Mechanical Failure Caused Crane Accident

An investigation indicates a mechanical problem caused a crane cab to fall at Boeing Co.’s Renton plant this month, killing the crane operator, an internal Boeing memo says.

Dean Morris was killed June 10 when the cab fell 60 feet from an overhead crane to the floor of a wing assembly operation.

“The internal investigation team found that there was a mechanical failure,” vice president Jim Jamieson wrote in a memo Wednesday to 58 Boeing managers.

Boeing’s investigation continues, as does an investigation by the state Department of Labor & Industries, Jamieson wrote in the memo, obtained by the South County Journal newspaper.

“According to a preliminary finding of the accident investigation, the two `stop dogs’ were stuck in an open position,” Jamieson wrote. “Stop dogs” are pieces that are supposed to stop the cab from rolling from one girder to another as it moves across the shop floor, unless the girders are perfectly aligned.

Because the stop dogs were stuck open, “this allowed the crane cab to drive off the end of the rails,” Jamieson wrote.