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New Age Trawler/Motorsailer; Kite assisted PowerYacht

Discussion in 'General Sailing Discussion' started by brian eiland, Nov 21, 2007.

  1. brian eiland

    brian eiland Senior Member

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    DynaRig Vessel(s)

    Dear HTM09,
    I believe if you visit this subject thread (extensive), you will find a LOT of discussions concerning the DynaRig,....and quite a bit of participation by myself:
    http://www.yachtforums.com/forums/perini-navi-yacht/2487-perini-navi-maltese-falcon%3B-sailing-yacht.html

    I was, and still am, fascinated by this development project that Tom Perkins undertook in a a very bold manner.

    BTW since you seem to be quite interested in this rig technology, here is another discussion thread with lots of pics and subjects (some duplications, but some new)
    Maltese Falcon

    Cheers, Brian
  2. HTMO9

    HTMO9 Senior Member

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    The DynaRig(g)

    The DynaRig was to far ahead of its time at the time of its invention. Only with the developement of new materials like GRP, Aramid fibres and CRP plus the new possibilities of computer added design and computer based mathematics, like finite elemente, it was possible to adapt this type of rig for yachts.

    Legions of aerodynamic scientists have searched for the ideal wing and the perfect airfoil. But mother nature had already invented this ideal airfoil, the eliptic Zenonia plant seed (see picture below). The seed is released by the tree and glides a significant distance before landing. This seed was the model for the DynaRig sail and airfoil.

    The DynaRig combines the advantages of a square rig with the advantages of a schooner or sloop rig. Because of the almost 360 degree free turn angle of the yards combined with the hands off trim and reefing (no crew has to climb the rig, under normal circumstances), both windwards and downwind sailing, the DynaRig is superior.

    But there are big disadvantages also (up to now). A large DynaRig is very expensive and requires high quality materials and manufacturing. There are only a very few naval architects and builder capable of designing and building a large yacht with a DynaRig. And to my knowledge, a high performance DynaRig is very expensive to maintain and to operate. Rumors say, the DynaRig of Maltese Falcon is a sail eater. It means, the wear and tear on DynaRig sails is higher than on conventional rigs. Plus the royals (the upper sails) are designed to sacrifice themself by blowing in case of strong gust, in order to safe the rig.

    But having said all that, watching Maltese Falcon maneuvering under sail is breathtaking. No other type of sailing ship could be handled in this manner. What kind of performance one would see, if MF had a modern hull, made of Alustar. Yaw dropping at least, I would say.

    This is only said for a monohull type ship. A multihull with DynaRig is a different story. A monohull will heel in gusts or windbursts and relieve some of the stress on the rig. The multihull will not and cant do that. That is the reason, why the constuction of rigs for multihulls is a total different story. The beam of a conventionell rigged multihull has only to carry the vertical pressure of the rig, whereas the beam carrying the bearing of a DynaRig mast has to withstand all the possible forces and momentums of this construction. What a challenge for the naval architect, confronted with this task. I would not like to be the victim, who plays the customer, which pays for all this.

    DynaRig on cargo vessels is easier. The rig will be made of high-tensile steel. Weight savings are not of highest priority. The mast can be used as the support for cranes and most important the sails are not the main kind propulsion, they are only used to assist the engine(s).

    TBC

    Attached Files:

  3. brian eiland

    brian eiland Senior Member

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  4. brian eiland

    brian eiland Senior Member

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  5. brian eiland

    brian eiland Senior Member

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    I was looking for my quite extensive subject thread I made on this site, but could find no reference to it now. It did concern itself with kite propulsion, AND it did reference a big 200 foot trimaran motoryacht "White Rabbit" that a very bold yachtsman had built for himself in Asia.

    Just the other day I was looking back thru issues of my BI magazine and discovered a VERY interesting article on a new 276 foot "White Rabbit" tri-hull motor yacht.
    Has anyone seen the latest article on the 276 ft tri-hull motoryacht "White Rabbit" in Boats International mar 2019,....a real eye opener in terms of sea keeping and efficiency.

    This is the same BOLD owner that had the first White Rabbit built. Perhaps I will have the extract a few passages to this article, as it also addresses the MYOPTIC view a great number of non-believers have adopted from early on.

    When I posted my original subject thread I wasn particular drawn to another tri-hull motoryacht by Humpphreys,...

    Design Humphreys: (note:MY FAVORITE)
    This 40m Motoryacht represents a new development in yachting, merging the benefits of a low resistance, fuel-efficient hull form with an unusual propulsive device - a fully automated, self-tending kite.
    PFD Concept

    [​IMG]
  6. brian eiland

    brian eiland Senior Member

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  7. brian eiland

    brian eiland Senior Member

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    I have written an email to the author of that BI article asking his permission to utilize some of his quotes from his article. The opening sentence in his article really caught my attention,...

    I had a feeling this was going to be interesting :cool:
  8. brian eiland

    brian eiland Senior Member

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    looks like someone has finally come forward to do such a project,.....

