Shipyards are high-risk industrial facilities where vessels are built, repaired and dismantled. Welding, grinding, painting and fuel transfer happen simultaneously. NFPA 312 (Fire Protection of Vessels During Construction, Conversion, Repair, and Lay-Up) defines dry dock fire systems, hot work permits and gas-free certificates.
Dry Dock Fire System
- Seawater main: hydrant every 60 m, 4,000 L/min flow
- Foam monitor: AFFF or F3 fixed monitor, 10,000 L/min
- Mobile pump: diesel-driven, accesses vessel hull
- Dock-side water curtain: above wooden jetty
Hot Work Permit
- NFPA 51B: hot work standard - permit mandatory
- Fire watch: second person, 30 min after-watch
- Spark blanket: contains spark spread
- Portable extinguisher: 2A:40B:C within 1.5 m
- Flammable liquid: 10.7 m separation or physical barrier
Gas-Free Certificate
Before tanker repair:
- Marine Chemist (AIHA-certified) samples tank
- O2: 19.5-23.5 percent
- LEL: <10 percent
- H2S: <10 ppm
- CO: <50 ppm
- Benzene (crude tanker): <0.5 ppm
Certificate valid 24 h, renewed each shift.
Onboard Fixed CO2
- Engine room: SOLAS FSS Code CO2 total flooding
- Design concentration: 40 percent (diesel), 50 percent (gas)
- Manual release: two-position release (anti-false activation)
- Special: LNG carrier - IG-541 or water mist alternatives
Shipyard fire with SprinkCalc
SprinkCalc computes seawater main, AFFF monitor flow and onboard CO2 total flooding per NFPA 312.
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Sources & Further Reading
NFPA 312, NFPA 51B, SOLAS FSS Code, OSHA 29 CFR 1915, AIHA Marine Chemist. NFPA 312 Vessels Construction standard.