September 29, 2011

The Concordia capsize

The ill-fated Concordia
 THE OFFICER OF THE WATCH simply didn’t know enough to avoid a capsize. That’s the conclusion of an investigation by the Transportation Safety Board of Canada into the loss of the 189-foot barquentine Concordia off the coast of Brazil last February.

The tall ship was part of an elite private-school program called Class Afloat, based in Nova Scotia, Canada, and was carrying 48 students, eight teachers, and eight crewmembers. The steel-hulled ship was built in 1992. All 64 people aboard were rescued from liferafts after two days adrift.

The investigation report says: “Despite changes in the wind conditions in the 60 to 75 minutes preceding the occurrence, and the fact that several squalls were being tracked, both visually and on the radar, the second officer did not perceive any threat to the vessel.

“As the apparent wind speed increased with the onset of the squall, the vessel’s heel angle reached roughly 23 degrees for approximately two to three minutes without mitigating action being taken.

“The forward and aft deckhouses had not been fully secured weathertight and, therefore, the vessel’s righting ability at large angles was reduced and protection against the ingress of water was compromised. As a result, downflooding progressed until the vessel lost all stability and capsized.”

The report added that while the second officer had the proper Canadian certification, his training “didn’t include sufficient information about stability guidance.”

In a radio interview, the ship’s master, Captain Bill Curry, who was below in his cabin at the time, said she suffered a 100-degree knockdown within 15 seconds and her masts were in the water. She sank in minutes.

The board of enquiry is now recommending that officers who have been certified to sail are trained in “stability guidance information.” Presumably that means knowing that a sailing ship can capsize.

Talk about bolting the stable door . . . is it possible that an officer on a square-rigger did not know his ship could capsize in a squall? Is it really possible that he just stood there and watched squalls approaching? Didn’t he know enough to reduce sail, close the doors in those ungainly deckhouses, and maybe change course to run downwind? Was the Concordia properly ballasted? Was she designed to recover from a knockdown, like any decent yacht?

So many questions, but the mainstream Press doesn’t know enough to ask them. But no matter what conclusions the board of enquiry came to, I’d like to hear the second officer’s story for myself.

Today’s Thought
Little minds are tamed and subdued by misfortune, but great minds rise above it.
— Washington Irvine, Sketch Book: Philip of Pokanoket.

“Are you sure your wife knows you’ve invited me home for dinner?”
“Of course, yes — we were still arguing bitterly about it when I left the house this morning.”

(Drop by every Monday, Wednesday, Friday for a new Mainly about Boats column.)


Matt Marsh said...

I haven't read the TSB report on this incident yet, so I'll leave the second officer's conduct for others to debate.

I do think it's fair to say that many larger ships have stability vulnerabilities, especially when they're not fully battened down. It is often perfectly acceptable in many cases for a freighter or tall ship to have a much lower angle of vanishing stability than would be expected in a yacht. Getting any reasonable self-righting ability from a 200 foot sailing ship would call for such a massive, deep keel that the boat would be unable to enter most ports. Vessels like this rely on the laws of scaling (stability scales as length^4) to reduce the probability of a knockdown or capsize, rather than attempting to self-right after the fact.

The naval architect would of course have made a few assumptions. For a 200 foot sailing ship, I would guess he assumed that she'd always have crew and officers monitoring the weather and reducing sail as necessary. I'd guess he assumed that she'd be fully battened down, with ports and hatches dogged shut, while underway.

We make these same assumptions for yachts; a 37' sloop claimed to be "self righting from 160 degrees" will go straight to the bottom in seconds if she's knocked down with all her ports and hatches open, and a 32' cat described as "extremely difficult to capsize" will nevertheless go (and stay) upside down if you drive her under full sail in a Force 7 with ten-foot breaking seas.

Any boat will take care of you if you know her limits and obey them. And any boat can turn on you if you push her past her limits, or if you ignore her warning signs.

Aaron Headly said...

Having read Parrott's Tall Ships Down, I must say I was startled to see such extensive (and porous) top-hamper on a boat built so recently.

Tragedy or tragic stupidity? I lean towards the latter. I'm glad that only the boat was lost.