Quant 28-foil assist keelboat / DSS

Discussion in 'Sailboats' started by Doug Lord, Jun 10, 2011.

  1. Doug Lord
    Joined: May 2009
    Posts: 16,555
    Likes: 295, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Cool 28 footer designed to use DSS-a sliding ,retractable horizontal foil that develops righting moment when deployed to leeward. One of the most advanced forms of monohull keelboat foil assist currently being developed! This is the kind of technological development that is going to change monohull keelboat speed and performance big time...... http://www.quant-boats.com/home.html

    from designer Hugh Welbourn:

    Its won its first couple of races and seems quick - 17 knots in about 14 TWS but its early days and getting sails sorted will improve things a bit.

    Off to Geneva this week to sail the Rolle and then Bol d'Or on the boat and then we'll see how we make out against the bigger quick boats.




    googlease translation-company blurb:

    QUANT28 is the boat for a performance-based and speed-drenched audience of experienced sailors than we thought. The boat enthusiastic people who want to participate in races open the one hand, but the kick off the race course are also looking. People who not only demanded but also boat will want to reward her by - with a rating, which for sailing boats of this size and nature seemed unthinkable just before, such as the VPP data show.
    The QUANT28 is not a boat for beginners. Experienced sailors are the requirements that the boat is on his side, however, gladly accept. Once familiar with the boat, they will love it for its performance.

    Key facts:

    The whole boat is built in Carbon (vacuum method)
    Similarly, all fins, the rig and retractable racks
    Built-in storage space for engine and equipment
    The wing extends into middle position on the boat and is hardly without tools from the boat to remove
    For storage, transportation, etc. The same to the windward mark for the plug-in rowing
    The boat can be a ramp geslippt



    =====================
    Specifications:
    --
    LENGTH 28'

    WIDTH 190 cm / 6.23' // 350 cm/11.48' ,rack extended

    WEIGHT 550kg empty w/o sail / 1210lb

    BALLAST 180kg / 396lb

    SAIL AREA 44.5 m 2 ( upwind) / 478.8 sq.ft
    --GENNAKER 80m 2 approx / 860 sq.ft

    SA thread: http://forums.sailinganarchy.com/index.php?showtopic=122886&st=0&p=3293773&#entry3293773



    click on image:
     

    Attached Files:

  2. sharpii2
    Joined: May 2004
    Posts: 1,866
    Likes: 86, Points: 48, Legacy Rep: 611
    Location: Michigan, USA

    sharpii2 Senior Member

    This design seems far more practical and workable than the 180 deg. canting ballast.

    It appears the foil is being used to increase righting arm rather than to lift the hull out of the water.

    The beauty of this is that:

    1.) if the foil is on the wrong side, it does little harm (unlike the extreme canting ballast) and
    2.) it is high up and protected somewhat by the keel, or at least the bottom of the boat.
     
  3. CutOnce

    CutOnce Previous Member

    Agreed on this ... but ...

    The increased righting moment gained through this foil is used to justify increasing sail area and rig power to the point where the DSS foil-created increased righting arm is necessary to balance the boat under normal conditions. If the foil is on the wrong side, the rig overpowers the boat without the foil and guess what is likely?

    This is somewhat less dangerous than the 180(+) degree canting keel, but to produce power and speed potential beyond today's top yachts, there are always increased risks.

    --
    CutOnce
     
  4. Doug Lord
    Joined: May 2009
    Posts: 16,555
    Likes: 295, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Dss

    =================
    According to the designer, it's being used to do both. What I'm having a hard time with is : how do you keep the foil immersed enough(2.5 chords) is a seaway? And how do you do it w/o any leeward component to the lift? Does leeway adversely affect the production of lift?

