Overview
ISO 15084:2003 - Small craft - Anchoring, mooring and towing - Strong points specifies minimum requirements for strong points used to attach chains, cables and lines for anchoring, mooring and towing on small craft up to 24 m hull length (per ISO 8666). It defines what a strong point is, required minimum numbers and locations of strong points by craft size, structural and corrosion-resistance expectations, and owner‑manual information. The standard does not set anchor weights or line lengths and does not specify requirements for strong points used to tow other vessels.
Key topics and technical requirements
- Scope and definitions
- Applies to small craft with hull length up to 24 m.
- Defines “strong point” (bollards, cleats, samson posts, bow eyes, winches, etc.) and design categories A–D.
- Minimum strong-point provision
- All craft: one anchoring/towing point forward.
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6 m: at least one aft mooring point.
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12 m: at least one additional mooring point forward and aft.
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18 m: additional mooring points port and starboard.
- Strength assessment
- Breaking-strength assessment may be by: formulaic horizontal-load calculation, direct calculation (considering windage, hull form and intended area), or matching strength when stronger lines are supplied.
- Design-category coefficients: A/B = 1.0, C = 0.9, D = 0.75.
- If manufacturer supplies lines/chains exceeding base requirements, the strong point must be at least 125% of the supplied line/chain breaking strength.
- Owner/operational limit: supplied lines/chains generally should not exceed 80% of the strong point breaking strength.
- Detailed requirements
- Reinforce surrounding structure (doubling plates/washers) where loads concentrate.
- Use corrosion‑resistant materials; UV‑stabilize non‑metallic fittings and replace on signs of deterioration.
- Label strong points where intended use is not obvious.
- Owner’s manual
- Must include breaking-strength data, labeling guidance, towing cautions (slow speed, release under load), and replacement guidance for non‑metallic fittings.
- Synthetic rope guidance
- Annex B provides reference mechanical properties for common synthetic ropes and points to ISO rope standards.
Applications and users
ISO 15084:2003 is intended for:
- Boat builders, naval architects and marine engineers designing secure attachment points.
- Shipyards and fit-out suppliers selecting and installing cleats, bollards, winches and bow eyes.
- Marine surveyors, classification societies and regulators verifying compliance.
- Boat owners/operators and marina managers who need correct line/chain selection and safe operational guidance.
Keywords: ISO 15084, strong points, small craft anchoring, mooring, towing, breaking strength, synthetic ropes, corrosion resistance, owner’s manual.
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