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      A Few Simple Rules   05/22/2017

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Yachtdynamics

Volvo 70 design

217 posts in this topic

Nico said that the last Puma was fast, but couldn't be driven as hard as the Juan boats. Botin would have studied this and probably made some improvement but would have also tried to keep the edge old Puma had.

Yeah, I know that where you hang the lead and all that, but you are still going to concentrate weight in the hull structure, and where things are within the hull will affect the trim. Moving the tanks and engine aft a meter for example.

However there seems to be a difference within the Juan fleet as well. I thought Goupama was ballasted further aft, which would also explain the rake...although with canting keels location of he ballast is independent of where the center of lateral resistance is located. If they are trimmed ass down, they probably have a harder time in the light stuff.

I thought the rules would have something about sail bags, but it struck me hat the question of light or heavy sails was complex. Normally you want the sail inventory to be as light as possible. I'm sure the designers did the VPP analysis on this, but it seems that there might be an advantage for heavier sails on a Volvo 70. More sails are sitting on the high side than are in the air. So you might net out more stability with heavy sails.

All the fast ocean multis have gone for some form of crew protection. These guys aren't pussies, so I figure it just comes down to managing your health over he long haul. I saw the wave deflector on Camper and thought it was a bit of a lash up. I mean if there is someplace where you want the water to go it would be into the stack, where even with the best intentions, it's going to take some time to drain. I don't know what the solution is, but there is one.

Finally, I think the cost controls that VOR have put in place are undesirable from a performance and safety standpoint. Essentially they have driven the teams to set off in boats that cannot be modified after they have been measured, and they more or less can't leave the builder without being measured. I understand the need to prevent a moding race where boats are reassembled from a vast kit of parts for each leg of the race. But it also seems harsh for a team to have to flog a dog all the way around the world when a fairly simple rework would make them more competitive. Also you should be able to sail enough to understand you boat at sea in abusive conditions and correct whatever you need to to be safe.

It would be really important for VOR to determine how to make it possible for boats to go around more than once. Rule stability would keep 2012 boats in the mix, but also more flexibility for teams to modify those boats for future races so they are more competitive than Sanya would improve the chances of getting more teams involved.

SHC

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It would be interesting to estimate how the increased panel weight compares to the difference in total hull weight in this version of the rule. My guess is that they added more panel weight than they added hull weight and, as a result, they reduced the amount of structure that could be built. Does anyone have a copy of the V70 Rule from the last go round?

Panel weights haven't changed since version 1 of the rule. Structural requirements have only changed due to the ISO standard going from a draft standard in 2003 to being a final standard for the 2008 race. In the process the standard increased structural requirements in the slamming area slightly. No changes were made for this version from a structural point of view apart from the all up weight increase.

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It would be interesting to estimate how the increased panel weight compares to the difference in total hull weight in this version of the rule. My guess is that they added more panel weight than they added hull weight and, as a result, they reduced the amount of structure that could be built. Does anyone have a copy of the V70 Rule from the last go round?

Panel weights haven't changed since version 1 of the rule. Structural requirements have only changed due to the ISO standard going from a draft standard in 2003 to being a final standard for the 2008 race. In the process the standard increased structural requirements in the slamming area slightly. No changes were made for this version from a structural point of view apart from the all up weight increase.

WYD,

 

Pat S from FYD had been quoted as saying that there was enough weight available in the rule for the designer to distribute structure with some 'flexibility'. Sorry for the pun. Perhaps he will wish to rethink that comment, but can you comment on it's validity? I work with ISO 12215-5 about every day, and I think that a VO70 must far exceed the rule limit in many areas. It is a fair minimum standard, but created around the idea of production boats, not offshore one-offs.

 

Steve, you are not serious with the value for VOR in going around with an old boat, are you? Isn't the condition of Sanya enough to convince you of the folly? Noncompetitive an used up, putting it kindly. It would be different if they would initiate two classes as is being done in IMOCA, maybe. Big maybe, because where will the money come from to fill that class? Even with an old boat, the cost of a VOR race is huge. The boat will need a rig, and sails, crew, and new kit to get around the race track at all.

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If they want to see more than 5-6 new boats on the line, at these costs, using old boats seems necessary. If the scantlings are strong enough then carbon can go around more than once, numerous Open 60s, etc.,.

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If they want to see more than 5-6 new boats on the line, at these costs, using old boats seems necessary. If the scantlings are strong enough then carbon can go around more than once, numerous Open 60s, etc.,.

Um, they got 5 new boats on the line. In the worst of times. How are old boats necessary?

 

I am trying to point out two things. One is the money. I am saying that saving the design fee, the mould cost, and the boat building doesn't make the dent in campaign costs that some think it does. With one sailor on board, 2/3 shore crew, those savings represent a somewhat bigger % of the whole. With 10/11 on board, plus a shore crew of 4/5, and all of the "consumables" you are looking at a much smaller % of the total cost. They are not sailing for free. And for what prize? 2nd to last? That is the second point, the competitiveness. Once you are in the VOR, for X dollars/yuan, I am guessing like 15-20% more, you get a much better potential outcome. Was black Betty competitive 2nd time around, no. Is Sanya Lan, no. There is just nothing to be gained for teams (nor the VOR itself) to be thinking about the old boats in this regatta. Not that they can't have a second life.