    If the foil was 4.62' long with an 8" chord, a 63412 section with a .6CI(just within the drag bucket) it would develop about 737 lb of lift 2' from the side of the boat at 12 knots-not too shabby......(assuming no negative affect from leeway or proximity to the surface).
    In addition ,the vertical lift would result in an approximately 8% reduction in wetted surface
    or 7.125 sq.ft(est.), slightly better than the 6 sq.ft. of the foil.....

    pix-DSS foil but not on Quant-click on image:
     

    Attached Files:

  5. sharpii2
    Joined: May 2004
    Posts: 1,866
    Likes: 86, Points: 48, Legacy Rep: 611
    Location: Michigan, USA

    sharpii2 Senior Member

    My guess is when the foil gets closer and closer to the surface, it produces less and less lift until it reaches a sort of equilibrium. If the boat manages to go even faster, the bottom surface of the foil may simply plane. The beauty of this system is that if the foil's lift fails for any reason, the boat merely gets knocked down.

    As Cut Once has pointed out, the main purpose of the foil is to enable the boat to carry more sail. But if the foil fails, or gets stuck on one side, the sails can always be reefed, leaving the skipper and crew a still seaworthy boat. Because, on the wrong side, most of the foil would be out of the water most of the time.

    When you talk about real innovation, this boat is a good example.

    If the foil counteracts heeling, it by definition, also lifts the hull to some degree, much the same way a float on a trimaran does.
     
  6. Doug Lord
    Joined: May 2009
    Posts: 16,555
    Likes: 295, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

  7. Doug Lord
    Joined: May 2009
    Posts: 16,555
    Likes: 295, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Quant 28

    From Hugh Welbourn on SA today:

    Rolle race was good learning curve for the boat and in fact on TCF corrected then 2nd class/2nd overall out of 240 boats and as a w/l course mostly and not having any reaching time then pretty pleased. Sure is quick in the light, and we know a bit of power reaching its seriously quick. Amongst similar boats...then the tricked up T30 with trapezes and canting keel got away well at the start but once we got going we sailed up, past and then away from them all the time - at the Rolle mark we were sandwiched between the old Full Pelt ( water ballast ) and new one ( canter and 5 trapezes ) and having raced on both of those then that was fun:))
    They got away downhill but few knots more wind for us to get up and whizzing, or less and then waterline length not really counting and reckon we would have hung in with them.

    Bit of an extract from Michi on the race....


    But back to the race of saturday

    it was quite hard to get of the starting line. no wind and all the big boats (here that means 12 to 14m and huge rigs, like cathedrals) in the spot we had to go also. so just waiting desparately for about 10 minutes to get some air to move the boat at least some m.
    then slowly the bigger boats got away some 100meters and we also started the little rocket with the help of the new headsail (pole half out, up to the top and clew to the middle of racks, sheeting point same as for chute) we got from North-Sails with the help of Kos. after 20minutes we could sail the course we liked to and we started to catch up very very quickly. in fact by then we were the fastest monohull at all. so we sailed along the shoreline and passed one boat after the other on leeward side. after maybe 1 hour we got the lead over all monohulls. all the boats of our size were out of sight totally. we just sailed up the lake by ourselves. i had to concentrate very hard as Kos is quite a tough teacher, shaking is head, when i am not keeping the boat on the proper course (too deep or too high:).
    we sailed about 5.5 to 7.2kts in maybe 3 - 4 kts of breeze. but it is quite hard to estimate true windspeed as you sail almost completely on the apparent wind. then this breeze seems to be dying for some minutes, what was good for us. we extended the lead. slowly the direction of the airflow changed and after some other minutes we were on a real upwind course which of course was not ideal for as us also windspeed was picking up. by then we had to sail another fourth of the course to the first mark. we peeled sails to the basic jib sailing up to 7kts of bsp. then we put out the foil as it got choppy as the waves going on the shore came back out where we had to sail. Nevertheless we raised speed up to 7.3kts. (in my better moments at the tiller - Kos was gettng nervous). i love how this boat is going upwind. it was nice to sail like this but for this race it was a bit too much or too less of windspeed for us. further out 5 or 6 of the bigger boats came up slowly and passed us on weather. we had to tack two times and the hobbycats came down crossing us - a lot of turbulence. we rounded the mark 4.10 pm. hoping to catch up going completely on the foil while reaching. in the first moments we had a few surfs but we saw that it will be not enough going on the foil really. we changed on the big kite. the race more and more turned out to be a real up and down course and the wind was dropping again instead of increasing. it took us about another 2 hours to go back to Geneva, gybing 4times i think and Kos was driving the last part as i got tired a bit. I enjoyed sailing in this quiet and pleasant mode although i was hoping for more wind or a change of a wind direction. sailed real time we ended up as 8th monohull (out of about 320). in our division second elapsed and second corrected. the one boat in front of was a 42 footer with a huge rig ( which should sail in the big-boat division - but he maybe found out to be able to win in our division - you know sailing with rating coefficients is like this.....) it was displacement sailing where length is the thing to have.
    as a conclusion: this second place is of big value for us as we know now that this boat is incredibly fast even in conditions not ideal for the boat. All the more as we were too heavy for the conditions maybe.
    sailing back into the harbour of the SNG the guys of the big boats were cleaning their yachts - all of them put away what they were doing for a moment looking us passing to our berth, surprised and wondering what tha means. they have to get used to the fact that even small boats can beat them. And if you analyse the time sheets it shows the quite amazing performance of the Q28. not to think about the same situation going downwind in a bit more of wind....
     
