Asleep at the wheel: Accidents caused by exhaustion
What happens when our root-cause-analysis of a problem leads to “operator tired” or “operator fell asleep”? If we stop there, and blame the operator, we are missing an important opportunity to improve the safety of our organization, and potentially prevent another problem from occurring.
One of the causes of the EXXON VALDEZ oil spill is that the Third Mate who was actually manning the bridge was exhausted due to long work hours and too little sleep. The collision of two metro trains in Washington D.C. in 2003 was caused by an operator who had worked a double shift, from 8 a.m. to 11 p.m., then returned the next day to do it again. A few hours into his first shift, his train rolled backwards more than 2,000 feet into another train and caused millions of dollars worth of damage. The investigation team determined that the brake had never been pressed. There have been some recent studies that show that people suffering from excessive sleep deprivation perform some tasks about as well as someone who is legally drunk. Naturally, this is a concern for anyone operating heavy machinery or performing surgeries. Yet rotating shift work, excessive work hours and too little time between shifts continue to occur . . . and sometimes have tragic consequences.
Based on these concerns, some organizations are trying to alleviate fatigue problems caused by their work standards. For example, the Accreditation Council for Graduate Medical Education’s common duty hour standards took effect on July 1, 2003. These standards reduce the number of hours medical residents can work in a week, and require adequate rest between duty periods.
When we end up with a cause on our root-cause-analysis of “operator tired” or “operator fell asleep”, it is essential that we continue to ask “Why?” to determine the factors that led to exhaustion. Many times, regulations to ensure adequate rest before duty do not exist. In some cases, company policy encourages or requires workload that does not allow for adequate sleep. If we do not continue our root-cause-analysis to determine the reason that the operator is tired, we run the risk of having the same problem - or worse - happen again.