Vo70

D'ARTOIS was right...

Scuttlebutt quoted this article that reveals that Paul Cayard is very concerned about the safety of the Farr designed boats. Most importantly the article points out that some of the SAME interior structural damage that was seen on Movistar is present on Cayards boat.(!) Sad, really sad.....
Telegraph | Sport | Cayard fears for Volvo 70 safety
http://www.telegraph.co.uk/sport/ma...AILS&grid=&xml=/sport/2005/11/17/soyots17.xml
Note in the article what it says about how the canting keel is attached. I was wrong earlier this IS a problem that goes to the heart of the canting keel system at least on the Farr designed boats.
Also click on the article at the bottom-more on the Movistar failure.

 

its going to be very bad if one or more of these boats comes to a nasty end in the southern ocean. All canting keel boats, not just the VO 70s, have been somewhat dangerous to sail because of the loads generated. Unfortunately, this Volvo Race may be when something goes terribly wrong. Skandia was lucky last year in the Sydney Hobart race when her crew were able to get off. If one of these Volvo 70s disintegrates its not likely that the crew will survive. Perhaps these boats are under-engineered in their initial versions, and hopefully for the next running of the race the boats will be more structurally sound.

 

I think the maximum weight part of the rule is at fault. Maximum weight rules produce extreme machines, F1 used to have a maximum weight limit. You could put your weight into more HP or stiffer chassis and better brakes. Guess what, the rule produced huge engines with flimsy chassis. Not as big a problem when after the chassis breaks you can walk home. In a VO70 the same thing looks to be happening, lots of power and boats that are breaking.

"Honest folks, this Volvo SUV won't leave you stranded like the Volvo 70's"

Something as simple as requiring the hull to remain watertight was overlooked in both the rule and the designs.

The VO70 rule allows the keel pivot to be inside the hull. That can be done with a watertight hull. All you have to do is enclose the entire system in a watertight compartment. If the seal at the hull surface fails, the compartment floods and the boat slows, but it would not be in danger of sinking. Enclosing the rams and much of the hydraulic system inside the keel box would also limit the exposure of crew to highly stressed components.

I hope that this series of races for large dinghies is replaced by a single around the world race like the Whitbread.

Strange that Volvo, with it's reputation for safety and solid reliability has created a series that has produced the boats that are racing today. What will equating Volvo with extreme, high performance, fragile machines do for sales?

 

Maximum weight limit?

I would think tht a minimum weight limit would be more apropriate in this situation. In a race envirorment it seems that there needs to little discouragement from building slower boats that might be safe as opposed to faster boats that might be unsafe.

Also, There seems to be a lot of experience of racing in the great southern ocean to draw from. They have been doing it for decades. The claim that most of the likely stresses are unknown just doesn't seem to wash. I, for examble, would engineer such a boat so that it could be dropped from a ten meter hieght with its canting keel fully canted out into deep water without anything breaking.

From what I have read about the conditions these sailboats are sailed in and how hard they are driven, I would surmise that such an event would be very likely to happen in real life. From what I've read, the waves out there are huge. And they are all over the place. Comming from any direction at any time.

Hardly the place for what are little more than big, decked over, high performance dinghies. Compared to these boats, even the most extreme Open 60's seem conservative and even sedate.

You wouldn't send Pee Wee Herman into the middle of an NFL scrimmage, would you?

Bob

 

What we should do is getting those rules for the building here. Somebody must have them and shuld post them.

In any case, it is sure that the Sydney - Hobart showed the possible weaknesses of the canting keel system.

The basic wrong element in the design-procedure of the VO70's is the fact that the modelling process goes without the technical specs and that later on adaptions are made to fit both together. So, this is where it all goes wrong.

First of all - the whole keelsystem is the center of everything and the boat's function falls or stays with the technical integrity of the system.

A fact is - and that count for most desiners - that during their design carreer, they develop a specific formula on which all their designs are based. Therefore they are so recognisable as being a boat of............ fill in the name.

Actually it should have been vice versa. First of all, desin a malfunction freecanting system, generating forces that are similar of those that can be met in real time situations.

Earlier, most desiners went with their clients in the field and were confronted with teir faults and mistakes in the actual circumstances. So they could learn and adapting the following design so that specific malfunctions could no occur anymore.

On the METS I saw a young guy lecturing about boatdesign on a large PC - turning around the design and playing around with it. What are you actually showing the people, I asked him.
He looked at me if I was just a ghost.

Too many rely on the pc which is only an instrument, a mere vehicle, because most of the guys cannot draw anymore and are basing their models on already excisting models that have been developed before.

In fact, in the old days one began with the layin of the keel. I am a strong promotor of the design that starts with the keelsystem and where the boat will be modelled around the rig and keel and not vice versa - becaus the shape of the hull is unimportant and can be moddelled the way you want, not
the reverse mode.

The designers of the Vo 70 are pretty arrogant, that I know from own experience - if they are willing to learn something is highly questionable:
my polocaptain told me: people who think that they know, that they have the final wisdom, will never learn!

 

Fast boats designed for good water will no longer cut it in the open seas?

