Capsize

clarivoile · Post by **clarivoile** » Sat 02 Jul 11, 13:27

Minute 3'48"

http://www.youtube.com/watch?v=9oXItwWi ... r_embedded

Looks like a dragonfly

EarthBM · Post by **EarthBM** » Sat 02 Jul 11, 20:05

16 Dragonflies raced, vs 9 Corsair/Farriers, plus 5 more in the class of 30. 10 Dragonflies finished. 3 Corsair/Farriers finished.

30kt winds. So if you push a Dragonfly it may capsize. We know that.

For those that finished, elapsed times:

Elapsed Corrected Design Name
05:45:15 06:44:59 Dragonfly 920 ISCHNURA
06:00:14 06:50:18 Farrier 27 trimaran ORIGAMI
04:52:31 06:54:12 FIREBIRD 8m ORION
05:38:47 07:23:48 Farrier Trimaran F9R TWISTER
06:09:05 07:35:49 Dragonfly 28 DRAGONFLY
06:19:13 07:44:10 Dragonfly 920 Extreme NITRIC
06:25:44 08:10:39 Farrier F9-AXR TRIOHE
06:47:10 08:25:18 Corsair Farrier F27 WANDERING GLIDER
06:39:02 08:28:22 Dragonfly 920 Extreme MAD HATTER
07:45:25 08:39:24 Dragonfly 28 PEEKABOO
07:00:39 08:39:55 Dragonfly 28 THREE WINS
07:31:48 08:54:56 Corsair Dash 750 MILLY MO
07:21:30 08:58:38 Dragonfly 28 Touring TRI TO FLY
07:28:06 09:38:57 Dragonfly 800 STRONTIUM DOG
DNC DNC Farrier F25C DADDY LONG LEGS
DNC DNC One off Trimaran SERENDIPITY
DNC DNC Kurt Hughes 37 EQUINOX
NOD NOD Dragonfly 920 Touring TRILLEACHAN
NOD NOD Corsair Farrier F27 SPEECHLESS
NOD NOD Dragonfly 920 cruising LILANNIE LASERMET
NOD NOD TANCREDE 23 MCF ORCA VI
NOD NOD Dragonfly 920 ESCAPE
NOD NOD Dragonfly 920 BALELA
NOD NOD Dragonfly 920 MAKWAKU
RET RET Dragonfly 28 TINKERBELL
RET RET DRAGONFLY 1000 EXTREME
RET RET Corsair F31R SMITHY
RET RET Shuttleworth Arrow WILLY TIPPIT
RET RET Farrier F9A ALINI
RET RET Dragonfly DF800 FORZASETTE

clarivoile · Post by **clarivoile** » Sat 02 Jul 11, 21:10

These are the actual results in real time:

With:

sail number/name /rating /real time

GBR704M....ISCHNURA...............1.173......05:45:15
GBR601M....ORIGAMI.................1.139......06:00:14
001............ORION................... .1.416......04:52:31
GBR676M....TWISTER.................1.310......05:38:47
GBR283......DRAGONFLY.............1.235......06:09:05
46..............NITRIC.................. .1.224......06:19:13
GBR634M....TRIOHE...................1.272......06:25:44
160X..........WANDERINGGLIDER..1.241......06:47:10
DEN96........MAD HATTER............1.274......06:39:02
GBR1029....PEEKABOO...............1.116......07:45:25
GBR2837....THREE WINS.............1.236......07:00:39
115............MILLY MO..................1.184......07:31:48
GB2816......TRI TO FLY................1.220.......07:21:30
90X.........../STRONTIUM DO.........1.292.......07:28:06
2826 /SPEECHLESS /1.236 /NOD
GBR744M /BALELA /1.184 /NOD
NED92017 /MAKWAKU /1.186 /NOD
FRA35957 /ORCA VI /1.066 /NOD
39X /LILANNIE LASERMET/1.259 /NOD
GBR2820 /ESCAPE /1.224 /NOD
149 /TRILLEACHAN /1.172 /NOD
GBR155 /EXTREME /1.263 /RET
GBR726M /WILLY TIPPIT /1.224 /RET
GBR742M /ALINI /1.179 /RET
338 /TINKERBELL /1.173 /RET
GBR618M /SMITHY /1.241 /RET
GBR752M /FORZASETTE /1.187 /RET
NED1 /EQUINOX /1.172 /DNC
540M /DADDY LONG LEGS /1.164 /DNC
92036 /SERENDIPITY /1.192 /DNC

The first one is a D 920 Extreme

Coming from this page

http://www.roundtheisland.org.uk/web/co ... &submit=Go

EarthBM · Post by **EarthBM** » Sat 02 Jul 11, 22:32

Yep my original table got scrambled somehow, showing Farrier designs as too slow. Fixed above.

