Overview
ISO 24041:2020 - Ships and marine technology - Shark jaws and towing pins - specifies requirements for the design, manufacture, operation, performance and acceptance tests of marine shark jaws and towing pins driven by electric, hydraulic, diesel or steam power. The standard covers definitions, types (fork and triplex), structural forms, material and strength requirements, performance specifications and mandatory acceptance tests for deck machinery used to secure and lead towlines.
Key topics and technical requirements
- Scope and types: Differentiates fork shark jaws and triplex shark jaws, and defines towing pins and support boxes (including left/right/central configurations).
- Materials & stresses: Component permissible stresses shall not exceed 0.67 × yield strength; support structures limited to 0.5 × yield strength.
- Safe Working Load (SWL) and sizing: Tabled values relate nominal rope diameters (examples in the standard range from small to large sizes) to SWL and minimum working times. Typical working-time limits are specified (e.g., shark jaws: ~8–15 s; towing pins: ~10–25 s depending on size).
- Load alarms and monitoring: An alarm must activate at 50% of rope breaking load or 50% of shark jaw SWL. Provision for load measuring devices and overload alarms on the wheelhouse and portable control.
- Emergency release: Defined emergency-release load criteria by SWL band:
- SWL > 5 000 kN → emergency release load = 40% of SWL
- 1 200 kN ≤ SWL ≤ 5 000 kN → 20% + 1 000 kN of SWL
- SWL
