Deck Container Fire Involving Class 5.1 Oxidiser Next to Acid and Paint
MV Coral Venture, a 4,200 TEU container ship, is in the North Pacific at 34°N 158°E bound for Yokohama, in 25 knots of north-westerly wind and 3 m seas. At 0340 the deck watch reports smoke and a sharp chlorine-like smell from a 20-ft container in bay 14, tier 3 on deck, stowed against the ship's side. The manifest shows UN 2880 calcium hypochlorite, class 5.1, 16 t in drums. The adjacent stack in bay 16 contains UN 1263 paint (class 3, packing group II) and UN 1789 hydrochloric acid (class 8). There is no fixed extinguishing system for deck cargo. The ship has a deck boundary-cooling line, one fire main supplying sea water at 6 bar, a foam monitor on the bridge front, and two sets of fireman's outfits with SCBA. The crew is mustered. Smoke is blowing across bays 14 to 16. The nearest land is 480 nm away and a patrol aircraft is due overhead in six hours.
1. Select the extinguishing agent and method for this fire, justifying the choice chemically and stating the agents you would refuse.
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Why this is not an ordinary container fire. Calcium hypochlorite is an oxidiser: it supplies oxygen to its own decomposition, which is strongly exothermic and produces chlorine and oxygen. The smell reported confirms decomposition with chlorine evolution. Any agent that works by excluding oxygen from the fuel is therefore of limited value, and the fire will continue to generate heat and toxic gas until the material is cooled and the reaction is suppressed.
Agent chosen. Water, in large quantities, applied as a spray or fog from an upwind, protected position - to cool the drums, cool the container shell, and cool the class 3 paint and class 8 acid in bay 16, which is the real escalation risk. The combination of hypochlorite with hydrochloric acid is precisely how chlorine gas is generated, so keeping the acid container cold and intact is a priority second only to cooling the seat of the fire.
Agents refused. CO2 and dry powder: ineffective against an oxidiser supplying its own oxygen, and impossible to hold in an open deck container. Foam: not appropriate for class 5.1 and it will not blanket an oxygen-generating decomposition. A straight jet: it can scatter burning drums and injure the crew; spray is required.
Method. Approach from upwind and from behind cover, no closer than the boundary, with SCBA and full protective clothing; never open the container doors, because the introduction of air will accelerate the fire and release a concentrated gas cloud.
2. Decide whether to fight the fire in position, alter course, or prepare to abandon, and state the criteria that would drive the decision.
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First, keep the crew out of the gas. The chlorine hazard, not the flame, is the primary threat. I would alter course to bring the wind on the starboard quarter, so smoke and gas blow clear of the accommodation and the fire teams work upwind. That is a command decision taken immediately, not after the fire is assessed.
Fight, but defensively. With no fixed system, one fire main and a single set of spare SCBA, this is a boundary-cooling operation, not an attack. I would set the boundary cooling on bays 12, 14 and 16 and the adjacent deck, keep the fire teams in short rotations with a standby team and a charged hose, and monitor for container bulging or rupture.
Criteria for disengagement. (1) Any breach of the accommodation boundary or the paint stack igniting. (2) Failure to hold the acid container cool. (3) Chlorine concentrations at the fire team's position that cannot be controlled by wind and distance. (4) Loss of the fire main or SCBA air. If any of these occur, I would withdraw the teams, close up, keep the ship upwind, and prepare the crew for abandonment while broadcasting a distress alert.
Jettisoning. Only as a last resort, if the container can be put over the side without endangering the crew and the ship is clear; it must be reported, with position, to the RCC, and the floating hazard noted, since a drifting oxidiser container is a danger to other traffic and a pollution issue under MARPOL Annex III.
3. State the notifications, records and post-fire actions required.
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Immediate notifications. Distress or urgency alert to the RCC via Inmarsat/ HF DSC with position, course, speed, nature of the casualty and the dangerous goods involved; a safety broadcast to shipping in the area; the company/DPA and the designated person ashore; and the charterer's operations desk. Given six hours to aircraft arrival, I would also request a specialist DG firefighting team or a tug with external firefighting capability if the fire is not controlled by then.
Records. Times of detection, first response, course alterations, boundary cooling start, agents used and quantities; the full DG manifest and stowage plan handed to the fire teams; the IMDG Code Emergency Response Procedures for Ships Carrying Dangerous Goods schedules consulted; SCBA set logs and team rotation times; the official logbook and a statement of facts. In a casualty investigation, the decision trail is the evidence.
Post-fire. Keep the container under observation for re-ignition; do not enter it until the atmosphere has been tested and the drums identified; arrange a port of refuge or discharge port for inspection and class attendance; preserve damaged drums and packaging for the surveyor; ventilate and wash down, controlling the wash water; and review why a class 5.1 oxidiser was stowed against the ship's side next to a class 8 acid, since segregation under the IMDG Code is the real root cause.