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Quick question for the uninitiated. How the **** do sailing boats manage to sail faster than the prevailing wind speed
The sails provide lift. It's like asking how they can sail upwind. It isn't the wind blowing them along it is the shape of the sail generating force (like the wing of an aeroplane, only horizontally, not vertically)
Others will I am sure answer with more detail but there are 3 factors.
1. A vessel only really cares about the wind it experiences. The apparent wind. As it speeds up both the velocity and the direction of that apparent wind changes. You can design a craft to take advantage of that.
2. Drag - reduce the drag through the water (and the air) and the vessel can accelerate much more swiftly and get beyond the speed of the prevailing wind. If you are a displacement vessel pushing huge volumes of heavy water out of the way you just can't produce enough energy to move fast enough. Vessels that either plane or foil can do this much more easily as their drag once up on the plane or foiling is a fraction of a displacement vessel.
3. Angle of attack - Viking Galleons mostly needed the wind from the side or behind to go forwards. Modern aerofoil shaped sails generate lift like an aircraft wing and can stay very effective when the wind is coming from in front. Not totally on the nose, but close to it. As a vessel goes significantly faster than the prevailing wind the vector or direction of the wind is more and more from in front of the vessel. Moderns sails or foils on boats and windsurfers have got increasingly good and using this wind direction to generate forward motion whilst minimising drag. Partly by changing the angle of the sail relative to the boat as the speed increases and the angle of the apparent wind changes and sometimes by changing the 'chord' or shape of the sail as the speed increases and the direction changes which reduces bottom end grunt needed to get it goes but improves the angle to wind it can operate at whilst reducing the drag.
Well, something like that.
Grrr, forum seems to have eaten my post.
Another good example is wind turbines.
At the centre the blade is almost inline with the wind with a deep chord to produce maximum lift at low rotation (c.f. boat) speeds.
At the tip the blade is almost flat (low chord) and almost perpendicular to the wind because it's moving at 120mph (or even more on big offshore turbines). This produces lift and minimises drag based on the apparent won't as the tip sees it. Although you reach a point of diminishing returns as you can only make the sail so efficient , and the lower the engine the further away from forwards the lift is pointing (lift being always perpendicular to the aerofoil, drag being the same direction as the airflow). In boat terms this is why even going downwind they have the sails sheeted in hard (And don't use a spinaker).
Even in a displacement boat you exploit this by pulling the Cunningham on hard upwind which pulls the maximum depth in the sail forward, and flattens the top third to reduce drag when going upwind. Going downwind you release it, the centre of effort moves back and the top of the sail deepens to produce more power as now the drag that results is pointing sideways/forward rather than backwards.
On a plane it's like putting the flaps down and increasing the angle of attack to produce far more lift at low speed Vs normal.
It’s a squeeze between the power being generated by the sail and the opposing force of the foils/keel. Think of a wet block of soap between your fingers and how fast it moves when you squeeze it! Far quicker than your fingers’ closing speed.
Holy ****, that LR boat is a rocketship.
Blimey. Fair play to the Italian team.
Sad to see team GB end not in the final - I had real hopes they would be the final challenger.
Ok, im still calling NZ as winners, but it's going to be close.
We were outgunned in boatspeed and tactics. The Italians thoroughly deserved it.
Feel sorry for Ineos but I’m sure they were giving it their all.
The Italians were always fast, even in the RR losses, but bad comms & lots of mistakes.
Since then they’ve been flawless, and got the light air that suits them.
So 3rd out of a field of 4 that bothered to build a boat. Beating a boat that broke. Not a great result in all honesty.
Given such a small number of teams elected to come to play and the drubbings handed out at every stage I wonder how far back you have to go to find a collection of losing boats that touched the water in anger an infrequently before meeting the great angle grinder in the sky as this time around.
Shame for Ben and the team. Luna Rosa look impressive, and I'm hopeful for some good racing with NZ
I’m hopeful for some good racing with NZ
So am I, but I have a feeling that one boat will just be faster and sail off into the distance. I think that's TNZ's strategy - just spend the Prada Cup time developing the boat to be fast so that they aren't pushed into making mistakes and don't need to win every start.
just spend the Prada Cup time developing the boat to be fast
They didn't need the Prada Cup time - they wrote the rules and then agreed them with LR, both had a head start, made more important by Covid and not having the delay while their boat was shipped across the world.
We were outgunned in boatspeed and tactics.
I think you'll find that boatspeed makes pretty much anyone an amazing tactician!
I've not watched any of the finals (couldn't really see the point) but LR seemed to have great speed and there's very little you can do about that.
So 3rd out of a field of 4 that bothered to build a boat. Beating a boat that broke. Not a great result in all honesty.
Hmmm. That's bollocks.
They did a great job and at least had the balls to put the campaign together and produce a good boat. Hopefully this will form the platform of a future campaign (unless the Italians win and it goes back to leadmines - which is a possibility).
The team that relaly need to be looking at themselves is Team USA - it seems they had some basic stuff wrong that lead to the boat not really being controllable.
How the **** do sailing boats manage to sail faster than the prevailing wind speed
Simple answer:
Wind passing over the sails generates a pressure difference on either side of the sail - the faster the wind passes over the sail the greater the pressure difference. This pressure difference is converted into forward motion.
On a windless day stick your hand out of a car travelling at 30mph - you've got a 30mph wind. The faster the car goes the stronger the [apparent] 'wind'.
If you remove enough drag from a boat it will start generating it's own [apparent] wind and keep going faster.
The limiting factor is mainly drag from the hull/foils and aerodynamics.
I have a feeling that one boat will just be faster and sail off into the distance. I think that’s TNZ’s strategy
This...I think it may be very dull...like the Prada cup was when one boat was so clearly outclassed
Giles Scott’s interview post race was quite illuminating. He basically said this wasn’t a surprise to us.
