Top speed in a race

[nroose 189]

It doesn't really matter, but I am curious about tracking the top speeds in races for each team.

Today it was  50.29 for UK and 49.35 for ITA. Is that the first time one of these boats exceeded 50 during a race?

[Kiwing 382]

Rumours say they have touched 60 knots reaching but who knows only them?

But it is VMG that matters ??

[Rennmaus 2,307]

Can anyone remember what the Top speed in SF was (LVC or AC)?

[NotSoFast 19]

1 hour ago, Rennmaus said:

Can anyone remember what the Top speed in SF was (LVC or AC)?

 Wiki involves a link to a source too, and claims 47.57 knots as fastest race speed during AC34.

Quote

The fastest race speed recorded was on Emirates Team New Zealand which was 47.57 knots (88 km/h, 55 mph) in 21.8 knots of wind (2.2 times the wind speed) on September 24, 2013.

 

[Rennmaus 2,307]

35 minutes ago, NotSoFast said:

 Wiki involves a link to a source too, and claims 47.57 knots as fastest race speed during AC34.

 

Thanks!

[Doot Master Flex 13]

2 hours ago, Kiwing said:

Rumours say they have touched 60 knots reaching but who knows only them?

But it is VMG that matters ??

no way its in the 60s. mid 50s at most 

[jaysper 575]

14 minutes ago, Doot Master Flex said:

no way its in the 60s. mid 50s at most 

It would seem unlikely as that would put it only 5 knots shy of sail rocket 2.

They are already going faster than the original sail rocket.

[JALhazmat 1,166]

Just now, jaysper said:

It would seem unlikely as that would put it only 5 knots shy of sail rocket 2.

They are already going faster than the original sail rocket.

8 kts 

they had a 68 peak, awesome bloke is mr Larsen 

[jaysper 575]

3 minutes ago, JALhazmat said:

8 kts 

they had a 68 peak, awesome bloke is mr Larsen 

Ah fairy nuff.

I was quoting the average but you are right, instantaneous speed is a much fairer comparison.

But still, these boats could probably reach mid to high 50s which is super impressive for boats not purpose built for maximum speed in a single direction like sail rocket.

Still hate these boats but their speed is still objectively impressive.

[JALhazmat 1,166]

If they were actually ever set up for top speed it could be very interesting, foil design as it is they never will be as they just aren’t optimised as it’s all upwind downwind at the best angle

 

[enigmatically2 758]

With the 1nm record at only 55kts plus change I reckon they might not be far off that in the right conditions

[jaysper 575]

7 minutes ago, JALhazmat said:

If they were actually ever set up for top speed it could be very interesting, foil design as it is they never will be as they just aren’t optimised as it’s all upwind downwind at the best angle

 

Imagine the record if one of the AC teams set their mind to it.

The additional computing power, people and (presumably) algorithms would surely see it beaten by a truck load.

[JALhazmat 1,166]

There are two projects currently underway looking at an 80-120kt average 

swiss going for 80, French going for 120

 

[nroose 189]

3 hours ago, Kiwing said:

Rumours say they have touched 60 knots reaching but who knows only them?

But it is VMG that matters ??

The issue with tracking VMG is that measuring it accurately is not feasible. I follow the sailing speed records loosely, but here I am talking about in-race top speeds, which makes it kind related to VMG and kinda official.

[jaysper 575]

5 hours ago, JALhazmat said:

There are two projects currently underway looking at an 80-120kt average 

swiss going for 80, French going for 120

 

The french one will presumably do 120 knots backwards, no? LOL!

[Nutta 387]

14 minutes ago, jaysper said:

The french one will presumably do 120 knots backwards, no? LOL!

With a white surrender flag clutched in their garlic stained claws...

[jaysper 575]

4 minutes ago, Nutta said:

With a white surrender flag clutched in their garlic stained claws...

Yup.

You obviously got the analogy with their tanks. 1 forward gear and 5 reverse. LOL!

