THE IMOCA thread, single/double handed & TOR

Varan

Varan

Super Anarchist
6,847
2,029
The February issue of Seahorse magazine features David Raison’s rise through the mini and class40 fleets, and now his new Imoca projects. Raison believes a non-foiling Imoca can be up to one tonne lighter than a foiling one by eliminating the foils, their structures and their control systems. He also noted “We take a pre-foiling boat from 2012, we improve its polars by one percent and we are matching the overall times of the foilers in the last round-the-world race.” He continues… “Why bother chasing foiling when we know that we’re are going to gain significantly more than one percent with our non-foiler by having a more modern hull?”


“We think we are actually working more in the real world, because the foiler system as it currently exists in Imoca really does not work very well.” When asked about the new build he designed for LeCam and Bellion for the 2024 Vendee Globe, Seahorse reported “if you imagine Guillaume Verdier’s design Holcim without foils you may be somewhere in the ballpark”, but Raison declined to provide details. LeCam described it as a big class40 with twin daggerboards and a canting keel. It will be interesting to see what they actually came up with.
 
Bagheera

Bagheera

Member
222
332
Alaska
Varan said:
“Why bother chasing foiling when we know that we’re are going to gain significantly more than one percent with our non-foiler by having a more modern hull?”
Click to expand...
That was my conclusion after months of calculating as well.
I have actively been working on a campaign to participate in the vendee Globe myself for about 7 years. The objective of my campaign was to build a competitive boat at half the cost and half the carbon footprint of modern IMOCA's. I have come really close to signing sponsor contracts on several occasions, but in the end the project was to ambitious and I'm too unknown. I have not given up on this project yet, but for the next few years I am busy with another sailing project.

Those foils weigh roughly 450kg a piece (mostly carbon) and cost more than a million. The very complex control mechanism is also several hundreds of kg's. Now traditional dagger boards of course have a weight as well. I estimated that I could ditch just a little over 940kg's (12% of the boat weight) to go without foils. Half the teams of the foilers measured negative speed gains due to the foils in the southern ocean because most of the time they could not be used and they were lugging around a ton of extra weight.

Anyway, it remains the most interesting type of boat to me. I believe that foils can be made more reliable and more effective, but it might still take some years to iron out those details.
 
E

eliboat

Super Anarchist
2,426
797
3to1 said:
personally, I'd love to see this class go back to daggerboards.
Click to expand...
This whole discussion is what makes the class so intriguing. Given the IMOCA class’ track record, I think it’s pretty clear that they know how to keep things going, despite the cost of these programs. That said, the cost of an IMOCA program pales in comparison to an AC program, yet delivers an equivalent level of innovation and far better ROI for commercial stakeholders. JLC’s new build will be fascinating and to watch squaring off against the foilers. Imagine if in the last VG he had had the boat he is building!
 
Bagheera

Bagheera

Member
222
332
Alaska
@Varan i do too. Though I would also love to see the other old master, Roland Jourdain take another stab at it.
I also admired Vincent Riou's attempt in the pre-last Vendee to take on the foilers without foils. To bad he hit a UFO before he even reached the Southern Ocean to show that he could keep up with the foilers down there.
 
W

Wetbum

New member
3
9
Clarisse has been dropped by Banque Populaire due to concerns about achieving sufficient mileage to make the cut for Vendee 2024:

(Badly auto-translated from Clarisse's facebook):
"
POPULAR BANK DECIDES TO LEAVE ME ALONE
I gave birth to a baby girl November 2022 While nothing obliged me, I had informed my sponsor Banque Populaire as of February 2021 of my child's project. They still chose me for this new Globe Vendée and communicated our mutual commitment in fall 2021.
I learned last Friday that Banque Populaire had finally decided to replace me. By their decision, and despite my constant will, I will not be part of the Vendée Globe 2024.
Vendée Globe rules for the 2024 edition require all skippers to compete based on race miles. On this note, I of course fell behind the other competitors at the start, this maternity left me out of qualifying for a year.
Today Banque Populaire decides that it represents for them a "risk" that they ultimately do not want to take.
I am in shock, other projects launched much more recently are still going on without an eyebrow. 2 full seasons left and 4 transatlantic to get back on the level I was on the edge to finish my rehab asap.
But for Banque Populaire it would be "let fate choose in their place", while they "must" be at the start of the Vendée Globe. They're willing to take on the risk of a giant trimaran, and all the natural, technical and human hazards of racing offshore, but obviously not motherhood.
If offshore racing exists today it is because sponsors choose it as a communication lever and use it to tell beautiful sporting stories and therefore, a priori, human. I am totally confused with the story this sponsor is choosing to tell today: "The Globe Vendée, at all costs." "
The organization Vendée Globe, on the other hand, is content with being "sorry to me" but "can't do anything". She writes the rules though. Let's recall that 4 years ago I would have been selected automatically as a finisher of the previous edition. Reminder that 13 new boats (1/3 of the fleet) have a discount to be officially selected at the next Globe Vendée to support innovation.
The rules of a competition are supposed to ensure fairness and sportsmanship. Today, the rules chosen by the Vendée Globe prohibit a woman from having a child, even though she would be a well-known athlete, already finishing the previous edition. In the 21st century, who do we want to believe that such rules would be fair? We have a nice game of deplorable, then, the small number of women on the starting lines.
I want to thank the people who have supported me and will recognize themselves. I am determined to sail again, under the colors of a trusted partner with whom I will share human convictions. My passion for sailing remains intact, and I will quickly overcome the disappointment I live today.
Thinking especially of all women, athletes and others, who go through similar struggles without having this opportunity to speak. What does equality mean to women? To behave just like men and therefore especially not to be pregnant? If I speak out today, it is not out of revenge, to gain attention or to complain, but to provoke thought, and in hopes of advancing our society."
 
