Experience with keel stubs or other foils on T21?

[Michael Dougherty]

Anyone have any experience with keel stubs or other foils? I spotted some under Cooking Fat in a photo, but don't know anything about them, or if others have tried.

Any experiences to share? Shape, size, change in upwind performance? 

Getting ready to take our Tiki on a 750-mile race from Washington to Alaska, much of which is upwind!

[Pius Bielowski]

Hi michael!

I spoke with Hanneke Boon about small keels. She pointed out that the form is crucial. They must be rectangular with a clear edge and not rounded. This is to hinder the waterflow. And it would be easier to add some aluminum or stainless steel strips to protect them when beaching. 

I wish all the best for the race to alaska! 

Pius

[LastParadise]

At one time I considered a Tiki type cat. I instead build a Woods Vardo. She has 16" deep keels about 10' long at the top and maybe 6" at the widest point. She sails better than most cruising monos her side to windward in 2-3' less water. I had emailed Rory about the keels in his boat, but he didn't seem to have many details. To me they look like the Tiki 38 keels. My best advice would be to keep the boat as light as possible and consider a different mainsail. Wharram BS aside the boat do sail OK when litely loaded, but the Tiki 30 I sailed had the Jekles stock mainsail and it was hopeless was eased off just a bit. I would contact a multi racing sailmaker and get them to build you the biggest square top you can fit with a rigid boom. FYI, we beat all comers with the Vardo this year at the Georgetown, Bahamas regatta.

[LastParadise]

PS when does the race start? I am looking to get some people interested in racing the Clipper Ship route along with the Bieker/Brown proa later this year. Wrong coast for you guys. Maybe Rory would be keen?

[Pius Bielowski]

I also think that the main sail makes the big difference. Much more than the little leeway you would avoid with the keels. I assume that a fully battened bermuda main will perform better to windward than the wing sail. And the jib sheet lead could also be placed more to the middle...

[LastParadise]

What is your manual propulsion? Richard Woods designed a 28' cat for the race with twin rowing stations and standing headroom in the cabins for changing in and out of the gear that may/will be required. Not sure one got built. will be interesting to see how the proa does against the F boats. I may build one as a near shore toy this fall if it performs as good as it looks in the YouTube first sail video. Have fun and be safe!

[Michael Dougherty]

Thanks guys for the input!

I have changed the rig quite a bit - I have a rotating mast from a SuperCat 20, and I've fitted a Hobie 18 mainsail (fully battened, very roachy) and a rigid boom. My jib is from an E-22, I cut it down a bit to fit the new mast. 

For context, the previous rig was a 20' aluminum round tube, and sails were a polytarp crab claw and polytarp jib that had no real shape to it. It was great off the wind but quite poor upwind, unsurprisingly. 

The boat's sailing much faster now, but upwind performance is better but still wanting. I have moved the jib sheet lead way inboard, and with both sails sheeted tight the telltales flow beautifully, but the GPS shows that we're still tacking through about 115 degrees, which is quite poor. Any ideas?

As for manual propulsion: I have two pedal drives fitted at the moment. One is a SeaCycle borrowed from a friend, the other is a Rick Willoughby system - we are using one of his propellers and his general design. With two pedalers going simultaneously, we can do about 3 knots, though we haven't yet tested our endurance at that speed. Lots of tests still ongoing. 

Have seen the proa on land, but not yet seen it out on the water. It's got to be the race favorite, assuming it holds together!

[Michael Dougherty]

Thanks Pius - I want to be sure I understand correctly, the keels would be rectangular with a sharp edge when viewed from astern or from the bow, correct? Any thoughts on size or shape otherwise?

Thanks!

Pius Bielowski said:

Hi michael!

I spoke with Hanneke Boon about small keels. She pointed out that the form is crucial. They must be rectangular with a clear edge and not rounded. This is to hinder the waterflow. And it would be easier to add some aluminum or stainless steel strips to protect them when beaching. 

I wish all the best for the race to alaska! 

