An engineroom fire may result from the most innocuous of causes, but the consequences can be dire in the extreme
Disabled by fire west of Marseille on 28 July this year, the roro Marfret Niolon became the latest vessel to suffer that most feared of sea-going events, an engineroom explosion.
Although the crew managed to extinguish the fire and the ship got back to Marseille, the incident serves to highlight the ever-present dangers that exists wherever hard-working engines are present.
At the time of writing it is far too early to expect any conclusive report on what triggered the fire aboard the Marfret Niolon or how it was extinguished, but a series of recent investigations into engineroom fires show all too clearly that fire-fighting in these high-risk spaces rarely goes to plan.
Explosions and the subsequent fires often rapidly cause damage that impedes the entire extinguishing process, as they engulf equipment intended to help fight the flames. As the Bahamas Maritime Authority report into the fire on board the 28,600-tonnes Black Watch cruise ship – on 1 July 2016 when it was 260 nautical miles off the coast of Madeira – showed very clearly, the resulting heat and smoke were so great that it quickly led to a succession of subsequent problems.
The voltage stabiliser on the emergency generator was knocked out, causing intermittent loss of power that affected just about every fire-fighting item of equipment, including fire pumps, bilge pumps, lighting, breathing apparatus compressor and communications. The intermittent loss of communications led to confusion between the bridge and engineroom about exactly what was happening. These equipment failures almost certainly resulted in engineroom fire burning longer than it otherwise would have done. Having started at 8.38am, it was not extinguished in the auxiliary engineroom until 11.09am.
As the fire raged, with temperatures in the engineroom hitting 660°C, it began to trigger alarms in cabins located directly above and to port, with other hot spots turning up nearby. It was about this time, almost exactly an hour after the fire started, that the emergency generator failed and rendered useless a whole range of essential fire-fighting equipment “integral to support the fire-fighting effort,” according to the report. And when the ultra-high frequency internal communications went down a further six minutes later, the bridge had to resort to runners for the next nine hours to find out what was going on.
In engineroom fires one thing quickly triggers another, as the report into the Black Watch made clear. Because the fire was not immediately extinguished, it “led to multiple secondary fires becoming established within the space while the transfer of heat to adjacent compartments was evident both vertically and horizontally.”
Blink of an eye
As the smoke thickened, it also became impossible to know whether the Flexi FOG extinguishing system was functioning correctly. “By the time the first fire team entered the auxiliary engineroom…the smoke was so dense [it] was unable to confirm whether Flexi FOG was operating,” noted the report.
Investigators also highlighted unsatisfactory maintenance procedures in the fire alarm control panel as well as a lack of familiarity among the technical leadership with exactly how the fixed-foam system worked.
As Mumbai’s SHM Shipcare, a manufacturer of extinguishing equipment, warns: “All the fire-fighting appliances and systems [must] work in the blink of an eye in the case of an emergency.”
They certainly did not in the case of Mississippi towboat, the 45-m long Leland Speakes, when its 41-year-old, two-stroke port engine suffered a “catastrophic failure” in the early morning of 21 February 2018. The investigation by the National Transportation Safety Board found that flames and black smoke engulfed the engineroom almost instantly, leading to the usual chain of unwanted events.
Within two minutes, the heat was so great that the crew could not fight the fire inside the engineroom and they could not activate the fire pump because the heat had damaged the wiring in the remote start. Also, there was no fixed fire-extinguishing system in the engineroom. Next, emergency water pumps failed to operate effectively because some parts were missing in older suction hoses. A portable “dry-chem” extinguisher had no effect on the flames.
“Shortly thereafter, the captain determined that without propulsion, steering or an operating fire pump, there was nothing more he could do and [he] left the wheelhouse about 20 minutes after the fire started,” having already ordered the crew to take to the barges from where they were rescued by nearby vessels. Eventually, emergency craft managed to ground the towboat and the flames were extinguished about 14 hours later, but only after foam was poured onto the vessel.
Engineroom fires often start with seemingly minor failures. In the case of the Black Watch, investigators concluded the trouble probably began when escaping fuel fell onto hot engine parts and was ignited.