[alanjs 1]

Sailrockets achievement was very significant but it's Vs/TWS ratio was well short of what the AC75's are achieving. At somewhere just above 50 knots the AC will run into cavitation issues. Sailrocket could cope with cavitation as it is a single-tack reaching machine and moderate leeway was not an issue.

[Kiwing 382]

I would not be too sure the AC75s have not pushed the cavitation boundary up quite a bit not sure to where but closer to 60 than 50.

[JALhazmat 1,166]

1 hour ago, alanjs said:

Sailrockets achievement was very significant but it's Vs/TWS ratio was well short of what the AC75's are achieving. At somewhere just above 50 knots the AC will run into cavitation issues. Sailrocket could cope with cavitation as it is a single-tack reaching machine and moderate leeway was not an issue.

They did their run in average 24kts and hit a peak of 68ish averaged 64ish 

Yesterday 17kts of wind peak of 50 average of ? 
 

What SR did in terms of efficiency still stacks up even with how far tech had moved on. 

[JALhazmat 1,166]

As for the French effort? They aren’t lacking testicular fortitude from the pilot, he is the kite record holder with an average of over 57kts

[K4W 0]

Would a foiling kite beat an AC boat around the course? 

 

[JALhazmat 1,166]

Sub 8 kts without a tow up for  the 75 from a chase boat I recon so. They are going in 4-6 with 23m kites 

angles might be a bit shit down wind but they would give it a bloody good go 

If the boat gets going in a puff and can keep at it then it’s game over though

if the boat had enough to stay foiling the entire time then not a chance for  the kite 

[MaxHugen 677]

On 1/24/2021 at 5:42 PM, alanjs said:

Sailrockets achievement was very significant but it's Vs/TWS ratio was well short of what the AC75's are achieving. At somewhere just above 50 knots the AC will run into cavitation issues. Sailrocket could cope with cavitation as it is a single-tack reaching machine and moderate leeway was not an issue.

Sailrocket used a special foil designed for cavitation, similar in profile to this:

It's designed to allow the cavitation zone to flow along the foil to the rear where it forms a trailing cavitation bubble:

Larsen cleverly then utilised ventilation to "fill" that cavity with air, which is at a higher pressure than the very low water vapour pressure, and thus reduced the drag to some degree.

[mad 3,825]

On 1/23/2021 at 10:08 PM, JALhazmat said:

8 kts 

they had a 68 peak, awesome bloke is mr Larsen 

68.33 to be precise.

[mad 3,825]

On 1/23/2021 at 10:35 PM, JALhazmat said:

There are two projects currently underway looking at an 80-120kt average 

swiss going for 80, French going for 120

 

Anymore details on those projects??

[mad 3,825]

On 1/24/2021 at 8:06 AM, JALhazmat said:

They did their run in average 24kts and hit a peak of 68ish averaged 64ish 

Yesterday 17kts of wind peak of 50 average of ? 
 

What SR did in terms of efficiency still stacks up even with how far tech had moved on. 

27 knot average with a peak of 29kts. 

[JALhazmat 1,166]

1 hour ago, mad said:

Anymore details on those projects??

SP80

Syroco

plenty if you google them, vids for each on you tube 

 

[dullers 385]

On 1/24/2021 at 4:42 AM, Nutta said:

With a white surrender flag clutched in their garlic stained claws...

Nothing wrong with French soldiers. (Verdun) plenty wrong with French politicians and leadership in WW1 and WW2.

[mad 3,825]

4 hours ago, JALhazmat said:

SP80

Syroco

plenty if you google them, vids for each on you tube 

 

Thanks, i wasn't even aware of them

[Boybland 548]

23 hours ago, K4W said:

Would a foiling kite beat an AC boat around the course? 

 

I'd be really interested to know the angles of the kite upwind from someone who really knows. But I can't imagine they get close to the ridiculous VMG the AC75 is pulling.

Off the wind I iimagine things are pretty close though.

[nroose 189]

I guess AM got a new top speed in a race yesterday! Over 53 kts. They seemed fast but not able to really control the boat and so couldn't maintain a fast average.

