Boiler fire aboard the livestock carrier Mawash AL Gasseem

Summary

The 46,265 deadweight tonne livestock carrier Mawashi Al Gasseem arrived in the port of Adelaide on 7 September 1995 to load fodder and water. The vessel was on a ballast voyage from Jeddah, in Saudi Arabia, to Napier, New Zealand, where it was to load a cargo of sheep for the Middle East.

Mawashi Al Gasseem was built as a tanker in 1973 and converted to a livestock carrier in 1983. At sea, steam for fuel heating, deck machinery and hotel services is provided by an exhaust gas economiser unit, while in port it was provided by a single Hitachi Zosen two-drum, water-tube, oil-fired auxiliary boiler.

On the morning of 9 September 1995, Mawashi Al Gasseem was at No.1 berth, Outer Harbour, Adelaide, with the auxiliary boiler in use supplying steam for the auxiliary services. The oiler on watch had joined the ship, for the first time, the previous evening. Shortly after coming on watch, he began to encounter problems maintaining steam pressure and water level in the boiler. At about 0920, when he was asked to supply steam to the deck machinery, he called for the assistance of the Fourth Engineer, who, when he saw the low water level in the boiler, immediately shut off the fuel to the burner.

Five or ten minutes later, the Fourth Engineer saw what he believed was still a fire in the furnace, but was, most probably, the boiler internals glowing white hot. He shut off all the valves in the fuel system, but the fire appeared to continue burning and the boiler casing around the aft end of the side water-wall began to glow red hot and give off smoke.

The ship's staff used a number of foam and CO2 extinguishers in an attempt to cool the casing. Hoses were then rigged and used to cool the casing more effectively. At 0950, the fire brigade was called and arrived at 0957, by which time the apparent fire in the furnace seemed to burn itself out and the furnace was cooling down. The fire brigade took over from the ship's staff and continued for the next hour to cool down the boiler casing.

After some inspection doors in the casing had been removed, a cursory inspection of the boiler gave the impression that, apart from some distorted tubes, it had suffered no damage. However, when the Chief Engineer went into the furnace that evening, he found that the boiler had been severely and extensively damaged. The side water-wall and refractory had collapsed, the rear water-wall was burned out and most of the screen tubes were burned out. Most of the furnace tubes in way of the radiant heat from the burner showed signs of having reached white heat and had begun to melt.

The evidence indicates that the damage to the boiler was caused primarily by the burner being fired without water in the tubes. Accumulations of soot, oil and scale on the boiler tube surfaces, caused by poor operating and maintenance procedures, may have contributed to the apparent fire.

The incident was investigated by the Marine Incident Investigation Unit under the provisions of the Navigation (Marine Casualty) Regulations.

Conclusions

These conclusions identify the different factors which contributed to the circumstances and causes of the incident and should not be read as apportioning blame or liability to any particular organisation or individual.

It is concluded that:

1. The extensive damage to the boiler water-walls, refractory and screen tubes in the auxiliary boiler of Mawashi Al Gasseem was caused by firing the oil burner after the water level had been lost, following a failure of one or more boiler tubes. Indications of a tube failure were present 1 hours or more before the apparent fire.
2. The subsequent symptoms of fire were caused by overheating of the port side boiler casings by intense radiant heat from the furnace, after a collapse of the refractory behind the water-wall on the port side of the furnace.
3. A build-up of soot and oil on the tubes and water-walls may have contributed to the incident, these deposits occurring due to poor operating and maintenance procedures.
4. The boiler water level, observed by the watchkeeper, in the gauge glasses may have borne no relation to the actual level in the boiler on account of the steam cocks on the gauge glasses having been shut and no gauge glass drill was carried out to check the accuracy of the level shown in the glasses.
5. The main factor leading to the failure of the first tube, causing loss of water level, was progressive tube wastage, due in turn to the age of the boiler, lack of maintenance, poor combustion control and insufficient control of the chemical parameters of the boiler water.
6. The investigation revealed, among those of the crew who were interviewed, a considerable lack of knowledge and experience in the operation and maintenance of steam plant.
7. Had the automatic control systems on the boiler been in good working order, the incident would probably have been prevented, as the fuel trip valve would have shut off fuel to the burner as soon as the water level dropped.
8. The ship's crew successfully contained the heat from the furnace until the fire brigade arrived by which time the furnace had begun to cool down, however, there was an unnecessary delay before hoses were used to cool the boiler casing.
9. The initial reaction to the fire by the Master and crew was not in accordance with the prescribed and practised procedures in as much as the Master did not take control of the situation from the bridge and there seems to have been some confusion and a degree of panic in the response by the crew.
10. There was a delay in calling the fire brigade, exacerbated by the absence of a telephone on board the vessel and the Inspector considers that a more immediate and reliable means of contacting the emergency services should have been used. VHF radio was not used to contact the port authorities to advise them of the situation and they were eventually informed of the incident via a fourth-hand report.