Rigging regulation study for ‘Bruine vloot’

Conoship International has recently completed a comprehensive regulatory study commissioned by the Dutch Ministry of Infrastructure and Water Management (ILT) on the rigging of traditional sailing passenger ships, commonly known as the Bruine Vloot. The study was initiated following several serious incidents involving failures in rigging components.

The research has been conducted by our engineers, and researchers Riemer Halbertsma and Jules Blokhuis. The research critically reviewed the current ES-TRIN standards (the European Technical Requirements for Inland Navigation vessels).

The goal of the research:

”To assess whether these standards are sufficient to guarantee safety and practical applicability across the diverse fleet of historical sailing vessels.”

Key findings and recommendations for:

1. Expanded tables for rigging components: New strength-based criteria were developed to fill gaps in the ES-TRIN tables for spars such as masts, booms, bowsprits, and gaffs.
2. New norms proposed:
   1. Jib booms (fokkebomen) and yards (ra’s): No specific rules currently exist; the report introduces calculation models to define safe dimensions.
   2. Wishbone gaffs: Due to their diverse configurations, a case-by-case engineering assessment is recommended rather than a general rule.
3. Standing rigging:
   1. For ships that deviate from the prescribed number of stays, analyses show safety can still be undisputed, provided strength requirements are met.
   2. Small vessels (<30 m³ displacement) were shown to safely qualify for reduced stay strength, confirming existing ES-TRIN allowances.
4. Running rigging
   1. ES-TRIN’s requirement for too many sheaves in a tackle is often impractical; the study recommends a maximum requirement of six blocks to improve handling without compromising safety.

Impact:

The findings help close critical regulatory gaps, replace outdated assumptions by calculations, and better align legal standards with the real-world sailing and maintenance practices of the Dutch charter fleet. The proposed adjustments are expected to improve both safety and operational feasibility.

The full report is available for download on the website of the Dutch Ministry of Infrastructure and Water Management: Analyse regelgeving tuigage Zeilende Chartervaart | Rapport | Inspectie Leefomgeving en Transport (ILT)

The full Bruine Vloot report is only available in Dutch.
Feel free to reach out to us for more information about the topic!