Does anyone know which DF capsized?

clarivoile · Post by **clarivoile** » Sun 03 Jul 11, 16:48

that's good now.

Large differences, a bit surprised by the 28 performances, as well as the excellent result for the first one

Baboonty · Post by **Baboonty** » Mon 04 Jul 11, 11:29

I'm not sure it is a Dragonfly, amas looks assymetrical as the DF 28 and it's definitely not one...

Ipe Piccardt Brouwer · Post by **Ipe Piccardt Brouwer** » Mon 04 Jul 11, 12:35

Why isn't it? Looks like a DF 28 to me. Tinkerbell RET ?

Roland · Post by **Roland** » Mon 04 Jul 11, 16:03

It was a DF28 which capsized.

This is from the MOCRA group facebook;

''John Turner, the owner of Escape, has asked me [ Matthew West ] to make this statement on his behalf concerning the capsize of his boat.

'We were sailing comfortably under spinnaker and reefed main when we broached and rudder grip was lost, all sheets were released immediately and we expected the boat to right itself, however it capsized. there was no structural failure at any time which can be confirmed by many pictures on You Tube etc and taken bu other passing boats. It has been confirmed to us by the divers and salvage team that a lobster pot buoy was firmly jammed on the waterstay.
As it was heading for the rocks a desperate attempt was made to right it which resulted in much of the structural damage to the boat, subsequent salvage proceedings have further compounded the damage'

We passed Escape in Wandering Glider whilst there was still a person on the upturned hull and confirm there was no structural damage at that stage.''

I am the skipper of ISCHNURA.

We moored behind Escape on the Friday night of the race, and went onboard Escape to say hello, and have a look. I hadn't been onboard an unfolded 28 on the water.

I agree with just about everything that was said by Werner B ( and by him on behalf of his wife, which I endorse - the feminine side of me, I guess ) in a comparator 920 Extreme/28 thread of a little while ago.

The main hull volume of the 28 is significantly larger, which is particularly noticeable around the galley and the under cockpit berth/storage area.

There are some neat improvements eg a proper ridge between the cabintop and the tramps to walk on when folded.

The 28 in design and some construction detail is built to a price - I do not say this in a denegratory fashion at all - this is plainly instrumental in the price difference as new. Put another way, some of the construction detail of the 920 has to bear significant cost.

ISCHNURA is 920 Hybrid ie she has an Extreme hull with a standard rig.

It was noticeable how much wider we were when we moored behind Escape.

I think the 28 will be quicker in light conditions ( assuming sail areas are roughly equivalent ). She weighs less, the windward hull will lift earlier, reducing drag/slapping etc, and she'll accelerate more quickly to additional wind.

On the RIR the wind was 20-30 knts, with 3-4 metres seas. The seas were worst at the Needles, and at St Cats, near where Escape went over.

We carried full sail all the way round, bar the first 45 minutes when beginning the beat from Cowes to the Needles. The 28s and Extremes were unable to do so as far as I'm aware, and certainly not in the first beat. We were the quickest of all the DFs on the beat.

From our experience I would venture that in heavy seas and big winds a 920 Extreme/Hybrid will be at least as quick as a 28 on just about all points of sail.

Both remain lovely boats.

Regards

Roland

Ipe Piccardt Brouwer · Post by **Ipe Piccardt Brouwer** » Mon 04 Jul 11, 18:18

Under previous ownership my 920 has capsized on the same stretch of water under similar circumstances (fast spinaker sailing without being overpressed). The previous owner was convinced that something like a hookup with a lobsterpot had to be at the base of that accident, though no trace was found. This story however seems to underline the probability of that explanation.

Double Horizon · Post by **Double Horizon** » Mon 04 Jul 11, 18:42

Lobster pot? You folks must have BIG lobsters in the UK.

In my humble opinion, carrying a spinnaker in 30k winds is asking for trouble. All it takes is an uncontrolled jybe or accidental round-up, stuff a wave (or even a freak snag on a fish trap) and your boat's apparent wind goes from around 15k to 30k in a few seconds. A spinnaker and main in 30k apparent is just too much, and you ARE going over.

I call it operator error.

