Bridle Foils??

General Sailing Discussion
DanBerger
Professional
Posts: 280
Joined: May 3rd, 2004, 3:29 pm
Boat Make/Model: SC 15 w/ spin!, SC 19
Location: Norfolk, VA

Bridle Foils??

Post by DanBerger »

Why don't we see more bridle foils on Supercats--especially the wide ones? Does the factory have plans for them?

I attached a pic of Bill at the Steeple Chase, thinking his spinnaker pole was a bridle foil. It looks like it from the angle. I can't delete the attachment.

I guess it is another opportunity for Supercat porn.
You do not have the required permissions to view the files attached to this post.
Matt Haberman
Administrator
Posts: 601
Joined: November 10th, 2003, 8:22 pm
Location: Minnesota
Contact:

Re: Bridle Foils??

Post by Matt Haberman »

Dan,

There are a lot of reasons we have stayed away from the bridal foil. For starters there are really no advantages of the bridle foil approach over a well rigged spinnaker pole with pelican striker, but on the flip side there are numerous disadvantages.
Two main disadvantages are weight and drag. Drag induced by both air and water, but water being the most problematic. Take the picture of Bill that you posted. In that circumstance if he had a bridle foil that photo would have looked a lot different. Odds are pretty high that with the leeward hull buried that far he and Eric would have gone swimming in a spectacular way if they had a bridle foil. With the added drag from the foil in the water it is doubtful the leeward hull would have ever recovered, the boat would have come to an abrupt stop and the rest would be history....
That is only one reason of many more, but that is a big enough one for me to stay away....
Matt Haberman
Aquarius Sail Inc.
http://www.aquarius-sail.com
J Drew
Professional
Posts: 104
Joined: September 9th, 2013, 12:39 am
Boat Make/Model: SC 20
Location: n. florida

Re: Bridle Foils??

Post by J Drew »

Matt,
I can see your point about the bridal foil.
That being said, the next maybe irrelevant.
I look at that picture and am envious.
I wish I could spend moments like that with my dad ... !!!
Assuming that's Bill and Eric

After thinking about it, envy is a bad choice of words. Admiration is more fitting
Kevin Keller
Professional
Posts: 362
Joined: September 24th, 2006, 2:56 am
Boat Make/Model: SC-20, ARC22
Location: Honolulu

Re: Bridle Foils??

Post by Kevin Keller »

Looks like a a little seaweed wrapped around the daggerboard.
J Drew
Professional
Posts: 104
Joined: September 9th, 2013, 12:39 am
Boat Make/Model: SC 20
Location: n. florida

Re: Bridle Foils??

Post by J Drew »

No, that's a mermaid
DanBerger
Professional
Posts: 280
Joined: May 3rd, 2004, 3:29 pm
Boat Make/Model: SC 15 w/ spin!, SC 19
Location: Norfolk, VA

Re: Bridle Foils??

Post by DanBerger »

I was thinking more about the foils just for older 20s--there is a lot of pressure pushing in on the sides and pulling up. It seems like a good idea for tired hulls. I think the Hobie 17 style spreader or Nacra NA spreader would be a good idea because they sit about 6 inches off the deck. Even in the picture above, it probably wouldn't be in the water.

Now, installing one like on the Getaways so that you can have a forward tramp would be cool, but...You would definitely do an unrecoverable nose dive.

But, I'll listen to the factory advice and move on to something else..
Kevin Keller
Professional
Posts: 362
Joined: September 24th, 2006, 2:56 am
Boat Make/Model: SC-20, ARC22
Location: Honolulu

Re: Bridle Foils??

Post by Kevin Keller »

You can always put an extra layer of fiberglass on the forward hull to beef it up a little.
Bill Roberts
Expert
Posts: 515
Joined: November 17th, 2003, 9:13 pm
Location: Stuart, Florida

Re: Bridle Foils??

Post by Bill Roberts »

Hey Guys,
Bridle foils are not streamlined and they are very draggy. They make boats pitchpole sooner, not restore the boat. The fineness ratio of a SC20 hull is 20 to 1. Have you ever seen an aluminum extrusion with a fineness ratio of 20 to 1? There are plenty of aluminum extrusions with a fineness ratio of 2 or 3 to 1 but they just make drag, no lift when submerged.
Relative to the picture: I am the forward person. The leeward bow is under water and I an NOT running for the rear beam. Why not? I have felt the submersion rate of the leeward hull reducing and coming to a stop. I know in another moment the bow will pop up out of the water and all is well. This is the beauty of the SC family of hull designs.
You guys who wrote about the need for a bridle foil and used the above picture to justify it are too use to a Hobie or a Prindle or Nacra or some other flat decked beach cat's pitchpole characteristics. SCs are much more foregiving. They can be pitchpoled but they are much more forgiving than flat deck boats. The SC foredeck hull design, 1976, gives the sailor more time to take corrective action before pitchpole is in motion. On any other beach cat hull design, when there is liquid water on the foredeck, the boat is commited to pitchpole, it is gone, it is all over.
Remember the AC boat, the first ORACLE. It pitchpoled! WHY??? The foredeck height had been significantly lowered from a normal catamaran side view profile. This reduced forward hull volume which reduces restoring moment from near pitchpole and the boat did pitchpole. Results, several million dollars and critical training time were lost.
BTW, according to the experts, A cat foredecks are coming back up, too easy to pitchpole and that makes then slow.
DanBerger
Professional
Posts: 280
Joined: May 3rd, 2004, 3:29 pm
Boat Make/Model: SC 15 w/ spin!, SC 19
Location: Norfolk, VA

