Sunday, July 13, 2008

A Peoples Foiler at last?

From Adam May:
"Oh and Linton's latest foiler - a more of a foiler for the masses was also out yesterday evening. I didn't get any pics of it foiling, and few details are known about it yet so I'll save that for another post if I can find the time."

Also a mystery foiler was seen with a jib in Weymouth 7/13/08

I wonder if they are using manual control? Any true peoples foiler will need it, especially when jumping.

Saturday, July 12, 2008

Repeating past glory

Well the X21 is moving along-Time to work on it is a strruggle between my internet forum posting commitments. I was quite suprised the other day when someone brought up my past success the Kona Kat.

Building the Kona Kat was a great experience despite the idiots that said it was completely pointless and that it would be slower and heavier than a windsurfer.

Well we showed them-we sold 180 units and I got my first patent for the cone-shaped member.

Sport Boat Foilers

With the phenominal new Super Foiler Mirabaud making history NOW it seems like a good time to revisit these ideas I've thought about and worked on for several years:

There are some really exciting sportboats available now and at the end of this post are some interesting websites particularly the one with comparison statistics of a few current boats. For purposes of this post I'll define sportboats as high powered keelboats between about 20' and 40'. Some boats are much higher powered than others as you'll see in the comparison table. They should be able to plane (or foil). Ocean racing versions should be self-righting.
After doing an exploration of the feasibility of a foiling 60' monohull keelboat, it occurred to me that the next big advance in monohull foiling would probably be with a boat that fits the definition of sportboat so I 'm presenting very preliminary numbers for a two person and three person "Sportboat Foiler":
Two Person
---LOA 24'
---LWL 24'
---Beam 18.6' (overall, incl. racks)
2.4' at waterline
---Draft 6.5' keel,foils retractable
---Sail Area 586sq.ft. upwind and downwind
---Boat weight,incl. rig and ballast-1100lb.
---Ballast 490lb. (110° canting keel) 44% ballast/displacement ratio w/o crew
---Displacement (incl crew)-1420lb.
Three Person:---LOA 24'

---LWL 24'
---Beam 10.73' (overall incl. racks)
2.4' at waterline
---Draft 6.5' keel and foils retractable
---Sail Area-600 sq.ft. upwind and downwind
--- Boat weight- including rig and ballast-1100lb
--- Ballast 490lb.( 110° canting keel) 44% ballast/Displacement ratio w/o crew
---Displacement, incl. crew 1580

---LWL 24'
---Beam 18' (overall incl. racks)(2 on trapeze optional)
2.4' at waterline
---Draft 6.5' keel and foils retractable
---Sail Area-650 sq.ft. upwind and downwind(except in light air then 1200 downwind)
--- Boat weight- including rig and ballast-1100lb --- Ballast 490lb. 44% ballast/Displacement
ratio w/o crew
---Displacement, incl. crew 1580
Take Off Boat Speed is 6.5 knots which would be achieved in a 6-7 knot wind with 650sq.ft SA
Configured for early take off using a 63412 section at a mainfoil angle of attack of 6 degrees and a 20 degree mainfoil down flap angle.


Other comparisons:
-- -Sail Loading(weight divided by SA)- Two Person=2.42 lb. sq. ft. ; Three Person= 2.69 lb. sq.ft.; Three FIXED 2.43(#2 & #3 this ratio better than a MOTH)
---Mainfoil Area- Two Person=7.1 sq.ft. ; Three
Person= 7.48 sq.ft., Three Fixed 7.64 sq.ft
---Mainfoil Loading- Two Person=158lb. per sq.ft.
Three Person=169 lb. per sq.ft.
---Sail area per sq.ft. mainfoil area- Two Person =82.5 ; Three Person=80.2 ; Three Fixed=86.8
Note: Two person takeoff profile is approximately equal to a Moth with Rohan Veal aboard;
Three Person approx. equal to a Moth with a 160lb. person aboard.
---D/L Two=45.6 Three= 51
---SA/D Two= 74.3 Three=70.9 Three Fixed=78.4
---SCP/total weight Two=42% Three=34% Three FIXED 38%
Three person fixed keel would be 100% selfrighting w/o crew interaction:BALLAST/DISPL. RATIO SIGNIFICANTLY BETTER THAN T780. Ballast in this keel is not used for sailing RM-just for RIGHTING. Boat sails with 20 degrees veal heel adding 21 % to RM.
Both canting keel boats would be designed to be rightable by moving the keel; and a 100% self-righting foiler(no crew action required) is possible------------------
Weights for the hull and rig were derived from EXISTING boats that have hulls ,for the most part, twice as wide with over double the area anticipated with these boats. The hull would be very narrow -not much over three feet wide(at the deck) with possible flare out forward for a minimal cuddy cabin. The hull would be double-ended. In comparisons with the other boats in the table below the Sail area to wetted surface ratio of both versions above is probably greater than any other boat even INCLUDING the wetted area of the hydrofoils.(8.27/1 vs. 4.7/1 for the Martin 243).

