Originally posted July 4, 2014
When fire broke out in 2008 on aircraft carrier USS George Washington in an unmanned space that was being used to improperly store flammable materials, it took more than 8 hours to find the source of, and extinguish, the fire. In this root cause analysis example, we'll explore what they found
In the Navy’s investigation report, Admiral Robert F. Willard, commander of the US Pacific Fleet, stated “It is apparent from this extensive study that there were numerous processes and procedures related to fire prevention and readiness and training that were not properly functioning. The extent of damage could have been reduced had numerous longstanding firefighting and firefighting management deficiencies been corrected.”
Start with the outline
The processes and procedures that were implicated in the investigation of the fire can be examined in a Cause Map, or a visual root cause analysis. This process begins by defining the problem by filling in an outline with the background information and identifying the goals impacted. In this case, the primary goal impacted was the safety goal. Thirty-seven sailors were injured; one was seriously burned. There were no fatalities. In addition, the damage to the ship was estimated at $70 million and left the ship unusable for 3 months.
Ask 'why' questions
Beginning with the impacted safety goal, asking ‘Why’ questions allows us to develop the cause-and-effect relationships that led to those impacted goals. In this case, the injuries to sailors resulted from the extensive fire aboard ship. In addition, some of the affected sailors (including the sailor who was seriously burned) did not have adequate protective clothing. Specifically, liners worn underneath firefighting gear were not available in one repair locker because they were being laundered. Both the fire and the inadequate protective gear were causally related to the injuries so they are both included on the Cause Map and joined with ‘and’.
Add more detail
Asking additional ‘why’ questions adds more detail to the Cause Map. When investigating a fire, it’s important to include the factors that resulted in the initiation of the fire (heat, fuel and oxygen) as well as those that allowed the fire to spread. In this case, the ignition (or heat) source was believed to be a cigarette butt. On-scene evidence showed that smoking was occurring in the area, against regulation. The ship was found to have inadequate training regarding the smoking policy and inadequate control over the locations where smoking was occurring, because regular zone inspections were not being held.
The initial fuel source was determined to be refrigerant oil and other flammable materials improperly stored in an unmanned space where the fire began. The oil was not turned in as required by procedure over a concern about the difficulty of retrieving it. Because the oil was never entered into the inventory control system, the storage discrepancy was not noted. The unmanned space in which it was stored was not inspected. Unmanned spaces were not included in zone inspections and the area had not been designed as a tank or void to be identified in the void and tank inspection.
Once a fire breaks out, the speed in which the source is found and extinguished has the most impact on the safety of personnel. In this case, the source of the fire was not found for eight hours. Not only did the fire begin in an unmanned area, the drawings showing the layout of the ship were inaccurate, because the ship was in the midst of alterations.
Evaluate work processes
Developing the causes that resulted in the impacted goals allows for identification of all the processes and procedures that need to be re-examined to reduce risk of recurrence. In this case, the report identified multiple processes and procedures that were re-evaluated in the wake of the disaster, including those for hazardous material storage, training, inspection and firefighting.