Barrier Failure and Fire Escalation in a Non-Class Wooden Fishing Vessel: A Structured Safety Assessment of the Hentri-I Engine-Room Fire

Engine-room fires remain a dominant loss pathway in non-class wooden fishing vessels where combustible construction coexists with high thermal and fuel loads in confined machinery spaces. Using the Hentri-I engine-room fire (North Tanimbar, Indonesia; 3 September 2021) as an evidence-bounded case, this paper converts an official investigation into a barrier-performance model and derives engineering actions for vessel equipment, layout, and operation/maintenance. A Bow-Tie was developed around the top event “uncontrolled engine-room fire,” mapping report-supported threats to prevention, detection, suppression, and consequence-management barriers. Barrier availability and effectiveness were coded from documented arrangements and survivor statements and used to prioritize feasible retrofit options for resource-constrained operators. The analysis shows a prevention set weakened by fuel/heat vulnerabilities and combustible interfaces, while escalation was accelerated by absent detection, non-isolable natural ventilation, and suppression limited to portable extinguishers without a dedicated fire pump or fixed system. These gaps compressed the effective response window and shifted the outcome toward abandonment offshore. A minimum viable retrofit package is proposed, including fuel-line hardening, heat-source shielding, ventilation isolation provisions, early detection, and a basic machinery-space suppression/attack capability, supported by a barrier-focused comparison to small-vessel safety requirements.