DRAGONFLY Trimarans User Forum

A few days ago a DF35 had an accident in Denmark due apparently to a human error.
I've received today the following email from Jens Quorning:

Dear Bo,

I do now know, whether you have heard of this incident, but we want to
inform the sailing public about the truth of this incident, which was a
human error and not a breakage caused due to bad or weak design of the
boat.

I think that the Dragonfly User Forum is the right place to inform about
this.
www.dragonfly-trimarans.org/DF35_Capsiz ... _Error.pdf

With kind regards,
QUORNING BOATS ApS

Jens Quorning

Pictures of the accident can be found at:

www.baadmagasinet.dk/index.php?sid=1&ci ... 1223298910

(Thanks Mal for sending the link)

When I got my first DF920 I made myself a check list of all the things I should be doing before and after leaving port.

A system not dissimilar to a pilot's check list which every pilot must use before takeoff.

It started with:

• - Disconnect shore power cable
  - Shut all port holes etc

and finished (if I remember rightly) with

• - Put pin into alu bar at back

Now maybe we should make a list to help those who might forget a vital action as the skipper of the DF35 did. It can happen to the best.
As I've said every pilot must use his check list.

Send me your suggestions and I'll try to compile a general list for all swing wings.

Going out - Open thru hull fittings, engine water intake, head water intake.
Remove speed transducer blanking plug and insert speed transducer.
Check swing wing lines and rope clutches. Check backstay tension.
Lower centerboard, and rudder.

Returning - putting away boat - Close thru hull fittings for engine and head. Batteries off, blanking plug back in speed transducer, board up and locked in place, tension off backstays a bit. Secure mooring lines with anti-chafe.

Just a few of mine.
Ted

As I've said every pilot must use his check list.

I have flown airplanes for more than 25 years now, 23 professionally....I do not recall ever not using the check list.

Having said that, I never made one for the boats......

And have forgotten a few things here and there....
Maybe I'l make one for the DF25.

I was surprised about this accident - and must say its a little strange that this secure system dont function automatically. The Dragonfly 35 is the latest design - and you should think that some lazy or not expert person could do this error again. So it should defenitely be a system that this was secured in a way that no checklist is necessary - if you need a procedyre like a plane to go out sailing -its too much for daily life of a family boat.

Dragonly make the best trimarans ever (total view) and the system is very good - but not idiot-proff - as it should be.

I don't think there is any boat that is "idiot proof". Your T-35 must have some equipment that could fail or cause major problems from operator error -- rudder, centerboard, rigging, through-hulls, winch over-rides, etc. If boats were "idiot proof" there would be no sinking, capsize, collisions, or groundings.

Some systems are not redundant, but in this case there was a backup that wasn't used and two things had to go wrong.

By "idiot-proff" I mean the folding system -of course things can happend - but a folding system is an extra advantage on a tri - that can cause special damage if not used correctly. We can just mention the Farrier/Corsair system -that locks and support the strengt of the boat when folded out - but the Dragonfly system has other advantages - but have one problem -as this accident shows - you can do a " easy to forget error" and capsize the boat.
I am pretty sure the Quornings are working on a solution to this as we speak.

TomTrimaran wrote:By "idiot-proff" I mean the folding system -of course things can happend - but a folding system is an extra advantage on a tri - that can cause special damage if not used correctly. We can just mention the Farrier/Corsair system -that locks and support the strengt of the boat when folded out - but the Dragonfly system has other advantages - but have one problem -as this accident shows - you can do a " easy to forget error" and capsize the boat.
I am pretty sure the Quornings are working on a solution to this as we speak.

Someone could just as easily forget to tighten the bolts that lock the Farrier folding system, and that would be less obvious (visually) to the operators than a bow stay that's not attached. This is no different than running a diesel inboard engine without remembering to open the sea water intake, or turning off the engine battery switch while the diesel is still running. The operator error is minor but the consequence can be major.

The bow stay is a backup system that is attached as the last step when opening the boat. The boat needs to be able to be used while folded to maneuver in/out of a marina slip. I have owned three Dragonfly tris (a 920, 1000, and 1200) and have assisted in assembling a DF-35 following shipment. I understand these boats and their operation. Based on the information presented I don't view this as a Quorning error or a design error.

Double Horizon wrote: Based on the information presented I don't view this as a Quorning error or a design error.

I agree - its not a design error - but its something that is not perfect - and maybe possible to be solved better. If the same system is in place on the 920-1000-1200 - and this NEVER have happend before - I would agree that its just to go on as now - but if the 35 has a slightly different system - and it happends already on a new design - its something that needs to be adressed.

The last couple of posts made me think;- am I missing something here? On the previous boats, the 'back-up' was the rear aluminium tube with a stainless pin that had to be inserted. I thought that the floats were held out fundamentalloy by the winched system which also tensions the tramps.

If the bow wire just replaces the aluminium tube 'back-up', why would failing to secure it result in the float swinging back in? Surely the winched system should be holding the DF35 float out;- isn't the bow wire just 'back-up'?

Am I being thick?

Incidentally;- Farrier claims that the F boat folding sytem will still stay in place even if the inboard bolts are not done up.

I'm quite sure that it is a backup system. So the primary system failed first. The line broke, or someone accidentally opened the wrong clutch.

there is no back post on the 35 as on the 920 the bow to float cable is the back up and as i understand this had not been put in place

david wrote:the bow to float cable is the back up and as i understand this had not been put in place

I am sure the bow to float cable was not put; this is clearly to see at

http://www.baadmagasinet.dk/online/cont ... 222362.jpg

(at least on the port side).

Was the checklist mentioned above made? If so, where could I find it?

-Thanks