The perils of edgy design offshore

[Doug Lord]

The Perils of Edgy Weather in Any Boat

Here is a modified Kiwi 35-deeper keel, no wings ,larger rig:

clcik on image-

 

[DennisRB]

Looks stiff without the wings

 

[Doug Lord]

Perils of Edgy Weather in Any Boat

From Scuttlebutt tonight:

SHERIFF INVESTIGATION COMPLETE

The Charlevoix County (MI) sheriff's eleven week investigation is complete
that looked into the deadly July sailboat accident that killed two sailors
racing in the Chicago to Mackinac Race.

The morning of July 18th was a fateful one. 51 year-old Mark Morley, the
skipper of the sailboat WingNuts, and 40 year-old Susan Bickel died from
blunt force trauma to the head and drowned when their sailboat capsized.
Six other crew members survived

"The interesting part is to see what went right and what went wrong,"
explained Charlevoix County Sheriff Don Schneider.

In a 150-page report that took 100 work hours to complete, the Sheriff
noted two major points of concern that could have lead to even more deaths
that night. The first deals with the personal flotation devices (PFD) the
crew was wearing.

"If you've got a self-inflating PFD, and you find yourself upside down in
the boat, under the boat, that self-inflating PFD could cause your death,
because it could keep you under the boat when you can't get our from under
it," explained Schneider.

The second point speaks to the tethers connected to the sailors. When the
boat tipped, the report says the surviving crew had a hard time freeing
themselves. -- Read on: http://tinyurl.com/Chi-Mac-100911

 

[upchurchmr]

Some years ago there was a case where a trucker burned to death when he could not get his seat belt to release (the cab was upside down from an accident). There was a test to see if a normal automotive seat belt could be released supporting the full weight of a person. As you might expect, it was impossible to release. An aircraft seat belt was tried and was easy to open in the same conditions.

A knife seems to be a sensible precaution, but there are going to be cases where it can't be reached or is dropped.

Perhaps an aircraft type buckle should be incorporated into the harness, given that you then don't need any tools to save your self.

Just a suggestion. The article was very impressive about the test.

 

[Doug Lord]

The Perils of Edgy Weather in Any Boat

From Scuttlebutt tonight:


Absolutely disgusting---From page 5:
As for WingNuts’ fate, the Coast Guard left the overturned boat adrift and it ended up offshore near Gray’s Reef, Michigan, where sailors claimed salvage rights and ransacked it, Schneider says, taking everything from the WingNuts crew’s clothes to the new Mercury 9.9 outboard motor. Although the sailboat was eventually recovered and towed to the backyard of the sheriff’s office in Charlevoix on July 27, the looting has complicated Schneider’s investigation.

Page 1-5:

IN TOO DEEP - BEHIND THE RACE TO MACKINAC TRAGEDY

At 333 miles, the Chicago Yacht Club Race to Mackinac is the longest annual
freshwater sailing race in the world. The grueling two-and-a-half or
three-day slog requires crews to sleep in shifts every two or four hours in
the beating rain, scorching sun and bitter cold that can cause frostbite
even in summer. Starting near Navy Pier and ending close to the quaint
vacation destination of Michigan's Mackinac Island, it is man versus nature
on the most basic level, even with its reputation as a rich man's sport.

Before the 2011 race, the event had never seen a racing-related death in
its 103 years. (There have been a few health-related incidents, including
several heart attacks, but nothing directly attributed to sailing.) In some
ways, the race's clean record is a wonder, especially considering Lake
Michigan's rapidly changing squalls, which can blow in and out much quicker
than ocean winds. The squalls make it harder to navigate and anticipate
conditions, causing boats to go over one choppy wave and smash right into
the next without reprieve.

Experienced sailors Mark Morley, 51, and Suzanne Bickel, 40, both of
Saginaw, Michigan, were among the 3,500 competitors placing their sailboats
in position on the afternoon of July 16, waiting for the firing cannon to
start the race. Soon after the loud report sounded, their boat, a Kiwi-35
named WingNuts for its unusual 14-foot-wide winglike extensions to the
deck, navigated with Mark at its tiller past 11 other boats in its
sportsman class. WingNuts followed the Wisconsin shoreline the first night
of the race, passing summer festivals as fireworks lit up the sky.

"The first day and first night were awesome," recalls Peter Morley, Mark's
younger brother, who was part of the crew. "We were having the time of our
lives and everyone was all smiles. This year, the race felt better. We were
going fast and passing boats. It was the second night that things went to
hell."

