Sir Thomas Lipton never lost the America's Cup because he never had it. Dennis Conner had it and lost it. Should have quietly gone off the stern the first time.
Sir Thomas Lipton never lost the America's Cup because he never had it. Dennis Conner had it and lost it. Should have quietly gone off the stern the first time.
Speaking of foils, these new race sailboats are hydrofoils and are up un underwater wings when they're at speed. Those are some incredible feats of engineering.
I saw a show about them one night in the middle of the night. The crews train like professional athletes to run the winches and move around the boat and work as efficiently as possible.
ΜΟΛΩΝ ΛΑΒΕ
Max speed is not at 90 deg to wind, more like 20-30 deg with these boats or even less. They sail very
much into the wind. How close a boat can sail to the wind direction is called "how close it points
to the wind". These hard wing boats point very close to the wind.
The wing "sail" creates lift when air moves over it. So the air is moving at some speed relative
to the water, say 25 mph. If the boat is going through the air at 20 mph the total air velocity over the wing is
20 + 25 or 45 mph. Well, 45 mph airflow over the wing produces a lot more lift than 25 mph . Lift on a wing
is proportional to the square of the airspeed, so at 25 mph you get some constants (based on wing shape and
size) times 25 squared = 625. At 45 mph you get the same constants (since wing shape and size don't change)
multiplied times 45 squared which 2025, so you have 3.24 times the lift. So the force driving the boat is 3.24 times
as much at 45 mph (wind speed plus boat speed) as it is with the boat going at zero speed (just wind speed).
Now, they lift the hulls out of the water on hydrofoils mounted on the centerboards (tall thin keels) and the
bottom of the tall thin rudders. This dramatically reduces the overall boat drag (which is water drag plus
air drag, water drag being much greater) so the boat accelerates as it get up on the hydrofoils. Increasing
the boat speed also increases the airspeed over the wing more - even though the wind speed hasn't changed,
and more airspeed means more lift, so the boat accelerates even more. Eventually, the lift force equals
the drag force and the boat speed stops increasing. But these things are going like stink at that point.
These things actually end up going 50-60+ mph in 23-25 mph winds. So they ARE really going more than
twice the wind speed.
A wing sail works NOTHING like an old square rig sail mostly caught the air like a parachute and
you could mostly go downwind(ish) and FAR slower than the wind. Bigger and better keels helped
the boats point a bit upwind but maybe only within 45 degrees or more of the wind direction.
Later square riggers had lots oftriangular sails and could rig their square sails to work a bit like
(bad) wings, so they could point up into the wind pretty well.
More modern sloop rigged sails with the big Genoa type jibs (front sail) work more like a wing,
although not a really good one because they only have one surface and are flexible, so not
in exactly the correct shape like a hard wing. Hard wings a nearly worthless going downwind,
so they pop huge spinnakers which pretty much are big parachutes. Downwind it is all about
area of sail since it is not acting like a wing.
Bill
Last edited by MtGun44; 09-21-2013 at 09:09 PM.
If it was easy, anybody could do it.
Only one to go, today, winner take all. http://www.nytimes.com/2013/09/25/sp...anted=all&_r=0
A good sloop rig can point close to 20 deg against the wind. Even a slow hull can come close to planeing down wind.
Whatever!
Amazingly, the US team has won 7 straight to fight back to even ground. Winner today
takes the series.
http://www.nytimes.com/2013/09/25/sp...anted=all&_r=0
Bill
If it was easy, anybody could do it.
WE WON WE WON
Just announced on the radio.![]()
WE WON. WE BEAT THE MACHINE. WE HAVE CCW NOW.
Sorry Jeff
Well, it was good while it lasted. Man alive that boat is fast.
Kiwi's merrily throwing themselves under buses as I type.
It's worth remembering though that both the boats were Kiwi designed........![]()
Thermal underwear style guru.
"Exclusive international distributor of Jeff Brown Hunt Club clothing."
Supplier to the rich(?) and infamous.
Cheers from New Zealand
Jeff.
Jeff,
Congratulations on a fantastic job by the New Zealand team. I am quite impressed that
such a small country can produce such an impressive array of skilled folks. Well done,
and WOW was the race series close. Your team almost won it a week ago.
Truly international teams, designers, captains, strategists and grinders from everywhere
working on teams based in different countries.
Bill
If it was easy, anybody could do it.
Revived this old thread as I am watching the preliminary racing between the new class monohulls racing on the Waitamata in Auckland New Zealand. A lot of tech has gone into the current designs and to watch 75foot boats blasting over the ocean at close to 60mph powered only by the wind is awesome.The last 3 days racing has mixed high tech with old fashioned sailing skills and cunning. As we head into the Americas cup races early next year things are only going to get better and the boats are going to get faster. The American boat looks very fast but I think the NZ boat has the edge.
The Bird of Time has but a little way
To fly-and Lo! the bird is on the wing
While the current boats are very impressive and technologically interesting I wish they would go back to a non foiling monohull. I really liked the 12 meters not only for the taking duels but because they were comparably affordable so you would get a wide field of challengers. Folks like Charlie Morgan could build a "Heritage" and have a real shot.
Not saying I think they should return to 12m but some sort of roughly 50-60' planing monohull development class.
Eric
Americas cup racing is happening in Auckland NZ with Prada (Italy) the contender. Amazing speeds against the wind ,40knot speeds with a 10mph wind. Very exciting to watch. Makes a change from reloading today.
The Bird of Time has but a little way
To fly-and Lo! the bird is on the wing
I haven't followed or watched it in a few years.
Does anybody know if all the boat owners that lost still sue whoever wins?
In school: We learn lessons, and are given tests.
In life: We are given tests, and learn lessons.
OK People. Enough of this idle chit-chat.
This ain't your Grandma's sewing circle.
EVERYONE!
Back to your oars. The Captain wants to waterski.
I was kind of shocked just yesterday, was flipping channels and ran across the America's Cup, oh I haven't seen that in a long long time, I'll check it out.
Holy cow I got no frame of reference for what those folks are doing, pretty amazing stuff.
My wife used to occasionally crew as a substitute for her company's owner on his sailboat in local races around north Texas/DFW. She loved it. In those days it bore some superficial relation to what was happening in the Amercica's Cup, but not today!
Just watched New Zealand win the 36th Americas Cup against Team Prada from Italy. A very exciting series of races . Now all the excitement is over I can go back to reloading.
The Bird of Time has but a little way
To fly-and Lo! the bird is on the wing
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |