ARC

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The difficulty of making a rudder shaft strong enough also applies to what passes for a skeg on many boats.
It's a thin assembly of weak fibreglass. Keeps a few traditionalists happy and sells sold a few boats.
 
Wing Mark said:
The difficulty of making a rudder shaft strong enough also applies to what passes for a skeg on many boats.
It's a thin assembly of weak fibreglass. Keeps a few traditionalists happy and sells sold a few boats.
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Too true. I wouldn't back my skegs to win a knock down drag out with a rock or an orca. In fact, I'd far rather have the lift-up steel plates fitted to early Catalacs if I'm picking a fight with anything animate or inanimate.
 
Wing Mark said:
The difficulty of making a rudder shaft strong enough also applies to what passes for a skeg on many boats.
It's a thin assembly of weak fibreglass. Keeps a few traditionalists happy and sells sold a few boats.
Click to expand...
To be sure, any type of rudder requires adequate engineering input, but a spade rudder inherently limits your variables.

The higher labour, material and tooling costs for building a skeg & rudder may also have something to do with it's current lack of popularity.

On the other hand, it is easy to forget that a skegged rudder also has it's hydrodynamic advantages, such as enhanced directional stability and a significantly greater stall angle.

To me the interesting aspect is that, since I am not interested in racing where every second counts, I can choose whatever setup technically suits my needs best.
 
Stemar said:
Too true. I wouldn't back my skegs to win a knock down drag out with a rock or an orca. In fact, I'd far rather have the lift-up steel plates fitted to early Catalacs if I'm picking a fight with anything animate or inanimate.
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I can equally assure you that flat (steel or insert material of choice) does not make an efficient form of rudder and one that will stall out before you have time to put down your tea.

Adding skegs to the setup would have increased the angle of stall and would have improved control at higher rudder angles.

I do seem to recall that the early Catalacs had something of a steering problem.
 
I'm sure you're right. My rudders strike me as being on the small size, and I certainly can't spin Jazzcat under power as easily and tightly as I could my Snapdragon without a bit of help from the throttles. I've yet to try her under sail.

I do remember from an interest in aerodynamics as an air cadet that a flat plate gives next to no lift as the flow stalls at a very low angle of attack, but an orca that tries to take a lump out of a steel plate is going to get sore teeth
 
Stemar said:
I'm sure you're right. My rudders strike me as being on the small size, and I certainly can't spin Jazzcat under power as easily and tightly as I could my Snapdragon without a bit of help from the throttles. I've yet to try her under sail.

I do remember from an interest in aerodynamics as an air cadet that a flat plate gives next to no lift as the flow stalls at a very low angle of attack, but an orca that tries to take a lump out of a steel plate is going to get sore teeth
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On the upside, the faster your cat goes, the smaller her rudders can be.

You are correct that the stall angle for a flat plate is lower than for a profiled form, what is equally significant, however, is that resistance is three times greater and easily more than if you were towing several fixed props.

Mr. Orca doesn't have to take a nibble out of a flat steel rudder, it would be quite enough for him to casually "brush up" against it with his 3.5t to bend it out of any hydrodynamic recognition.
 
I'm wondering if a couple of long ropes deployed astern would be enough to put them of by having them think of fishing nets. Drogues would probably be required to prevent wrapping on your own prop, but they wouldn't need to be big enough to cause serious drag.
 
Tommarr said:
According to the YB tracker (ARC 2021 - YB Tracking Race Viewer) the previously abondoned Charlotte Jane III appears to arrived in the Carribean. Does anyone know how the yacht was recovered?
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Apparently it was salvaged along with the X yacht that was also abandoned when the skipper was sadly killed in a crash gybe.
 
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