Radical new “Loop Keel”

**GordMay** · 17-03-2007, 04:24

Howes-Macnaghten Technology Ltd in the UK has patented a new keel design that is claimed to offer significant benefits in both speed and seaworthiness, with the added advantages of a kinder motion and greater comfort at sea.
Goto: Loop Keel - Overview
And follow the links (benefits, theory, etc)

Pura Vida · 17-03-2007, 05:51

Interesting idea that might just go somewhere if...

Connemara · 17-03-2007, 08:48

Looks like a neat idea.

I wonder if they plan to offer this as some sort of retrofit. There's a hint of that (can't recall the phrase... it was more than two minutes ago that I read it) but I can't see how it could be done, without ripping the hull open.

Connemara

Gator81 · 17-03-2007, 08:59

Looks alot like a hydrofoil.

delmarrey · 17-03-2007, 14:36

The Catamaran industry has been experimenting with foils between the sponsons. One for strenght and the other as a wing. The problem they've incountered is that kelp, sea grass and other debree gets caught up on the foils.

As for monohulls one would have to strenghten the upper part of the hull to support such a system. That in turn would most likely raise the COG (center of gravity) but on the otherhand strengthen the chainplate/rigging areas.

It looks cute though!

And I'm not too sure, how well, it would take a grounding................._/)

DeepFrz · 17-03-2007, 15:24

Looks and sounds a bit too good. I would really like to see some unbiased test results.

SkiprJohn · 17-03-2007, 16:54

Wonder how many lobster pots you could catch in one pass? Kelp definitely would be a problem.
Hmmm! Don't think I'll get one.
JohnL

cooper · 17-03-2007, 20:44

Not quite the same but the bilge keeler lot have been mucking around with asymetrical foils for ages (and getting good results it seems). l could also see "stuff" running down the swept back section of the loop and then getting caught on the bottom, unlike a straight keel where hopefully it falls off the bottom.

swagman · 18-03-2007, 05:06

Another negative is maybe the loading on the windward foil - as the yacht heels and lifts, the hydrodynamic forces get applied further and further aft on the keel section still under the water.

Having once owned a 15 foot wide 30 footer who'd rudder did the same (and which saw us snap tillers and even nearly rip the transown hung rudder off) I'd be interested to see if this aft moving CoE is actually good for the crew (they boast reduces broaching inclinations) or bad for the boat (ripping keel off).

Guess we'll see once on a real boat.

JOHN

beau · 18-03-2007, 15:43

Whats a keel?
What do you use it for?

Oh thats right, its the thing under the boat that keeps hitting things and makes you anchor out in the deep water where you can roll around all night.

regards,
Beau
Multihull Enthusiast

**GMac** · 20-03-2007, 01:27

We played with a very similar set-up back in the early 80's. Found it worked damn well for cleaning the harbour of seaweed. Tried a few differing things with it but finally gave it away as the gains just were not there. It was actually slower at times and seemed to increase the pitching.

Maybe they have found something we didn't but it looks very very similar.

mudnut · 20-03-2007, 03:26

What a way to "Collar a whale."And a new concept in "Diving to the depths".China is making a bid for the America's cup,maybe we will see it there,along with a photo of Alan Bond.Mudnut.

rtbates · 20-03-2007, 07:35

Quote:

Originally Posted by beau

Whats a keel?
What do you use it for?

Oh thats right, its the thing under the boat that keeps hitting things and makes you anchor out in the deep water where you can roll around all night.

regards,
Beau
Multihull Enthusiast

It's also good for turning the hull right side UP after a roll!!

genepartridge · 20-03-2007, 07:59

Not for me. I see many problems with Lobster pots on that design. Could add a fish net to it and have a great place to catch your dinner.

Dunkers · 20-03-2007, 08:32

Could be useful for a navy minesweeper to catch moored mines. Also if it inverted you could use it as a goal for water polo

17-03-2007, 04:24	#1
GordMay Administrator Site Administrator Join Date: Mar 2003 Location: Thunder Bay, Ontario - 48-29N x 89-20W Boat: C.L.O.D. (Cruiser Living On Dirt) Posts: 9,455 Images: 232	Radical new “Loop Keel” Howes-Macnaghten Technology Ltd in the UK has patented a new keel design that is claimed to offer significant benefits in both speed and seaworthiness, with the added advantages of a kinder motion and greater comfort at sea. Goto: Loop Keel - Overview And follow the links (benefits, theory, etc) __________________ Gord May ~~_/)_~~ (Gord & Maggie - "Southbound") "If you didn't have time/$ to do it right in the first place, when will you get the time/$ to fix it?"

