New keel not bad

[otto 31]

 

Buggered if i know how this you tube bit works so cut-n-paste

[Mothership 6]

You can now have YouTube videos play inside the forums. To embed YouTube videos in forum posts, simply paste the base URL into the text box, highlight the text, then hit the youtube button shown above the box.

 

Note that the base URL is all of the address up to the end of the v=*** section (if there are any '&' present remove the & and everything following it).

 

So in this case, remove the &feature=player_embedded from the end of the link and it'll work

[otto 31]

 

lets see

 

 

getting closer

 

Thanks Mum but i'm a not onto it.

Last try

 

Na to hard

[w44vi 17]

Interesting concept, but not as efficient as the current canting designs maybe suitable for fast cruisers thought

[Steve Pope 243]

Hmmmmmmmmmm

[Mothership 6]

Ahh; it doesn't like https - needs to be http only.

[otto 31]

Thanks mum, i'll try & remember all that

[Marshy 30]

Cant really see that working. And the photos at the end are of two different boats

[Guest]

There are some problems there, that's for sure.

The basic idea that you don't need as much power to move the ballast and hold it in position is true though.

The hinge mechanism at the front is going to see some massive loading though. The keel would need to be pretty solidly engineered to take the twisting loads.

The ballast disc wouldn't be able to be a nice hydro shape as the leading edge out one side becomes a trailing edge out the other.

Lot's of surface area in the disc, even though it doesn't need the daggerboards.

It also doesn't get all the weight out at maximum efficiency, so would need to be heavier to get the same moment, so it is a dead duck really.

[Guest]

Actually- I could see this having some merrit..... certainly less to go wrong vs a canter..... with some design refinement it could revolutionise fixed feel boats. Not sure how well it would scale up- but on small boats- being able to move a winged bulb to provide more righting moment could be huge.

 

Would it be comlicated to operate though ?

 

http://sites.google.com/site/mgmorris3993/home

[Guest]

I'm not sure I agree with his conclusion as I don't believe it is faster or safer than a canter. He has a lot more proving to do.

 

We are talking race boats here right? So anything that is done is going to be done to the maximum possible efficiency = maximum righting moment for least weight and least drag.

To get max righting moment, you want the weight (bulb) to be extended horizontally when the boat is heeled.

 

It has already been said that his idea means that you cant get the most efficient shape = more drag than a canting keel.

 

In his mock up, the hinge is at the bottom of fin, with the bulb extending on a horizontal. Of course the efficiency will depend on the boats design heel. Lets compare to a fixed keel that has the same length added on as he has out the side. He starts with more moment, with a maximum at 45°, it then DECREASES. The fixed keel starts with no moment, is the SAME at 45°, but continues to increase with a maximum at 90°.

 

To get the most out of his design, you would have to put the swinging part on an angle downwards so that it is horizontal when the boat is heeled over, rather than angled upwards. To maximise righting moment, you would do away with his fixed fin and rotate from the bottom of the hull.

 

So, in design configuration you then get the same righting moment as a canting keel, except with a vertical hinge instead of a horizontal one, and a whole lot more drag. I can only see this as being slower and more likely to incur critical failure than a canter. (The force is going across the hinge instead of with it?)

 

There is a much simpler, less likely to break solution to his initial problem. It is called "not carrying lead." That is - skiffs and multihulls.