Similarly, the report by the National Transport Safety Board (NTSB) attributed the fire on board the vehicle carrier Alliance St. Louis on 16 January 2019, to a pipe plug on the fuel pump for the main engine’s no. 6 cylinder coming loose when the vessel was under way from Port Arthur, Texas, to Jacksonville, Florida. The fuel sprayed onto a hot exhaust gas pipe manifold, with inevitable consequences.
“The atomized fuel quickly ignited,” the report said. Although the fire was confined to the main engineroom and extinguished by the CO2 fixed fire-suppression system, property damage exceeded US$3.75M.
As SHM Shipcare observed in July, fuel leaks are all too common: “In such cases a fire can be caused simply due to a malfunction in the machinery or a leak in one of the several fuel pipes in the area.”
Maintenance procedures should go by the book, investigators advise. In the case of Black Watch, the investigators found that only eight of 22 items specified in Wartsila’s maintenance guide had been inspected, tested and checked within the stipulated number of running hours. “Therefore, the mechanical condition of [the auxiliary engine] could not be verified,” the report noted.
Similarly, the NTSB’s investigation into the fire aboard Carnival Liberty four years ago, traced its origin to something as simple and avoidable as a couple of loose bolts. The offending bolts were attached to a fuel supply inlet flange on a diesel generator in the aft engineroom, but they had not been properly tightened during prior maintenance and had vibrated loose over time.
As the vessel was moored alongside the dock at St. Thomas, US Virgin Islands, its first port of call on a seven-day cruise, the fuel supplying the engines was switched from heavy fuel oil to low-sulphur marine gas oil in what should have been a routine exercise. Crewmembers in the engineroom heard an explosion and saw a large fire at the no. 4 diesel generator. Images from the ship’s closed-circuit television show how rapidly engineroom fires can spread. Within a single second a small open flame had burst into a conflagration ripping through the open space.
The cause? “An uncontrolled fuel spray from the inlet flange [spraying] onto a hot surface on the diesel generator,” concluded the NTSB report.
Thus, loose bolts costing a few dollars caused US$1.75M in damage, not to mention the costs of repatriating passengers and a cancelled cruise. The agency’s inspectors also went through the instruction manual for the diesel generators and noted that “[it] did not list specific torque values for the bolts that connected to the fuel supply inlet flanges, but did list torque values for the bolts’ dimensions and strength class.”
The fore on board Carnival Liberty also illustrated how automatic fire-fighting systems should be managed. The Hi-Fog high-pressure water mist system did not activate immediately because it had been set to manual, due to hot work in the forward engineroom that might have set it off. The bridge had to tell the control room to put the system back on automatic on a “total flooding” mode. However, the system was designed to only operate at full pressure – total flooding – in one engine-room at a time and the water mist was thus less effective than its designed capacity.
Then the fallback, CO2 extinguishing system did not function as planned. When, 15 minutes after the first alarms had sounded, the decision was made to release CO2 into the engineroom, a directional valve failed to operate properly and a crew member had to enter the CO2 room and open the valve himself.
It took nearly five hours to fully extinguish the fire. Although nobody was injured – the passengers were evacuated onto the dock – Carnival Corporation has since implemented a more disciplined fire-fighting regime throughout the organisation. Training and certification, including a written test for its Hi-Fog fire-fighting system, has been introduced. New, more easily understood signage has also been introduced and drills are conducted more frequently. Importantly, training was extended beyond the engineroom to include accommodation and galley locations.
The overriding impression gained from the investigations by the NTSB, Bahamas Maritime Authority and others is that engineroom fires are usually the result of less-than-diligent maintenance, a lack of familiarity with extinguishing equipment, inspection failures and, sometimes, complacency.
“Almost all fires on ships are caused due to negligence,” says SHM Shipcare bluntly.
Water, water everywhere
Extinguishing a full-scale fire can have the unfortunate result of causing heavy flooding of the engineroom, resulting in the vessel listing to one side, an especially dangerous characteristic in big seas with little or no propulsion (as a result of the engineroom fire).
That is why container giant Maersk Line has started installing the Danfoss’ Sem-Safe low-pressure, water-mist fire protection system. The system aims to use as little water as possible to avoid liquid pooling in dangerous locations, upsetting the vessel and damaging equipment.
Released in a fine mist, the water evaporates quickly and the resulting steam starves the fire of oxygen while also cooling the machinery, says the company, adding: “We have seen fires being almost instantly extinguished by the system after its release, thus saving repair costs and off-hire periods.”