IMOCA 60 Proposed Rule Changes
- Thread starter Buckie Lugger
- Start date
Kalumder
Member
an adjustable flap at the back of the boat
"..Typically on power boats and ships, this device comprises a vertical plate, fitted to the transom, that drops down an inch or so (depending upon the size of the vessel) and is used to dampen pitching, but as Tom Weaver, newly moved over to the 'dark side' of the power boating world, informed us, is also in some cases used to improve lateral stability..."
here is a picture of Paprec Vibrac, you should be able to see it that the back part can be lowered/raised
http://www.jpdick.com/p-jpdickcompubfr/ima...469_640x451.jpg
here is a picture of the effect it causes
http://www.madforsailing.com/ism/articles....aa?OpenDocument
Initially, many skippers were worried the IMOCA could suffer an "ORMA syndrom", because of exploding costs. Which isn't a totally unfounded concern, BTW...
So they started talks about ways to reduce costs.
But it all degenerated into a battle around the power of the boats, and the alleged safety problems that come with it. In fact it's mostly the fear that Pindar could just outdate all other designs. Which I don't think will happen, BTW...
The cost issues have been long forgotten... The limits porposed today, if they ever get voted, will only make the boats more expensive.
moody frog
Super Anarchist
These are two different things.
Paprec and Gitana 80 have flaps which are hinged surfaces which can be either flush with the hull or at an angle to it.
Ecover and Aviva have a sliding plate (parralel to the transom) which can either be retracted in the hull or protruding in the water .
Only the later one is an interceptor.
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Kalumder
Member
Sorry for the mix up, and thank you for correcting me.
So which is faster?
So which is faster?
moody frog
Super Anarchist
Sorry for the mix up, and thank you for correcting me.
So which is faster?
Nobody knows
Speng
Super Anarchist
You may have a point regarding the legality of trim tabs but my guess is that there is no good definition for "appendage" either thus leaving a humongous loophole to drive thru. Of course since the rule is "open" you don't have to ask for a technical interpretation before building the boat (a la the America's Cup) you just build it then it's a fait accompli and nobody else will want to ban you in case you try to ban one of their ideas in the future.
I assume that is true but given some of the failure in keels particularly fabricated keels leads me to believe that maybe it is done at the time of manufacture and not necessarily ever again. The Class should require keels to be at least ping and dye penetrant (or what ever is the equivalent for carbon keels) tested yearly.
BGeff
Super Anarchist
Sorry for the mix up, and thank you for correcting me.
So which is faster?
According to the article in Dailysail, it is really not faster, just sort of stabilizes the boat downwind a bit better...in a nutshell.
Buckie Lugger
Super Anarchist
- Thread starter
- #30
I remember a few posts by Hugh Welbourn in the forums (where's he when you need him? ) saying that it's possible to use trim tabs as a replacement for water ballast. In fact, it was something that was proposed to the Volvo Ocean Race technical committee.
However, both the Farrs and Owen Clarke designs seem to be using them in conjunction with water ballast to provide another gear.
The legality of trim tabs has been questioned by some (including Mich Desj) as they sit in a hollow at the stern. Since hollows (i.e. the boat being concave in the lateral cross section) are banned under the IMOCA rule, the hull shape is said to be illegal. The tab itself doesn't violate any rules as far as I know. Please correct me if I'm wrong RedFlag.
Incidentally, the same argument may well apply to the spray rails on the Farr 60s.
Speng, I believe that the teams test the keels regularly. Paprec-Virbac's keel was found to be cracked after her delivery back from New Zealand, and Ecover 3's was found to have problems during a post-race checkover. The problem is that keels have a habit failing far sooner than they should.
) saying that it's possible to use trim tabs as a replacement for water ballast. In fact, it was something that was proposed to the Volvo Ocean Race technical committee.However, both the Farrs and Owen Clarke designs seem to be using them in conjunction with water ballast to provide another gear.
The legality of trim tabs has been questioned by some (including Mich Desj) as they sit in a hollow at the stern. Since hollows (i.e. the boat being concave in the lateral cross section) are banned under the IMOCA rule, the hull shape is said to be illegal. The tab itself doesn't violate any rules as far as I know. Please correct me if I'm wrong RedFlag.
Incidentally, the same argument may well apply to the spray rails on the Farr 60s.
