Bad, confusing design is a hazard we don’t hear about very much but in an emergency the difference between good design and bad design may be the narrow gap between success and tragedy. Take a look at the picture at the top of this page: Can you immediately tell which tags to pull to cut off fuel and which to pull to activate the CO2 fire suppression system? In the dark? In rough weather? In a hurry?
Unplanned releases of carbon dioxide can have tragic results. It can extinguish lives as easily as it can put out fires so it’s vital to ensure that the CO2 cylindre room is isolated when someone’s working on the fire extinguishing system, as a recent report from the UK’s Marine Accident Investigation Branch, MAIB, highlights.
It shouldn’t happen, but it does. Is your emergency response prepared?
On 23 August 2011, a shore-based service engineer was seriously injured on board the tug SD Nimble when six cylinders of carbon dioxide were accidentally discharged shortly after the tug had slipped from her berth in Her Majesty’s naval base in Faslane, Scotland.
The engineer was testing components of the vessel’s fixed carbon dioxide fire extinguishing system in the carbon dioxide cylinder room. The accidental discharge of carbon dioxide caused a depletion of oxygen levels in the cylinder room and aft hold causing the engineer to quickly lose consciousness. The tug was immediately manoeuvred back alongside and
the service engineer was quickly recovered onto the open deck, where cardio pulmonary resuscitation was started. The engineer was subsequently transferred by helicopter to the Southern General Hospital in Glasgow where, following a long period of recuperation and therapy, he made a good recovery.
CO2 not only puts out fires, it also puts out life. You really don’t want an engine room, or anywhere else flooding with it when there are people inside, as almost happened aboard Marsol Pride. Frighteningly it’s a case in which maintenance procedures were complaint with IMO requirements but the equipment was dangerous.
On 23 May 2010 the general-purpose oilfield support vessel Marsol Pride was conducting underwater operations within the Tui oil and gas field off the west coast of New Zealand. Marsol Pride was fitted with a fixed carbon dioxide (CO2) fire smothering system for its engine room. Late that night a valve on one of the CO2 pilot cylinders developed a leak and charged the system ready for release. A second leak in the main control valve then caused the entire system to activate resulting in an uncontrolled release of CO2 gas into the engine room. An automatic alarm in the engine room had warned the duty engineer there of the impending release so he had left the engine room to investigate the reason for the alarm. The incident caused one of the 2 main propulsion engines to shut down due to air starvation; other than that there was no damage to the vessel and no one was injured. An uncontrolled or inadvertent activation of an engine room fixed CO2 gas fire smothering system is a serious event because the CO2 gas displaces any air in the space so that it cannot sustain human life, and it can immobilise the ships propulsion and generator systems at a critical part of an operation.
A machinery space fire onboard a relatively new vessel was effectively responded to and extinguished by the vessel’s quick response team firefighters using portable extinguishing equipment.
However, before it was declared completely extinguished and approximately five hours after the fire started, the master of the vessel made the decision to release CO2 from the vessel’s fixed firefighting system. It failed to operate as designed.
Subsequently, crewmembers were unable to activate it manually and CO2 was never directed into the machinery space.
The following issues pertaining to the CO2 system were discovered.
It probably seemed like a good idea on the drawingboard: save money and space by using passageways and other rooms used by the crew as ventilation ducts. That idea contributed to what could have been a triple fatality aboard the open hatch bulk carrier Star Ismene in December 2009 says a newly released report from Norway’s Accident Investigation Board, AIBN.
As a result of the design it was unclear what constituted a confined space onboard and no risk assessment had been done which would lead to a more informed safety management system and educated the crew. Says AIBN: “this contributed to the ship’s crew establishing a practice that was regarded as safe, but without clearly understanding which parts of the ship were to be regarded as enclosed spaces at any time”.
The incident highlights the need to be cautious about entering spaces adjacent to known confined spaces. Says the AIBN report: “In the Accident Investigation Board’s opinion, it would have been expedient if these risks of personal injury had been identified already in the design phase”.
It also highlights the need to train seafarers not to enter a space to attempt a rescue with the proper equipment and support. Those who attempt to do otherwise most often become just another statistic.
One of MAC’s pet hate objects turns up in the report a non-ship-specific SMS: “The problem of the shipping company and the ship’s safety management system not being sufficiently ship-specific was not identified in the supervisory authority’s audits of the system”. Non-specific safety documents are themselves a hazard, among the victims of this trade in paper with little value, other than the magic word compliance, is BP.
In addition the Material Safety Data Sheet, MSDS, provided to the ship did not make it clear that the copper concentrate consumes oxygen and emits CO2.
Confined space hazards can crop up in the most unexpected places, as a recent report in the Confidential Hazardous Incident Reporting Programme’s Maritime Feedback shows. In this case it’s one your catering crew should be made aware of.
Says the CHIRP report: “The morning after taking three months’ provisions aboard the vessel, the chief cook proceeded to fetch some meat from the refrigerated meat room. Upon opening the door, he was affected by the atmosphere of the meat room. His eyes and nose were severely irritated by the atmosphere and he immediately closed the door.
The chief cook reported a ‘smell’ in the meat room to an officer who he encountered in the duty mess room. This officer subsequently entered the meat room to check for problems. After a period of 30 to 60 seconds he started to feel light headed and left the room.
Gard Academy’s 2010 Summer Seminar included an overview of ship air emissions from Frank Gonynor. It’s a worthwhile briefing that should be available to working seafarers, too.
It’s a forehead slapper, but if you want your CO2 extinguisher system to work when needed it might be a good idea to check, right now, that the safety pins have been removed from the cylindre valves.
Yes, it does happen.
Says a Marine Safety Forum alerts: “During an annual certification of critical equipment on a vessel, a contractor identified the safety pins used for transporting and disabling the system on the CO2 Cylinders had not been removed from the valves. This matter was brought to the attention of the Master on the bridge who subsequently removed the pins and informed the company byn incident report form for the identified near miss.
ANSUL – High Pressure Carbon Dioxide fire extinguishing systems:
There have been several instances where this particular fire extinguishing system has discharged without human intentional or accidental involvement.