On 12 June 2003, the tanker CHASSIRON called at Bayonne, France,
to discharge its cargo of petroleum products.
At 0500 on 13 June, the tanker departed Bayonne for Donges, France,
to load other cargo.
Two crew members began to clean the cargo holds.
A few minutes after the cleaning had begun on no. 6 port and no. 6 starboard holds,
in which 98 unleaded gasoline had previously been loaded,
a loud whistling noise was heard just before three instantaneous explosions and a fire.
An initial explosion occurred in no.6 starboard cargo hold,
followed by an explosion in no.6 port and then in no. 5 port.
The crew member who was in the vicinity of the no. 6 cargo holds was killed.
The other crew member at the loading/unloading manifold, located midship and forward of
the no. 6 cargo holds, was unharmed.
No. 5 port and no. 5 starboard cargo holds were also damaged as a result of the explosion.
The deck between the superstructure and the manifold was
completely destroyed. The fire was brought under control within an hour.
The tanker was permitted to return to Bayonne for repairs.
The levels of hydrocarbons and oxygen within no. 6 port and starboard cargo holds
were within the explosive limits.
While it is possible that the source of ignition may have been of a
mechanical origin (such as a malfunction of a cargo pump causing an increase in temperature),
it is likely that it was the result of an electrostatic origin
caused by the cargo pump or washing nozzle.
Issues Raised/Lessons Learned:
- Reducing the risk of the formation of explosive gas in the petroleum cargo holds.
- Reducing the possibility of ignition sources.
- Requiring the fitting of inert gas systems for tankers of less than 20,000 tonnes
carrying petroleum products having a flash point not exceeding 60ºC.
There do not appear to be any significant human factor-related issues
that have directly contributed to the accident.