Vo70

[brian eiland]

Originally Posted by Lorsail

See:
2005ericsson10.jpg
Address:[url:http://www.yachtsandyachting.com/photos/vor/2005ericsson10.jpg[/url]

I had suggested to Doug that he post the actual illustration in case the referenced website changed, etc. He was unable to do so because of his web connection, so I volunteered to do it.

[brian eiland]

Here's another observation I ran across in Scuttlebutt...

From Bill Leary:
It is no surprise to me that canting keels have been the cause of a majority of the problems thus far in this edition of the Volvo Ocean Race. Merlin was one of the first boats in the up to be competitive with the newer sleds in Transpac. We were on the wind in 15 knots of breeze 3 miles off the California coast on our first shakedown sail after the retrofit when the bolts connecting the ram mechanism to the keel failed.

Gravity kept the keel hanging straight down, but with no hydraulics there was nothing to keep the hull stable above it. We were very lucky to make it back into Santa Cruz that afternoon without sinking the boat. Thankfully the failure occurred in relatively benign weather and close to shelter. Had it happened in rough weather or well offshore and Merlin certainly would have been lost.

Canting keels don't belong on ocean going sailboats. Sailing is dangerous enough as it is without adding the unnecessary additional risk associated with canting keels. One of these days, perhaps in this edition of the Volvo, perhaps later, there is going to be a loss of life due to a canting keel failure. Perhaps then our sport's attitude about canting keels will change. Do canting keels make a boat faster? Certainly. Do canting keels make a boat better? Nope

Canting keels have a long, safe , record of hundreds of thousands of ocean miles and I believe they are an asset in the development of high speed monohulls. When fin keels were first introduced there were serious problems and there will always be potential problems with race boats sailing on the edge whether they have canting keels or more than one hull or carbon masts or whatever.
I hope the edge has not been cut too close with the Farr designed boats andthat the crews will remain safe. The problem is not with "canting keels" it is with design, engineering and/or building.

[brian eiland]

Originally Posted by Lorsail

.... I believe they are an asset in the development of high speed monohulls.

No doubt they are an asset to high speed monohulls, but the question remains are they a sea-worthy asset?? I wouldn't want to be on one of those boats in the southern ocean. Remember they can sink, and rather quickly, and in older days no hope for rescue that far from land in those frigid waters.

Brian, this year and last year were not the first uses of canting keels; they've been around for 20 years+. Because there are failures that are directly traceable to poor engineering and/or building on some of the boats it's simply not right to indict all canting keels just like it is not fair to indict all ocean racing multihulls because of the failures of numerous ORMA 60's.

[brian eiland]

Originally Posted by Lorsail

...it's simply not right to indict all canting keels...

I'm not trying to indict all canting keels. Hopefully no one would believe I want to indict experimentation and advancement of the sailing art after some of those 'unusual' proposals I've hung out there on the wash line.

I just don't think its wise to go off into the stormy, icy, southern ocean in an unproven vessel with quirks known about their keels, and particularly sense it involves a hole (shuttered) in the bottom of a ballasted vessel. These boats didn't have enough development time for me to hang my life out there for a faster speed.

BTW, I was also very concerned for some friends of mine going off on the big catamaran Team Adventure with only a month's worth of sailing time between launch and the start of the 'RACE'. And particularly sense your forcing a virgin product into a very nasty sea enviroment. I was concerned should some team member fall off, or get washed off by the seas up thru the trampolines. At full surfing speeds, and big seas, or at night, there is no way the vessel might turn around to pick them up, let alone some land-based rescue be of assistance.

They've all been lucky so far, and I've got my fingers crossed for them, but I can't believe it will continue at this pace of 'throw it out in the ocean and go for it immeadiately' will continue without some tragedy.

I sure would be interested to hear Grant Dalton's view on the subject. He raced in a number of these events including the Whitbread, Volvo, and then the RACE. And he knows boat preparation. I'll bet he wouldn't out there in these vessels. I also think back about another conversation I heard with him about a year after his very fast winning RACE around the world in the big cat Club Med. Something to the effect that he would never be interested in doing another race around the world in a monohull, but he would definitely consider it again in a cat.

I agree with your last post 100% ; there has been a tendency by posters all over to say everything going wrong with the VOR is the fault of canting keels. I've read similar stuff on three forums. The safety concern is serious and I hope they all make it.
Then there are those who think it is morally wrong, cheating, "not sailing" etc. to move a keel with power regardless of the conditions.
Cant win sometimes....

[RHough]

It seems to me that one of the design issues is the VO70 rule allowing the keel pivot to be inside the hull. It makes the opening in the hull larger than it would have to be if the pivot was normal to the hull surface.

From the images that I've seen posted, the pivot and rams don't share the same mounting structure. This requires that the system relies on hull stiffness to keep the parts in alignment. It wouldn't take very much flex to put strange loads on fittings that have limited freedom of movement.

That is the reason that rigging attachments should have freedom of movement, so the load remains in tension. If the rams are gimbaled. the hull can flex a bit and the loads on the ram system would remain in tension or compression.

From one image (that I can't seem to find now), it looked like one side of a forked fitting on the end of Ericsson's ram failed. From the image of the system posted here, it looks like neither end of the ram can move in the fore and aft plane. That could easily create shear loads at the end fittings.

---
edit

I found a quote:

"Ericsson was sailing on the wind at ten knots in 15 to 20 knots of wind some 200 miles south of Cape Agulhas when the keel system failed. It seems that the piston rod of one of the hydraulic rams that control the canting keel failed at the clevis fork close to the attachment to the keel. As designed, the other ram has the keel under control, but the boat is returning at reduced speed to Cape Town."

