ISO 18692-4:2023

Overview

ISO 18692-4:2023 - "Fibre ropes for offshore stationkeeping - Part 4: Polyarylate" defines the main characteristics and test methods for polyarylate fibre ropes used in offshore stationkeeping and mooring applications. It replaces ISO/TS 19336:2015 and supplements the general requirements in ISO 18692‑1:2018, providing material qualification, mechanical requirements, and type-testing protocols specific to polyarylate cores.

Key topics and requirements

• Material specification
  • Rope core fibres must be polyarylate with an average tenacity ≥ 1.8 N/tex and core tenacity ≥ 0.90 N/tex (measured per ISO 18692‑1).
  • Hydrolysis resistance: residual fibre strength ≥ 90% after immersion (2 weeks at 80 °C or equivalent accelerated conditions).
• Mechanical performance
  • Minimum breaking strength (MBS): values are specified per reference number (rope diameter) in Table 1 of the standard.
  • Axial compression fatigue: ropes must demonstrate residual strength ≥ 95% of MBS after the Annex B test procedure for axial compression fatigue.
  • Cyclic loading endurance: residual strength after cyclic loading must be ≥ 80% of MBS.
  • Torque properties: rope construction shall achieve torque-neutral or torque-matched behavior as defined in ISO 18692‑1.
• Construction and protection
  • Core particle ingress protection, protective cover thickness, and rope layout follow ISO 18692‑1 provisions.
• Testing and certification
  • Detailed type-test methods, sample counts, test machine controls, and reporting requirements are specified. Testing of current production, marking, labelling, packaging, and certification follow ISO 18692‑1.

Practical applications and users

• Target users:
  • Rope manufacturers and textile engineers developing high‑performance polyarylate mooring lines.
  • Offshore engineers and mooring system designers selecting stationkeeping ropes for floating structures, platforms, and FPSOs.
  • Testing laboratories, classification societies, and procurement teams verifying compliance and issuing certifications.
• Practical value:
  • Ensures reliable long‑term performance of polyarylate ropes under compression, cyclic loading, seawater exposure and particle ingress.
  • Provides objective acceptance criteria (MBS, core tenacity, fatigue and hydrolysis resistance) to support safe mooring design and supplier qualification.
  • Harmonizes manufacturer testing and certification for global offshore operations.

Related standards

• ISO 18692‑1:2018 - General specification for fibre ropes for offshore stationkeeping (referenced throughout).
• ISO 1968 - Fibre ropes and cordage vocabulary.
• ISO 9080 - (referenced for accelerated ageing/test-time equivalence).

Keywords: ISO 18692-4:2023, polyarylate fibre ropes, offshore stationkeeping, axial compression fatigue, minimum breaking strength, rope testing, mooring lines, particle ingress protection.