BTW I have snagged a lobster pot in my rudder and it kicked up (as it should) -- another thing that would cause accidental round-up. The only justification is taking a calculated risk by racing on the edge. When sailing downwind, any cruiser or day-sailor should be aware of the risk of suddenly being overpowered due to any of those situations.

clarivoile · Post by **clarivoile** » Mon 04 Jul 11, 18:55

I fully agree

guur · Post by **guur** » Mon 04 Jul 11, 19:14

It looks like there is something stuck to the stays for the bow sprit... Possibly That stay was misstaken for a waterstay? If so; that could be a reasonable explaination.

tpaliwoda · Post by **tpaliwoda** » Mon 04 Jul 11, 22:44

I have also hit lobster pots. They have stopped the boat dead!
I carry a very large sharp knife next to the helm whenever I sail in Long Island Sound!

Slowhand · Post by **Slowhand** » Sun 10 Jul 11, 0:35

Hi
Here is a sequence of pictures from the capsize - gives some better data for a qualified discussion on how to avoid this kind of event.
http://www.cowesonline.com/d/Round%20th ... %20Lge.mov

Steve B. · Post by **Steve B.** » Sun 10 Jul 11, 3:36

Especially the mainsheet.
It never got dumped as far as I can see.

Double Horizon · Post by **Double Horizon** » Sun 10 Jul 11, 12:53

Slowhand wrote:Hi
Here is a sequence of pictures from the capsize - gives some better data for a qualified discussion on how to avoid this kind of event.
http://www.cowesonline.com/d/Round%20th ... %20Lge.mov

Unfortunately there will be many more such events, because racers will need to take chances and carry enough sail to be on "the edge" or they will not be competitive.

For the recreational boater it is much easier, and (at the risk of repeating my post above) the simple answer is:
1) reef early, and reef for the gusts
2) downwind; don't carry more sails than is safe if your boat accidentally stops or rounds-up. (that would be boring for a racer)

EarthBM · Post by **EarthBM** » Mon 11 Jul 11, 22:30

Roland wrote:The 28 in design and some construction detail is built to a price - I do not say this in a denegratory fashion at all - this is plainly instrumental in the price difference as new. Put another way, some of the construction detail of the 920 has to bear significant cost.

ISCHNURA is 920 Hybrid ie she has an Extreme hull with a standard rig.

It looks like the 28 was built to squeeze under 10 meters when folded. At least in Italy you don't need to register boats <10m, with tax and other cost implications.

Here is my back of the envelope stability calculation. Sail force is linearly proportional to sail area, so at any given wind speed there is linear righting moment dependency on mast height, sail area, beam, and weight. 28sport is clearly pushing the envelope compared to 920 and 35:

________28t_28s__920t_920x_Ischnura_35t_35x
Beam m__6.5_6.5__6.8___7.8___7.8____8.2_8.2
Main sq m_35_42___37___44____37____54__65
Mast m__13.7_15.2_13.1_14.6__13.1____16_17.5
Displ, t___1.9_1.9__1.9___1.9___1.9____3.9_3.9
(Main X mast)/(displ X beam):
_________39_52___38___43____33____27__36

And sail force is a function of apparent wind speed squared, so at 30kt there was 4x as much capsize moment as at 15kt (I am assuming apparent = true on a broad reach).

EarthBM · Post by **EarthBM** » Mon 11 Jul 11, 22:58

I like both Dragonflies and Farrier designs. But you have to give credit to Ian Farrier for participating in the F-boat message system on Yahoo. Below is hist take, and he doesn't take as many potshots at DF as he could've:

There is an interesting sequence of photos of a Dragonfly 28 capsizing in this
years Round the Island Race in England at:

http://www.cowesonline.com/zonexml/story?story_id=11289

Type of boat is irrelevant, as all trimarans can capsize, and there are also
photos of capsized F-boats around, including on my website. However, seeing the
full sequence like this does have some good lessons for all trimarans.

The first is that capsizing can happen more frequently while racing, and any
cruising sailor sailing in such conditions with a spinnaker up is just ASKING
for trouble. So if you want to stay on your feet then reduce sail to suit the
conditions! The boat will not look after you when being sailed like this - you
have to look after it, and be ready to relieve the pressure when needed.

However, the photo sequence does show a number of factors, one being the problem
of having float bows with vertical join flanges along the gunwale. These mean
the submerged bow can act like a water scoop, making it harder for it to spring
back up again. As the sequence starts, it looks like boat is tripping over the
float bow, and it is always far better (and safer) to have well rounded deck
edges on float bows.

