Communication and English Container ship Cosco Busan, 2007

The pilot and the master did not understand each other in the fog. The ship hit the bridge.

On 7 November 2007 the container ship Cosco Busan, leaving Oakland in thick fog with a pilot on board, struck a tower of the San Francisco-Oakland Bay Bridge. About 200,000 litres of fuel oil spilled into the bay. Nobody was hurt; the bay's birds and beaches were.

Words in this case

master-pilot exchange: The briefing where master and pilot agree the plan before the manoeuvre.
to have the con: To be the person giving the helm and engine orders.
restricted visibility: Fog, rain or snow that hides other ships and dangers.
allision: A moving ship striking a fixed object such as a bridge or a berth.
to monitor: To keep checking position, course and the next danger, whoever is conning.

More words like these in the glossary and in listening practice.

What happened

Cosco Busan left her berth in visibility of a few hundred metres. The pilot was an experienced local man who knew the bridge well and was conning the ship on radar in his usual way, keeping a range ring on the island to bring him to the centre of the span. The master, on his first voyage in command of this ship, stood by with a bridge team that had joined recently. While tuning the radars before departure, the pilot noticed that the symbols on the ship's electronic chart, which was not a certified ECDIS, were not the ones he knew from paper charts, so he asked the master where the centre of the span was on that chart. The master pointed at two red triangles and said that was it. They were buoys, one on each side of a bridge tower. The master later told investigators he was "just guessing" and had not realised the question was serious.

A mile from the bridge the radar picture broke down: the bridge smeared on the screen, the racon marking the centre of the span stopped showing, and the pilot could see neither the towers nor the buoys. He stopped trusting the radar and aimed for the point the master had shown him on the chart. That point was a tower. The ship's side struck its fender, tearing open fuel tanks, and the oil spread across the bay in the fog before the size of the spill was even reported correctly.

The National Transportation Safety Board found that the pilot's judgement was degraded by prescription medicines, that the master had not monitored the pilot or the ship's position and had not spoken up, and that the communication between the pilot and the master had failed at the moment it mattered. On language the Board was careful: the master's English was good enough for him to hold his position, but he was not a native speaker, so challenging a confident pilot was harder for him than it would have been for one, and language and cultural differences blurred who was in charge. The vessel traffic service had seen the danger and had not called in time either.

Why it happened

The pilot and the master did not have a shared understanding of the plan or of the chart, and neither made sure the other had understood.
The master did not monitor the pilot and did not challenge him, partly because of language and partly because of the habit of leaving everything to the pilot.
The pilot's judgement was impaired by medication, which nobody on board could see or question.
The master answered a navigational question with a guess instead of saying that he did not know.
Fog, an unfamiliar ship for the master, and a bridge team that had not worked together.

What to remember on board

The master-pilot exchange is done before the lines are let go: the plan, the courses, the speeds, the bridge to pass under, in words both men repeat back.
Use standard phrases and numbers digit by digit with the pilot as you would with VTS; "yes" is not an answer to a question with two parts.
The bridge team monitors the pilot's conning as if there were no pilot: position, course, the next danger.
If you do not understand the pilot, say so. If the pilot does not understand you, say it again differently. Silence is agreement with whatever happens next.
When you are the one being asked, about your own ship or its charts, and you are not sure, say so. A guess can become somebody else's course.

What changed afterwards

The case led to tighter rules for pilots' medical fitness in the United States, guidance on master-pilot exchange and on the use of electronic charts, and a large clean-up bill that made "poor communication" an expensive phrase.

Three questions

The kind of questions a knowledge test asks about this case. Keys 1 to 4 answer, Enter goes on.

Source: Allision of Hong Kong-registered containership M/V Cosco Busan with the Delta tower of the San Francisco-Oakland Bay Bridge, 7 November 2007, National Transportation Safety Board, Marine Accident Report NTSB/MAR-09/01 (2009). Find the report.

On this site: SMCP basics · Pilot and VTS calls in listening practice.

Plain-English summary of an official investigation report. Facts and findings are the investigators'; the wording is ours. Nothing here is legal advice or a substitute for the report itself.