1.1     On Tuesday, 18.4.2000, the pleasure vessels "Dragon Venture", "Ananda II", "Universus 1" and "Benton & Dolly" were moored side by side at buoys numbered 2262, 2229, 2620 and 2161 respectively at the private mooring area inside Causeway Bay Typhoon Shelter "Dragon Venture", "Ananda II" and "Universus 1" were tied up with one another by breast lines in order to prevent their bumping with each other. "Benton & Dolly" was not tied up with the adjacent "Universus 1" on the starboard side but was tied up with another pleasure vessel "Oriental Queen II" on the port side. The speedboat PV92328 was moored to the starboard quarter of "Dragon Venture" by a wire rope. The Master of "Dragon Venture" returned to the vessel at about 12:00 p.m. for work. He was the only person on board as the Sailor was off duty. All the crew of the other vessels, "Ananda II", "Universus 1" and "Benton & Dolly" were off duty and there was no one aboard these vessels. On that day, easterly wind prevailed and the estimated wind speed was 14 km/hour. The maximum air temperature was 25 degree C. At about, 3:45 p.m., an explosion occurred in the engine room of "Dragon Venture", which ripped open both the port and starboard side hull planking. As a result, the machinery space and deck superstructure burst into flames and smoke. The fire from "Dragon Venture" spread across rapidly and set ablaze the adjacent "Ananda II". Within minutes, the blaze spread further to the neighboring vessel "Universus 1" and quickly ignited the next vessel "Benton & Dolly" (see Photo 1). The speedboat PV92328 moored to the starboard quarter of "Dragon Venture" also caught fire. Shortly after the explosion, the ruptured hull of "Dragon Venture" (see Photo 2) took in water and the vessel sank to the bottom by the stern at about 4:05 p.m. Fires continued until all the vessels sank by about 6:45 p.m. The sunken vessels "Dragon Venture", "Ananda II" and "Universus 1" left a small protrusion of deck fittings above the sea surface while "Benton & Dolly" and the speedboat PV92328 were completely submerged. Fire Services Department was alerted and firemen arrived the scene at about 4:00 p.m. The fire was brought under control at about 6:45 p.m.

1.2     After the explosion and fire, the divers of the Fire Services Department found the body of the Master of "Dragon Venture" inside the vessel at about 8:00 p.m. The Master had multiple lacerations on his head and severe burn on his limbs. The body of the Master was sent to Tang Shiu Kin Hospital where he was "certified dead before arrival" by the duty doctor.

2.1     "Dragon Venture" built in 1971 was a wooden motor cruiser propelled by two inboard diesel driven engines. She was 19.81 metres in length, 5.18 metres in width and of 3 decks construction. The explosion on "Dragon Venture" occurred inside the engine room. The most probable cause of the explosion was an ignition of accumulated vapour in the engine room. The presence of the vapour could have resulted from vaporization of petrol in the bucket which appears to have been used for cleaning the outboard engine component (see Photo 3). Petrol has a flash point of 45.5 degree C and would readily vaporize at the ambient temperature of about 25 degree C prevalent on the day of the incident. Evidence indicates that the engine room ventilation blowers were not switched on at the material time. The natural ventilators were not effective enough for dispersion of gas or vapour when the vessel was not underway. The engine room at that time therefore was virtually unventilated. Evidence indicated that the starboard generator was running. The source of ignition for the explosion was probably a spark resulting from a short circuit fault in the 110V electrical system. The location of the short circuit could not be traced because most of the electrical circuitry was severely damaged by fire.

2.2     The explosion led to a fire in the machinery space of "Dragon Venture". The fire was probably further fuelled by diesel oil released from the interconnected fuel tanks through the dislocated flexible fuel hose of the port generator as well as from the damaged fuel filters. The fire then appears to have propagated by way of the engine room hatch onto the deck and superstructure above.

2.3     The fire on "Dragon Venture" spread to the other vessels "Ananda II", "Universus 1", "Benton & Dolly" and PV92328. The fire spread across swiftly firstly because these vessels were moored in close proximity and were tied up with each other. Secondly, these vessels were constructed of glass reinforced plastics (see Photo 4) which burns rapidly when ignited.

2.4     The investigation has identified a lack of care on electrical insulation as a possible contributory factor to the cause of the explosion.

3.1     Important lessons should be learnt from this incident :-

1. Petrol has a very low flash point of 45.5  C. It evaporates very quickly and readily forms an explosive mixture with air in concentrations between 1.3% to 7.1% by volume. As a rough guide, a teacup of petrol is sufficient to cause an explosive mixture in a moderate sized enclosed space such as engine room of a pleasure vessel. Petrol should therefore never be used as a cleaning agent. Any container containing petrol or other volatile liquid on board a vessel should always be kept tightly sealed and should be stored in a ventilated space, preferably on deck.
   
   
2. Before commencing any work in an enclosed space such as engine room, adequate ventilation, preferably by mechanical means, must be ensured. If in doubt, concentration of any flammable gas that may be present should be regularly tested to ensure that it does not exceed 1% of the lower flammable limit.
   
   
3. All electrical equipment on board should be maintained in good state of repair and the insulation resistance of the electrical circuit should be tested at annual intervals to ensure that it remains within prescribed limits as recommended by the manufacturer or not less than 1 M if there is no specified standard.
   
   
4. For the purpose of preventing the spread of fire, pleasure vessels should not be tied up together in typhoon shelters unless it is deemed essential to do so.

Photo 1 - Fire across pleasure vessels
(From left top to right bottom : "PV92328", "Dragon Venture", "Ananda II", "Universus 1", "Benton & Dolly")



Photo 2 - Ripped hull side planking of "Dragon Venture"



Photo 3 - Outboard engine component



Photo 4 - Glass reinforced plastic made hull

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