Subject: Re: [harryproa] Re: BD with tandem keel |
From: "Rudolf vd Brug" <rpvdb@freeler.nl> |
Date: 1/4/2010, 4:24 AM |
To: |
Reply-to: harryproa@yahoogroups.com.au |
----- Original Message -----From: robertSent: Monday, January 04, 2010 3:02 AMSubject: [harryproa] Re: BD with tandem keelHi Rudolf,
I wonder if the loading on the aft rudder is NOW significantly less than it used to be. Do you notice any difference?
regards,
Robert
--- In harryproa@yahoogroups.com.au , "Rudolf vd Brug" <rpvdb@...> wrote:
>
> Hi,
>
> It has been some time since we put BD ashore next to our house.
> That was December 4th, earlier that week we sailed her with the tandem keel fitted.
> The keel was fitted using threaded rods in epoxy in the keel fins. We just drilled holes in the bottom of the hull,
> put the rods through them and floor timbers on the inside to distribute the loads.
> Plenty of sealant obviously. It took two hours including hoisting and relaunching.
> As usual I forgot the camera so no photos, sorry.
>
> Sailing with the keel fitted showed that we could get going with the wind at 90 deg. as with the leeboard.
> It was obvious though the leeboard was more effective, we could steer close to the wind but needed more rudder angle to keep control.
> Second test sail was with one of the old rudders fitted additional to the new ones.
> I wanted to see if this would cause a significant difference.
> We had the new rudders out of the water, so just one old rudder and the tandem keel. Sheeted in carefully and got going easily.
> When at speed no noticeable rudder angle, speed up to 12.5 knots could have gone faster but we didin't seek speed.
> Control with the old rudder was very precise, what I find to be missing with the new ones.
> After shunting returned with the new rudders, high rudder angles 11 knots max and we could feel the power that couldn't be put to use.
>
> It seems the keel works, although the leeboard was more effective. The leeboard would need more experimenting to come up with a good
> way of keeping at the right angle and prevent it from kiting. I think the leeboard would have to be handled at every shunt. That is one of the reasons the owner likes the keel better.
> Hopefully carefull finishing of the rudder blades will lead to smaller angles when sailing.
>
> regards,
> Rudolf
>