Several years ago, when a member of Saginaw Bay Yacht Club mentioned he had
a 1984 Kiwi-35 for sale, Mark and his brother Peter, along with their
cousins John Dent of Ann Arbor, Michigan, and Stan Dent of Midland,
Michigan, jumped at the chance to buy it. "It was a cool boat [and] fast,"
says Peter, who lives in Midland. "It needed some work, but that's what we
like to do." High-tech for its time, the unconventionally designed 35-foot
boat's eight-foot-wide hull and fold-up wings meant the crew could sit
farther out over the water than on most traditional boats. -- Time Out
Chicago, read on: http://tinyurl.com/TimeOutChicago-101611

 

[Doug Lord]

The Perils of Edgy Weather in Any Boat

This seems to be a good illustration of why some are convinced "wings"
were bad for Wingnuts:

click on image-

 

[MikeJohns]

This seems to be a good illustration of why some are convinced "wings" were bad for Wingnuts...

Not a particularly good illustration. Accentuated deck edges affect seaworthiness and that is nothing to do with conviction.

I posted before that if you put wings on a boat you compromise it's safety, I thought I'd explained why. Perhaps not very clearly.

The wave interaction is far more important than the wind. The wind adds a small heeling moment to the knocked down boat relative to the overturning moment from wave interaction.
The important aspect to understand is how the hull moves in response to a wave. It gets pushed sideways and rises with the wave encounter. If the craft heels enough to dig the wing into the water the overturning moment is accentuated considerably.

In normal physics of capsize If the heel angle dips the deck edge in then there is immediately an added overturning moment.
With a normal (non winged) hull there is a big difference in between say a small bulwark and a very well rounded deck-hull join. In the case of a winged boat there is 'deck edge immersion' as soon as the wing dips into the water and this occurs very early on in the event. By the time the hull is an 90 degrees the overturning moment from the immersed wing is considerable.

This is bog standard capsize physics in transverse wave encounter.

 

[upchurchmr]

SOS (same old stuff)

If you want better performance you accept other risks.

They could always have stayed at home and watched the TV or taken a slow boat on a cruise or had a typical boat (someone will win even if it was a cloned boat race).

Clearly when you dip a wing it will cause problems, just as if you stuff the bow on a catamaran or drive a Trimaran over the lee hull. Suffering a knockdown and taking on water in a typical mono can be pretty bad also. All 4 instances can be avoided - most of the time. Probably all 4 problems are "bog standard" physics.

 

[MikeJohns]

SOS (same old stuff) If you want better performance you accept other risks.

No you don't that's not sensible. Yacht racing isn't a death or glory sport, it shouldn't be intrinsically dangerous when it can just as easily be intrinsically safe without compromising prformance.

This is about understanding an Achilles heel. Or in this case two; one an abysmal lack of stability for a boat to be used 'offshore', and the second a large reduction in capsize resistance through an inbuilt tripping mechanism.
When you couple the two you almost guarantee the vessel will founder every time in a relatively small beam-on breaking wave.

The wind isn't required for this, sure it helps but posts like Doug's above will mislead and I suspect there's a desire to blame the wind rather than acknowledging the severe wave vulnerability.

They could always have stayed at home ........

To make that decision you need to understand your crafts vulnerabilities. You can't even compensate for them with skilled techniques if you don't understand them. The surviving operators of that boat were apparently quite surprised that it ended up inverted after it was hit by a wave. (Note hit by a wave not blown over by a strong gust).

Clearly when you dip a wing it will cause problems.....

The wings coupled with poor stability are principal reasons why the craft foundered in a relatively benign sea state ( 4 to 6 foot breaking waves). They also contribute to a fast and violent inversion and then act to prevent the vessel righting.


Understand that beam seas are the prime vulnerability for a monohull. We spend a lot of time and effort keeping that vulnerability below sensible limits to preserve the vessel and the life of those aboard. All the contributing factors in capsize are well described and documented, they just are not well disseminated. You have to go and look for that information, and to do that you need to know that it could be important.

The other factors you mention are operator related and well understood, if you flip your trimaran or bow dive your cat from too much sail/speed that's a calculated risk that you knew about and were presumably well prepared for.

But the role that accentuated deck edges play is apparently a poorly understood phenomena. The reference to bog standard physics is by way of saying this is not an opinion.

