ISO 6325:2024

Overview

ISO 6325:2024 - Ships and marine technology - Cable stoppers specifies requirements for the design, construction, testing and installation of cable stoppers used with marine windlasses and anchor capstans (as defined in ISO 4568). The standard covers types and sizes, strength and safety criteria, functional and operational requirements, acceptance tests, designation and marking - providing manufacturers, shipbuilders and operators with a uniform basis for safe and reliable chain-cable stopping devices.

Key topics and technical requirements

• Scope & applicability: Applies to cable stoppers for use with windlasses and anchor capstans; nominal sizes correspond to anchor chain sizes in ISO 1704.
• Types: Track-type (T), roller-type (R), combined track & roller (C), and combined with adjust block (D).
• Classes & strength:
  • Class A: withstands 80% of nominal breaking load without permanent deformation.
  • Class B: withstands 40% of nominal breaking load without permanent deformation.
• Materials & design: Environmental and material requirements referenced to ISO 7825:2017; designed stresses shall not exceed material yield stresses. Roller design must allow smooth chain passage and avoid high bending moments (see ISO 1704).
• Operational limits:
  • Envelope angle of chain ≥ 115°; horizontal sextant angle 0°–25°.
  • Manual operation force limits: ≤ 350 N for chain diameters < 80 mm; ≤ 500 N for diameters ≥ 80 mm (unloaded).
  • Lashing device (if fitted) must hold at least twice the anchor weight plus 10 m of chain; stresses in lashing ≤ 0.4 of yield stress; chain stress when lashed ≤ 0.2 of breaking strength.
• Safety & installation: Stoppers must lock reliably (prevent accidental opening), be easy and safe to operate, be fitted with locking devices on moving parts, and be positioned so anchor is close to storage location.
• Acceptance tests & inspection:
  • Visual inspection at manufacture (operation, roller rotation, surface/weld quality).
  • Tensile test on the first unit to class load (80%/40%) - factory inspection may be witnessed by classification society representative.
• Designation & marking: Standard defines detailed designation format (ISO 6325-A-L-R-100–3-115° example) and mandatory permanent marking (manufacturer, ISO number, class, chain size, grade, date, classification seal).

Applications and users

• Shipbuilders and naval architects specifying deck outfitting
• Deck machinery and marine equipment manufacturers
• Classification societies and surveyors for conformity verification
• Shipowners, operators and offshore vessel managers for procurement and maintenance
• Installation and maintenance crews implementing safe anchoring arrangements

Related standards

• ISO 1704 - Stud-link anchor chains
• ISO 4568 - Windlasses and anchor capstans
• ISO 3828 - Deck machinery vocabulary and symbols
• ISO 7825:2017 - Deck machinery - General requirements
• IACS UR W18 - Anchor chain accessories

Keywords: ISO 6325:2024, cable stoppers, ships and marine technology, windlasses, anchor capstans, chain cable, class A, class B, acceptance tests, installation.