Monday, June 21, 2010

Stability Trial

video

With the ~220 lbs of steel plate ballast secured to the floor, it was time for a stability trial. The video shows 2 trials with the mast below water level.

In the first trial, there are also a couple of sand bags (~ 2 x 60 lbs = 120 lbs) lashed to the floor in addition to the steel plate (6 pieces, ~ 220lbs total).

The second trial is without the sand bags, steel plate only. The difference is pretty subtle.

We also did a couple of tests with me in the boat (no video) and from my view it didn't seem like there was much difference in observed stability.

It is noteworthy that I was able to enter the boat when the top of the mast was in the water. The cabin coaming was still a few inches out of the water even with my weight on it while entering. If the boat were heavily laden, this might not be the case, but the hull would likely be even stiffer in that condition.

The boat is pretty tender when upright but stiffens up remarkably when heeled. The second trial was in deeper water. The boat stiffens up even more as soon as the deckhouse is in the water. It is a very noticeable increase. You can see in the video that I was trying to push the mast to the bottom but was not able to do so. All very encouraging.

Note also that in these first trials, the sail is down. In a real knockdown, the sail would be up, there would be more weight aloft and the rig might catch water and dig in as the hull is pushed toward it by wind and waves.

Back in the Water



Fantasma is finally back in the water after a long winter! We had her out on Chilkat Inlet near Haines, Alaska for some light wind sailing over the weekend. I am still refining some of her features and capabilities.

I have been having an issue with the boat developing the light weather helm it should have when on the wind. At Matt's suggestion, I trimmed 75mm off the rudder (oh, I hated doing that!). That did seem to help just a little bit but hasn't solved the problem. Next step is to fit a gripe (wood strip) on the forefoot. I will post on this and the results.

The other development is that I have secured the steel plank ballast to the floor with a couple of 1x2 hardwood strips along the interior of the chine in the cabin. (I get some pictures up of this too).
This allowed some basic stability tests to be done this weekend.