    This is about serious money dreams. For a German entrepreneur, that means commissioning a futuristic yacht with a unique approach to efficiency – a gargantuan kite that helps pull it along. Ice Kite, which is still in the design phase, was conceived collaboratively by Red Yacht Design, Dijkstra Naval Architects in collaboration. Ice Kite is 210 x 35.5 foot monohull that displaces 450 tons is powered by two 1000 hp engines and carries a 1700 square foot kite rig. Ah what! A 1700 square foot kite rig that soars 600 feet in the air (think kitesurfing, but a lot bigger, fancier, and more expensive) to improve its fuel efficiency. Ice Kites maximum speed is approximately 17 knots.

    Ice Kite hull is designed to be efficient over the entire speed range and not only in a restricted speed interval around the maximum speed. This is accomplished by waterline entries, a high slenderness ratio and low wetted surface area due to a round hull shape. Other significant features include increased comfort on-board with better sea keeping and wave reduction. A well proportioned daggerboard is applied to enable the yacht to make full use of the Kite propulsion system at closer wind angles. Ice Kite has an aluminium hull with a carbon fibre superstructure and light weight strong glass panels as windows etc.

    The buyer is also commissioning an 86 foot support vessel that will sail with Ice Kite, called ICE Ghost which can carry an Icon A5 airplane, a U Boatworx Superyacht Sub 3, a 12 metre custom-made performance RIB with a top-end speed of 60 knots, also designed by Red Yacht Design, and a pair of Seadoo jet skis on her main deck. There is a further garage space for holding diving equipment, SeaBobs, and an on-site maintenance area. The main deck of ICE Ghost can alternatively be used as a party space and two twin cabins below deck can host guests or staff. With a steel hull and carbon fibre exterior, ICE Ghost can reach a top speed of 16 knots.

    The jpegs are of the initial design(s) and gives a glimpse into future technology that may be applicable to multis.
    [​IMG]

    [​IMG]

    more images HERE
    Ice Kite | Red Yacht Design https://redyachtdesign.com/project/kite/
  9. yr2030

    yr2030 Senior Member

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  10. brian eiland

    brian eiland Senior Member

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  11. yr2030

    yr2030 Senior Member

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    Thanks Brian. They might need that sail, as the sun is getting colder.
    rtrafford likes this.
  12. brian eiland

    brian eiland Senior Member

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  13. brian eiland

    brian eiland Senior Member

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    I was reading back thru this subject thread, and this old posting popped out at me. makes me wonder what has happened to this kite-powered subject more recently??

    brian eiland said:
    Get Home Power (emergency power)

    In a recent discussion on Passagemaking Under Power, the subject of "Get Home Power" came up



    The response was interesting:

    We had looked at using a traction kite several years back on Swan Song. I had several emails, calls and proposals from a couple of companies interested in the project but when push came to shove nothing developed that could be purchased then.

    There have been many kite advances in the past few years and I think that a kite is a very viable aux power system for a passagemaker. Both as a "get home" and fuel saver on long passages. Significant power can be developed with a traction ( as opposed to a sport kite) kite in the off wind passages that most of us favor. I for one really don't like slogging into head seas/winds for days on end even tho our recent Mexico-Hawaii passage had two full days of this. Beam and aft wind/seas are much preferable. Most passagemaking, as opposed to delivery passage planning, should focus on making major runs with the wind/sea aft of beam. This blends into the strength of the kite.

    Kites can offer power from 110 degrees off the wind. This translates into a usable arc of ~140 degrees. All but 500 miles of our recent 2700 km passage, for example, would fit in this wind angle.

    A kite with a nominal pull of 20-25 HP would have given us a ~ 4 kt speed under kite alone or decreased our fuel consumption by about half. So we'd have a "range extender" and Swan Song would have an 8000 km range vs. the 4000 miles we have based on the MX-HI trip. A significant advantage, IMHO.

    How big a kite to do generate this pull? That is very dependant on the design. Spinnaker type kites are large but inexpensive and have several disadvantages mostly becoming a drogue :-( Rigid wing kites are much easier to fly, can be water launched and recovered from the water easily. They are controlled from a single control point with two or three lines. There are designs range from self inflating (not good for us). to ones with battens to those that are inflated with pressure for shape (best for us, I think). All of the rigid wings develop more power than the early spinnaker designs for a given size. Size and design is important in launching from a deck as we don't want to intentionally launch from the water nor have an unruly web of fabric/lines looking for a place to self destruct.

    Launching from a foredeck pylon, aka a small mast, could be easy and once launched the kite flies from just above deck level to what ever altitude you desire. The higher it is the more wind there is thereby the more available power. Parked over head they develop no power. As you pull the control lines they move forward of the boat and generate incredible power. Easing the trim and they depower instantly. Using the trim to move them from side to side increase the average power even more.

    Sitting a kite surfer of the foredeck in a chair strapped down to the deck with a seatbelt should be a good seat of the pants test as how one of these work and could be adapted to a passagemaker.

    This certainly would be far cheaper than a wing engine, I couldn't see more than $15K for the whole system, and it would not have the issues of space and additional fuel consumption of twins.

    I suspect we'll see someone doing this in the not to distant future...perhaps Patrick and his avid kite boarder friend can try it out and send us a picture with some data. Pulling around a Willard 40 in La Paz would be in the least a good tourist attraction and perhaps even a fun YouTube video ;-)