Pius

[LastParadise]

You may be a bit over trimmed. I find I to really foot with the Vardo but I do have keels so I get the lift of those when I keep the speed up. I probably tack thru about 105 to 110 on the GPS which is quite good for a cruising multihull I believe and the overall VMG is better than the 45' performance cruising monohulls we were racing and a
Morelli Melvin Leopard 40 and 46.

I hope the race results will show a good overall speed comparison of the Proa. I plan to build one if Bieker will sell the plans.

[Pius Bielowski]

As I understood Hanneke the keels dont need to be very big, the edges count. And yes, the sharp part should be visible form the bow, stern and from underneath. I cant describe it better, thats the limit for my english. Concerning the form I think the new MANA 24 reflects the latest findings of JWD. ( http://wharram.com/site/news/2014/mana24 ) And I think it is no problem, if you contact them for details.

I am very interested in your project R2A. So go ahead, the internet is hungry for photos and gossip.

[Michael Dougherty]

Thanks, that's a helpful tip & helpful data. Tried testing again today but it was blowing 25+ knots and I don't have enough reefs sewed into the new main yet! Will experiment a bit with sheeting & see how it goes...

LastParadise said:

You may be a bit over trimmed. I find I to really foot with the Vardo but I do have keels so I get the lift of those when I keep the speed up. I probably tack thru about 105 to 110 on the GPS which is quite good for a cruising multihull I believe and the overall VMG is better than the 45' performance cruising monohulls we were racing and a
Morelli Melvin Leopard 40 and 46.

I hope the race results will show a good overall speed comparison of the Proa. I plan to build one if Bieker will sell the plans.

[Roger]

Wow - that is quite a combination. Should really fly. Good luck with the race.

Michael Dougherty said:

Thanks guys for the input!

I have changed the rig quite a bit - I have a rotating mast from a SuperCat 20, and I've fitted a Hobie 18 mainsail (fully battened, very roachy) and a rigid boom. My jib is from an E-22, I cut it down a bit to fit the new mast. 

For context, the previous rig was a 20' aluminum round tube, and sails were a polytarp crab claw and polytarp jib that had no real shape to it. It was great off the wind but quite poor upwind, unsurprisingly. 

The boat's sailing much faster now, but upwind performance is better but still wanting. I have moved the jib sheet lead way inboard, and with both sails sheeted tight the telltales flow beautifully, but the GPS shows that we're still tacking through about 115 degrees, which is quite poor. Any ideas?

As for manual propulsion: I have two pedal drives fitted at the moment. One is a SeaCycle borrowed from a friend, the other is a Rick Willoughby system - we are using one of his propellers and his general design. With two pedalers going simultaneously, we can do about 3 knots, though we haven't yet tested our endurance at that speed. Lots of tests still ongoing. 

Have seen the proa on land, but not yet seen it out on the water. It's got to be the race favorite, assuming it holds together!

[Roger]

I agree with Last Paradise (nice Vardo BTW - green with envy) about footing. On the Tiki 21, the "foil" that gets you to weather is the V boat hull. So you need to think about maintaining water flow over the "foil". How this works for me is, after a tack, I come up to a close reach and gain max speed, and then let the boat slowly come up higher to the wind. There is a magic slot where the "foil" is working and the boat is making good progress to weather. A stronger puff at this point lets you point higher without losing speed, and drop in the wind means falling off to stay in the groove. It doesn't take much to kill the flow over the "foil" and you can feel the boat slow markedly - a slap from a wave, chop or a sudden drop in wind - then you have to start the whole process again. All so much easier with a steady breeze - a flukey light breeze is not going to work well to windward. On your boat, the tall mast and fully-battened mainsail is going to make a big improvement in light air.

LastParadise said:

You may be a bit over trimmed. I find I to really foot with the Vardo but I do have keels so I get the lift of those when I keep the speed up. I probably tack thru about 105 to 110 on the GPS which is quite good for a cruising multihull I believe and the overall VMG is better than the 45' performance cruising monohulls we were racing and a
Morelli Melvin Leopard 40 and 46.

I hope the race results will show a good overall speed comparison of the Proa. I plan to build one if Bieker will sell the plans.