Announcements
New Discussions
Previous Thread
Next Thread
Print Thread
Rate Thread
Hop To
Page 1 of 2 1 2
Does a spin lift leeward bow? And Hooter editorial #13535
11/26/02 12:10 PM
11/26/02 12:10 PM
Joined: Jun 2001
Posts: 64
Sandy, UT
SteveBlevins Offline OP
journeyman
SteveBlevins  Offline OP
journeyman

Joined: Jun 2001
Posts: 64
Sandy, UT
When I was trying to evaluate spin vs Hooter, for me it came down to 2 issues: Stress on the rig and lift of the leeward hull. What got me into spin sailing was an article in Performance Sailor starting off about 'what gets you to beach first, corrects out DFL, and puts a permanent smile on your face? A spinnaker!' and the observation by a fellow P-19 sailor that sailing with the spin just pulls the leeward hull 12" out of the water. So, I tried it for about $400 (Randy S sold me a used spin for $250) and found the reports true.
So, when it came time to update the rig I talked to the West Coast guys that had Hooter's and Calvert Sails. The consensus was that it does add stress to your rig, which may not be as serious as I thought, but in a good blow the spin can pull your whole boat out of the water, and my knee jerk reaction was to not add to that load. And I was told by Calvert Sails that the Hooter would tend to press the bow down and the Hooter sailors out here said the same thing. The Hooter sailors out here sail Nacras or similar so a little bow pressure doesn't hurt. But the last thing a P-19 needs going downhill is something driving the bows down.
Now, I do know that a spinnaker does help pull the leeward hull out of the water, and I assumed it was because of the fullness of the sail compared to the Hooter. But now after reading the Assymetric thread and reorganizing facts and semi-facts, the leeward hull lifting thing may be due to the angle of the luff of the spin, in which case similar results could be expected of a Hooter. I have never sailed a Hooter, so all I 'know' about Hooters is from experienced but non-racing sailors and 'experts' . So I now question what I 'know' and throw this issue out, not seeing any comments on this issue in the years I've followed this forum.
Additionally, as far as cost, ease of handling, and windage go, I believe it is a wash. There are ways to deal with each drawback of each system. It does not cost $3000 to get into a spin, and I doubt any but a very few spent over $1000 to get into their first spin.
Hooters ought to be allowed to compete and appraised. Maybe the ISAF hit is justified and the sail is so much faster but the techniques aren't being used to fully use it. Maybe it has conditions in which it is outstanding and conditions in which it is a substantial detriment. But if it has the potential to make us go faster and improve our understanding of the physics of wind and sail, as catsailors we need to be breaking down our comfort zones and learning some more. Obviously when you have an organization there are political considerations, they don't have to be evil, and they may need to change in the light of new ideas. Sometimes in these extended discussions I find myself aligning myself with what I like or believe and discarding the rest so that I get into a cycle of reinforcing what is comfortable to me and completely rejecting and tuning out the rest. I would sure hate to be 70 and find that sailing a Hooter improved my enjoyment of sailing and I could have done that when I was 40.

-- Have You Seen This? --
Re: Does a spin lift leeward bow? And Hooter editorial [Re: SteveBlevins] #13536
11/26/02 12:56 PM
11/26/02 12:56 PM
Joined: Aug 2001
Posts: 1,307
Asuncion, Paraguay
Luiz Offline
veteran
Luiz  Offline
veteran

Joined: Aug 2001
Posts: 1,307
Asuncion, Paraguay
Steve,

There is no need to complicate things:

Any headsail (jib, spi, hooter) lifts the bow, much like a windsurfer's sail inclined to windward. The differences in sail shape are less important then the relative positions of the sail's extremities.

The tack, hoist and clew of a sail define a plane. In the mainsail, this plane is vertical (or as inclined as the mast is raked aft).

In any headsail, this plane is inclined to windward, so the sail thrust always has a vertical component lifting the boat.

Placing the headsail further forward increases the leverage of the vertical component and raises the bow higher with the same sail thrust.

Simple, isn't it?




Luiz
A question about rig loading by a hooter vs. spin [Re: Luiz] #13537
11/26/02 01:08 PM
11/26/02 01:08 PM
Joined: Oct 2002
Posts: 50
Farmington, Utah
thouse Offline
journeyman
thouse  Offline
journeyman

Joined: Oct 2002
Posts: 50
Farmington, Utah
I think I follow the last post regarding bow lifting or loading. However, I'm not sure I understand why folks say a hooter loads the rig more than a spinnaker.

Indeed, (it seems to me) both can be sheeted hard or eased. Indeed, it seems both load the mast, rigging, sheets and front beam.

