ISO 1346:2021

Overview

ISO 1346:2021 specifies requirements and designation rules for polypropylene fibre ropes in common shipboard and general-service constructions. It covers 3‑strand hawser‑laid, 4‑strand shroud‑laid, 8‑strand braided and 12‑strand braided ropes made from polypropylene split film, monofilament and multifilament (PP2) and polypropylene high‑tenacity multifilament (PP3). The standard includes physical-property requirements (linear density, minimum breaking strength) and marking/packaging guidance, and it clarifies that manufacturers should be consulted because the document does not cover every variation in strength or performance.

Key topics and requirements

• Rope constructions: Defines four types - Type A (3‑strand hawser‑laid), Type B (4‑strand shroud‑laid), Type L (8‑strand braided) and Type T (12‑strand braided).
• Materials: Distinguishes PP2 (split film/mono/multifilament) and PP3 (high‑tenacity multifilament).
• Designation rules: Prescribes how to name a fibre rope (including the words “fibre rope”, the ISO number, construction type, reference number, material and UV protection status).
• Physical properties: Provides tables of linear density (ktex) and minimum breaking strength (MBS) for each reference number and construction. Linear density is measured under reference tension per ISO 2307; MBS values relate to new dry and wet ropes.
• Tolerances and testing notes: Specifies nominal tolerances on linear density and cautions that test breaking forces depend on termination type, knotting, bends, conditioning and test method.
• Marking and delivery: Requires marking, labelling, packaging and delivery lengths according to ISO 9554.

Practical applications and users

ISO 1346:2021 is directly relevant for:

• Rope manufacturers and designers specifying polypropylene ropes for general service.
• Marine and offshore operators selecting lines for towing, mooring, fendering and deck handling where lightweight, buoyant polypropylene rope is preferred.
• Procurement, quality assurance and inspection teams who need standardized rope designation, test properties (MBS) and marking for inventory and safety documentation.
• Engineers and safety officers assessing suitability of 3‑, 4‑, 8‑ and 12‑strand rope constructions for specific load scenarios (noting that manufacturer consultation is recommended for critical applications).

Related standards

• ISO 9554 - General specifications, marking, packaging and delivery for fibre ropes.
• ISO 2307 - Determination of certain physical and mechanical properties (linear density, breaking tests).
• ISO 1968 - Fibre ropes and cordage vocabulary (terms and definitions).

Keywords: ISO 1346:2021, polypropylene ropes, fibre ropes, 3‑strand, 4‑strand, 8‑strand, 12‑strand, PP2, PP3, minimum breaking strength, linear density, rope designation, braided ropes, hawser‑laid, shroud‑laid.