Overview
ISO 13797:2020 - "Ships and marine technology - Ship's mooring and towing fittings - Cruciform bollards" specifies the types, nominal sizes, dimensions, materials, construction, manufacturing, inspection and marking requirements for cruciform bollards used on sea‑going vessels. The standard ensures bollards meet normal mooring and towing performance and provides guidance for safe working load (SWL) determination and on‑board marking.
Key topics and technical requirements
- Classification: Two manufacturing types
- Type A: manufactured from steel pipes
- Type B: manufactured from steel plates
- Nominal sizes: Main post outside diameters - 150, 200, 250, 300, 350, 400 mm.
- Materials:
- Type B: weldable steel plates with yield point ≥ 235 N/mm²
- Type A: weldable steel pipes with yield point ≥ 215 N/mm²
- Dimensions & mass: Detailed in Table 1 (standard) - includes geometry for main post, cross pipe, welding legs and reference SWL values.
- Strength assessment (Annex A): Based on simple beam theory with stress limits under SWL: bending ≤ 85% yield, shear ≤ 60% yield, combined ≤ 100% yield. A 2 mm wear allowance is deducted where rope contacts the surface; corrosion margin is covered in the stress criteria.
- Construction & deck reinforcement: Posts formed from pipe or plate; deck under bollard must be reinforced by carlings or stiffeners as shown in the standard.
- Manufacturing & inspection: Surfaces (including welds) must be free of visible flaws; rope-contact surfaces must be free of roughness that could abrade ropes; external anti‑corrosion coating required.
- Marking & documentation: SWL must be recorded in the ship’s towing and mooring plan (per IMO Circular MSC/Circ.1175) and marked on the bollard (e.g., weld bead) in tonnes and placed so it is not obscured.
Applications and users
ISO 13797:2020 is intended for:
- Shipbuilders and shipyards specifying deck fittings
- Marine equipment manufacturers (bollard OEMs)
- Naval architects and design offices integrating mooring/towing arrangements
- Classification societies and surveyors verifying compliance
- Ship operators, shipmasters and port engineers using towing and mooring plans
Practical uses include selection and installation of cruciform bollards to ensure compatible SWL, correct deck reinforcement, safe mooring/towing operations, and consistent manufacture and inspection practices.
Related standards
- IMO Circular MSC/Circ.1175 - Guidance on shipboard towing and mooring equipment
- ISO 2408 - Steel wire ropes - Requirements
- IACS UR A2 - Supporting hull structures for towing and mooring fittings
- OCIMF Mooring Equipment Guidelines (MEG4)
Keywords: ISO 13797:2020, cruciform bollards, ship's mooring and towing fittings, safe working load, SWL, deck reinforcement, maritime standards.