Re: AS29, LM2, WW and Similar Rudders
Thanks for the very informative and helpful responses on these rudders.
Jon
Jon
Jon, I've sailed my modified AS29 in up to 10' seas and never had the rudder break out. Upwind, under sail, it breaks out at around 20 degrees angle of heal, and the boat rounds up.. My motor was mounted on the stern for easy access. Heading out to sea with rollers in the channel, it would break out unless full power was applied to hold the stern down. I found the rudder to have too much area forward of the post on my boat. It was so nuetral that it would fall to one side when making way if you turned it loose for any length of time. I prefer a more positive feel and will change the rudder as part of my rework. If you trim your sails properly and balance the sail combination for the conditions, then the rudder is only a trim-tab for correcting the varying inputs of wind, waves, etc.
If my motor was in front of the rudder, I'd lock it in place to prevent the engine torque from turning it. But, since mine was mounted behind the rudder, I want to design an arm to move the motor in conjuction with the rudder for better manueverability when docking.
For pictures of the boat and her modifications, go to "photos" and look at "Island Time". While the underwater shape of the hull is as designed, she isn't your typical AS29 and may behave differently than a "stock" boat.
Tom
If my motor was in front of the rudder, I'd lock it in place to prevent the engine torque from turning it. But, since mine was mounted behind the rudder, I want to design an arm to move the motor in conjuction with the rudder for better manueverability when docking.
For pictures of the boat and her modifications, go to "photos" and look at "Island Time". While the underwater shape of the hull is as designed, she isn't your typical AS29 and may behave differently than a "stock" boat.
Tom
--- Inbolger@yahoogroups.com, "adventures_in_astrophotography" <jon@...> wrote:
>
> The rudders on these designs are all shallow, end-plated, and partially balanced about a shaft. They are also pretty small compared to the sail area. I always assumed they could be so small because they trap the flow between the hull bottom and end plate, maximizing their effectiveness. I'd be interested to know from folks with experience in these and similar designs how well this type of small rudder performs. Are there ever situations where you wish you had more rudder area? Do they ever pitch out?
>
> How about the motor location used with these rudders - do the motors ever pitch out while under power? How well do these rudders perform under power? Do you leave the motor free to turn?
>
> Thanks in advance,
> Jon
>
Jon, I had such a rudder on my boat Wolftrap . I sailed her In the
Chesapeake Bay up to about 6ft short chop quite a few years and only had
the rudder come out of the water one time. The boat had it's original
cat yawl rig and was over canvased at my request from Mr. Bolger with
the idea that I would reef sooner. Well I didn't, so the bottom plate
was already jacked up within about 8inches of the that plate coming out
of the water. I changed the rig to schooner later (my favorite rig) and
I 'm sure the big sail aft tended to drive the stern down some. Because
the boat had good direction stability she did not change course at all
when she broke out. If course the rudder was out of the water only seconds.
The rudder on Wolftrap was aluminum as was the whole boat and had 3
wings on it one just above water level, one below water at mid level and
one on the bottom. I sailed back from the Bahamas In what was said to be
15ft seas. I thought they were less maybe 8-10 ft. WE sailed into Lake
Worth on a broad reach throwing water all over the place. A good friend
said we were the most magnificent thing coming in there, he had ever
seen. Anyway I trusted her helm completely. When backing up under power
we had none of that thing of her backing to one side. The boat could be
steered in both directions. I liked being able to climb up the wings to
get on board. All In all I think it was the best rudder I ever had on a
boat. Doug
adventures_in_astrophotography wrote:
Chesapeake Bay up to about 6ft short chop quite a few years and only had
the rudder come out of the water one time. The boat had it's original
cat yawl rig and was over canvased at my request from Mr. Bolger with
the idea that I would reef sooner. Well I didn't, so the bottom plate
was already jacked up within about 8inches of the that plate coming out
of the water. I changed the rig to schooner later (my favorite rig) and
I 'm sure the big sail aft tended to drive the stern down some. Because
the boat had good direction stability she did not change course at all
when she broke out. If course the rudder was out of the water only seconds.
The rudder on Wolftrap was aluminum as was the whole boat and had 3
wings on it one just above water level, one below water at mid level and
one on the bottom. I sailed back from the Bahamas In what was said to be
15ft seas. I thought they were less maybe 8-10 ft. WE sailed into Lake
Worth on a broad reach throwing water all over the place. A good friend
said we were the most magnificent thing coming in there, he had ever
seen. Anyway I trusted her helm completely. When backing up under power
we had none of that thing of her backing to one side. The boat could be
steered in both directions. I liked being able to climb up the wings to
get on board. All In all I think it was the best rudder I ever had on a
boat. Doug
adventures_in_astrophotography wrote:
>
> The rudders on these designs are all shallow, end-plated, and
> partially balanced about a shaft. They are also pretty small compared
> to the sail area. I always assumed they could be so small because they
> trap the flow between the hull bottom and end plate, maximizing their
> effectiveness. I'd be interested to know from folks with experience in
> these and similar designs how well this type of small rudder performs.
> Are there ever situations where you wish you had more rudder area? Do
> they ever pitch out?
>
> How about the motor location used with these rudders - do the motors
> ever pitch out while under power? How well do these rudders perform
> under power? Do you leave the motor free to turn?
>
> Thanks in advance,
> Jon
>
>
The rudders on these designs are all shallow, end-plated, and partially balanced about a shaft. They are also pretty small compared to the sail area. I always assumed they could be so small because they trap the flow between the hull bottom and end plate, maximizing their effectiveness. I'd be interested to know from folks with experience in these and similar designs how well this type of small rudder performs. Are there ever situations where you wish you had more rudder area? Do they ever pitch out?
How about the motor location used with these rudders - do the motors ever pitch out while under power? How well do these rudders perform under power? Do you leave the motor free to turn?
Thanks in advance,
Jon
How about the motor location used with these rudders - do the motors ever pitch out while under power? How well do these rudders perform under power? Do you leave the motor free to turn?
Thanks in advance,
Jon