T

timotheysski

Member
61
57
jimmy_81 said:
Interesting video from Pip on some of the work being done on Medallia:



Can anyone with a better grasp of foiling design explain why larger foils need to be further forward in the hull? Couldn’t immediately figure that one out…
Click to expand...

My guess is that with the small foils, they were around the middle of the boat to support the boat at its very widest point for righting moment and ease the weight of the whole boat while having the bow glide up.
These big foils generate a substantial amount of lift that would fully raise the bow out of the water, and are large enough that you don't have to worry about being at the widest point (though I suspect the new placement is not far from the old one anyways and that isn't much of a factor).

I believe the main reason is to asymmetrically support the boat, in the sense that the front section benefits more from the lift than the aft section. On these boats, the idea is to lift the front out and have the stern/quarter skimming the water like a tripod. Thus, it's okay to move the foil forward since the boat can support itself with its stern when it pitches up.
If the foil were farther back, you might risk getting super powered up, speeding up, flying high and parallel to the water, and then pitching down with the foil still driving, essentially power-crashing down while the whole boat is still fully powered up. Obviously, that would be insanely violent and absolutely terrible. But with the foil forward, if the boat gets high, the angle of attack will increase and the foil will stall and it will crash down, instead of speeding up further as the foil continues to drive it on its descent into the next wave.

I hope this makes sense.
 
J

jimmy_81

New member
35
36
UK 🇬🇧
timotheysski said:
My guess is that with the small foils, they were around the middle of the boat to support the boat at its very widest point for righting moment and ease the weight of the whole boat while having the bow glide up.
These big foils generate a substantial amount of lift that would fully raise the bow out of the water, and are large enough that you don't have to worry about being at the widest point (though I suspect the new placement is not far from the old one anyways and that isn't much of a factor).

I believe the main reason is to asymmetrically support the boat, in the sense that the front section benefits more from the lift than the aft section. On these boats, the idea is to lift the front out and have the stern/quarter skimming the water like a tripod. Thus, it's okay to move the foil forward since the boat can support itself with its stern when it pitches up.
If the foil were farther back, you might risk getting super powered up, speeding up, flying high and parallel to the water, and then pitching down with the foil still driving, essentially power-crashing down while the whole boat is still fully powered up. Obviously, that would be insanely violent and absolutely terrible. But with the foil forward, if the boat gets high, the angle of attack will increase and the foil will stall and it will crash down, instead of speeding up further as the foil continues to drive it on its descent into the next wave.

I hope this makes sense.
Click to expand...
Ah, yes that does make a lot of sense. And I guess they also want to keep the boat erring on the side of aft-down pitch to ensure the rudders don’t lift out & lose grip too.
 
D

DELETED

Anarchist
641
316
iu

If he and the centre of gravity move forward or back the wet foil angle or position or size must change to maintain lift and speed and balance.
 
H

huey 2

Super Anarchist
3,716
1,881
syd
So they plan...what a team..


326397709_715021266642175_5250533155314750571_n.jpg

25Jan 2023
The new Imoca Nexans - Art and Windows has taken its winter neighborhoods.
, On the agenda of the next months, a long work of transformations and optimizations that will allow the boat to gain both reliability and performance.
A work carried out in close collaboration with Vincent Riou who brings his performance expertise and Merfyn Owen, architect of Cabinet Owen Clarke Design - Yacht Design and Naval Architecture - the origin of the design of the boat - both arrived in Lorient today.
Merfyn Owen: "Delighted to be working with the Fabrice team on this boat I designed back in 2008, at the time for Mike Golding. We will replace the keel, remove foils and replace new drifts, ballasts reviewed and gauged, and also work on the cockpit ergonomics for better protection for the skipper. Lots of perspective shifts to make the most reliable and lightest boat possible, very exciting challenge"
 
You must log in or register to reply here.


Latest posts





Top