DF35 Capsize - Human Error

For issues which concern all or several type of DFs and which DO NOT fit into any category below!
Post Reply
Bo Wetzel
Site Admin
Posts: 166
Joined: Thu 01 Jan 70, 1:00
Your Country: France, Provence

DF35 Capsize - Human Error

Post by Bo Wetzel »

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)
Bo Wetzel
Site Admin
Posts: 166
Joined: Thu 01 Jan 70, 1:00
Your Country: France, Provence

Check List contra Human Error

Post by Bo Wetzel »

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.
tpaliwoda
Posts: 215
Joined: Fri 03 Nov 06, 3:05
Your Country: USA, Raritan YC, Perth Amboy, New Jersey

Check list to counter human error.

Post by tpaliwoda »

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
Ted Paliwoda
D'Fly 1000 ; HN #1
Nice Tri
Raritan YC, Perth Amboy, NJ, USA
Oscar
Posts: 148
Joined: Tue 26 Aug 08, 23:10
Your Country: USA, North East

Post by Oscar »

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.... :roll:
Maybe I'l make one for the DF25.
TomTrimaran
Posts: 3
Joined: Sat 01 Nov 08, 10:01
Your Country: Oslo Norway

Human error

Post by TomTrimaran »

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.
Have a T-35 trimaran made in Sweden by Stefan Tørnblom. The Seaon 96 is more or less developed from the T-35 design. 10.50x8.30m 1300kg mailsail 58m2 selft-tack jib 17m2. Sleeps 5 - roomy and fast boat.
Double Horizon
Posts: 440
Joined: Wed 09 May 07, 0:18
Your Country: USA

Re: Human error

Post by Double Horizon »

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.
Larry - Former Owner DF-1200
TomTrimaran
Posts: 3
Joined: Sat 01 Nov 08, 10:01
Your Country: Oslo Norway

Human error

Post by TomTrimaran »

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.
Have a T-35 trimaran made in Sweden by Stefan Tørnblom. The Seaon 96 is more or less developed from the T-35 design. 10.50x8.30m 1300kg mailsail 58m2 selft-tack jib 17m2. Sleeps 5 - roomy and fast boat.
Double Horizon
Posts: 440
Joined: Wed 09 May 07, 0:18
Your Country: USA

Re: Human error

Post by Double Horizon »

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.
Larry - Former Owner DF-1200
TomTrimaran
Posts: 3
Joined: Sat 01 Nov 08, 10:01
Your Country: Oslo Norway

Re: Human error

Post by TomTrimaran »

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.
Have a T-35 trimaran made in Sweden by Stefan Tørnblom. The Seaon 96 is more or less developed from the T-35 design. 10.50x8.30m 1300kg mailsail 58m2 selft-tack jib 17m2. Sleeps 5 - roomy and fast boat.
Mal
Posts: 83
Joined: Thu 02 Nov 06, 16:48
Your Country: Wales

DF35 Capsize

Post by Mal »

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.
DF920 Pelican, Swansea
Ipe Piccardt Brouwer
Posts: 64
Joined: Wed 01 Nov 06, 17:17
Your Country: Netherlands, Winkel NH

Post by Ipe Piccardt Brouwer »

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.
Ipe Piccardt Brouwer
DF920-28 'Ngalawa', Medemblik
david
Posts: 6
Joined: Sun 17 Dec 06, 19:05
Your Country: UK, CHICHESTER

Post by david »

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
Niko
Posts: 10
Joined: Fri 13 Apr 07, 0:53
Your Country: Switzerland, Zurich Area

Post by Niko »

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).
TC
Posts: 61
Joined: Fri 31 Dec 10, 20:26
Your Country: USA, Sedro-Woolley

Checklist

Post by TC »

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

-Thanks
TC

Formerly of:
Strider
DF 1000 #17
Post Reply