So why it there more loading of the front beam when using a hooter, than when using a spinnaker...or is there more loading....???

Thanks,

Tom H.

Re: Does a spin lift leeward bow? And Hooter editorial [Re: Luiz] #13538
11/26/02 01:16 PM
11/26/02 01:16 PM
Joined: Aug 2002
Posts: 74
Fulshear, TX
SGalway Offline
journeyman
SGalway  Offline
journeyman

Joined: Aug 2002
Posts: 74
Fulshear, TX
I don't quite follow your comment about there always being a vertical component, could you expand on that?


Shannon Galway
Fulshear, TX
YoNav! Flying Phantom
www.yonav.net
Re: Does a spin lift leeward bow? Loads [Re: SteveBlevins] #13539
11/26/02 01:19 PM
11/26/02 01:19 PM
Joined: Jun 2001
Posts: 138
California
Sailing Pro Shop Offline
member
Sailing Pro Shop  Offline
member

Joined: Jun 2001
Posts: 138
California
A sail like a NORTH CODE ZERO or reacher or similar requires substantial amount of luff load to maintain sail shape. This high amount of luff load translates to rig compression and puts additional stress on the rig as compared to a relatively softly loaded spinnaker. The sail materials also make a difference on rig compression. The less stretchy reached and code zero sails also increase rig strain.

As to penalties: There is a far greater range of TWA (True wind angle) capabilities on a reacher compared to a spinnaker. The wider range increases the penalty to compensate for the additional use and MPA (Maximum projected sail area or at least potential) over the full range of the course.

LIFTING THE BOWS...? Sails with an acute angle of rake provide additional lift. Witness AUSSIE 18s where only their rudder is in the water at times downwind.

In my experience a flat spinnaker provides more lift than does a reacher or "hooter".

MM


Mark Michaelsen http://www.sailingproshop.com (800) 354-7245
Ahh but is isn't that simple ! Read this [Re: Luiz] #13540
11/26/02 01:56 PM
11/26/02 01:56 PM
Joined: Jun 2001
Posts: 9,582
North-West Europe
Wouter Offline
Carpal Tunnel
Wouter  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 9,582
North-West Europe

Surely an angled luff produces vertical lift forces trying to lift the bows up BUT it also produces horizontal thrust forces which in turn are trying to push the bows down.

What will the net result be ?

Read this analysis made by a Finnish sailmaker.

http://www.sailingsource.com/cherub/aero.htm

Clearly guys this issue is more complex than we would like to believe.

I can tell you from my own analysis that the diving is not only the result of a balancing act between thrust and lifting but also the course is an important factor. Typically spinnakers and gennakers sail noticably deeper than spi less boats and this more instrumental in reducing dive tendency than the headsail lifting characteristic is.

Sorry Luiz, it's not that simple.

Wouter


Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
Re: Ahh but is isn't that simple ! Read this [Re: Wouter] #13541
11/26/02 02:13 PM
11/26/02 02:13 PM
Joined: Apr 2002
Posts: 591
Bradenton, FL
Sycho15 Offline
addict
Sycho15  Offline
addict

Joined: Apr 2002
Posts: 591
Bradenton, FL
So... he's saying that the sails themselves are generating lift, but since they are also pulling the boat forward from so far above it, they are "pushing the bows down" (because they are, in effect "tripping" over the bows").

This is why lighter crews have less tendancy to pitchpole? Because the entire boat has less weight and is therefore more easily driven (or accellerated) by the sails?

Sounds good to me, I only weigh 145lbs and I usually sail solo! I guess that means I'm just more likely to capsize than to pitchpole

Why don't we settle this once and for all. Someone give me a spinnaker pole, a spinnaker, and a hooter. I'll go sailing as much as I can for a year and get back to you with the results


G-Cat 5.7M #583 (sail # currently 100) in Bradenton, FL Hobie 14T
Re: A question about rig loading by a hooter vs. spin [Re: thouse] #13542
11/26/02 08:06 PM
11/26/02 08:06 PM
Joined: Jun 2001
Posts: 12,310
South Carolina
Jake Offline
Carpal Tunnel
Jake  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 12,310
South Carolina
The hooter requires fulltime tension on the luff, even when furled, and adds to the mast compression at all times (which is then carried to the forward beam). I also believe that the hooter can be carried a lot higher than a spinnaker and wish it would be more fair to run either (I remember a N6.0 at RTI that carried both! - that must have been a painfull portsmouth hit!).


