Please select your home edition
Edition
Mackay Boats

Kiwi 35 'probably as stable upside down as she was upright'

by Eric Sharp, Detroit Free Press on 22 Jul 2011
WingNuts - just as stable when ’turned turtle’ as when upright SW
Two sailors died last week in the Chicago-to-Mackinac race, after the Kiwi 35 Wingnuts turned turtle, without losing her keel. Top Yachting writer, Eric Sharp of the Detroit Free Press (freep.com) writes:

Online sailing forums have been full of comments about the deaths of two people last week aboard WingNuts in the Chicago-to-Mackinac race. The Kiwi 35 capsized during a midnight storm on Lake Michigan, killing skipper Mark Morley, 51, and Suzanne Bickel, 41, from Saginaw. Six others were rescued.

Several yachts of similar design are entered in the Port Huron-to-Mackinac race, which starts Saturday, and some say those boats aren't safe offshore.

Yet a sailor who knows as much about Kiwi 35s as anyone, someone who helped Morley set up his boat two years ago, said Morley seems to have done everything possible to avoid the disaster.

Mike Kehew of Middletown, R.I., said Morley probably was the victim of bad luck and of the unconventional design that makes the Kiwi 35 so fast. From what I've been able to piece together, I tend to agree.

Keel yachts rarely roll over, but it isn't unheard of if the seas are big enough. What is weird is for a keel yacht to 'turtle' in modest waves and then stay upside down if she hasn't lost her keel. That's what happened to WingNuts.

But Kehew, who raced a Kiwi 35 along the East Coast for five years, said a yacht designer once told him: 'The Kiwi 35 was the only monohull he knew that was probably as stable upside down as she was upright.'

'The reason is the wings,' Kehew said. 'They are essentially buoyancy tanks. And below (in the cabin) you have lockers on either side that are basically airtight. Once it went over, it would stay that way until it was pulled back upright.'

Photos of the overturned boat also made me think the culprit was the hiking wings that extend beyond WingNuts' deck.

In one photo, the mainsail is stowed on the mast that sticks down into the clear water, something a prudent skipper would do with a storm approaching. So there's no big spread of fabric underwater to hold down the boat. You can see the fin keel is intact, including the 1,000-pound bulb at the bottom.

Most yachts over 25 feet depend on a heavy keel and internal ballast for stability. On a Kiwi 35, crew weight substitutes for much of the lead ballast.

Because it is so light, and with so little wetted surface area, the boat can hit 18-20 knots (20-23 m.p.h.) in 15-22 knots of wind. As the wind tips the boat to one side, the crew climbs out on the windward wing to keep the boat flat. It's simple leverage. More wind requires more weight on the wing.

It's difficult to understand why WingNuts turtled in what were reported to be modest seas of 4-6 feet, a bit rough but nothing extreme for Great Lakes sailors. A 35-foot boat should handle waves twice that big.

But if WingNuts was hit by a big wave or gust of wind and tipped to one side, the wing on the leeward side (away from the wind) would dig deep into the water. It would happen so quickly there would be little chance for the crew to get on the windward wing to hold the boat down.

If the high wing on the windward side was then hit from below by another heavy gust, it might be enough to lift the hull and pivot it upside down.

'I agree,' Kehew said. 'I think that's exactly what happened.

For the rest of this story http://tinyurl.com/3o8a84w!click_here and also see the links to other stories on this tragedy on the left sidebar