It’s become like F1 as opposed to NASCAR. Richest team wins. Standard boats would make for great racing.
It’s become like F1 as opposed to NASCAR. Richest team wins.
Ferrari are the richest team in F1. Hasn't helped them. TNZ have never been the richest team in the AC. Doesn't seem to have stopped them winning. Obviously, you need an adequate budget, but once you have that, there are only marginal gains from more money and just adding more people doesn't work if you don't have good managers to keep everyone focused.
TNZ get to write the rules for boats and sailing to suit themselves though. I remember a few years back there was an agreement to stick to one class for successive Cups. NZ when they won declined.
TNZ get to write the rules for boats and sailing to suit themselves though.
To be fair, 4 years ago no one had built a large foiling monohull, it wasn't much more than a simulation, and as the development process proved, they didn't always produce optimum results.
I have a feeling that one boat will just be faster and sail off into the distance. I think that’s TNZ’s strategy
Maybe, but the boats are pretty different from each other, so there could be surprises around which one is faster.
And either LR has gained several knots boat speed or was sandbagging for 2nd place in the opening rounds. So unless ETNZ have done the same then that's an improvement on before christmas.
And I'm not convinced tinkering time in the shed is really worth that much more than 2-boat testing in the real world.
TNZ get to write the rules for boats and sailing to suit themselves though. I remember a few years back there was an agreement to stick to one class for successive Cups. NZ when they won declined.
New Zealand never signed up to the agreement in the first place, so obviously didn't back out after winning.
It was a bit odd, wanting to change the format to every two years, I guess in the hope more countries would participate and the cup would change hands more often.
NZ wanted to keep things the same, whereby the holders and the challenger of record determine the format.
I suspect that if ENZ do win, that the next defence will be somewhere more tv/spectator friendly- the cost/reward ratio doesn't seem to work for NZ gov and public, and Emirates would probably rather be somewhere with a higher profile.
Excellent first day of racing.
Well now that's an interesting first day.
That was enjoyable. Should be a fun series.
all the various FB and analysers comments suggesting that TNZ were 5-10% faster due to various clever stuff maybe were wrong, and actually they are going to be very very close. Will be interesting to see in light and/or stronger winds to see who has the best all round package.
On the last 2 legs ETNZ were eating up the lead very quickly. Another 30 secs would have been interesting......
On the last 2 legs ETNZ were eating up the lead very quickly. Another 30 secs would have been interesting……
I've only skipped through the highlights but there's a big difference between catching up and getting past.
LR would have been quite happy to give up lead to make sure they were in the right place to keep the lead.
So, getting in front at the start and keeping the other boat behind are a winning strategy then!
So, getting in front at the start and keeping the other boat behind are a winning strategy then!
Yep..saves time tho...you only need to watch 2:10 of pre-race and about a minute of the race and then it's all over
the Kiwis are suddenly very quiet on social media.
the Kiwis are suddenly very quiet on social media.
what's your implication?
Kiwis seemed to sharpen up their tacks in that last race. Race 3 they were losing every manoeuvre, but race 4 LR struggled to keep it up exiting tacks.
what’s your implication?
they were very noisy before the match started. predictions of 7-0 etc. basically saying its not worth starting the AM as TNZ are so fast and so much better design known one else got a chance. So much so that in the last few months it really put me off NZ people. (yeh i know the internet it full of trolls an all that, but it was really in your face sort of stuff. Every article about any another boat, the NZ folk would jump in a blurt rubbish all over it.)
Nice to see two good days of racing. I think that both boats have different strengths, and winning the start allows the leader to lever an advantage in a certain area. LR were sailing nice and high to the wind after winning the first start, and NZ suffered. And in the second race NZ could chose the angle after winning the start and make their boat speed count.
Turning without foil down was pretty big mistake from LR, but love the way the boat looks and it's them I'll be cheering for.
I love it! Kids off to school at 8, sat with a coffee before work.
Yep cheering on LR as it looks super cool and the skipper for NZ is so bloody dour on interviews.
It'd be nice if there was a bit more dueling after the start, but some of the camera angles when they're ripping through turns are amazing still.
what’s your implication?
they were very noisy before the match started.
oh right...yeah makes sense. I thought you meant just after today's racing.
Yep cheering on LR as it looks super cool and the skipper for NZ is so bloody dour on interviews.
I'm cheering on NZ because (I think) that if LR win, they've said they'll go back to boring displacement boats. (Also, I don't like Jimmy Spithill, for no reason whatsoever :-))
As boatspeed goes up the tactical side of the racing becomes different. You can’t tack on every tiny shift without losing speed so keeping in the windy side of the course is critical unles a major shift comes through. You want to cover the other boat you have to sail your own race when you are clear in the lead and look at the bigger course picture.
You want a lot of duelling check out Lasers or Toppers on a gusty shifty day.
And again I enjoyed today. Looking forward to watching this series develop.
Definitely seeing a pattern here.
So interesting that for a couple of years all the focus has been on the technology, the boat control etc.
It's actually coming back to the basics of good starts, tactics, giving opposition bad air etc.
There is an element of boat speed, but so much is 'normal' sailing racing.
Enjoyable.
I really want to see them racing at the top end of the legal wind range
Bloody hell! Four minutes!
yeah but one gust away from being 4 minutes the other way!
Jesus they were two great races. I'm loving this.
Wow. Another nailbiter.
Having watched I cant say i really get into this type of racing. Seems too high tech, too elitist and removed from regular racing which has always been semi pro or very experienced crews to out and out pro using boats that are completely removed from regular yachts types.
Used to be round the cans sailing sausages before heading in for a round of cans and some sausages.