BRM Ch10 Error Chain

Technical questions What is an error chain? How can we recognize one? What is error trapping? Which principles of BRM can be involved in an error chain?

Case study: U.S. Coast Guard Cutter Blackthorn collided M.V. Capricorn. On January 28, 1980, the U.S. Coast guard cutter Blackthorn and the U.S. Tankship Capricorn collided in Tampa bay, Florida. As a result of the collision, the Blackthorn was capsized and sank, and 23 coast guardsmen were drowned. Although refloated, the Blackthorn was a total loss. The Capricorn experienced hull damage from the collision and subsequent grounding. The cost of repairs to the tankship was estimated at $600,000 and the cost of salvaging the Blackthorn was estimated at $1 million. Figure 10.1

Error Chains Defined Rarely is a mishap attributable to one single catastrophic cause. A series of errors of omission (things not done that should have been done) and/or errors of commission (things done that should not have been done) that combine to a catastrophe. Inadequate planning Inadequate rest Talking too much (distraction) or talking too little Paying too little attention to the big picture Too much attention to the little things

Error Chains Defined When these individual errors link together, we call the result an error chain. If there is one key element to BRM, it is the breaking of these error chains, or error trapping. When we see a series of BRM principles being violated, we realize that we may be building an error chain.

Exxon Valdez Error Chain The third mate may well have been fatigued. The chief mate was exhausted from 24 hours of nearly continuous work loading cargo. Thus contributed to the captain’s extra workload. In piloting waters, either the captain or the chief mate had to be in the wheelhouse. The ship would not be put in autopilot while in pilot waters. Why did the captain go below? The lookout reported to the third mate twice, that the ship was leaving a buoy on the wrong side.

USS Dwight D. Eisenhower Error Chain 4 minutes error was intolerable. The judgement of these two officers was almost clouded by fatigue. Why these two officers made speed change without notifying the captain. The secretary of the navy, the captain’s supervisors and members of the press were in the bridge. (at least 30 people in the bridge) Perhaps no one on that bridge had good situational awareness.

Royal Majesty Error Chain No one in the bridge really knew where the ship was. None of the officers checked GPS navigation system with other fixing system. There was no true cross-checking. The mate on watch chose to disregard the fact that he had not seen the buoy that he should have seen. Blatant falsification is the worst sort of communication failure.

Blackthorn-Capricorn Error Chain It almost always takes a series of errors, or violations of BRM principles, before a ship will sail into catastrophe. If we strive to find and fix as many individual errors as possible, we will almost certainly break the chain. With the advantage of hindsight, however we can see that breaking any of the links might have stopped the catastrophe.

Voyage planning Blackthorn’s voyage planning No one in the ship attempted to find out what traffic would be encountered in Tampa Bay. Capricorn’s chief mate did follow a check for entering port, and the pilot did know, at least, about the outbound Kazakhstan.

Standardized procedures Every licensed officer has had to meet the same standard. Blackthorn’s navigator and watch officer had both been certified by their captain as being qualified to stand watch officer of the deck. Yet Blackthorn’s executive officer did not know the name of the channel the ship was operating in, and her captain mistook an inbound radar contact for an outbound ship.

Situational awareness and voyage monitoring How aware was the executive officer of his situation if he did not even know the geographic name of his location? Ocean Star report she would be “out of the way” when replying to Kazakhstan. This was not a response to Blackthorn’s executive officer’s request for a passing arrangement with Capricorn. No one in the Blackthorn’s pilot house was assigned specifically to monitor traffic. Sighting vessels at the last minute shows a lack of situational awareness.