ISO 24045:2021

Overview

ISO 24045:2021 specifies requirements for adjustable roller‑type chain stoppers used in ships and marine technology. The standard covers design, strength, safety, function, operation, structure, materials, acceptance and marking for these devices. Adjustable roller‑type chain stoppers are fixed to the ship structure (installed between the windlass and hawse pipe) to guide, lock and bear anchor chain loads during navigation and anchoring.

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Key topics and technical requirements

• Design and strength
  • Must withstand a design load equal to 80% of the nominal breaking load of the corresponding anchor chain (aligned with ISO 6325 Class A cable stoppers).
  • Design stress shall not exceed the material yield stress; calculations are specified in Annex A (strength calculations).
  • Components and dimensions given as reference in tables; final sizing should be based on strength calculations.
• Function and operation
  • Installed between windlass and hawse pipe to control and lock anchor chain and bear specified loads.
  • Manual operation required under no load; maximum operating forces specified:
    • Anchor chain diameter < 84 mm: ≤ 350 N
    • Anchor chain diameter ≥ 84 mm: ≤ 500 N
  • Locking devices required where unintentional movement could endanger operators.
• Structure and components
  • Main parts include support, roller, bushing, shaft, chain guide groove, lever, pins, balance weight and stop plate.
  • Left‑hand and right‑hand variants are defined by viewing orientation from the gypsy to the chain stopper.
• Materials
  • Supports, pins, balance weights, adjusting blocks, stop plates: weldable steel, min yield strength 235 N/mm² (or equivalent).
  • Shafts: steel with min yield strength 550 N/mm².
  • Levers: steel with min yield strength 350 N/mm².
  • Rollers and chain guide grooves: steel castings min yield 235 N/mm², carbon ≤ 0.23%.
• Acceptance and marking
  • Visual inspection requirements at manufacture: device operation, roller motion, surface finish and weld integrity.
  • Permanent marking must include: name, reference ISO 24045:2021, applicable anchor chain diameter, anchor chain grade (AM3), and handedness (L or R).

Applications

• Securing and guiding anchor chain during anchoring, mooring and navigation.
• Deck machinery design and outfitting for commercial vessels, offshore units and workboats.
• Equipment procurement specifications, manufacturing quality control, and in‑service maintenance checks.

Who uses this standard

• Ship designers and naval architects
• Deck machinery manufacturers and fabricators
• Marine engineers and maintenance teams
• Classification societies, shipbuilders and ship operators
• Procurement and regulatory/compliance personnel

Related standards

• ISO 1704 - Stud‑link anchor chains
• ISO 3828 - Deck machinery vocabulary and symbols
• ISO 4568 - Windlass and anchor capstan
• ISO 6325 - Cable stoppers
• ISO 7825 - Deck machinery general requirements

Use ISO 24045:2021 when specifying, designing or accepting adjustable roller‑type chain stoppers to ensure consistent safety, load capacity and interoperability with anchor chain systems.