Fire on Board the Liberian Passenger Ship Ecstasy, Miami, Florida ...

Analysis 74 Marine Accident ReportCarnival Cruise Lines owns seven other Fantasy Class ships that may have similarpropulsion system arrangements as the Ecstasy. In correspondence to Safety Boardinvestigators, the cruise ship company did not indicate whether it had examined orintended to examine its other vessels to identify design problems in their propulsionsystems. The Safety Board, therefore, believes that Carnival should examine thepropulsion systems on the ships in its fleet and, if necessary to provide redundancy,modify the arrangement of the auxiliary voltage circuitry to the high-speed breakers wherea single source supplies both port and starboard propulsion systems.The company that designed the Ecstasy’s propulsion system, ABB, is a majorsupplier of cycloconverter propulsion systems to marine customers. Consequently, othervessels might be operating with an ABB propulsion system similar in design to that on theEcstasy. The Safety Board, therefore, believes that ABB should advise its customers withships having the same propulsion system design arrangements as the Ecstasy of thepotential for system failure from the loss of auxiliary voltage to the high-speed breakersand recommend design changes to the propulsion system that would minimize theseeffects.Even though the Ecstasy’s propulsion system had a number of design features thatwere intended to reduce the likelihood that both port and starboard systems would fail as aresult of single fault, the importance of isolating the auxiliary voltage source to the highspeedbreakers was not identified before or during the vessel construction. ABB officialsstated that they did not do a formal failure analysis, such as an FMEA, of the propulsionsystem design because SOLAS, LR, and Carnival did not require them to perform one.A qualitative failure analysis, such as the FMEA method, can identify potentialfailures and rank them according to the probability of occurrence, the severity of effects,and the probability of detection. System failure analyses are widely used in many otherindustries as part of the overall movement toward quality improvement in processes andproducts. In addition, IMO now requires that a failure analysis be performed during thedesign of navigation equipment and bridge systems. The Coast Guard has required the usequalitative failure analysis techniques in evaluating the reliability and safety of vitalsystem automation on U.S. flag vessels since 1988. In proposing the regulatoryrequirement that designers, manufacturers, and/or shipyards perform and submit systemfailure analysis, the Coast Guard stated that the use of advanced automation technologiessuch as electronics and microprocessors made it increasingly difficult, “at timesimpossible, for the Coast Guard, ship owners/operators, and classification societies toevaluate safety.”Classification societies, however, have not seen the need to require failure analyseson vital automation systems in spite of the fact that these systems are becoming even morecomplex and difficult to evaluate. The LR stated that during its plan approval and surveysof the Ecstasy’s construction, it was not provided details of the propulsion system’sinternal connections. Therefore, LR was not aware, prior to the casualty, that thepropulsion would be lost if the cables to the high-speed breakers were burned through.