; specific clearances for shackles and pins.
- Non-destructive testing (NDT): cast and forged parts to be inspected per IACS REC.69 and IACS REC.68.
- Painting: two coats (asphalt + black) standard unless agreed otherwise.
- Test methods:
- Drop test: drop from 4.0 m onto steel lining; followed by hammer test and NDT if abnormal.
- Proof test: proof load is based on nominal mass equal to 1.33 × actual mass; residual deformation limits and fluke rotation specified (Annex B).
- Holding power test at sea: procedures provided (Annex C).
- Marking and certificate: marking requirements and inspection certificate contents are defined.
Applications and users
ISO 24061:2021 is intended for:
- Shipbuilders, offshore and marine equipment manufacturers specifying or producing HHPB anchors
- Naval architects and procurement engineers selecting anchors for vessel outfitting
- Classification societies, surveyors and QA/QC inspectors performing acceptance and proof tests
- Ship operators and owners requiring documented anchor performance and traceability
Practical uses include technical specifications, production quality control, factory and sea trials (proof and holding power tests), and supporting compliance and procurement documentation.
Related standards
- ISO 3828 (Shipbuilding - Deck machinery vocabulary & symbols)
- IACS Recommendations (REC.68, REC.69) for NDT procedures
Keywords: ISO 24061:2021, high holding power anchors, balance anchors, anchor design, anchor test methods, proof test, drop test, marine standards, ship outfitting.