[strider470 791]

We should have two categories: top speed while bearing away and top speed maintained for at least 10 seconds in straight line. And top VMG up and downwind.

[Sailbydate 2,560]

1 hour ago, nroose said:

I guess AM got a new top speed in a race yesterday! Over 53 kts. They seemed fast but not able to really control the boat and so couldn't maintain a fast average.

VMG was shit compared to LRPP but. They sailed substantially greater distance in both races.

[hoom 567]

43kt upwind after the tack here, last starboard tack on last upwind/leg7, race 2 of LRPP vs AM semi-final

They're low-mode in a rightie but still a great angle, a big chunk of 40+ either side of the stretch of 43kt & peaking 32kt VMG.

[nroose 189]

3 hours ago, Sailbydate said:

VMG was shit compared to LRPP but. They sailed substantially greater distance in both races.

Sure. But for me it's fun to see the top speed. Actually, I think one of their issues was that they were faster than they had practiced and could not control the boat at the speeds the boat wanted to go.

[Redreuben 64]

On 1/24/2021 at 6:07 AM, jaysper said:

It would seem unlikely as that would put it only 5 knots shy of sail rocket 2.

They are already going faster than the original sail rocket.

Isn’t the mid 50’s where Sailrocket hit a wall and had to get a new foil design to break through to 60+ ?

[Mozzy Sails 649]

More interesting than top speed would be top acceleration.
Would also be interesting to look at the acceleration away from the wind in a bear off, i.e. not boat speed, but acceleration purely in the direction of the wind. 

Often the top speed are generated when teams fail to accelerate downwind, and instead get trapped in the death zone. Citing these top speeds as some sort of achievement is actually the complete opposite of what the teams will be looking for. I.e at the windward mark the idea is to go from making VMG upwind to making max VMG downwind as quick as possible. Not reaching off at 50+ knots toward the boundary out of control 

 

[JALhazmat 1,166]

48 minutes ago, Redreuben said:

Isn’t the mid 50’s where Sailrocket hit a wall and had to get a new foil design to break through to 60+ ?

The wall isn’t what mattered, it’s where they ended up.  And that along way past there’s boats. 
 

boats built for upwind down wind course vs single way speed record = no comparison 

[JALhazmat 1,166]

1 minute ago, Mozzy Sails said:

More interesting than top speed would be top acceleration.
Would also be interesting to look at the acceleration away from the wind in a bear off, i.e. not boat speed, but acceleration purely in the direction of the wind. 

Often the top speed are generated when teams fail to accelerate downwind, and instead get trapped in the death zone. Citing these top speeds as some sort of achievement is actually the complete opposite of what the teams will be looking for. I.e at the windward mark the idea is to go from making VMG upwind to making max VMG downwind as quick as possible. Not reaching off at 50+ knots toward the boundary out of control 

 

Maintaining the highest average is what matters, get to top speed as fast as possible for a given course stay there, smallest loss through a turn and repeat until you cross the line. 

[Kiwing 382]

For me top speed id cavitation speed 50+.  But most teams are turning to max VMG, so screwing more VMG before hitting cavitation speed. Avoiding cavitation speed seems to be the go.

[dullers 385]

11 hours ago, Kiwing said:

For me top speed id cavitation speed 50+.  But most teams are turning to max VMG, so screwing more VMG before hitting cavitation speed. Avoiding cavitation speed seems to be the go.

Both AM and INEOS have hit over 50 in a race. Possibly INEOS is the first sail boat to go over 50 in a race and AM now has the fastest record with over 55. All done when rounding the marks.

[JALhazmat 1,166]

53.

[strider470 791]

19 minutes ago, dullers said:

Both AM and INEOS have hit over 50 in a race. Possibly INEOS is the first sail boat to go over 50 in a race and AM now has the fastest record with over 55. All done when rounding the marks.