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Doug,

You know the numbers better than most,I respect what you're saying. I thought that with rule stability, durable structures and upmoding potential a competitive effort would be possible but if not, not.

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The debate about Team Sanya sailing Tele Blue is moot. It was far too late to build a 3rd gen VO70 by the time the funding was in place. Moose's plan is long term...to build on these commercial relationships for future editions. His "prize" is to achieve that not a position on a leaderboard.

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The debate about Team Sanya sailing Tele Blue is moot. It was far too late to build a 3rd gen VO70 by the time the funding was in place. Moose's plan is long term...to build on these commercial relationships for future editions. His "prize" is to achieve that not a position on a leaderboard.

Totally agree that it could not be done so late, but I think the entire concept was put together past any possible choice, with the help of VOR (as in the past). I guess that is a contradiction of my own statement that VOR has little interest in old boats. They do, to fill out the fleet. Maybe they do need to make it serious and get 5 legacy boats on the line with it's own trophy, and prize money.

 

I think the multi edition concept has some merit in theory, but comes to fruition far less than 1/2 of attempts, in all types of racing (AC, MiniTransat, VOR, etc). Telefonica has never stated this as a goal, yet there they are again and again. Puma never had that plan, they also repeat because the ROI for the sponsor and something to prove in the racing team. Delta Lloyd did plan to grow the next generation and fund a full-on winner. Didn't happen.

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There has been a lot of good discussions regarding sandwich panel debonding/delamination, but it would be interesting to see some more background information from the design process. Often the debonding is a secondary effect of the real failure mode, which is face sheet wrinkling. A simple design rule often used is the Hoff equation sigma=0.5*(Ef*Ec*Gc)^(1/3). This formulae is very simple to use in an anlysis and you see that the simplest way to increase the wrinkling resistance would be to use a higher E-modulus the fiber or core (increased core desity). But this simple equation does not take into account the face sheet thickness itself and can therefore in some cases lead to non optimized design. It oversimplifies the design. So if you are pushing the design envelope without having verified your FEM analysis with practical testing, your could experience some premature failure. I am not familiar with which tools are actually used in the design of the sandwich structures of the Volvo 70, but it would be very interesting to know and discuss.

 

Work by sadwich panel guru D. Zenkert has shown that even the stacking order of the face sheet is important. An optimized stacking order could significantly increase your wrinkling resistance, and this is done without any weight penalty :-)

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The debate about Team Sanya sailing Tele Blue is moot. It was far too late to build a 3rd gen VO70 by the time the funding was in place. Moose's plan is long term...to build on these commercial relationships for future editions. His "prize" is to achieve that not a position on a leaderboard.

Totally agree that it could not be done so late, but I think the entire concept was put together past any possible choice, with the help of VOR (as in the past). I guess that is a contradiction of my own statement that VOR has little interest in old boats. They do, to fill out the fleet. Maybe they do need to make it serious and get 5 legacy boats on the line with it's own trophy, and prize money.

 

I think the multi edition concept has some merit in theory, but comes to fruition far less than 1/2 of attempts, in all types of racing (AC, MiniTransat, VOR, etc). Telefonica has never stated this as a goal, yet there they are again and again. Puma never had that plan, they also repeat because the ROI for the sponsor and something to prove in the racing team. Delta Lloyd did plan to grow the next generation and fund a full-on winner. Didn't happen.

 

 

I think another issue is that boats designed for previous races would have been designed with a different course, different scoring and different timing considered. The design is always optimised to the expected conditions of the next race. If the one after has less weighting on the in port race and has more light wind or upwind conditions expected then the design brief will be slightly different. Tele Blue was never expected to go round Cape Horn in late March, she was designed to have just left Rio by then, after 3 weeks of maintenance.

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There has been a lot of good discussions regarding sandwich panel debonding/delamination, but it would be interesting to see some more background information from the design process. Often the debonding is a secondary effect of the real failure mode, which is face sheet wrinkling. A simple design rule often used is the Hoff equation sigma=0.5*(Ef*Ec*Gc)^(1/3). This formulae is very simple to use in an anlysis and you see that the simplest way to increase the wrinkling resistance would be to use a higher E-modulus the fiber or core (increased core desity). But this simple equation does not take into account the face sheet thickness itself and can therefore in some cases lead to non optimized design. It oversimplifies the design. So if you are pushing the design envelope without having verified your FEM analysis with practical testing, your could experience some premature failure. I am not familiar with which tools are actually used in the design of the sandwich structures of the Volvo 70, but it would be very interesting to know and discuss.

