[Ayrstest] some stuff4--enough to go over the min digest limit

[Dave Culp]

Delivered-To: daveculp@oberon.dnai.com
=46rom: Dave Culp <dave@dcss.org>
To: dave@dcss.org
Subject: KiteShip=81 progress
Newsgroups: rec.kites
User-Agent: MT-NewsWatcher/3.0 (PPC)
Date: Mon, 11 Sep 2000 17:40:40 -0700
Status:  U

OK, OK here's the scoop:  If you want the short story, we came, we flew,
it was awesome. See the web link below for pics. For the longer version,
read on...

We took delivery of our new 27.5 meter Jorden Air Antelope-series kite
on the 17th of August (yes, that's 300 sq ft; all in a single kite.
Rectangular planform ram air water foil; 30' by 10' chord). Loft owner
Dean Jorden came from Florida to Santa Cruz, California to deliver the
kite, tune it and generally to raise hell and see what we're all about.
We immediately gave him the helm and asked, "What's next, skip?"  ;-)

You can see a number of photos of the kite, and the 24' proa it powers
at:  http://www.kiteship.com

Some stats on the setup:

Boat:
LOA               24'
LWL               23'
BOA               7' (Kites do not heel the boat,
=20                   so no special need for beam)
BWL               11"
Ama LOA           16'
Disp, dry         350 lbs
Disp, 2-up        750 lbs (we're big boys)
Boards            twin spade "rudderboards," counter-rotating,
=20                  2.5 sq ft each
L/B, main hull    25:1
Bruce No.         1.91

Kite:
SA                300 sf; 27.5 sq meters
Type              5-valve ram-air water foil, bridled at every cell
=20                  (our spec, not the designer's; he thinks we can
=20                  halve the bridles)
Material          37 gsm Icarex polyester
Bridle material   primaries, 150 lb Spectra; secondaries,
=20                  300 lb Spectra
Weight, incl.
bridles           8.5 lbs.
=46lying lines (4)  125'. Mains/front lines; 800 lb Spectra;
=20                  backs; 500 lb Spectra

Bruce No. isn't as high as I thought it'd go, but then, the rig is not
coupled to the boat, so is free to accelerate sooner, and to fly faster
than the hull, which means traditional SA/weight ratios don't mean a
whole lot. The boat is pretty powered up.

We flew only in dead light winds during the 8 day shake-down trials (not
over 7 kts); the kite was a brand new series, not a "scaled up"
anything. We want to stress it slowly and measurably. The several design
points of this boat dictate we're using prototype launching and control
gear, with predicted teething pains. The kite is attached to the boat;
design point for most rig stresses is 1200 lbs total line tension, max.

After preliminary setup and finish work, we flew the kite from hands at
UC Santa Cruz on a deserted soccer field. With no fine tuning and
perhaps half inflation, the kite immediately launched and responded to
both 2-line and 4-line control. It inflated easily and fully and pulled
like a truck. We played around most of an afternoon, putting the kite
down repeatedly after being dragged 100-200' across the field. We spent
some time on rear line tuning, working for faster, crisper control. We
also wanted faster, complete inflation prior to launch, so purchased a
Sears Kite Inflation Device (KID). Strangely, Sears markets these gas
powered tools for blowing leaves off front yards, but we know better.
The Sears KID works perfectly, fully inflates the big kite (400+ cu ft)
in about 2 minutes, weighs less than 7 lbs.

Next trip, we launched the boat, and flew first a Quadrifoil XXL, than
an XL. These are production kites, both well under 100 sq ft. The
purpose was to familiarize the out-of-towners with the boat, and to
shake down the largely untested self-launch and control equipment on the
boat. Sailing went well, the boat making 6-8 kts in winds under 10 kts.
We managed to capsize the boat, to windward (kites don't *necessarily*
heel the boat, yet they can be coaxed into doing so, either to leeward
*or* to windward!), though without mishap. Self-righted it, with both
crew on the rudderboards. We are building and will install
battery-driven control and launch/recovery winches on this boat (to
replace the current manual ones); are re-thinking inverted conditions.
;-)

Next trip out, Kite's Etc. owner Steve Kent joined us from Southern
California. We set up the big Antelope on the public beach, to give
Steve a feel for it, hand flown, and to get his advice. Pretty lifeguard
jogged over to remind us the wind picks up quickly here, fellas. It did
(to 10-12 kts) and we rolled up the kite, unflown. Watched cute
lifeguards and surfers through the middle of the day, then took the big
kite back to the soccer fields for the dying evening breeze. We launched
the kite in 3-4 kts of wind and spent an hour of near perfect flying.
The big kite in 3 kts true was just about all we could fly from the
hand, without dragging. See some outstanding photos on the web site.
Tuned the bridles a bit, discussed giant-kite launch sequences and went
to dinner. Handling big kites is thirsty work!

The next morning, in fog, was our big test. With only 2 crew on the
boat, we were committed to self-deploy and launch the big kite, on the
ocean, and to sail the boat. To the best of our knowledge, no one has
done this; self-launched a big parafoil kite, in deep water, on short
lines, then fly it out to full length and sail away. We did not anchor
or tie off the boat; the proa is designed to heave-to dead across the
wind and stay there--and did so repeatedly, despite our best efforts to
disturb it. On the flip side, the instant the kite is up and drawing,
the boat can be gotten under way simply by taking either tiller in hand.

We set up the kite for minimum "wet lag" time (kite on the water,
possibly filling with same), fastest inflation time and pulled the cord.
Inflation went well and quickly, and the kite was away. Despite horrible
control problems (things which work *perfectly* under test loads cock up
immediately at their rated specs; Mr. Murphy put in his expected--and
daily--appearance, etc., etc.) The kite launched, crashed, launched
again, crashed again. Sat on the water for more than 20 minutes,
docilely, then *insisted* on launching, trailing edge first and
inverted. Continually responding to control inputs (Dean's truly expert
handling coming into play), the kite finally self-launched, precisely as
we'd first envisioned it doing so, more than 4 years ago. Harldy a drop
of water inside, as the photos show. Winds were building, once again, so
we made the trip short and sweet.

We know now just what the control system needs, just what tweaks the
kite wants, and we're looking forward to a winter of low wind shake-down
work.

Check out the web site.

Dave Culp
http://www.kiteship.com