  8. Tanton
    Joined: Nov 2003
    Posts: 992
    Likes: 17, Points: 28, Legacy Rep: 294
    Location: Newport RI

    Tanton Senior Member

    Hydroplaning Wing Sailing Craft.

    Using hydroplaning surfaces with the emphasis given to reduce drag.
     

    Attached Files:

    1 person likes this.
  9. Doug Lord
    Joined: May 2009
    Posts: 16,555
    Likes: 295, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    ----------------
    Thanks, Yves-Marie. Could you elaborate a bit more on the design? Its hard to understand with just that view.
     
  10. Doug Lord
    Joined: May 2009
    Posts: 16,555
    Likes: 295, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

  11. Tanton
    Joined: Nov 2003
    Posts: 992
    Likes: 17, Points: 28, Legacy Rep: 294
    Location: Newport RI

    Tanton Senior Member

    Hwsc

    Hydroplaning Wing Sailing Craft.
    Abstract from Palmquist Patent Document 1982-1987.
    "A HWSC comprising a single buyoant hull having mounted transversely across the hull a hydroplaning wing having forward sweep and inverted gull wing shape. The wing having a positive angle of incidence providing hydroplaning lift and buyoancy to counteract the heeling moment and thrust of the sail."
    The rendering is an excersize to see what it could look like on a 24 footer.
     

    Attached Files:

  12. Doug Lord
    Joined: May 2009
    Posts: 16,555
    Likes: 295, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    =========================
    Very interesting! Would the windward foil pull down?
    The problem I see with DSS -and that is obvious on the video is the problem of keeping the foil underwater. However, maybe they've found that the gains outweigh the drag and perhaps partial immersion is ok. The boat appears fast in the video.

    ==============
    I thought I remembered this from earlier- http://www.boatdesign.net/forums/sailboats/hugh-welbournss-dss-25-a-32138-2.html
     
  13. Tanton
    Joined: Nov 2003
    Posts: 992
    Likes: 17, Points: 28, Legacy Rep: 294
    Location: Newport RI

    Tanton Senior Member

    Hwsc

    The wing is in one piece. From side to side. Would be complicated to articulate.
     

    Attached Files:

  14. Doug Lord
    Joined: May 2009
    Posts: 16,555
    Likes: 295, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    ===========
    What is your thinking on how the foil would work ideally?
     

  15. Tanton
    Joined: Nov 2003
    Posts: 992
    Likes: 17, Points: 28, Legacy Rep: 294
    Location: Newport RI

    Tanton Senior Member

    Hwsc

    First: any hull shape could be utilized with this invention. The rendering shows a dinghy wraped around the original very narrow hull. This for show.
    Second: the hydroplaning wing, with buoyancy producing lift is placed in opposition to the total effort of the sail.
    Third:the boat at speed, rocks on its wing tip, while the hull is barely skimming the waves. Hull drag decreases because of less wetted surface, while the wing drag decreases being inversely proportional of the velocity.
    Reference: Wingmaran by M.J Palmquist. US. Patent delivered in 1987.
     

    Attached Files:

    Last edited: Jun 21, 2011
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.