Wednesday, July 25, 2012
On July 25, 1956 the ocean liners Andrea Doria and Stockholm collided near Nantucket. Fifty-two passengers and crew members on the two vessels died and hundreds were injured. Eleven hours after the collision, the Andrea Doria sank to the bottom, where she remains today.
More than forty years after the Titanic sinking, the lessons learned in that earlier disaster were incorporated both into the design of the Andrea Doria, and in the response of her crew when the collision occurred. The collision made half the lifeboats on the Andrea Dorea unusable or inaccessible, but more than 1600 passengers and crew members were rescued and survived. Watertight compartments were properly secured, unlike in the Titanic incident, giving rescuers time to get most people to safety. Of the 52 dead, most had died in the initial collision.
There was no formal finding of fault. The two shipping companies that owned the Andrea Doria and Stockholm reached out of court settlements with each other and survivors, so no legal determination was ever made. An initial inquiry placed most of the blame on the officers of the Andrea Doria for improperly maneuvering their vessel in the minutes before the collision. Later investigations point to the Third Officer of the Stockholm and his misuse of a new technology called radar.
In the study of human error, fixation is the tendency to focus on one or two inputs when things get stressful. Fixation has been a factor in industrial accidents like the one at Three-Mile Island nuclear plant, in aircraft crashes, and in maritime accidents. In the Andrea Doria incident, many believe the Stockholm’s Third Officer was so focused on his radar that he not only ignored other sources of information, he didn’t even notice the radar was set at a different scale then he believed it to be: the Andrea Doria was only five miles away; he thought she was twelve.
Following the collision, radar set designed was improved to make such mistakes less likely, and radar training requirements for bridge officers put into place.
Sutton Technical Books: Human Reliability Analysis