I did this to show how incredibly close we are to having one of these boats actually built; the technology required to do this is available now and I hope it won't be long before "Flying Keelboat" really means flying...

Friday, July 11, 2008

Foiler 18vs "Normal" 18

Thomas Jundt sailed the 18 europeans with his 10 year old 18 with foils -not Mirabaud. I thought their chances were pretty poor sailing a 10 year old wide 18 converted to a foiler. In no way is this ideal or representative of the utmost in bi-foil technology. A skinny hull would be faster especially in marginal conditions. If "rules" weight would make the "new" foiler 18 artificially heavy -then fuck the rules-the point is to demonstate the technology-not antique rules.

Let me summarize it-as I understand it: when there was wind the foiler kicked ass. A foiler as light as the newer 18's would have probably kicked ass on and OFF the foils-particularly with a big lite air spin.

Thomas sent me an email and here is what he said about how he went.

In none flying conditions we are slower (the second race) :

- a bit slower upwind, the additionnal drag of the foils seams not to be too penalizing

- but much slower downwind, our head sail was a 20 sqm code 0, way not enough against the 65 sqm assymetrics

My conclusion :

- dispite the fact that our boat weighs 220 kg compared to the newest ones at 155 kg (class rule minimun since 2005) we are competitif when foiling (wind at least 10 knots)

- the additionnal drag of the foils seem to be acceptable when non flying

- in non foiling conditions downwind without the big assymetric you're dead

- a new boat 155 kg, with foils in the hands of a trained crew would beat everybody by a big margin in most conditions

- unfortunately, foilers seem not to be welcome in the class



I'm not sure that with all the rancor there is-like outright hostility to Thomas at the Euro's-the 18 foiler class will develop. The Moth class has shown that seahuggers and foilers can co-exist in the same class. It would be a shame if the 18 class doesn't embrace foilers-a new class may result that will be much faster than the current boats. If thats the way it has to be -so be it.......

The potential speed of the FOILER 18 is huge! According to Rhoan Veal A Moth in the right hands can beat current 18' cats(that have repeatedly beaten 18 skiffs).

"Each race of our division started 5 minutes behind the F18's, but by the end of my three laps, I had nearly caught and passed most of them. The highlight was passing them one at a time (to windward and leeward) on a reach with their kites up! Only a few of the top guys on a Tornado and Hobie Tigers stayed ahead, but they wern't anymore than 2-3 minutes in front. Needless to say I am feeling extremely confident with my Mk4 Prowler now that I have all the configuration and teething issues sorted out. It took 8 months, but I think Moth development is a case of one step backward, and two steps forward. "

Anecdotal evidence for sure, but when combined with what Thomas Jundt says shows that a FOILER 18 designed from scratch as a foiler would beat the crap out of ANY boat its own length.

A few people I've talked to think a the next big area of foiler development will be a two handed foiler. I agree if it is designed from scratch as a foiler-and not a coverted I14( or converted anything). Converted 14's on foils (and Mirabaud):

My first BLOG post

Since everyone else is BLOGGING about their foiler achievements, I thought I should too. First some history. Most people that know me keep asking what I have been sailing. Here is the list in no paricular order 


windmill(many firsts incl District Championship), thistle,fish class(many lasts and a few firsts),hobie 14,hobie 16,e scow, US 1(several 1sts etc),14'high performance experimental tri, 16' experimental cat,20' high performance experimental tri,TS 18(80+),Kona Kat (about 180) aeroSKIFF One, aeroSKIFF 2-X21-T(as we speak),worlds first production rc sailing multifoiler,worlds first rc monofoiler(as far as I know),worlds first production rc spinnaker boats,worlds first video piloted rc helicopter, 4 US patents including K Foil,"3D SAILING" trademark(sold),numerous other trademarks. Several new patents in various stages on foiler control systems.
Oh, yeah: learned much from Dr. Sam Bradfield and a book or two......