Pages

Wednesday, December 12, 2012

545.3 Vendee Globe 2012

                        We are talking about miles over a 24 hour period in the Vendee Globe Race.


Besides the weather routing, wind and options in tactic, superficially I want to analyze the best of the Imoca 60's. Macif and Banque Populaire are the current leaders as they approach the Western side of Australia. The two boats are the latest VPLP/Verdier collaboration in design. Under present condition and for that matter nearly all the time, M and B-P. seem to have an advantage in speed over the rest of the fleet. On the Vendee Globe web site, I gather that M. is the lightest of them all, that both M. and B-P have rotating masts which I consider essential to make a substantial difference in performance. This can explain the small deficit of the close sistership Virpak-Paper who has a conventional standing mast and rigging configuration. From my point of view the drawback of the rotating mast is presented in the form of the fragile and cumbersome outriggers. They have been the cause of problems past and in present circumstances. I think there is a better solution as explained in one of the comment                                        

                                         
Now, as the three leaders remain in position as they go up the Atlantic, I regret the absence of Cheminees Poujoulat. I think the boat has potentials and probably would have shone in an upwind battle. I say that because analyzing the various keels as displayed by Tagland, C-P has a larger surface which could have made a difference against the three close sisterships mentioned above. We will not know for a while.



                                Cheminees Poujoulat. Juan K. Design                                                                      
 
                          
Virbac-Paper lost her keel.
One thing that surprised me in the last Volvo Race is apparently the absence of major problems associated with the pivoting keels. It seems that  keeping keels in place is still very much an issue with the current and recent Vendee Globe Racers. The fact that the keel is swinging from a single fore and aft bolt with fairing pieces is not easy to solve from an engineering point of view. Jean-Pierre Dick ended up sailing over 2000 miles without a keel. Amazing piece of seamanship associated with a lot of courage. I met J-P once at the Old Armchair sailors Bookstore here in Newport, we had a nice chat.

                                Macif, winner of the Vendee Globe 2012. VPLP/Verdier Design.

3 comments:

  1. We are impatient to get more about this idea !!!!

    ReplyDelete
  2. Buffon a dit quelque chose au sujet de la patience.
    Anyhow. To replace the outriggers poles adopted by the Vendee Globe boats with rotating masts,it is of my opinion that the lift-producing system with such a mast is of great advantage. Because of the speed of the IMOCA's 60, the apparent wind is more often than not forward of the beam. The boom is not eased to any large amount, permitting the aft fixed shrouds to be anchored further astern. The idea of the outriggers is to increase the open angle between the mast and the point of anchorage.
    I think I can propose a similar arrangement without the poles. I would add on the mast a long spreader equal to the width of the boat. A light way to reinforce the spar, with the standing rigging set in a diamond fashion to equalize the compression on the mast. The shrouds and stays adequatly placed with opposite forces, including aft shrouds implanted on the side deck. The above making a stronger and even lighter proposition.
    Now,of course with the spreaders able to rotate with the mast the whole sail plan and specially the fore triangle will have to be carefully designed. The jibs with the exception of the outboard reacher have to take account of the obstruction presented by the rotated spreader. The limit of 110% overlap with a hollow leech is taking care of a 8 t0 10 degrees inboard sheeting angle, as seen on the rendering above. I think that the poles can be eliminated.

    ReplyDelete
  3. Rotating rigs without deck spreaders have been around since the Vendee Globe in 2004 (Ecover 2). In the 2008 VG Aviva and Ecover3 had a rotating rig with one set of fixed spreaders. In this VG Mike Golding had got rid of the rotating rig in order to reduce wweight on his OCDesign 60.

    ReplyDelete