http://www.ntsb.gov/publictn/2007/MAB0703.htm

The National Transportation Safety Board has blamed Norwegian Cruise Line and class society Bureau Veritas for the Norway’s fatal boiler blast on 25 May 2003. Eight crewmembers were killed and 17 were injured when the header of Boiler No. 23 ruptured as a result of extensive fatigue cracking. According to the NTSB’s final report, NCL and water chemistry subcontractors failed to adhere to water chemistry composition limits for the boiler. The number of boiler cycles was not taken into account during maintenance and the boiler was stressed by severe thermal transients (from heating and cooling too quickly) and by frozen boiler support feet.

Weld repair procedures were “questionable”, added the NTSB. Furthermore, BV surveyors and NCL inspectors did not conduct appropriate non-destructive testing and BV surveyors were given “inadequate survey guidance”. The NTSB concluded: “The probable cause of the boiler rupture on the Norway was the deficient boiler operation, maintenance, and inspection practices of NCL, which allowed material deterioration and fatigue cracking to weaken the boiler. Inadequate boiler surveys by BV contributed to the cause of the accident.” In a financial filing last week, NCL re-affirmed that the Norway explosion “is currently subject to a criminal investigation by the US Attorney’s Office through an impaneled grand jury”.