Protector - 660 x 82PredictWind.comBarz Optics - Kids range

Related Articles

New addition to North Sail for Volvo Ocean 65 racing machines
Their sails have powered eight out of nine Volvo Ocean Race winners since 1989-90, with Steinlager 2. Instead of assembling cloth panels into a particular sail shape, the Volvo Ocean Race sails are composites. This means that 3Di material 'tapes' are laid in a specific arrangement, offering stable structure to the sail where it is needed most.
Posted today at 2:02 pm
America's Cup - Practising in Bermuda's Great Sound - April 23 - Video
Emirates Team New Zealand had their first solid day of training on Bermuda's Great Sound on April 23, 2017 Emirates Team NZ had their first solid day of training on Bermuda's Great Sound on April 23, 2017. Winds during the session were averaging 10kts gusting 15kts. As with the other video it is impossible to gauge boat speed, or form an accurate impression of relative speed. However the infrequency of splash down is apparent, as is the very slick gybing and tacking while remaining foil borne.
Posted today at 8:32 am
America's Cup - Tech Tuesday - Why AC50's sail bow down - Video
OTUSA tactician Tom Slingsby (AUS) explains why the AC50's sail with bow down trim Why do the America's Cup Class catamarans sail with bow down trim? It's a common question. Helmsman and Tactician Tom Slingsby? provides a detailed answer in this #TechTuesday feature.
Posted on 23 Apr
America's Cup - Touchdown and take-off for Emirates Team NZ in Bermuda
Today the team's America’s Cup Class race boat was out sailing on Bermuda's Great Sound for the first time It is just over three weeks since Emirates Team New Zealand was sailing in New Zealand, and today the teams America’s Cup Class race boat was out sailing on Bermuda's Great Sound for the first time under inquisitive gaze of an armada of competitors' chase boats getting a first hand glimpse of the kiwi boat
Posted on 23 Apr
America's Cup - Emirates Team NZ has first sail in Bermuda + Video
Emirates Team NZ has just completed for their first sail in Bermuda, in preparation for the racing phase of AC35 Emirates Team New Zealand has just completed for their first sail in Bermuda, in preparation for the racing phase of the 2017 America's Cup campaign. The team, the last to arrive in Bermuda, returned to their base in the Royal Dockyard around 7.15pm local time (1015am NZT).
Posted on 22 Apr
America's Cup - Images from Practice Race Session 2 in Bermuda.
Images have just been posted by America's Cup organisers of the second Practice Session conducted between April 6-7. Images have just been posted by America's Cup organisers of the second Practice Session conducted in Bermuda between April 6-7. Images are not available from the third session which finished on April 12. The next Practice Session is a five day one beginning on April 24 to April 28.
Posted on 22 Apr
35 days to go until the start of the 35th America's Cup
Friday 21st April is another milestone in the countdown to the start of the 35th America’s Cup Friday 21st April is another milestone in the countdown to the start of the 35th America’s Cup as it marks exactly 35 days to go until the greatest race on water begins in Bermuda.
Posted on 22 Apr
Crewsaver appointed as Official Safety Provider to 35th America’s Cup
Crewsaver has announced today that it has been selected to be the Official Safety Provider to the 35th America’s Cup Crewsaver has announced today, 21st April 2017, that it has been selected to be the Official Safety Provider to the 35th America’s Cup, which will take place in Bermuda from 26th May to 27th June 2017.
Posted on 22 Apr
America's Cup - Oracle Team USA's Jimmy Spithill does a flying leap
Oracle Team USA skipper, Jimmy Spithill became the latest AC50 sailor to go overboard Oracle Team USA skipper, Jimmy Spithill became the latest AC50 sailor to go overboard with an epic leap after he crossed the AC50 during a manoeuvre and was unable to stop when he reached the new helm position. In a split-second decision the twice winner of the America's Cup had to decide whether to drop, slide and try and grab something, or just keep going and leap clear of the rudder foils. H
Posted on 21 Apr
America's Cup - Practising in Bermuda's Great Sound - April 20 - Video
The America's Cup Teams were training on Bermuda's Great Sound on April 20, 2017 The America's Cup Teams were training on Bermuda's Great Sound on April 20, 2017 including Oracle Team USA, Land Rover BAR and Groupama Team France in AC50's.Sailed in moderate to fresh breezes the teams seemed to be sailing OK but with some significant splash-downs and broaches.
Posted on 21 Apr