 

Yes, that rule (maximum weight) is plain weird. In Sanxenxo the guys from Sunergy and friends had to cut some part of the keel ballast because they had "too much weight". It looks that building slower but stronger is not an option, because you have to respect a maximum limit weight that is so slim that even some of the present racing boats has difficulty in complying with.

About keel problems...it is not necessary to hit anything to have a lot of problems and structural ones as well:

"Before announcing the boat’s retirement from Leg 1, Paul Cayard, the Pirates skipper sent out the following missive, “After properly inspecting the Black Pearl, we are now in a position to report on the damage.

"1. Bulkhead C, midway from the bow to the mast, has broken. There was shearing of the frame along with compression of the vertical beam.

"2. The "bomb doors" which seal the keel box at the hull, have been ripped off.

"3. A bolt that holds the keel pins in has sheared.

"That is the main damage. ...
....
"The reason why I don't want to sail the boat to Cape Town is that it is unsafe to sail without the "bomb doors".

"To explain: The keel cants 40 degrees each side of centre. The axis of this rotation is 150mm up inside the boat. Therefore there is a hole in the bottom of the boat that is about 400mm (1.5 ft) wide. his hole is the bottom of the keel box which is "recessed" into the boat. The bomb doors not only make the hull fair as the keel swings from side to side, but they protect the inside the keel box from high pressure water force. Without them the lid to the keel box and the rubber gaskets that seal the hydraulic ram arms, which actuate the swinging of the keel, are exposed to high pressure water. When we discovered the situation early Sunday morning, the lid to the box was bulging upward and straining the fasteners, while water was squirting into the boat due to the 35 knots of water pressure, and the ram seals were bulging like cows' udders. Not one to withdraw from racing easily, in this case, I immediately called for the crew to take all sails down and slow the boat to less than ten knots."

http://www.volvooceanrace.org/news/article/2005/november/behindthebikesheds/index.aspx?bhcp=1

 

Most engineers I know would have designed the keel box and ram seals so that they would still hold even without the bomb doors. Then again, sound engineering practice isn't exactly a hallmark of the VO70. I'm curious as to why the Pirates captain didn't seem to care much about ripping a structural bulkhead to pieces....
Maximum weight limits have their place. Solar cars, for instance, where excess weight can overload highly stressed tires. But when a weight limit forces a vehicle to be too weak for its intended conditions, that's a sign of a dumb rule. A minimum all-up weight, coupled with a maximum limit on the fraction of the displacement that can be due to ballast, might work- any thoughts?

 

To call this class, the cream of a crop is abusing the word.

 

limits

I like the idea of a minimum weight hull/rig and a maximum weight/ fin bulb.
The canting keel seal needs serious work; I've seen designs (including by a couple of posters here) that are superior to the one Cayard describes. Maybe there should also be specific design criteria for that whole system agreed to by everybody and rigorously tested with input from the best canting keel design engineers in the world not just the most popular.

 

Both ABN AMRO boats seem to have broken the 24hr record ... 538 and 533.

Bailing every 30 minutes ... LOL!

The boats are fast, no question.

 

yes but..."“... the whole boat is shuddering and shaking as we crash through one wave to the next, all the winches and blocks are screaming and cracking like cannon fire under the load. Water is pouring down the deck and into the hatch so we have to bail out every half an hour or so to avoid turning the leeward side of the boat into a swimming pool.

““On deck things aren't much easier, it is like standing in front of a fire hose and you have to hang on to stay in the cockpit; only an hour ago Bicey was swept of the stack and down the cockpit whilst trimming.

“ ...sailing these boats ...It's a difficult feeling to describe, a mixture of adrenaline and excitement, fear and apprehension. You don't know if something is about to break ...."

D'Artois says these are disposable boats, that they will be done after the race.
I doubt if they have the strength to finish the race...at least if the weather turns really nasty...and this has been a bad year in what wheather concerns.

 

I'll add some fuel...
Stupid rule, stupid boats.
Why not use a performance one-design that is somewhat over-engineered. You'd have close racing, lower costs, exciting for spectators. The race organisers could bid out for a performance design that would be strong enough to make it through the race, cheaper to build, still fast, and safe. The costs for entry should be much lower, so more entries, again more exciting to watch.
Who cares if you have a rocketship boat, and none can finish the race, or someone gets hurt or killed?

 

I think a large part of the idea behind the Open 70 is that they are the lightest, swiftest and most technologically cutting-edge boats in their size range. Apprehension over what'll break next, or whether a boat will finish, is part of what keeps spectators tuned in. To a sponsor, it doesn't matter whether the boat places 4th or 7th; the sponsor wants that hull on TV and in the papers as much as possible. Up on blocks on a pier, the sponsor's logo is still just as visible and just as powerful as when the boat is zipping along in the water. And the boat on the pier, or under the rescue chopper, always gets media coverage; the 3rd-runner-up who has no problems rarely does.

 

"Free Willy" on Ericsson

Great boats aren´t they

Actually I´m a great fan of VO 70 really exciting crafts!

Still I can´t understand why they don´t get rid of those antique led weighted things and use modern top performance multis.

Anders M