17-03-2007, 15:24	#6
DeepFrz Registered User Join Date: Mar 2006 Location: Winnipeg Boat: None at this time Posts: 746	Looks and sounds a bit too good. I would really like to see some unbiased test results. __________________ The man who keeps faith with reality wants to act truthfully in the here and now, not to derive a secondhand here and now from a purpose. - Karl Jaspers

17-03-2007, 20:44	#8
cooper Registered User Join Date: Nov 2006 Location: Back of the Dandenongs, Australia Posts: 932 Images: 6	Not quite the same but the bilge keeler lot have been mucking around with asymetrical foils for ages (and getting good results it seems). l could also see "stuff" running down the swept back section of the loop and then getting caught on the bottom, unlike a straight keel where hopefully it falls off the bottom. __________________ One ferro 30 on the water, one steel 38 on the land, .........not a lot of time.....

18-03-2007, 05:06	#9
swagman Registered User Join Date: Sep 2005 Location: On the yacht half the year - in the New Forest UK the other half. Boat: Hanse 461 Swagman Posts: 1,119 Images: 5	Another negative is maybe the loading on the windward foil - as the yacht heels and lifts, the hydrodynamic forces get applied further and further aft on the keel section still under the water. Having once owned a 15 foot wide 30 footer who'd rudder did the same (and which saw us snap tillers and even nearly rip the transown hung rudder off) I'd be interested to see if this aft moving CoE is actually good for the crew (they boast reduces broaching inclinations) or bad for the boat (ripping keel off). Guess we'll see once on a real boat. JOHN __________________ Read our boring cruising blog via http://www.yotblog.com/swagman/2274/

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17-03-2007, 05:51	#2
Pura Vida Registered User Join Date: Apr 2006 Location: Galveston Boat: C&C 27 Posts: 721	Interesting idea that might just go somewhere if...

17-03-2007, 08:48	#3
Connemara Registered User Join Date: Oct 2006 Location: Toronto, Canada Boat: Mirage 27 Connemara Posts: 238 Images: 2	Looks like a neat idea. I wonder if they plan to offer this as some sort of retrofit. There's a hint of that (can't recall the phrase... it was more than two minutes ago that I read it) but I can't see how it could be done, without ripping the hull open. Connemara

17-03-2007, 08:59	#4
Gator81 Registered User Join Date: Aug 2006 Location: Utah Posts: 68	Looks alot like a hydrofoil.

17-03-2007, 14:36	#5
delmarrey Registered User Join Date: Mar 2003 Location: Puget Sound, WA Boat: Choate 40 Posts: 3,456 Images: 115	The Catamaran industry has been experimenting with foils between the sponsons. One for strenght and the other as a wing. The problem they've incountered is that kelp, sea grass and other debree gets caught up on the foils. As for monohulls one would have to strenghten the upper part of the hull to support such a system. That in turn would most likely raise the COG (center of gravity) but on the otherhand strengthen the chainplate/rigging areas. It looks cute though! And I'm not too sure, how well, it would take a grounding................._/)

17-03-2007, 16:54	#7
SkiprJohn Registered User Join Date: May 2006 Location: Kea'au, Big Island, Hawaii Boat: Cascade, Cutter, 42 - "Casual" Posts: 3,767	Wonder how many lobster pots you could catch in one pass? Kelp definitely would be a problem. Hmmm! Don't think I'll get one. JohnL

18-03-2007, 15:43	#10
beau Registered User Join Date: Dec 2006 Location: Brisbane Australia Posts: 280 Images: 1	Whats a keel? What do you use it for? Oh thats right, its the thing under the boat that keeps hitting things and makes you anchor out in the deep water where you can roll around all night. regards, Beau Multihull Enthusiast

20-03-2007, 01:27	#11
GMac Moderator Site Helper Join Date: Oct 2005 Location: North of the Bridge, thankfully Boat: R930 Posts: 1,151	We played with a very similar set-up back in the early 80's. Found it worked damn well for cleaning the harbour of seaweed. Tried a few differing things with it but finally gave it away as the gains just were not there. It was actually slower at times and seemed to increase the pitching. Maybe they have found something we didn't but it looks very very similar.

20-03-2007, 03:26	#12
mudnut Registered User Join Date: Dec 2005 Location: Australia Posts: 664	What a way to "Collar a whale."And a new concept in "Diving to the depths".China is making a bid for the America's cup,maybe we will see it there,along with a photo of Alan Bond.Mudnut.

20-03-2007, 07:59	#14
genepartridge Registered User Join Date: Mar 2007 Location: Rochester NH Boat: 48' Custom Built Pilothouse Cutter Posts: 2	Not for me. I see many problems with Lobster pots on that design. Could add a fish net to it and have a great place to catch your dinner.

20-03-2007, 08:32	#15
Dunkers Registered User Join Date: Jul 2006 Location: Tintern, Wales Boat: Westerly 33, Dunkers of Tintern Posts: 83	Could be useful for a navy minesweeper to catch moored mines. Also if it inverted you could use it as a goal for water polo

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