Speng, I believe that the teams test the keels regularly. Paprec-Virbac's keel was found to be cracked after her delivery back from New Zealand, and Ecover 3's was found to have problems during a post-race checkover. The problem is that keels have a habit failing far sooner than they should.
Buckie Lugger
Super Anarchist
- Thread starter
- #31
I'd agree with that being a possibility. I don't think that the sport gets sufficient media coverage to justify the current budget levels, so the individual teams will have to depend on corporate hospitality to give their sponsors a good return.
Straying slightly off-topic, which boat (or boats) do you rate? And why don't you think that Pindar will dominate?
I personally like Safran's approach the best (ease of use and power-to-weight through lightness) though I think that either Loick Peyron or Mich Desj has the best overall package.
moody frog
Super Anarchist
Speng ,I can assure you that keels are tested at least once a year and in a much more sophisticated way than just dye penetration.
The class has even gone, since last June, as far as starting to build a data base of keels natural frequencies at various times, to check if they may loose their properties after a number of racing miles.
The latest numerous keel swaps, including a number for carbon just illustrate that faith in fabricated steel as a proper way of making keels has just vanished. Too many unknown factors or risks, I would say (but I hv always be biased against them)
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You're right. And unfortunately, I think this is one of the biggest problems the class is facing at the moment. Some technical details have been accepted that should never have, just because it is not possible to change the boats once they're built. Things that everyone wanted to do but refrained to because it was against either the spirit or the letter of the rule. Things like the emergency exit in the cockpit (instead of the transom, thanks to Farr and Riou), or hull hollows around the keel (thanks to Juan K), etc...
You're right. But since even the hollow they sit in is an add-on to the hull, they say it is all an appendage. Of course, you have to break the epoxy bonding to remove the add-ons, which is totally impossible without damaging it or the hull. That's not an appendage IMHO.
The spray rails may be OK, since their lower face is horizontal: The rule says that the depth of the hull shall not get smaller as you move closer to the centerline. They're still ugly though
moody frog
Super Anarchist
I thought the boat's full drawings had to be sent to the technical committee (for stability calcs) prior any measuring session, which IMHO is a problem as the Tech Com head is a competitor.
IMHO, these boats need to be light and powerfull. Safran is light but not powerfull. Pindar is powerfull but heavy.
Mich and Loïck seem to be the logical favorites, but I think the Finot's are under-rated. There's little doubt Hugo Boss would have won the Barcelona if they hadn't had their rudder problems. They displayed impressive speed.
No, no. Just the "basic" hull, deck, keel and rudder shapes are sent to the chief measurer, who is not a competitor.
Vincent Riou being head of the technical comitee is a problem in other circumstances, though. You know, impartiality and all...
moody frog
Super Anarchist
OK, so: just what's needed for the calcs, still it gives some nice insight to some
Again its a classic "who should run a class ?" problem: competitors run classes have shortcomings, not as much as designers run classes though (R.I.P IOR)
russell_2878
Member
I for one would loose interest if they restriced the class.
Imoca should focus more on expanding the market for these boats, aussie asia and the us come to mind. i've done a couple of short two hande races down under and would love to see these thing (even the old ones taking part) most boats down here are nomal racers with an auto pilot added.
some small crewed races would be good also, eds atlantic challenge comes to mind, and maybe some inshre races with a couple of lacal ameuters would be great.
i'd like two see a single handed start line for the syd-hob, run every second year with standar divisions, mini, class 40 and open 60.
the avs might be able to be teaked but is not as imprtant with a self righting rule (should be standart for all offshore/ocean races along with bulckheads) i'd like to see bowsprits a bit longer, same as on ORMA 60 as i belive the ones on the class 40 are longer the the current open 60's. and maybe change list angle from 10 degress to 12.5
Imoca should focus more on expanding the market for these boats, aussie asia and the us come to mind. i've done a couple of short two hande races down under and would love to see these thing (even the old ones taking part) most boats down here are nomal racers with an auto pilot added.
some small crewed races would be good also, eds atlantic challenge comes to mind, and maybe some inshre races with a couple of lacal ameuters would be great.
i'd like two see a single handed start line for the syd-hob, run every second year with standar divisions, mini, class 40 and open 60.
the avs might be able to be teaked but is not as imprtant with a self righting rule (should be standart for all offshore/ocean races along with bulckheads) i'd like to see bowsprits a bit longer, same as on ORMA 60 as i belive the ones on the class 40 are longer the the current open 60's. and maybe change list angle from 10 degress to 12.5