I know that this numbers may sound nice to achieve, But it seems the maximum raw speed bearing away is just a collateral effect. Going towards the boundary at full speed risking foils cavitation is not the main purpose. Let's stick to VMG

[dullers 385]

Just now, strider470 said:

I know that this numbers may sound moce to achieve, But it seems the maximum raw speed bearing away is just a collateral effect. Going towards the boundary at full speed risking foils cavitation is not the main purpose. Let's stick to VMG

Read the post heading.........

[strider470 791]

2 minutes ago, dullers said:

Read the post heading.........

Yes, yes I know. It was just a thought, that maybe I'd like to know the top speed maintained upwind and downwind, apart from the value reached for a few seconds after the mark.

[dullers 385]

Just now, strider470 said:

Yes, yes I know. It was just a thought, that maybe I'd like to know the top speed maintained upwind and downwind, apart from the value reached for a few seconds after the mark.

Fair enough. I do agree with you as it is the mixed component that matters. But 50 is a sexy number in a race.

[strider470 791]

8 minutes ago, dullers said:

Fair enough. I do agree with you as it is the mixed component that matters. But 50 is a sexy number in a race. 

True. Yesterday I was watching some races of the 2013 AC and the old cats seem slow elephants in comparison to these boats! And at the time they were astonishing!

[Chris UK 173]

From 2:45:07, AM were over 44Knts upwind. The highest figure I spotted was 44.8knts, unfortunately we loose speed data just as they seem to accelerate again at 2:45:12, in the final seconds before the infamous tack....I think Terry may have mentioned 47kts as their top speed.......anyone got the top speed figure for this final upwind?

Checked Virtual Eye, it shows 45 knots.

 

 

[enigmatically2 758]

One of the races (I assume day 3 as it was the windiest) I'm sure  saw GB clock over 48kts downwind (not just after a mark rounding). didn't notice the VMG.

I'll have to re-watch to see if I can find it again- though didn't someone find the speed plots for all the races- can we see on there?

[dullers 385]

1 hour ago, strider470 said:

True. Yesterday I was watching some races of the 2013 AC and the old cats seem slow elephants in comparison to these boats! And at the time they were astonishing!

Be interesting to look into the future and see where we are even in 10 years time. At some point some sort of ceiling will be reached. Perhaps the sound barrier.

[Nutta 387]

3 minutes ago, dullers said:

Be interesting to look into the future and see where we are even in 10 years time. At some point some sort of ceiling will be reached. Perhaps the sound barrier.

Easy, there will be no boats, no water, just an E-Sports ACxx.

[strider470 791]

10 minutes ago, dullers said:

Be interesting to look into the future and see where we are even in 10 years time. At some point some sort of ceiling will be reached. Perhaps the sound barrier.

For sure there will be people remembering the good old days, wanting the AC to switch back to the traditional foiling boats because at least they had masts and sails. :-D :-D The defender Cup will be Gucci, Armani and Valentino against Prada.

[dullers 385]

4 minutes ago, strider470 said:

For sure there will be people remembering the good old days, wanting the AC to switch back to the traditional foiling boats because at least they had masts and sails. :-D :-D The defender Cup will be Gucci, Armani and Valentino against Prada.

Be like when the new fangled sextant came in. No doubt we will be thinking how slow they are compared to the next AC.....If the Italians win it I am sure it will have more leather than carbon in it.

[Nutta 387]

6 minutes ago, dullers said:

Be like when the new fangled sextant came in. No doubt we will be thinking how slow they are compared to the next AC.....If the Italians win it I am sure it will have more leather than carbon in it.

Nothing wrong with a good sextant. I've got a nice one here...

[dullers 385]

19 minutes ago, Nutta said:

Nothing wrong with a good sextant. I've got a nice one here...

I have a couple but unused since the early noughties. Nice to look at and get all salty over them.

[nroose 189]

13 hours ago, strider470 said:

I know that this numbers may sound nice to achieve, But it seems the maximum raw speed bearing away is just a collateral effect. Going towards the boundary at full speed risking foils cavitation is not the main purpose. Let's stick to VMG

The issue with VMG is that we don't have accurate numbers and will not likely ever have accurate numbers.