 

[Doug Lord]

The wind isn't required for this, sure it helps but posts like Doug's above will mislead and I suspect there's a desire to blame the wind rather than acknowledging the severe wave vulnerability. .

=====
If you're attributing such a motivation to me you're flat dead wrong!!!

 

[Doug Lord]

The Perils of Edgy Weather in Any Boat

Chicago-Mac US Sailing Report released 10/29/11:

 

[MikeJohns]

=====
If you're attributing such a motivation to me you're flat dead wrong!!!

Is this your way of saying you absolutely totally agree .

The wind is ultimately to blame of course since it produces the waves as well....

 

[upchurchmr]

Mike,

I don't know where you got the wave caused inversion, but the posted report clearly listed this as a wind induced capsise. That doesn't mean there cannot be other reports which have validity, but..... Actually from flipping catamarans in several different manners I have to believe your explanation makes sense after the wind caused the wing to dig in and the boat stopped making headway. Perhaps they should have been able to raise the leeward wing underway? All kinds of fantasys might be possible, including turning it into a trimaran (whose got a slam for that?)

Does everyone think we should legislate safety to a point where there are no "out of the box" alternatives? If the two crew who died had the same luck as the other 6 this would not be such a cause - actually that is a near quote by one of the co-owners. They also discussed multiple instances of knockdown that did not cause loss of life.

Lets mourn the dead, console their families, and celebrate the spirit that continues to take chances. Its failures/accidents like this one that advance the state of the art.

A possible value to this kind of a forum is proposed changes. What could have kept the performance up but increased the safety?

 

[DCockey]

From page 23 of the report:

Mark immediately shouted, “Roll the jib!” He turned to his left, grabbed the furling line, and
pulled on it so hard that he leaned backwards toward Suzanne, seated to starboard. He had the jib
about half-way rolled up when the boat lifted to a wave, and the wind suddenly went forward and
increased viciously, blowing the boat over on her side with violence. The windspeed indicator
went to 50. Peter soon saw 67.

“We went through 90 degrees pretty quick. I don’t remember any pause at all. It went straight
over,” Stan recalled. “We’re used to being knocked down,” echoed Peter Morely. “We went up
to the windward side and waited for the boat to come back. But this was not a short puff but a
steady blast. What stood out was the gust’s longevity. ”

Note the comment about that "the boat lifted to a wave" just before it capsized. Perhaps the combination of the wave and wind gust was what caused the boat to go on over this time.

Also it's a 35 foot boat with a 14 foot beam but only 4000 lb displacement. Add the flat underside of the wings and the wind overturning moment to displacment ratio when rolled to 90 degrees could be closer to some multihulls than most monohulls.

 

[MikeJohns]

......I don't know where you got the wave caused inversion, but the posted report clearly listed this as a wind induced capsise. ..................

I hadn't seen that report until now but I did note the early statement as follows: “We didn’t expect it would get much worse. Then this one wave got us, picked us up and pushed us straight over.” WingNuts flipped to its right and capsized, Dent said.
He also said the wind was blowing at 45 knots at the time . I see that's become 65 knots from one member and 50 from another.

It's almost impossible for waves not to be contributory for this event in a short steep sea. That's the very action (wind wings and waves) that leads to a much more violent inversion too.

But if they did get 65 knots then windage could well have tipped them over the edge. Although there were plenty of other boats with poor stability that didn't capsize which suggests that there needed to be other contributable factors. In fact the Naval Architect indirectly refers to capsize dynamics with his comments about the accentuated side decks and that they are detrimental to capsize resistance and that the Stability Index should accordingly have been 74.4 rather than 100.7 ! That makes a lot more sense and fits the bill.

Either way the design was abysmal and it's good to see the poor boat design clearly blamed for a significant contributable factor in the deaths that occurred.

The following are clearly indicated:

The boat design was dangerous for offshore use
The weather was atypical but not exceptional
Bad weather was very well forecast
The crew seemed completely unaware of the vessel dangerous design features.

So the next step presumably is to regulate these boats out such races. It's interesting too that important findings from other tragic events go largely unnoticed. The Fastnet , the Sydney Hobart, The Gaum Osaka race all have had their deaths and vessel design trends clearly illustrated and commented on.

For example findings from the 98 S-H recommended that tethers should be long enough to allow the tethered to swim free of the upturned boat without having to cut or disconnect their lines.