rudder discussions

Wow... I sure do love my fresh water venue.
(By the way, what's a zinc?)

Zincs are lozenges you give your boat to cure a bad ODE
(anode/cathode - together they're called corrode by saltwater sailors.)

Zincing (pronounced 'sinking') is the feeling you get
when you're damned sure you haven't done enough to save your boat.
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http://www.sailingscuttlebutt.com/2013/05/30/photo-whe

A 157 has been on freshwater for 50+ years, almost hate to put her in the seawater but don't think I can resist going for a voyage or two (in water that I can swim in). Wonder if a composite rudder and shoe would solve the problem, would be interested to hear your thoughts on that Ebb. Dr. LED states that the navy used his led lights so there must not be too much RFI with his products.

After a certain number of years, an Ariel/Commander rudder would probably need to be rebuilt.
Threads here on Pearson Ariel. org have many fine and many differnt rudder rebuilds.
You may want to stay with the original bronze and mahogany because you want to restore what she has. Building a new rudder is something imco any woodworker can do. The original rudder is a beautiful piece of work that ties the folkboat heritage of Alberg's beginnings with the new polyester and glass productions of the Pearson's in the early 1960's.

If you are going with an internal engine you probably need a new rudder, and all that goes with it: an apperture in the keel (which is most like there to be excavated), a two part bent bronze shaft, and propeller drive shaft with apperture in the blade. We hear the original rudder was two part bronze - yours may have an insert (that matches the one in the keel) that closes the hole.
The rudder you have, if it needs to be rebuilt for offshore, will be the model for a new one.
It could be taken apart carefully. Fresh water won't have done anything to whatever bronze was used. Therefor, replacement of the mahogany may be all that's necessary.

The original rudders have lasted an amazing long time. They must be a pretty amazing rudder!
Maybe you need not do anything until your rudder tastes salt. Unless you have noticed issues with the heel fitting/rudder shoe, the shaft end in the shoe, the gudgeon strap, the unseen part of the shaft above the water in the bustle, wear at the top of the shaft at the tillerhead, wear of the tiller head and other etceteras. If things are good here, or can fairly easily be upgraded or fixed....you are good to go!
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On the otherhand, if you have to replace, stay tuned.

I've just dragged out my new rudder shaft with it's welded 3-strap armature. (no pics here yet.)
On which I'll construct a composite blade of epoxy, glass, kevlar cloth, kevlar thread and divinycell - applying
NACA00XX airfoil profile to the surface of the quadrilateral blade Alberg has drawn behind the original
you can see in the lines drawing on page 144 in the Association Manual.

The new thickness of the rudder will start at the width of the keel
- around 2" wide, and trail to 1/4". The 'airfoil' will be the aft half of the NCAA foil. The traling half, which has a long fairly flat curve.
The idea with symetrical foil is to reduce the drag of a flat blade. Decrease turbulence. And I hear, to stop stalling.
Airfoils are usually applied to more or less retangular shapes of wings, fin keels, standalone rudders & daggarboards.
But I see no reason why streamlining can't be applied to the nearly triangular rudder Alberg has drawn.
Discussion would be great.

My rudder really doesn't look too bad. I am a little concerned about going out bluewater with it though. I like your idea of tapering thin near the trailing edge. I am going to buy a Cape Horn steering gear and an emergency rudder can be purchased to go with that so maybe there is not much to worry about as long as I have a back up. After looking at Yves gear and his movie I am comfortable with what he has developed over the years. He has encouraged me to outfit a larger Chris Craft Cherokee that I have but I have had it out in some blows and it gets a little squirrly. I have raced the Ariel in 25-30 by myself and actually won, and it was pretty laid back. I missed out on a rudder that went up for sale here on the forum, otherwise I would own a new one. If your interested in building another rudder let me know. I know it sounds crazy but I probably won't take an auxiallary, so I won't need the cutout for a prop

Captcraig,
Wouldn't contemplate taking the boat anywhere until you have taken the rudder out of the boat.

Might get all its history from the former owner. Anything he has done for the rudder system.

I would recommend stripping the paint (using a non-caustic remover) to get a complete understanding of what you have there. EG, you might find you have a two part shaft with a aperture plug.

If you don't do the work youself, make friends with a good traditional woodworker.
Look up everything the board has here on rudders.....there's plenty.
There are different ways to have a copy of the original rudder made that will allow a NACA00XX foil and a trailing edge.

You might find a fledgling naval archetect to design the rudder.
Or contact EricSponberg www.sponbergyachtdesign.com with the problem. You'll be doing all of us a favor.

My solution for A338's new rudder is pretty radical and untried.
So far as I know, the constellated alternative rudder for an A/C has not been documented.
( Nobody has faired their rudder to the width of the keel. Or worked an NACA0012 foil onto the blade.)
The triangular rudder will be airfoiled.
Also going to use an untried technique (suggested by Chuck at Duckworks) that will sew the rudder skins together with kevlar thread.


I'm barely able to get things done for myself.
Can't take on making a second rudder.

BUT THERE ARE PROFESSIONALS ON THE BOARD WHO MAY BE PERSUADED TO BUILD A NEW RUDDER FOR YOU.
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* A traditional bronze and mahogany rudder cannot be shaped to a thin trailing edge because of its construction.
Don't try it. There is bronze dowel, nuts, washers and screws inside the blade.
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It has been said by sailors that adding a foil to our rudder might indeed make little if any difference to speed.
There can possibly be improvement in stalling rudder angles and going to weather, but it's unknown.

