Inappropriate automatic activation of fixed fire-fighting system

What happened

The fixed firefighting system in the engine room on a harbour tug automatically activated and all the gas in the tanks emptied. This occurred after two consecutive blackouts on the tug within 24 hours. No-one was harmed.

What went wrong

• It was discovered that the firefighting system was activated by a sudden rise in battery voltage following the malfunction of the solenoid valve on the pilot cylinder, after the blackout;
• Our member considered that the low voltage (24v) electrical system in the tug may not have sufficient power to supply the critical equipment it was being used for;
• There was a lack of indication on the bridge or in the engine room regarding the operation of the electrical system; it was not possible to discern whether it was in emergency mode or normal operational mode.

Lessons to learn

• Check the functionality of vessels’ general emergency response systems:
  • Review the ships’ electrical system, especially systems affecting critical equipment – is there sufficient current supplied to operate the system in all cases?
  • Review blackout and emergency drill protocol in case of loss of power;

Members may wish to refer to:

• Inadvertent activation of condensed aerosol fire extinguishing system leads to a fatality
• Wrong key for the CO2 room
• MAIB: Blockage of fixed CO2 fire extinguishing system pilot hoses

Members may wish to review the incident of the cargo vessel Dali hitting and destroying the bridge in Baltimore. A Vessel blackout may have been one of the causal factors. IMCA hopes to make a safety flash on this incident available when a full report with findings is published.