Sailrocket 2 set to launch

[P Flados]

From their notice

"After 16 or so months of constant design and building. The new VESTAS
SailRocket is set to be unveiled to the public for the first time on the *8th
of March*. The mood seems to have changed from fighting to get it out the
shed to trying to hold it in!"


http://www.sailrocket.com/stories

[mojounwin]

It's going to be a wicked machine, can't wait to see it in the water.
The big question is what will she be able to do?

Cheers
Mojo

[Doug Lord]

Sailrocket unveiled: http://www.vestas.com/en/media/news/...=3&NewsID=2600


click on image:

[P Flados]

I have been a close follower & big fan of these guys since before they went to Walvis bay. I felt that many of the lessons to be learned from SR version 1 were pretty obvious. They seem to have come pretty close to my metal wish list which went something like

1. Move the cross beam to the rear
2. Go with front steer
3. Put the pilot more to the front
The above all serve to get better high speed "ballistic stability". This involves moving natural center of rotation (at the CG) forward and moving large surfaces such as wing and main foil aft. This keeps the craft more stable in response to momentary upset loads and should help to avoid any more take offs
4. Separate the planing surfaces from the hulls to allow canting and/or reconfiguring to see if Kite Board style operation works when scaled up
5. Not sure if they picked up my last item. It would probably improve overall efficiency to dial in some "twist" in the airfoil for the cross beam. The beam should provide up-lift out at the wing and down-force in at the hull. As long as the right foil is used & and the angle of attack is small, the righting moment provided is real close to free in terms of drag. This reduces the vertical forces that need to be provided by the wing and main foil to allow them to operate more efficiently.

[Doug Lord]

Video describing Sailrocket 2 from SA-note that the "V" shape of the wing is not apparent in the pictures but is clearly shown in the video:

http://vimeo.com/20780602

More info and pictures here: http://www.sailrocket.com/



Pictures-Sailrocket 2 hoisted by crane, RC model tests, click on image:

[mojounwin]

I was fortunate to be at the launch yesterday. This boat is awesome!! Definately a huge evolution from the previous boat. There is going to be some great footage come out when they get to Africa and get sailing.

Cheers
Mojo

[Doug Lord]

Originally Posted by mojounwin

I was fortunate to be at the launch yesterday. This boat is awesome!! Definately a huge evolution from the previous boat. There is going to be some great footage come out when they get to Africa and get sailing.

Cheers
Mojo

============
Mojo, did it appear to you that they would test sail it in the UK prior to shipping south?

[mojounwin]

Hi Doug,
Nah, the boat will be going straight to Nambia. This time next week the boat will be on a container ship heading south. The container will become a mobile workshop, so any mods or rebuilds that need to be done can be done onsite.

Cheers
Mojo

[Doug Lord]

from the website today:

Once we have a couple of other small details sorted, hopefully today, we will take the boat with the wing onto the water and start exposing the wing to some wind.

For the first trials I will remove all the elements which are not necessary and try and test one at a time, adding a new element for each test. We won't need the lower horizontal wing extension for a while as we work through the boats low speed performance... so that will stay in the container.

The lower 'wing fillet' that is the highly curved lower corner element of the wing is always necessary as that is where the wing hitches onto the beam and is also the junction for most of the upper and lower components. It always has to be on to join the wing to the boat.

For the first test we will only go out with the large main/middle wing section which is designed to be fully 360 degree feathering. This means we will remove the upper tip section and the lower 2 meters below the VESTAS logo. We should be able to raise the rig in the yacht club and launch the boat with this raised as it should develop very little power when not sheeted in.

That's the plan.

Yesterday, we fitted the foil raising and lowering system that will allow us to do this operation from the cockpit and even when underway at low speed. We are very happy with how well this functions.

Today is going to be a very windy day. Way more than we need. I'm dead keen now to try this wing out. How well it rotates/feathers may well determine just how fast this whole program progresses.

Hopefully this program will begin tomorrow.

Cheers, Paul.

[Doug Lord]

from the website-mods:

On another note we are looking at decreasing the 'hump' drag in the floats. We want them to release from the water and plane/skid on the surface with less effort. I suspect that as much as the front of the float is lifting as the water flows over it, the back section is sucking down. It is only when the air gets to the 'step' in the bottom that the hull releases and the suction is broken. At low speed, this 'step' is too deep and the air can't get to it. We are going to try adding a simple and light second step on the aft surface to try and break this suction cycle. It is an easy experiment that may have a big effect on how well the boat accelerates from stand still. Ben is on the case today.

Other improvements were to the system that allows us to raise and lower the foil from the cockpit. I must admit that this has worked a lot better than I expected. It's a beauty and surely one that saves the foil tips on numerous occasions. Jeff is on the case of making it all neat and tidy... hmmm... perhaps not the best person for this

Yesterday we also tried swinging the beam fore and aft with the rig up. Overall it went pretty well although we need to increase the range to around 2.5 meters from the current 1.5. This will be how we steer the boat from standstill when the little rudder is ineffective. It will be very important to get this whole system safe and reliable. We have to be in full control of this beast at all times as we do expect to be sailing her in winds up to 30 knots. Whilst this is nothing by wind or kitesurfer standards... it's pretty punchy for larger craft.

Yesterday will mark two weeks since the container doors first opened on Namibia. I hope we can hit the water again for some trials with the wing up this time.

Good progress is being made every day.Cheers, Paul.

picture- YOU CAN SEE THE SECOND STEP AS RECOMMENDED BY MALCOLM DRAWN HERE. IT WILL BE CLEAR OF THE WATER OVER 10 KNOTS. WE WILL MAKE IT OVERSIZE FOR STARTERS SO IT CAN EASILY BE CUT DOWN ON THE BOAT:


click on image-

[Doug Lord]

Testing continues-a few snags here and there-getting closer: http://www.sailrocket.com/blogs

[Daniel Noyes]

To my eye sail rocket II is a Yellow Pages Endevour with slightly different sail and cross beam configuration.

the model appears to be sailing well, were the full size floats built to the models design?

[Doug Lord]

Milestone as Larsen solves low speed hump: http://www.youtube.com/watch?v=2XwlS...ature=youtu.be

Sail Rocket specifications:

Empty weight: 275 kg (605lb)
Length: 12.2m, 40’
Width: 12.2m, 40’
Total wing area: 22m2 (236.7 sq.ft.)
Projected wing area : 18m2 (193.7 sq.ft.)

[Doug Lord]

Picture during first sail at 20 knots:
http://www.sailrocket.com/

click on image-

[peterchech]

This boat is so cool... compared to hydroptier such a low-cost approach to breaking the record... love it...