However, the 00XX foil is an aestheticly pleasing shape. The full wing is fattest back from the nose one third of its chord - the curve continues for two thirds to the trailing edge. I've layed out a TWO THIRDS 0012 foil.
To my way of thinking the front one third of this keel-hung blade is the boat itself.
Since the foil is not a complete wing but just the trailing of the foil from its thickest dimension to its thinest trailing edge.......
if I put (on the drawing paper) a straight edge from that point of the fullest section to the trailing edge.....
the actual curve of the foil (the bump-out on the blade over the span of its surface) above the straight edge......
is barely 1/4".
Not breathtaking dramatic.
This is using the NACA 0012 formula for a 1" half foil (the full symetrical thickness being 2")
I'm now checking out some 'bigger number' foils, but it's obvious - given the max thickness of the rudder - that any change in the curve (like a more pronounced curve) can't happen using this series of section profiles.
Don't know if anybody else here has a handle on this anomaly. A more dramatic curve is only possible with a thicker rudder.
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AN APPROACH FOR A NEW ARIEL RUDDER
Imco, with modern construction on the 1" rod** backbone, using welded-on plates and supreme marine plywood like meranti, epoxy, and cloth for the blade..... it is entirely credible to have a rudder properly faired to the A/C keel (at approx 2").....and also foiled to a cut-off racer's edge. There will be a bit of fudging, especially where the rudder swings at the keel.
The trailing edge of the whole aspect of our round shaped rudder CAN be brought to a NACA0012 thin trailing quarter inch termination.
It will NOT look weird, but tight, right, and handsome. And it'll be a correct and genuine UPGRADE for Alberg's traditional blade.
It's the right thing to do, imco.
A round rudder is LESS likely to get buried in mud, get damaged aground, or crab potted. If I was going to do it over, I would go for
the round one and make it with a cutout for the prop (with a plug) so that a new owner will have the option.
And not call me a DFO.
(Oh, lay out your hydrofoils on waterlines - not perpendicular from the keel)
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**OnlineMetals - six feet of "exotic" 655 silicon bronze 1" rod = $217.
OnlineMetals - six feet of 316L s.s. 1" rod = $99.

A plug in the rudder is a good idea, I may change my mind about an inboard. My goal is to voyage by 2016 so I have a little time. If I can duplicate the original within reason I would be happy with that but a more high tech would be even better. This pic is an older one before I brought it south. A lot of that paint came off over last summer and I peeled some more off with a putty knife. I gave the rudder a workout last summer and didn't notice failure of any kind, but I will take it off as you suggest.Attachment 9165 Attachment 9164

I'd rather be sailing

Hey Ebb, I did want to say something about the speed of the Ariel, Commander and how an improved rudder might effect the speed. Last season I raced A 157 against a somewhat competitive handicap fleet here in OKC. You can look at the race results of over 15 races I competed in by going to okcboatclub.com go to race program and then race results. No brag just fact. Yes I am proud of the results. Many believe that the handicap numbers are a bit high for the A/C and that mya be true, because in some of the races we finished ahead of all competitors. Rudys Commander has very slick VC-17 bottom with a very fair rudder, oversized main and other nice headsails. I believe his boat is actually faster than mine due to the very slick bottom. I would have to go back and count but I think we had at least 10 first place races for the season and won the fleet championship. My point is that our boat sailed very well and fast even with these objects dragging in the water and with a pretty rough bottom paint.

Attachment 9169Attachment 9168 Major Drag

My conclusion was this: It is very hard to improve on the boat as far as speed is concerned. Every little bit helps for sure but hull speed is reached and then some and then after that you just can't push em any faster. One reason we did well is the boats exceptional handling when its blowing like stink. Several of the races I mentioned were in 25mph and up. Its very windy here. Some of our competitors dropped out because of strong winds Bill please forgive me for posting the mast base photo twice, I am a klutz on the computer.

One more thing, the reason I posted the knotmeter instrument is to say that I have removed it. I could not find a replacement prop. I am considering making a taffrail type unit using the knotmeter head and making a box to contain it, dragging a prop behind the boat, because the head still works beautifully. I have installed a modern knotmeter in the bulkhead but it uses power and probably won't last 50 years like this old one, lol

Captcraig I did go look at the okc race results and was impressed. Well done. I do have a question, why does Rudy have a different rating? Here in the SF Bay area both boats had the same rating. In fact when the Ariel class raced as a one design the Commanders raced boat for boat. Just curious???……..ed

Hi Ed, Thats a good question. I strongly objected to the lower rating that I was given but relented after a explanation from our PHRF chair. Our club gives 3 points to a boat with roller furling, the reasoning is that the tack is raised and decreases performance. I'm not sure that I agree with that but thats 3 points. I also sail without a motor of any kind. Rudys boat has an outboard onboard, not in the well. That is also a 3 point increase. We both sailed with a plug in the outboard well so I don't really agree with that increase as the weight of a small outboard is minimal and even ballast when in the cabin. My biggest complaint was that generaly speaking the Ariel is much more top heavy than a Commander and not as streamlined as a Commander. The PHRF committee didn't take that into account and I'm not sure why. I could protest but the numbers didn't seem to hinder me much although I did lose a couple of races by correction only.

Hi Craig, I guess that just shows that each PHRF board is a creature to their self. The comment re motor weight would be consistent with our local board, but the comment about roller furling makes no sense. While I agree that as a class boat will suffer going to weather, off the wind the same boat would have an advantage.

In terms of streamline vs. top heavy I think the key number would be displacement and I think both types are pretty close regarding that number.

All that said you guys are doing really well, keep going and keep bring home the pickle dishes……ed