[D'ARTOIS]

Doug, Your statement of the canting keel being around for more than 20 years, having hundreds of thousands of nautical miles of safe passage.....can you back that up?
I simply don't believe it.

According to me the canting keel is only in use say 3-4 years maximum.

That the priniple is around for a long time - that I accept as being trustworthy, not the actual existence - therefore my post about the availibility in production vessels.
Can you clarify this point?

[brian eiland]

Originally Posted by RHough

...From the images that I've seen posted, the pivot and rams don't share the same mounting structure. This requires that the system relies on hull stiffness to keep the parts in alignment. It wouldn't take very much flex to put strange loads on fittings that have limited freedom of movement....

Very good observation.

Originally Posted by RHough

... It seems to me that one of the design issues is the VO70 rule allowing the keel pivot to be inside the hull. It makes the opening in the hull larger than it would have to be if the pivot was normal to the hull surface.

And think about how this "opening" (hole) in the bottom of the hull might impact the fore/aft stiffness of monohull vessels that heretofore were very much dependent on some sort of 'backbone' either as an external keel or an internal stringer.

[brian eiland]

....courtesty of Scuttlebutt...

SANDERSON DEFENDS "DANGEROUS" RACE
In a frank log from ABN AMRO ONE late last night, Skipper Mike Sanderson addressed [Volvo Ocean Race safety] concerns over the safety of the boats competing in the race. Speaking from ABN AMRO ONE just after passing the scoring gate and extending their lead at the top of the leaderboard by picking up an additional 3.5 points Mike said, "I heard through the grapevine that there is a growing concern that these boats are dangerous and that we are being reckless out here. I just want to take this opportunity to say that I will happily sit down with anyone and explain to them the thousands of hours that have gone into making TEAM ABN AMRO's keel systems as safe as possible. We need the keels to stay where we want them during the race for two reasons, and the good news is that they both go hand in hand. Firstly, it is a safety issue and secondly you have to have a keel that's working properly to keep racing. In a race like this where all the legs count, as a team you have to finish all the legs without a break down. But the safety of everyone is at the top of the list no matter how you look at it."

"Every Volvo 70 that has had a problem so far, since the first boat was launched in January last year has got back into port without assistance," continued Sanderson. "In the Open 60 solo race that I did last year, three boats had to receive aid from rescue boats, one guy was picked up by a container ship as his carbon keel had snapped and two with broken masts had to be rescued from the mid Atlantic by chartered support craft. Now, we are not allowed carbon keels in the Volvo and the rig weight is adequate that unless you break something - the rig should stay up. With the Open 60's there is a massive rating advantage in having a high modulus mast, in fact their rigs are more Grand Prix then an America's Cup boat. But still like the Volvo 70, the Open 60 is just an amazing high tech race yacht and is the fastest growing offshore class out there at the moment.

Everyone called for a more exciting boat, both the public and the sailors and guess what..... we got it! To think that these boats have gone out at just 70 feet long and have on three occasions broken the 24 hr record that was set by Mari Cha IV (a boat very dear to my heart since I was involved with it from conception), which was built for the purpose of beating records, just blows me away. Volvo has supplied us with a rule that makes fantastic boats. The fact that they we are having a not such a high attrition rate is only the fault of the teams and designers. The breakages are all from weight reduction decisions that have been made by either the design team or the racing team and we all knew the whole time that we needed a big bulb on the keel to win the race. We also knew that we needed to finish the legs to win the race and it will be he who has walked that fine line correctly at the end of the day that will come out on top - and we wont know who that is for another seven months yet..."

[brian eiland]

Originally Posted by D'ARTOIS

...That the priniple is around for a long time - that I accept as being trustworthy, not the actual existence - therefore my post about the availibility in production vessels....

Just thought I would put the website link in here to the other major discussion on this subject:
Canting Keels in Production Yachts by D"ARTOIS

[Vega]

And they have done it again:

ABN AMRO TWO‘s navigator Si Fi had a few words to say on the subject, “It has been a very special day for us so far as we have broken new ground and taken a monohull past the 550 mile mark in 24 hours. Better still, just minutes ago, I received a message from Race Headquarters saying we had raised the bar to 563!

And they keep pushing hard...I hope, not too hard

“What can I say, the boys are ecstatic! However we are holding the celebrations for a while as the wind continues to blow hard and the fleet around us continues charging hard.
....
“For now though we are just trying to keep the boat in a 90 percent mode. If we can keep this baby in one piece and have it fully 100 percent still at Eclipse, I think that will give us more chance of winning the leg. That's my theory at the moment anyway.”

...Paul Cayard:
“We had the longest run just before the scoring gate, 140 miles for six hours, that is 560 miles a day pace. The boat is slamming downwind very violently. No one can sleep when it is this rough. As you go from 25 to 30 knots of boat speed, the keel hums to a higher and higher pitch. Then you feel the boat un-weight it self, you go a bit weightless like in an airplane sometimes and you just cringe in your bunk as you know the bottom of the waves is coming.
“Sometimes it is just a big snowplow and rapid deceleration which makes you hold onto your bunk so you don't slide forward on top of the guy in front of you. Those are the ones which create two feet of white water rolling down the decks. Other times we find the bottom by doing a violent belly flop which shudder and sends vibrations throughout the boat. I am sure the others are doing the same because they are going as fast as we are.
“It is not hard to spend time wondering how long these boats can take this type of punishment.”

http://www.volvooceanrace.org/news/a...ght/index.aspx

[RCSail]

One other team did push it to hard:http://www.volvooceanrace.org/news/a...age/index.aspx
PotC suffered major structural damage to the keel area again, but is continuing under reduced power.

[Vega]

Look at the new video...Scary!


http://www.volvooceanrace.org/mediap...4-f3cbcbcd67d8