Then the spinnaker is released, but the boat is now being slewed around and held
down by the mainsail, which cannot be released downwind. Demonstrates the
hazards of running off the wind with a roachy squaretop main, even if reefed -
better to get it down as much as possible, or even fully down. If the worst
happens, then be well aware that there's NO chance of relieving mainsail
pressure, which is likely being pressed against the rigging, and this may be
what puts the boat over.

However, in this case, as boat continues to heel, the pressure from the main
does ease, due to the very high heel angle, to where main is being sheltered by
the nets and actually backwinded. But then it looks like the wingnet windage
takes over, to eventually put boat right over, even though main is no longer a
factor.

Wingnets must thus always be of open mesh to let the air through, and anyone
with close mesh cat style tramps may want to take a close look at this and
reconsider their options. I have always strongly recommended against the use of
close weave nets, and will never use them myself.

The capsize sequence is actually a good example of how a submersible tri can go
over, with main hull staying in the water, which usually makes them very hard to
capsize as they can spring back (self right) up just like a mono. One one early
TRAMP the mast had hit the water, two of the three crew bailed out, but the boat
(with open weave wing nets) then righted itself.

Too much weight aft may be another factor, as the D28 does have a very long
cabin, which ends just in front of the aft beams, with a relatively short
cockpit at the aft end. I always prefer to have the cabin ending further
forward, so as to allow at least two to sit side by side in front of the aft
beam. Less interior room, but I think the boat is better balanced.

However, I think the wing nets were the main problem on this occasion. Larger
floats or a lighter boat may have been better, but then whole boat would have
been much higher in the air (flying main hull), and exposing two wing nets to
the air. Capsize may have then been more likely, but larger floats 'may' have
also prevented the initial trip.

Nick Wood's F-27 ORIGAMI (2nd on corrected and third fastest) did particularly
well in this race for a 27 year old design, as did Peter Newland's F-9R (second
fastest). Results can be seen at:

Multihull Mocra Results: http://www.roundtheisland.org.uk/web/co ... &submit=Go
(Click on the boat name in this list to see the boat details)

While a photo of Nick Wood's F-27 in the thick of it can be seen at:

http://www.f-boat.com/pages/News3/RoundIsland2011.html

Ian Farrier

Farrier Marine (NZ) Ltd
Farrier Marine, Inc

Also a good pic of the conditions in this race:
http://www.f-boat.com/Media4/Miscellane ... ldown.jpeg

Double Horizon · Post by **Double Horizon** » Tue 12 Jul 11, 4:51

Ian Farrier is just buttering his own bread. His comment "One early TRAMP the mast had hit the water, two of the three crew bailed out, but the boat (with open weave wing nets) then righted itself." reads like B-S to me. The mast top hit the water and then it righted? No way. OK maybe the bows buried, and maybe the mast base was reached by a wave top, but was it flying a full main and chute in 30 knots and stayed upright? Highly doubtful.

He makes some valid points, but he lives in a glass house and is throwing stones. Refer to this link for just one example http://www.dragonfly-trimarans.org/phpB ... ec080d91b3

There are plenty of documented F-boat capsizes, probably more than DFs. Any F-boat or Dragonfly that stuffs the bows in 30-knots true while flying full main and chute is going over -- rounded bow tops or not. All boats have limits. It still comes down to operator error.

clarivoile · Post by **clarivoile** » Mon 18 Jul 11, 19:48

that I Farrier is focusing on the 8 sqm net, and not on on the mast and rig weight and their moment, neither on he waves effect

EarthBM · Post by **EarthBM** » Tue 19 Jul 11, 2:47

I bought my DF with no expectation if ever selling it, so if a competitor designer writes something half constructive I am grateful. Not like there is an oversupply of expert opinion in this tiny niche. If Jens had anything to say I'd be all ears (and eyes). I still think the primary issue is 28sp basic geometry, but tri's righting function being diminishing the way it is, fine mesh tramps may have a large percentage impact at critical angles.

Double Horizon · Post by **Double Horizon** » Tue 19 Jul 11, 4:53

Half constructive is about right.

I was surprised to see that image of the net, however, and agree that's not good. The nets on my past and current DF have spaces about 1/4" (6cm) in the mesh, and the vinyl weave is also about the same 1/4" thick. So they are about 25-50% open area. That's about as far as it should go and I think more-open would be better (although less comfortable to sit on).

tpaliwoda · Post by **tpaliwoda** » Wed 20 Jul 11, 0:22

Back in my younger days (1980's) I used to race a Hobie 21 Catamaran.

