Dragonfly Trimaran Boat Functions – The Swing Wing System
Here is an in-depth guide to using the Swing Wing System on a Dragonfly Trimaran, including how everything works, the backup safety system, tensioning the backstays and folding the hulls in.
00m 31s – The Swing Wing System
00m 31s – Introduction
01m 51s – How it works #1
03m 42s – Backup safety system
04m 37s – How it works #2
05m 36s – Tensioning the backstays
06m 56s – Folding the hulls in
To many people this is a new system, however, Dragonfly developed this system back in 1989. It is the same principle on all Dragonfly Trimarans. On the Dragonfly 28 and 25 models, it all happens manually, on the 32 and the 40, it is backed up with electrical winches. The system is based on a block and tackle system.
We have what appears to be 2 lines that come out from the cockpit combing. This is actually one line on a continuous loop that runs through the system. The inside line is for pulling the hulls in, and the outer line is for pulling the hulls out, it’s very simple.
The system is based on using no tools, only by operating these two lines.
How it Works #1
Both lines are kept in place with a cleat.
To pack away: When the cleat is released, the boat will fold up by itself. This is because the floats are higher when we are sailing, and when we fold in the floats they are designed to drop down about 1-foot, raising the centre hull to provide better stability. Dragonfly Trimaran’s do not have a keel with lead inside like a monohull, and the centre hull does not have stability itself, this is why the floats push up the centre hull when they come in.
To set up: When you open the cleat, you will see that the buoyancy of the float will force the float outwards which makes the setup very easy. In the video, you can see that for the first half of the setup the float moves itself, you only need to pull and winch on the line for the second half of the setup. Winch until there is tension on the trampoline, then lock off the cleat. You will see a mark on the line indicating how far you need to tension the line. Now, pull in the slack on the backstay.
Backup Safety System
These lines are made of high-quality Dyneema, however in the event that a line was to break, or someone was to open the cleat, there is a safety backup system to prevent the boat from folding in while sailing.
There is a safety cable going down to the centre hull which can be clipped on once set up, preventing the boat from being physically able to fold in. On the smaller boats, 5-6 people can stand on either trampoline, on the bigger boats up to 10 people.
How it Works #2
Now for setting up the second float to complete the setup process. On the inboard line, there are markings on the line which indicate where the float lines are set-up or retracted to the correct extent.
To fold the port side out, take the endless line, put it around the winch with 1 turn and open the cleat. The float will automatically shoot out, then just like the other side, pull on the line to take up slack on the trampoline, add another few turns on the winch and take in until properly tensioned as indicated by the marker on the line. Everything is pulled tight in one operation.
Pull in the slack on the backstay.
Tensioning the Backstays
When both floats are extended, you can tension the backstays.
The backstays offer the same function as a turnbuckle on a side stay, however, turnbuckles require tools and too much time. This is why we have a block and tackle system to tension the rigging and forestay.
Once both floats are folded out, on the smaller Dragonfly Trimaran’s pull on the backstays as hard as you can manually. On the bigger Dragonfly Trimaran’s, pull on the backstays as hard as you can manually, then use a winch handle and tighten as much as you can with one hand only.
Connect the safety cable – we are now all set to go sailing!
In 2 minutes the boat transforms from a single hull that can fit on a trailer or in a marina, to a trimaran, so you can enjoy the advantages that a trimaran offers you.
Folding the Hulls In
After sailing when you are ready to fold the hulls back in focus on one side at a time, never both sides at the same time. This is a system designed to be used in protected waters, with a maximum of 20-25cm (less than 1 foot) waves, like a harbour or marina. Always either head to wind, or head downwind which will provide even less motion from the waves.
First, remove the safety cable. Carefully release the backstay, there can be quite a bit of tension on it so make sure you have a good grip on the line, then ease it off completely.
On the swing-wing system’s ‘endless line’, take the inboard line and put two wraps around the winch. Pull in the slack by hand, carefully open the cleat, and start pulling on the line to fold one hull inwards. When you need assistance, put a third wrap around the winch drum and use the winch handle to pull it the rest of the way in, until you reach the marking on the line indicating it has been pulled in all the way.
You need more force to pull in the hulls (than release them), because you are forcing the floats underneath the centre hull, raising the centre hull at the same time. You will be on a little bit of an angle until the other side is folded in too.
Everything packs by itself, including the trampoline. You don’t need to do anything else.
On the starboard side to finish folding in the hulls one important thing is that on a boat with a folding bow sprit, the bowsprit needs to be packed in and secured before you start folding everything else in.
Unhook the safety cable, and repeat the same operation as on the port side. You will find that the backstay is slack, this is because the other side has already been released. You will also find that when winching in the hull it is more difficult on the 2nd side, this is because you are also lifting the weight of the centre hull at the same time.
Make sure that the lines on deck are tidy and can not get caught on itself or in a winch.
Once the hull is winched in, close/lock off the cleat and remove the line from the winch drum.
The Dragonfly 28 which is in the video, works the same way as the Dragonfly 25. These boats are trailerable boats because the floats disappear under the main hull. On the smaller boats, the only tool you use is a winch handle.
On the bigger boats (Dragonfly 32 and Dragonfly 40), the floats stick out a bit further past the centre hull. To set up, you would use the same method but instead, all of this would happen with an electric winch.
Now you can move safely into our normal slip, like everyone on a monohull.
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