USCG: Gas-free certification & compliance for vessel hot work

The United States Coast Guard issued safety alert 03-24 warning of the critical need to ensure a gas-free environment before performing hot work on vessels. It focuses on a recent incident where a diesel fuel tank exploded on a commercial fishing vessel during maintenance, causing injuries and one fatality. The incident is currently under investigation by the Coast Guard Sector Honolulu and Hawaii State Fire Investigators.

The safety alert was issued on 26 August 2024.

Key Incident Details:

Preliminary findings revealed that the explosion was caused by welding conducted on a fuel tank vent pipe that was not certified as gas-free. The welding work led to the ignition of diesel fuel vapors, which triggered the explosion. The vessel failed to comply with the "Hot Works" permit guidelines issued by the State Department of Transportation (DOT), which authorized maintenance work on a water tank hatch, engine room stairs, and spotlights, but not the fuel tank. Despite this, unauthorized welding was carried out on the fuel tank vent pipe, violating the permit requirements and critical safety protocols. Furthermore, the area had not been certified as “Safe for Hot Work” by a certified marine chemist, as required under the permit.

Regulatory Background:

Uninspected commercial fishing vessels, like the one involved in this incident, fall under 46 Code of Federal Regulations (CFR) Subchapter C. These vessels are subject to limited oversight from the U.S. Coast Guard or recognized class societies. As a result, the responsibility for ensuring safe practices during maintenance and repair work rests heavily on the vessel’s owners and operators.

The alert highlights key safety regulations and industry standards that are crucial to preventing similar accidents during hot work operations:

Occupational Safety and Health Administration (OSHA): Under 29 CFR 1915 Subpart B, OSHA mandates that personnel conducting hot work around fuel tanks must ensure the work area is certified as safe. A "Gas Free" certificate must be issued, confirming the space is free of flammable vapors. Compliance with these measures is essential to avoid dangerous explosions or fires during welding or other hot work.
National Fire Protection Agency (NFPA): NFPA standard 51B outlines comprehensive safety guidelines for welding, cutting, and other hot work activities, focusing on fire prevention and protection. This includes the need for hot work permits, fire watches, fire suppression equipment, and additional safety precautions in confined spaces where the risk of explosion may be elevated.

Recommendations for the CFV Industry:

In response to this incident, the Coast Guard strongly recommends the following actions to prevent future accidents in the commercial fishing vessel industry:

Strict Compliance with OSHA Regulations: Ensure that personnel conducting hot work are fully aware of and follow 29 CFR 1915 Subpart B regulations. This includes proper atmospheric testing to confirm the space is safe for hot work.
Adherence to NFPA Standards: Operators should familiarize themselves with NFPA 51B guidelines to prevent fire and explosion risks during hot work operations. The NFPA 51B document is available for purchase, and its standards should be followed rigorously.
Full Compliance with “Hot Works” Permit Requirements: No unauthorized deviations from the approved scope of work should occur during maintenance. Any changes to the work plan should be pre-approved by the relevant authority, and hot work should only be conducted in certified safe environments.
Qualified Welders: Only certified welders should be employed for such tasks. Welders should be qualified by recognized organizations such as the U.S. Coast Guard (USCG), the American Society of Mechanical Engineers (ASME), the American Bureau of Shipping (ABS), or the American Welding Society (AWS).

Conclusion:

This safety alert serves as a reminder of the critical importance of following established safety protocols during hot work operations, especially around fuel tanks and confined spaces. The Coast Guard underscores that this alert is informational and does not override any existing safety or operational requirements. Vessel operators must remain diligent in ensuring compliance with all safety regulations to avoid similar incidents in the future.