At the time it was one of the fastest production beach cats built (actually there was a Pro-sail circuit for the boat with the 40 footers). Well the boat had a nasty problem that the only time it would flip was when the wind got under the tramps and pushed the boat over. At that time the boat came with solid vinyl tramps - not real smart, but after all it was Hobie Cat.

Well after one season we got the guys at Sunrise to make mesh tramps for the boat with about a 1/4" mesh.... Boat never flipped again. It would fly a hull all day, staying almost still in the water , but would not go over!

I know on my 1000 the tramps have about 14" mesh also. I can tell you they drain well, but can't tell you how the air flows through them because we have never even been close to that sort of situation.

So if the mesh was tighter it would be possible for the wind to aid in making a bad situation worse.

EarthBM · Post by **EarthBM** » Tue 27 Sep 11, 5:47

Went for a sail in 35kt on Sunday, with a big chop. Double reefed main and single reefed genoa were a little too much, meant steering was for survival, not for speed. Anyways, on a couple of moments when the leeward ama got burried on a close haul, I wished the mesh was more open on the windward trampoline. The holes on mine are only about 4-5mm (not cm) wide.

Steve B. · Post by **Steve B.** » Tue 27 Sep 11, 17:27

I was singlehanding once a few years ago when I was in a similar situation to Ivan.

The feeling of the higher the ama got, the more it felt like it wanted to go higher was not good.
The ama thankfully dropped during a lull.
It was obvious to me at the time that the tight net weave was the cause of the lift.

EarthBM · Post by **EarthBM** » Tue 27 Sep 11, 23:50

Not that I am anywhere close to needing a new tramp, but if I were replacing mine I would want a much more open mesh. Hopefully it would result in more grip too – the current one is too steep and slippery if you step on it just outside where it attaches to the main hull.

Mal · Post by **Mal** » Sat 01 Oct 11, 22:32

My tramps are coming up for replacement in the next 12 months, & I would like the option of a more open weave. The DF tramps are really very good in many ways;- they feel safe to walk on. I had an F27 before, and tended to go across the tramps on that bent double, with hands walking as well as feet! However, the comments about the DFs needing a more open weave are pretty valid, I think. Safety of a tramp is more complicated, though, than simply open weave for extreme situations;- day to day safety is just as important, and the 'walkability' of the DF tramps is very good in that respect. I'm sure that the design and rigging method of the DF tramp would allow for a more open weave, yet still retain the safe-to-walk-on feel.

Two years ago, I stepped down off the cabin-top onto the tramp, and as other contributor mentioned, my foot slid away on the steep part of the tramp adjacent to the retaining extrusion along the main hull. I suffered a really bad ankle sprain, was unable to walk for a few days, and was on crutches for 6 weeks. We now have a 'rule' to get down off the coachroof only at the front crossbeam, where there is a pulpit to hang onto. I would imagine that a more open weave mesh would reduce the likelihood of a foot sliding over the surface of it?

Steve B. · Post by **Steve B.** » Sun 02 Oct 11, 3:39

I don't know who made them, but I recently walked around on an open weave trampoliing on a Catana 431 and a 471.
Both tramps were identical and quite open weave, but soft to the bare feet.
They had a rather 3 dimensional weave with holes about 5mm.

They felt not too stretchy, but buttery soft with a fair amount of traction as well.

Here's a very useful forum. Do a search for multihull trampoline replacement or some such.

http://www.cruisersforum.com/forums/

Double Horizon · Post by **Double Horizon** » Sun 02 Oct 11, 14:02

Related to the comments about slippery nets: http://www.dragonfly-trimarans.org/phpB ... =2577#2577

Mika Harju · Post by **Mika Harju** » Wed 12 Oct 11, 5:37

This might be the same DF?
http://www.youtube.com/watch?v=bMoHhilUSoU

EarthBM · Post by **EarthBM** » Wed 28 Feb 18, 19:25

Another turtled DF28: https://m.youtube.com/watch?v=8u0wP1mP7v8

Here it looks like attaching a bridle to the ama and main hull bows and towing it over the stearn could right it at sea. And this was the water has the clear escape path from the cabin.

DRAGONFLY Trimarans User Forum

Capsize

Capsize

Well

yes

Capsize

CAPSIZE

Yep

A little slow on the sheets...

How to avoid this type of event? Don't race to win.

surprising

trampoline mesh

Close to the edge

Trampolines

Open weave tramps

Re: Capsize