NE Dory rudder authority on slow tack (stock barn door version)

Hi all,

Just finished my NE Dory from plans (I'll include pics on next post), and had a wonderful test sail out in the Inner Harbor of Baltimore, yesterday. All in all, I am extremely happy with it, and surprised at how it got up to speed under light air (and heeled over quickly under the stronger air in the main channel). 

I have a question that perhaps others might have an answer for: has anyone had experience modifying the rudder for more authority in slow tacks? 

I ask this because when I would perform a slow tack (not creeping, just slower than snapping it around, really), I noticed that I would have to push the rudder all the way hard around; almost 90-degrees to the transom at times. It appeared that the Dory had wonderful authority getting up to, say, the last 20 degrees of heading into the wind, but then as I slowed, the rudder lost authority in a huge way.

I do know that slowing down does impact rudder authority, but I was quite surprised at how much it was with the stock barndoor rudder. I used to race Lightnings and the deeper and sharp rudder was never a problem at slow paces. I may have answered my question, here, but thought I'd throw it out to the forum.

Great boat plans, CLC!
Sonny


8 replies:

« Previous Post       List of Posts       Next Post »

RE: NE Dory rudder authority on slow tack (stock barn door version)

Sonny,

I do not know how practical it is, given the rake of the rudder, but endplates are often used to increase rudder authority. However, I cannot believe that John Harris would design an ineffective rudder. I suspect it's probably an issue of technique and hopefully you'll get useful advice from some of the many Northeaster Dory owners. For years, I was a keelboat sailor and it took some re-thinking to learn handle a sailing dingy.

Cheers,

Dick

RE: NE Dory rudder authority on slow tack (stock barn door version)

Perhaps the kick up rudder is the solution to your problem. It sticks down deeper than the stock rudder and in the description it says that it "will provide improved handling out at the edges of the performance envelope:  very light air or very heavy air."

RE: NE Dory rudder authority on slow tack (stock barn door version)

  On my virgin sails with my sloop rigged dory this summer, I also had problems on tacks with light air, and even some problems on moderate wind tacks and coming about, until I figured out about jib dynamics.  (The jib was tending to push the bow around so I would end up jibing.)  The other thing that seems to affect the boat is center of mass -- I found that ballast in the bow seemed to help the steering, even with solo sailing.  (I used a kitty-litter bucket filled with water.)  The ballast placement also helped the boat handling when my wife was sitting on the transom seat -- well out of the way of the boom when coming about.

Dave M. 

RE: NE Dory rudder authority on slow tack (stock barn door version)

One thing to remember is that the Northeaster Dory is VERY light. In sailing trim, probably even less than a Laser or a Sunfish, and certainly a fraction of what a Lightning weighs. 

This translates into not much momentum when you tack. "Slow tacks" are okay, as long as you keep the sails pulling as long as possible and you steer very smoothly and deliberately.  "Sailing through the tack" is the jargon in this case.  Any time you're sailing a boat this light, turns are best made with some speed on.  Otherwise you're just going to run out of momentum and stall.  

Racing Lasers all through college, I had this beaten into me. Now THERE'S a boat with lousy rudder authority. The Northeaster Dory piruoettes by comparison.

RE: NE Dory rudder authority on slow tack (stock barn door version)

   Here is my new (protorype) kick up Dory rudder laid on top of the original Dory rudder.  The new one doesnt seem to do as well as the original in light air tacks. It has not been faired at all, square corners...maybe that will help but your advice is welcomed on reshaping the blade...maybe make it narrower and shaped more like a Hobie cat rudder blade?

Curt

 

RE: NE Dory rudder authority on slow tack (stock barn door version)

>>The new one doesnt seem to do as well as the original in light air tacks.

Maybe John knew what he was doing? :-)

 

RE: NE Dory rudder authority on slow tack (stock barn door version)

My NE Dory is generally forgiving when I've not sharply put "helm's alee."  A few pumps on the tiller is usually enough to bring her round, but the rare times I've been caught head to wind sliding backwards, I've simply put the helm over opposite to steer the stern off, and she gently falls off until the sail begins to fill, and goes on her way on the new tack.  There's none of the stubbornness caught in irons as one experiences on a Laser, for example.  She's the most forgiving boat I've ever sailed.

RE: NE Dory rudder authority on slow tack (stock barn door version)

   Hi all,

Many thanks for the replies. 
John, I believe you are spot-on with respect to the "mass." 

As I consider it, this is absolutely the lightest boat I have ever sailed. All of my other experiences were in boats that had considerable mass. 

When the mass is added to the equation, the turn and tack makes sense...the light weight of the Dory, if not given a lot of speed, translates into not that much forward momentum into and through the tack. I believe that this is it. 

Therefore, the suggestio of sailing through the whole tack is perfect. I'm going to head back out this weekend (if it is not too hot and there is at least SOME breeze) and just keep at it on the stock configuration.


Thanks!
Sonny

« Previous Post     List of Posts     Next Post »


Please login or register to post a reply.