Jake Kohl
Re: A question about rig loading by a hooter vs. spin [Re: Jake] #13543
11/27/02 01:08 AM
11/27/02 01:08 AM
Joined: Jul 2001
Posts: 364
Andrew Offline
enthusiast
Andrew  Offline
enthusiast

Joined: Jul 2001
Posts: 364
Actually, the rating hit for carrying two or more additional headsails, based on actual race results, is less than that for carrying only one. Apparently, the extra mess on the boat, parasitic drag, and the hassle of dropping the spin to raise the hooter (and vice versa) takes a bit of the benefit away. Checking the mod table now, it remains: .955 hit for carrying extra headsail in a distance race, and .958 for carrying two or more.

sail fast!


Andrew Tatton Nacra 20 "Wiggle Stick" #266 Nacra 18 Square #12
Re: A question about rig loading by a hooter vs. spin [Re: Andrew] #13544
11/27/02 02:26 AM
11/27/02 02:26 AM
Joined: Aug 2002
Posts: 37
Cedar Creek, Tx
cappydec Offline
newbie
cappydec  Offline
newbie

Joined: Aug 2002
Posts: 37
Cedar Creek, Tx
Hi Andrew, how is your spinnaker pole setup coming? Check out the notation just above the modification table.. It reads: For clarification: For class normally without spinnaker carrying a second one or carrying another headsail in a long distance race, apply both modification factors.
For class normally with spinnaker carrying one or more additional headsails, apply modification factor for each.
I interpret this to mean that if I carried two headsails such as a spinnaker and a reacher, I would take both the 0.955 hit for the 1st headsail and the 0.958 hit for the additional headsail. Can anyone shed more light on this?
Don Caldwell
Supercat-20 w/spin and/or reacher

Re: A question about rig loading by a hooter vs. spin [Re: cappydec] #13545
11/27/02 02:58 AM
11/27/02 02:58 AM
Joined: Jul 2001
Posts: 364
Andrew Offline
enthusiast
Andrew  Offline
enthusiast

Joined: Jul 2001
Posts: 364
I have the pole; it's a 100% carbon windsurf wave mast @465 cm, official weight is just under 4.7 lbs, and official cost was $95. Base fitting just needs some more grinding for a good interference fit; the tip already has a thick aluminum liner (dead Gary Fisher handlebar section, about 2 1/2" long) Wested in. I have some ideas for the strut(s); one recommendation was to make them 12" long and about 30 degrees apart, but I'm thinking a bit longer. I want the high point of the pole to be as high as possible, while still taking max advantage of the 15' length to lower the hound on the mast and "lay" the chute back for more bow lift a la the skiffs. God knows the P-19 needs it!

As for the "clarification:" I know it has been scored the other way, with the lesser hit for two sails than for one. I also know that I haven't seen Beuerlein carry both headsails in quite some time...it's very possible that they began scoring according to the "clarification" and the 2-headsail rig lost a bit of its "charm", shall we say.
Anyway, if you have facilities for welding/otherwise fabricating aluminum, please email me.
thanks, and
sail fast


Andrew Tatton Nacra 20 "Wiggle Stick" #266 Nacra 18 Square #12
Excelent article - thanks! [Re: Wouter] #13546
11/27/02 09:01 AM
11/27/02 09:01 AM
Joined: Aug 2001
Posts: 1,307
Asuncion, Paraguay
Luiz Offline
veteran
Luiz  Offline
veteran

Joined: Aug 2001
Posts: 1,307
Asuncion, Paraguay
Wouter,

Thanks for the very good article - it is recommended reading for serious catsailors.

Cheers,
Luiz


Luiz
I got a few more articles like that go to : [Re: Luiz] #13547
11/27/02 09:21 AM
11/27/02 09:21 AM
Joined: Jun 2001
Posts: 9,582
North-West Europe
Wouter Offline
Carpal Tunnel
Wouter  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 9,582
North-West Europe


I got a few more articles like that go to :

http://www.geocities.com/kustzeilen/

and scroll down

Especially the article by Tom Speer, Jim Boyer and the article by Bethwaite about the 49-er are interesting. And lets not forget JSD with "Airfoils and airflow"

In the future I hope to update the page with several more links to interesting articles.

Have fun.

Wouter


Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
Exactly ! (nm) [Re: Sycho15] #13548
11/27/02 09:23 AM
11/27/02 09:23 AM
Joined: Jun 2001
Posts: 9,582
North-West Europe
Wouter Offline
Carpal Tunnel
Wouter  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 9,582
North-West Europe

Wouter


Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
??? [Re: Wouter] #13549
11/27/02 09:53 AM
11/27/02 09:53 AM
Joined: Jul 2001
Posts: 2,844
42.904444 N; 88.008586 W
Todd_Sails Offline
Carpal Tunnel
Todd_Sails  Offline
Carpal Tunnel

Joined: Jul 2001
Posts: 2,844
42.904444 N; 88.008586 W
I'm currently in a 12 step program for spinnaker flying.

