CARBON FOILS: LEARNING FROM THE TRANSAT JACQUES VABRE 2015

With all the Ultime, Imoca and Multi 50 home in Italja, Brazil, it is now time to look at we learned from the 2015 Edition of the Jacques Vabre 2015.

The best chances of international success, on paper was probably with the HUGO BOSS pair Thomson and Altadill on the brand new VPLP/Verdier design. With the Vendee Globe, the premier solo round-the-world race, starting in a year, Thomson was testing a new generation of innovative carbon hydrofoils in the 5,400-mile Transat Jacques Vabre. However the team clearly suffered from a lack of time to learn the new boat and although they are an exceptional partnership, matured and experienced the challenge was too big. Four days after the start of the race, Thompson and Guillermo Altadill, had to be rescued off the tip of Galicia, Spain, with Hugo Boss dismasted and sinking.

The Transat race may prove that the new yacht technology has been pushed too soon into the ocean racing world? But more stunning is that five of the new VPLP-Verdier designs started the 20-boat race, but only one finished. That boat, Armel Le Cléac’h’s Banque Populaire VIII, was forced to sail in a conservative way to not overstress the structure when sea conditions were serious, keeping in mind that all similar designs had to retire from the race from structural failure. Causing to the brand new Banque Populaire to be unable to pass a previous-generation VPLP-Verdier model, PRB, which won the Imoca 60 class,

The VPLP-Verdier boats are the most complex monohull sailboats ever built, and the innovation provided is expected to be a quantum leap in yacht design. If successful, the concept will not only break the Vendée Globe record of 78 days, but could also change the sailing world, making boats much faster.
The boats have innovative L-shape daggerboards that stick out both sides of the hull, combined with the fully canted keel they both provide dynamic lift able to reduce by 50 % the displacement, like a power boat the new 60-footers nearly clear out of the water. Less wetted surface area, less dynamic displacement means more speed. These carbon daggerboards concepts are really not new as it has been on drawings for years, like one drawing of a new concept 52’ offshore designed by Frederick Courouble in 2014, still to be built.

The original hydrofoil concept was developed by Verdier and Emirates Team New Zealand for the 2013 America’s Cup. The breakthroughs launched 72-foot catamarans out of the water onto their foils at speeds nearing 50 miles per hour. We all remember the spectacular accelerations in San Francisco bay but it appears that transferring this technology to monohulls has proved tricky and dangerous especially on ultra-light boats getting faster and faster.

VPLP-Verdier reported that the suffered breakages occurred in the ribs used for the new, complex arrangement of longitudinal carbon stringers that serve to stiffen the ever lighter hulls. “The construction and gluing of these pieces must be precise or they will fail”, Verdier said. This is where improving the strength of light carbon through nanotechnology makes sense and a lot of research are being done on this topic around the world. However it seems that the breakages cannot be pointed at the carbon itself but at the manufacturing of the part. For offshore racer in particular for the forward slamming areas, switching sandwich laminate panels to a single skin with multiple stringers layout, like a metal hull framing is logical. However the design governing factor is hidden within the strength/weight ratio. To meet this critical design goal, the stringers/hull skin can be thin and light only if the stringers are numerous splitting hull surface area in very small hull panels. It implies more manufacturing parts and where the bonding is becoming extremely critical. With the multiplicity of small parts, proper glue with enough strength and resilience is a key for durable bonding. We predict that until we go to 3D printing or 3D weaving fabric to make the parts in one component with higher resistance carbon we will experience this type of problems.

“There are complications designing a boat with unknown potential, Verdier said. The most challenging, he said, is predicting the dynamic loads the hull must withstand not only as it runs into waves and debris at higher speeds, but also as it lands after being lifted into the air by the foils”. These comments are pointing to the level of resistance being required of such foils.

The traditional calculations being made are coming short and we have seen it several times. There is a big environmental difference between foiling at 50 miles/ hour in San Francisco bay and fighting North Atlantic in November in heavy seas.

Sailing in fast motion in waves rather than in flat water conditions, the dynamic loading can be multiplied by 2 to 2.5. The impact and the fatigue factors will over stress any exposed structure “There are some peaks of stress on the parts that are so high for a few mili-seconds that our traditional calculation are not adapted and our role is now to re-think thoroughly how can we improve our matrix and evaluate proper dynamic factors without over engineering the boat” . With new technology such as foiling or hard wings Speed is increasing and so the loading factors. Novel structural layout, materials and new fabrication method have to be elaborated.

We are entering in a new era of engineering modeling and construction method. Flying on the water is now a new dimension to be integrated at all level: from the Aero/hydrodynamic modeling, structural 3D simulation to fabrication assistance via CNC tooling. All derived from the Aeronautic industry these new methods are getting fully integrated at a faster path in the design and fabrication of new era of sail boats. said Frederick Courouble naval architect/Aerospace Engineer & President of California Carbon Industry.

A new era is starting that goes beyond the Marine industry and opens into Space and transportation it is an exciting time for California Carbon Industry!

*****************************************************************************
Mr. Frederick Courouble is a naval architect with a Master’s in Aerospace engineering: http://www.couroubledesign.com/ Mr. Courouble is also the President of California Carbon Industry, Inc.

California Carbon Industry, Inc. is focused on designing, developing, and manufacturing advanced carbon and composite materials and products for use in the aerospace, automotive, marine, art, furniture and construction industries.http://www.libra6management.com/california-carbon-industry-inc

Libra6 Management, Corp. invests in Cleantech and alternative technology and is currently leading an investment in California Carbon Industry. www.libra6management.com
http://www.libra6management.com/california-carbon-industry-inc

blog_image: 
blog_tags: