float broke off... trimaran capsizes

[Angélique]

Hi,

Dutch article:
http://www.schuttevaer.nl/nieuws/act...den-gered.html
".... een van de drijvers afbreekt en de trimaran omslaat."

Google translation in English:
http://translate.google.com/translat...state0=&swap=1
".... one of the floats broke off and the trimaran capsizes."

Is it a Dragonfly 920 ?











I feel very sorry for those folks...

Regards,

Angel

[Doug Lord]

I think you're right-sad.
http://www.dragonfly-trimarans.org/d920_photos.htm

[Joe Moore]

Ouch, at least nobody hurt and by the looks of things all of the boat was recovered. Is there any info on what happened? I guess a waterstay failed somehow?

[gonzo]

On the good side, she stayed afloat

[Fanie]

Those ama's have quite a bit of flotation, the beams should be at least strong enough to submerge them comfortably without breaking off.

Yes, it is a pity, she looks like a nice boat !

[catsketcher]

It looks to me like the crossbeam may have failed just above the waterstay. The front beam, the one under most stress seems to be folded where you would imagine it to go. The float seems to have buckled under.

The rear beam or waterstay could have gone first and then broken the front beam. We will need more info.

cheers

Phil

[Fanie]

If there was a cable running through each beam, tied to the ama and the hull, could it have prevented a capsize ?

[bad dog]

Yep, this is a 920 alright, just the same as the one I have been sailing for 2 years. This is the first mishap I have heard of on any of the DF series tris. I wonder if we'll get an explanation?

They are just so impressive when you work them. The connections are really over-engineered (but very smooth and easy to move), with additional bracing in both lateral and vertical planes. It's got me beat - must have been a catastrophic failure somewhere!

On close inspection I can see the collapsed (starboard) side beams have folded back into docking mode. DFs fold laterally, not vertically like a Farrier. There is also no fat cable brace from bow to fwd outer beam - a safety brace on the newer models which prevents accidental folding. I wonder if these two things point to a "whoops I forgot to lock the outwinder!" moment. Bugger.

Why the float would break off remains a mystery - the arms fold together normally, but perhaps under pressure of sail and chop, things got out of sync?

Love the translation from Dutch!

[bad dog]

This comment from Aussie Dragonfly agent:
"That is an old 920, before they started making curved beams. I’ll bet is was operator error."

[Angélique]

Something about the circumstances. It happened on the IJsselmeer, a big shallow lake of 1100 km² with an average depth of 5 to 6 m. It's known for its steep short waves which give a nasty chop at 6 Bft. But that should not be dangerous for a DF 920 with an experienced crew. It is not known yet if it was an experienced crew and if they knew how to operate the easy folding system of the DF 920 correctly. The wind was 6 Bft according to the KNRM (Royal Netherlands Sea Rescue Institution) rescue report.

Here is the KNRM rescue report in Dutch:
http://www.knrm.nl/30waar_wij_zijn/1...cle=13979&hm=3

It's the same story as in the newspaper (the newspaper got the story from the KNRM) but the original KNRM report has the wind data at the bottom ‘‘Wind SW 6 Bft’’

IJsselmeer: http://maps.google.com/?ie=UTF8&ll=5...97388&t=h&z=10

Angel

[Nordic Cat]

Similar thing happened up here last year. Turned out it was operator error, they forgot to mount the pins that lock the amas in the open position!

Dragonflys are extremely solidly built, probably why they don't do well as racers in general.

Alan

[Angélique]

Originally Posted by Nordic Cat

Similar thing happened up here last year. Turned out it was operator error, they forgot to mount the pins that lock the amas in the open position!

While looking for something else I just came across these articles about that incident...

‘‘Dragonfly 35 lost one pontoon just before the start’’ (Google translation)




‘‘Human error caused wreck... Security procedure was not respected...’’ (Google translation)




Good thing is... whatever you do... they stay afloat...

Cheers,
Angel

[Manfred.pech]

Originally Posted by Nordic Cat

Similar thing happened up here last year. Turned out it was operator error, they forgot to mount the pins that lock the amas in the open position!

Dragonflys are extremely solidly built, probably why they don't do well as racers in general.

Alan

ONE accident happened October 2008 in Oeresund (Dragonfly 35 Number 1, http://forum.yacht.de/showthread.php...gonfly+kentert). Another Capsize with a DF 920 occurred Oct. 2009 in Enkhuizen http://picasaweb.google.com/ctcneder...at=directlink#. You are right it was an operators error with the DF 35 (http://www.dragonfly-trimarans.org/D...uman_Error.pdf). The 920 broke a front beam, which had an accident before and was repaired. The accidents has been discussed extensively in most forums.

[Angélique]

Originally Posted by Manfred.pech

ONE accident happened October 2008 in Oeresund (Dragonfly 35 Number 1, http://forum.yacht.de/showthread.php...gonfly+kentert). Another Capsize with a DF 920 occurred Oct. 2009 in Enkhuizen http://picasaweb.google.com/ctcneder...at=directlink#. You are right it was an operators error with the DF 35 (http://www.dragonfly-trimarans.org/D...uman_Error.pdf). The 920 broke a front beam, which had an accident before and was repaired. The accidents has been discussed extensively in most forums.

Thanks for the info and all the links Manfred

After 1½ years I still wondered what caused the failure of the 920.

But the front beam can't be broken because of a good repair after an accident, so it must have been bad repaired..?? Do you have info on that..??

But whatever... I think if such a crucial structural element is damaged in an accident it's better to replace it anyway instead of trying to repair it . .

Cheers,
Angel

[Manfred.pech]

Originally Posted by Angélique

Thanks for the info and all the links Manfred

After 1½ years I still wondered what caused the failure of the 920.

But the front beam can't be broken because of a good repair after an accident, so it must have been bad repaired..?? Do you have info on that..??

But whatever... I think if such a crucial structural element is damaged in an accident it's better to replace it anyway instead of trying to repair it . .

Cheers,
Angel

Statement of Jens Quorning of QUORNING BOATS:

Damage report DF 920-77 Cruising "Vaya con Dias", built 2002
This DF 920-C was sailing on the Ijsselmeer, Holland on 3 October 2009 in wind force 5-6
Bft. (17-23 knots) with smaller frequent waves - one reef in the mainsail. Sailing course
was approx 70° to true wind, boat speed approx 11 knots. Onboard were 2 persons (owner
+ a sailing friend).
Suddenly there were cracking noises - the boat heeled over and both SB-side wings folded
back and broke up. The boat rolled over to Sß-side, and the owner had time to pick up the
VHF and call for help, where the professional water rescue service was nearby to assist. No
personal injury - the crew did not even get wet. The boat was towed into the nearest dock.
Mr. Jens Quorning from Quorning Boats has inspected the boat and found the following
conclusion to the incident.
The cause of damage is a chain-reaction of mistakes. In total, Quorning Boats has now built
165 of the Dragonfly 920ls since 1996, of which 110 are Cruising, Racing or Touring
versions and 55 in the Extreme version. We have found that the Swing Wing Iines and
maybe cables, sometime at an earlier stage have been replaced (not by Quorning Boats).
By replacement of this, the special Frederiksen block inside the aft wing has been
demounted and mounted again in the wrong position. This is a single block in stainless
with becket and a single Delrin sheave. By installing it all back, the Swing Wing outhaul
cable has been fitted in the becket end of the block only for rope (this has a 6 mm Cleves
pin only), and the rope was fixed at the strong end, where you have an 8 mm Cleves pin.
Like this, the rope also does not run correctly in the block.
This has resulted the block inside the aft wing - the small weak 6 mm cleves pin - to bend
the block open, and the cable for the Swing Wing outhaul system to come loose! Thus, the
actual Swing Wing system was out of function as backup! We still have the aluminum
safety tube fitted on the backend of the side of the cockpit and on to the aft wing though!
Why did the boat then collapse?
By a closer look at the boat and parts, we could see that the aluminum safety tube has
been secured OKby locking it with the stainless locking pin. However, this 10 mm stainless
pin was bent - arid, we found this aluminum safety tube in the boat - partly bent - one
end broken off by the hull side and at the "wing end11 the stainless fitting on the wing was
ripped off and was still attached perfectly to the aluminum safety tube. All the 6 special 6.5
mm MoneIl rivets were still perfectly intact, and these did not show any sign of darnage. as
if for example the stainless fitting and rivets were sheared off!
Going through the history of this particular boat, we know that it has had two collisions on
the SB-front wing. The last collision was so serious that the front wing had to be replaced
last year. The investigation of the boat proved to us that the whole stainless fitting at the
end of the aluminum safety tube had been punctured through the composite back wall of
the aft wing, which normally will never happen and which we have never seen before on
any other DF 920.
The aft wing has had hidden damages from the two earlier incidents at and around this
stainless fitting. The aluminum safety tube also c1early shows older defects, as the holes for
the locking pins were quite elongated and was dramatically different from the port side
tube on the same boat, wh ich looked safe, sound and in normal condition.
Obviously, we are very sad at Quorning Boats to see things like this happen, where the
boat quickly gets blamed for the damage, and we must urge the owners of DF 920 Cruising,
Racing and Touring models to carefully check this part of their boat, if they have run into
some kind of collision with the boat.
However, this can be backed up by a forward diagonal safety cable from the bow of the
centre hull to the outer end of each forward wing like on the DF 920 Extreme and the DF
35 models. This is an easy thing to install- on existing boats as weil.
The damaged boat, IIVaya con Dlos'', has suffered amazing little damage. On photos
everything from the incident looks dramatic, but basically there is only a very small GRPrepair
under each SB-side wing base. Two new wings are needed and repair on the deck of
the SB-side float. All inside interior is OK. Mast and rigging are all intact - except for windex
and top light as weil as a bent/broken head foil and a new SB-push pit in the cockpit.
The boat will be back sailing on the Ijsselmeer next spring.
For and on behalf of
QUORNING BOATS ApS
Jens Quorning