Overview
ISO 13795:2020 - Ships and marine technology - Ship's mooring and towing fittings - Welded steel bollards for sea‑going vessels - defines requirements for welded steel bollards intended for normal mooring and towing on sea‑going ships. The standard covers classification by type, nominal sizes, dimensions, materials, construction, manufacturing and inspection, marking and the basis for strength assessment. It replaces the 2012 edition and includes updated technical guidance on selection, D/d ratios and strength assessment.
Key topics and requirements
- Types and nominal sizes: Bollards are classified as Type A (compact base plate) or Type B (wide base plate). Nominal post diameters range from 150 up to 600 mm with size variants (e.g. 250A/250B, 300A/300B, etc.) specified in the tables.
- Dimensions and SWL: Detailed dimensional tables and safe working load (SWL) and towing values are given for one‑rope and two‑rope use. SWL markings are expressed in tonnes (t) and must be visible during operation.
- Materials: Base plates and posts are made from weldable steel with a minimum yield point of 235 N/mm²; posts may be formed from plate or steel tubes.
- Construction: Posts may be pipe or plate formed; fins are required to keep ropes low and reduce bending loads. An eye plate for stopping‑off rope/chain is required.
- Load assessment: Annex A provides the basis for strength assessment using simple beam theory and defined load cases (figure‑of‑eight belay produces a resultant 2P; two ropes can impose up to 4P shear at the post base).
- Manufacturing & inspection: Surfaces (including welds) must be free of visible flaws; rope contact surfaces must be smooth to avoid abrasion. External anti‑corrosion coating is required; low‑friction coatings are not recommended as they reduce holding force.
- D/d ratio and rope effects: Selection guidance addresses the D/d ratio (bollard diameter to rope diameter) and notes that rope tensile strength can be reduced by tight bend radii per rope manufacturer advice.
Applications and users
ISO 13795:2020 is used by:
- Shipbuilders and naval architects specifying deck fittings
- Bollard and deck‑fitting manufacturers
- Ship operators, shipyards and maintenance crews for procurement, installation and inspection
- Classification societies and marine surveyors verifying compliance
- Port and towing equipment planners integrating mooring/towing plans
Practical benefits include standardized dimensions and SWL values for safe mooring/towing design, clearer marking and inspection criteria, and improved interoperability of fittings across vessels and suppliers.
Related standards
- IMO Circular MSC/Circ.1175 - Guidance on shipboard towing and mooring equipment (normative reference cited in ISO 13795:2020)
- Work developed by ISO/TC 8 (Ships and marine technology), SC 4 (Outfitting and deck machinery)
Keywords: ISO 13795:2020, welded steel bollards, ship's mooring, towing fittings, safe working load, SWL, D/d ratio, mooring lines, shipbuilding, deck fittings.
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