Join Date: Jan 2000
Thanked 0 Times in 0 Posts
Rep Power: 0
Vendée Globe Speed Machines
As the Vendée Globe fleet streaks south in their marathon race around the world, sailors and non-sailors worldwide are watching in anticipation of what will happen when these competitors begin flirting with the fringes of the Southern Ocean, and really put their new boats and designs to the test. Interest is even more acute considering what happened in the last race four years ago when one sailor and his boat were lost at sea, and three others had to be rescued from the freezing waters of this forbiding region. Questions about those incidents continue to haunt all of us, from the casual observer to the seasoned veteran. Have these extreme vessels gone too far and are they safe?
I had a chance to study many of the new designs when I was in France prior to the start of the Vendée Globe, and with my background as a solo sailor to draw upon, I have some basis from which to comment. Let me start by saying that I have never seen such an amazing and innovative fleet of boats assembled for any regatta. The diversity and imagination of some of the designs was astounding, and being a fan of progressive, free-thinking designs, I was in the right place for a first-hand look at some of the recent advances that have been made in this demanding class.
French sailors have dominated solo sailing for some time, with yacht designers Jean-Marie Finot and his partner Pascal Conq sitting at the epicenter of this domination. The fleet in this event is no exception as eight of the entries are from their CAD system. But Marc Lombard has also made some inroads in this discipline, as has Briton Merfyn Owen and the design consortium that created Ellen MacArthurs new boat Kingfisher. To the casual observer, however, there might appear to be very little difference between the designs, and I even heard one person comment; "these boats all look the same, they look like space ships." The differences are subtle, and at this level, the devil is in the details. But its the small differences that set these vessels apart, and its a collection of those differences that, over the course of 25,000 miles, will allow one boat to finish ahead of another by what I expect will be a matter of hours.
Lets start by looking at hull shapes. To most people these amazing machines seem like big dinghies and thats really what they arelight, fast, planing hulls that are easily driven and easily controlled on a big surflike that found in the southern ocean. It might be surprising to many, but the newer boats are narrower than they were a few years ago. At that time (say six-plus years ago) water ballast was the most common way of adding stability to an Open Class 60. Each boat carried massive water tanks in the broadest portion of the boat, and to add stability the sailor would pump a few tons of seawater up to the high side. Then the canting keel was introduced, and later refined, and now most Open 60s have either a canting keel, or a combination of water ballast and a canting keel (Fourteen of the 24 boats that started this race have swing or canting keels.) Aboard some boats, water is added not solely for stability, but also for additional weight so that the boats have some punch when sailing to windward in a seaway. Some of these vessels, like Kingfisher, have tanks forward of the mast, on centerline, and the extra weight here is intended to steady the boat when sailing on the wind.
The newer hulls on Open 60s are narrower in part because they do not need the righting moment that extreme beam offered, however, these designs are still quite wide in order to allow a flat, stable surfing platform for downwind sailing. Only one boat, Joe Seteens ultra-narrow Nord Pas du Calais/Chocolate du Mondea veteran of four circumnavigationshas a pinched-in stern. Jean Luc Van den Heede, who made three circumnavigations aboard this vessel, told me that it did not handle well off the wind when compared to the newer designs.Another obvious difference among the current fleet comes in the form of appendagesthe rudders, centerboards, and other bits that hang off the hull. With canting keels being the most effective way of adding stability, designers have been forced to add tracking fins and centerboards to enhance the directional stability of the boat. A tracking fin is usually located on centerline and is ordinarily not retractable, although the one aboard Michel Desjoyeauxs PRB can be raised. This appendage is there to provide lift when sailing to windward as well as to keep the boat on track when surfing downwind.
The most common appendages, however, are asymmetrical daggerboards. Most of these are retractable (and removable) so that they can be replaced if damaged. MacArthurs Kingfisher has daggerboards that are overly long so that the upper portion might be reinserted and used should the bottom portion shear off. Those designers who have fitted retractable daggerboards have done so in order to reduce drag and wetted surface when the board(s) are not needed. All of the new designs have boards and thus it was interesting to see their different sizes and locations. Only time will tell which option is right, and this will become obvious when the competitors reach the big seas down south and start to surf. One thing is certain: without these fins, the boats would be hard to sail, so having the ability to repair or replace them may become an important factor.
If you followed the last Vendée Globe, you know that Isabelle Autissier suffered a devastating blow when a whale broke off one of the rudders aboard PRB, forcing her to stop in Cape Town for repairs, which meant disqualification. All of the newest entries in the current race have twin rudders, the reason being is that the beam on these boats is carried so far aft that a single, center-hung rudder would not be very effective with the boat heeled over. With a twin-rudder system, the leeward rudder is almost always fully submerged and projecting its best airfoil shape to the water, while the windward rudder flies along out of the water. I was surprised to see just one truly new development in rudders among the fleet, but it didnt surprise me to see it aboard Michel Desjoyeauxs PRB. Desjoyeaux, one of the strongest pre-race favorites, has always been a proponent of design innovation. He was one of the first competitors to favor the swing keel, and that was over five years ago. His Finot-Conq-designed entry features transom-hung rudders that flip up when not in use, somewhat like the arrangement on a beach cat. While the leeward rudder does the work, Desjoyeaux can flip up the windward rudder to eliminate drag and avoid any chance of it hitting an object and breaking off. The beauty of this design is that if one of the rudders breaks, it can be easily removed and repaired, or replaced, and if necessary, Desjoyeaux can make it back to port with a single blade by alternating it from one side to the other. The foils themselves are asymmetrical so the blade will work more efficiently on one tack than the other, but its certainly a better solution than having to retire. One aspect of the rudder systems on all of these boats is that the components are easily accessible so that any chafe, wear and tear, or other problems can be easily seen and sorted out before they worsen.
Additional evidence of design evolution among the new Open 60s is found seen in the variety of bowsprits among the Vendee fleet. Some competitors opted for fixed sprits while others favored retractable ones, and yet others are using bowsprits that articulate off center. The majority of boats carried fixed sprits, leading me to assume that the designers and skippers have found the trade-off between efficiency and the potential for problems with moving parts not worth the risk. The rules for this race state that your boom and bowsprit together cannot overhang by more than 10 percent of the boats length. Because many of the boats have booms that project beyond the transom, the bowsprits are generally short and fixed.
Ill continue this review of the Open 60 designs in the Vendée Globe in my next article, wherein Ill examine the spars and sail plans. Look for that in a few weeks.
Suggested Reading List
- Showdown on the Atlantic by Dan Dickison
- Vendée GlobeEntering a New Era by Dan Dickison
- Single-Handed Transatlantic History by John Kretschmer
- SailNet Buying Guide - Roller Furlers