1. Vessel particulars

Length (LOA) 243.5 m Breadth 34.4 m Depth 18.7 m Draft 14.0 m Gross Tonnage 42,820 Deadweight Tonnage 81,589 Built 1976 at Hitachi Shipbuilding & Engineering Co. Japan IMO Number 7372141	General arrangement

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2. Departure loading condition (5 Nov 2002)

• Still water bending moment is 43% of allowable
• Vessel stability in compliance with approved loading manual
• CBT mode (Clean Ballast Tanks)

Cargo distribution

Cargo 76973 m tons Type Heavy Fuel Oil (M-100)

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3. Damaged condition (13 Nov 2002)
(to 15 minutes post incident)

• Vessel reportedly in severe weather, taking beam seas on starboard side, with reportedly extensive damage to gangway and manifold drip pans.
• As reported by master and crew, there was an "explosive" sound and shudder at 15.10 hours.
• Apparently this was one event and not sequential.

Consequences:

• List happened quickly with master reporting the vessel "started to list in 5 minutes".
  This was due from the assumed flooding starboard #2 aft and #3 wing tanks.
  
  
• Master reported a 24 degree list within 15 minutes.
  (Note: Damage stability calculations show that with cargo tanks intact and flooding starboard #2 aft and #3 wing tanks results in 26 degree list to starboard.)
  
  
• Still water bending moment 125% of allowable.
  
  
• Listed vessel rolling in waves up to 8 meters, as reported by the master.
  
  
• Master reports #4 starboard wing and #2 center spilling oil from butterworth openings.
  (Note: These are small openings with removeable covers.)
  
  
• All cargo tanks apparently still structurally intact, as no cargo leakage reported other than through the butterworth openings.

Cross section in way of #2 and #3 aft wing tanks

4. Possible initiating causes

a.	Potential external initiators - News reports stated that at least three (3) vessels lost part of their cargo. One vessel was carrying containers, another wooden logs and a third 1.10 m pipes. impact with floating logs impact with floating container breaking wave impact other
b.	Potential internal initiators explosion - unlikely because no evidence of explosive deformation in surrounding structure structural failure in way of Frame 71 to cause flooding of starboard #2 aft and #3 wing (see discussion in item 5)
c.	Potential operational initiators - The ramifications of the vessel being in bunkering service for two (2) years, from October 2000 to the start of this voyage, with a large fender positioned at Frame 71 starboard require further evaluation.
d.	Potential repair initiators - The ramifications of extensive structural repair in way of Frame 71 starboard in May 2001 require further evaluation.

5. Discussion of structure failure hypothesis

Investigation and analysis are underway but no apparent structural cause has yet been determined.
Findings from the initial assessment are:

Structure in sagging condition

Finite Element Structural Analysis Model showing centerline
cut out section of # 3 center and starboard wing tanks.

6. Counter ballasted condition (13 Nov 2002)

• To right the vessel and eliminate pollution through the deck openings the master ordered the counterflooding of # 2 aft port and # 3 port ballast tanks.
  
  
• No oil release reported.
  
  
• Analysis indicates that the counter ballasted condition further over stressed the hull girder (still water bending moment 154% of maximum allowable).
  
  
• In the flooded, overloaded condition and subject to wave loading in the open sea, the structurally damaged vessel was susceptible to subsequent failure of structural components and oil loss from cargo tanks.