 

Work by sadwich panel guru D. Zenkert has shown that even the stacking order of the face sheet is important. An optimized stacking order could significantly increase your wrinkling resistance, and this is done without any weight penalty :-)

 

Not a composites engineer, so maybe this is a stupid question. If is true about wrinkling, wouldn't that happen in the side of the panel subject to compression not tension loading? Are laminate schedules adjusted for this?

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In that case can you describe the differences in laminate and core?

 

 

 

The debate about Team Sanya sailing Tele Blue is moot. It was far too late to build a 3rd gen VO70 by the time the funding was in place. Moose's plan is long term...to build on these commercial relationships for future editions. His "prize" is to achieve that not a position on a leaderboard.

Totally agree that it could not be done so late, but I think the entire concept was put together past any possible choice, with the help of VOR (as in the past). I guess that is a contradiction of my own statement that VOR has little interest in old boats. They do, to fill out the fleet. Maybe they do need to make it serious and get 5 legacy boats on the line with it's own trophy, and prize money.

 

I think the multi edition concept has some merit in theory, but comes to fruition far less than 1/2 of attempts, in all types of racing (AC, MiniTransat, VOR, etc). Telefonica has never stated this as a goal, yet there they are again and again. Puma never had that plan, they also repeat because the ROI for the sponsor and something to prove in the racing team. Delta Lloyd did plan to grow the next generation and fund a full-on winner. Didn't happen.

 

 

I think another issue is that boats designed for previous races would have been designed with a different course, different scoring and different timing considered. The design is always optimised to the expected conditions of the next race. If the one after has less weighting on the in port race and has more light wind or upwind conditions expected then the design brief will be slightly different. Tele Blue was never expected to go round Cape Horn in late March, she was designed to have just left Rio by then, after 3 weeks of maintenance.

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In that case can you describe the differences in laminate and core?

 

 

 

The debate about Team Sanya sailing Tele Blue is moot. It was far too late to build a 3rd gen VO70 by the time the funding was in place. Moose's plan is long term...to build on these commercial relationships for future editions. His "prize" is to achieve that not a position on a leaderboard.

Totally agree that it could not be done so late, but I think the entire concept was put together past any possible choice, with the help of VOR (as in the past). I guess that is a contradiction of my own statement that VOR has little interest in old boats. They do, to fill out the fleet. Maybe they do need to make it serious and get 5 legacy boats on the line with it's own trophy, and prize money.

 

I think the multi edition concept has some merit in theory, but comes to fruition far less than 1/2 of attempts, in all types of racing (AC, MiniTransat, VOR, etc). Telefonica has never stated this as a goal, yet there they are again and again. Puma never had that plan, they also repeat because the ROI for the sponsor and something to prove in the racing team. Delta Lloyd did plan to grow the next generation and fund a full-on winner. Didn't happen.

 

 

I think another issue is that boats designed for previous races would have been designed with a different course, different scoring and different timing considered. The design is always optimised to the expected conditions of the next race. If the one after has less weighting on the in port race and has more light wind or upwind conditions expected then the design brief will be slightly different. Tele Blue was never expected to go round Cape Horn in late March, she was designed to have just left Rio by then, after 3 weeks of maintenance.

I think you are missing the point

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...

...

...

 

Right on brother, Sailed on DHL (Former EF Language) for a couple Hobarts. The shitter was through Forward Hatch on right side with the striptease poll being the only thing that kept you from launching. Once closed the door it was an unbelievable experience to be alone in the Bow section of one of these Yachts while racing.

 

The harden the fuck up crowd are idiots and can't understand that if Risk can be prevented they should have a serious look at what we are doing. Not sure if you are aware of the SpeedDream project to create the world's fastest Monohull. Pretty slick and using wave piercing hull will remove a lot of the loads the current fleet are challenged with. Saw Vlad and Brian give a presentation here in Marblehead and they will have the 27 ft prototype done by May. This could be the future of the Volvo, and looks to get the right balance between speed and crew abiility to manage. Check it out. Sure arm chair crowd will have something to say on here, but these guys are doing something pretty cool and they fully admit they have some ideas that may or may not work. Gotta love innovation.

 

So, which of you guys are which? :D

 

Hehe... see front page today!

:rolleyes:

(actually I did enjoy a lot reading the full "interview", as I tend to share their view on limiting power rather than length (as long as that doesn't lead a slightly-smaller-than-now-mast put on a superlight skiff)

 

C.

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Some actual information on the current designs

http://chevaliertaglang.blogspot.fr/2012/04/volvo-ocean-race-yacht-drawings-design_17.html

Hull lines show actual shape differences between Botin, Juan K, and Farr designs.

Note that Camper's keel is about a meter forward of the others.

SHC

Depends on your definition of "actual" doesn't it? This is no mean feat to determine the hull lines from images. To my eye, his lines, especially the waterplanes (apparently all drawn by hand) somewhat exaggerate rather than match the unusual features of the boat. The flat bow on G4, the tapering canoe of Azzam' stern, and the flatness of Campers aft section for example. I would love to hear the feedback of a builder (if they even get to see the lines plan anymore) to find out about accuracy. Bear in mind I have not been up close and personal with this generation of yachts, yet.

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