Re: Bridle Foils??

Post by DanBerger »

Bill,

I think you're missing my point--I think we all understand the value of the rounded bows and the buoyancy the Supercats have, BUT, a lot of us are getting older boats that more than likely have weakened hulls.

I just picked up an older 20 and I already have to replace the bow tangs. Like any older Supercat, it has wrinkles in the hulls around the bulkheads, so it raises some concern about the integrity of the hulls. I would much rather pitch pole than have a hull break in half at the beam and sink the boat. Supercats are known for their great structural qualities, but time and wear eventually take their toll.

Tom wrote somewhere that the plan was to have 20 sailors replace their worn out hulls with new 22 hulls. That sounds awesome, but REALLY expensive. I think there would be a (very small) market for bridle foils for the people that aren't quite there, yet. Granted, there aren't a whole lot of 20s out there..

So what does a new set of fiberglass 22 hulls run these days??
Mac M
Professional
Posts: 232
Joined: June 13th, 2012, 5:05 am
Boat Make/Model: SC17
Location: Lugoff, SC

Re: Bridle Foils??

Post by Mac M »

That would be a nice way to go if my hulls ever busted, especially with the amount of money I've put in redoing my 20!
havliii
Professional
Posts: 272
Joined: March 27th, 2011, 8:12 pm
Boat Make/Model: SuperCat 19, Modded SC20
Location: Fredericksburg Virginia

Re: Bridle Foils??

Post by havliii »

DanBerger wrote:
Like any older Supercat, it has wrinkles in the hulls around the bulkheads
Dan, have you got any pictures of these wrinkles that you speak of? am not sure that I know what to look for.
Mac M
Professional
Posts: 232
Joined: June 13th, 2012, 5:05 am
Boat Make/Model: SC17
Location: Lugoff, SC

Re: Bridle Foils??

Post by Mac M »

Here's a picture of the wrinkles Dan is talking about, I assume. This is from the red one I redid a couple years ago and just bought back. It had a failure at this same spot on the other hull (pictured). The white one that I just finished has the same look at the bulkheads under the front beams.


Image

Image
DanBerger
Professional
Posts: 280
Joined: May 3rd, 2004, 3:29 pm
Boat Make/Model: SC 15 w/ spin!, SC 19
Location: Norfolk, VA

Re: Bridle Foils??

Post by DanBerger »

The wrinkles on Mac's boat are a little worse than on mine, and most of mine are on the outside of the hulls. Mac's red boat failed at the bulkheads and could have broken in half if the boat was sailing. Luckily for the guys who owned the boat, they noticed it on the beach.
havliii
Professional
Posts: 272
Joined: March 27th, 2011, 8:12 pm
Boat Make/Model: SuperCat 19, Modded SC20
Location: Fredericksburg Virginia

Re: Bridle Foils??

Post by havliii »

Thanks for sharing Mac. Thankfully my boat doesn't show any issues like that.

This might also be a good argument for narrowing the beam, I reduced the beam by 25% (3 feet) and probably also reduced the loading by an equivalent amount. I have the 33 foot mast and have no issues holding her down. If I WERE to see similar issues I would sand the bejesus out of her and load on some vac bagged carbon patches.

Andy

SIDEBAR: L Vaught and Mac, I will be encamped and sailing Kerr Lake, NC for 4 days June 6,7,8,9. Come on out and play.
havliii
Professional
Posts: 272
Joined: March 27th, 2011, 8:12 pm
Boat Make/Model: SuperCat 19, Modded SC20
Location: Fredericksburg Virginia

Re: Bridle Foils??

Post by havliii »

DanBerger wrote:The wrinkles on Mac's boat are a little worse than on mine, and most of mine are on the outside of the hulls. Mac's red boat failed at the bulkheads and could have broken in half if the boat was sailing. Luckily for the guys who owned the boat, they noticed it on the beach.
let me get this straight................... that major crack underneath the cross beam happened while the boat was 'on the beach?' to paraphrase from Hamlet "me thinks something be rotten in the state of Denmark"
Post Reply