My name is Todd Bouton, and I fly a spin on my cat.

I agree with most of what's been said, especially Wouter's comments.

Before I got to his post, I didn't agree with this major lift thing, especially since:

I'VE STUFFED (PITCHPOLED) AND CAPSIZED MY CAT, MORE THAN ONCE, AND IT WILL PROBABLY HAPPEN AGAIN!
IF THERE'S ALL THIS LIFT (SINCE THERE IS AT TIMES), THEN WHY DO PEOPLE STUFF A BOW FLYING A CHUTE?

(I'll quit yelling now) And I've seen Many, that's right many, others do it also. PI Sailing on their I-20 in Rough Riders, etc.

It ain't ALL Lift!

Todd Bouton
N6.0na+
#111


F-18 Infusion
#626- SOLD it!

'Long Live the Legend of Chris Kyle'
And they are also good... [Re: Wouter] #13550
11/27/02 12:54 PM
11/27/02 12:54 PM
Joined: Aug 2001
Posts: 1,307
Asuncion, Paraguay
Luiz Offline
veteran
Luiz  Offline
veteran

Joined: Aug 2001
Posts: 1,307
Asuncion, Paraguay
...but Tom Speer's article is too complicated and Jim Boyer's is practical, but too simple. JSD is my preferred. Two years ago I printed the entire book hoping to learn how to fly ... and then started to build the Catri.


Luiz
Mea culpa [Re: Todd_Sails] #13551
11/27/02 01:17 PM
11/27/02 01:17 PM
Joined: Aug 2001
Posts: 1,307
Asuncion, Paraguay
Luiz Offline
veteran
Luiz  Offline
veteran

Joined: Aug 2001
Posts: 1,307
Asuncion, Paraguay
Todd,

It's my fault . The lift is there, but the torque of the sail's thrust also has to be considered (and there is even more to consider - but you can read about it in the articles indicated by Wouter).

Focusing in the torque only:

The sail's thrust can be considered to be acting in the center of the sail area, which is HIGH. The torque generated by the thrust tends to bury the bow. What keeps the boat from pitchpoling is the bow's flotation. Lack of flotation there is a big problem.

The effect of the torque generated by the sail's thrust is usually greater then the effect of the lift, thus your initial confusion.

Super simplified conclusions:

1-A big foresail increases the risk of pitchpoling, due to the higher thrust generated by the greater sail area creating a pitchpoling torque.

2-A big foresail MAY reduce the risk of pitchpoling, if it is placed sufficiently forward for its lift to generate a torque which is bigger then that of the sail's thrust.

This is the reason why 49rs have loooong bowsprits...

I hope it helps.


Luiz
Re: Mea culpa [Re: Luiz] #13552
11/27/02 02:21 PM
11/27/02 02:21 PM
Joined: Jul 2001
Posts: 57
J
Jacques Offline
journeyman
Jacques  Offline
journeyman
J

Joined: Jul 2001
Posts: 57
What about the wave piercing designs then?

Almost right ! [Re: Luiz] #13553
11/27/02 06:50 PM
11/27/02 06:50 PM
Joined: Jun 2001
Posts: 9,582
North-West Europe
Wouter Offline
Carpal Tunnel
Wouter  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 9,582
North-West Europe

all yes, BUT that diving is in turn counteracted by the fact that the craft sails deeper downwind. Why this is is more complicated.

However I too noticed that a spi boat sailed well has less tendency to dive than a spi-less driven well too (often meaning at a higher angle much closer to reaching)

Wouter


Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
Wave piercing - it helps [Re: Jacques] #13554
11/28/02 09:28 AM
11/28/02 09:28 AM
Joined: Aug 2001
Posts: 1,307
Asuncion, Paraguay
Luiz Offline
veteran
Luiz  Offline
veteran

Joined: Aug 2001
Posts: 1,307
Asuncion, Paraguay
Jacques,

The wave piercing design has to do only with the bow shape above the water line. Its only effect is reducing the difficulty for the bow to emerge after burying. For bows with equal volume, this is the only difference.

Is this what you wanted to know? Or did I miss the point?


Luiz
Page 1 of 2 1 2

Moderated by  Damon Linkous 

Search

Who's Online Now
0 registered members (), 656 guests, and 182 spiders.
Key: Admin, Global Mod, Mod
Newest Members
Darryl, zorro, CraigJ, PaulEddo2, AUS180
8150 Registered Users
Top Posters(30 Days)
Forum Statistics
Forums26
Topics22,404
Posts267,055
Members8,150
Most Online2,167
Dec 19th, 2022
--Advertisement--
Powered by UBB.threads™ PHP Forum Software 7.7.1