Results 1 to 17 of 17

Thread: Radical Bay 8000

  1. #1
    Join Date
    Dec 2008
    Location
    Now cruising in the SUN! In Malta.
    Posts
    1,055

    Default Radical Bay 8000

    I have the pleasure of crewing and racing on the original Radical Bay 8000 here in Cape Town.

    Sailing a bi-rig cat is interesting, especially the tacking aspect which we perform as follows:

    When ready to tack, we dump the windward sail and turn with the leeward sail sheeted in hard. Not touching the rudders nor the dumped sail, she will turn through the wind. Once the wind catches the new windward sail she turns further to leeward and starts picking up speed. Only when she has picked up sufficient speed and we have rudder control do we slowly sheet in the new leeward sail.

    I have attached two pictures, the frontal view shows us having just rounded a racing mark doing approx. 15kts.
    Attached Images Attached Images
    Roger

    ------------------
    I look to the future, because that's where I am going to spend the rest of my life - George Burns

  2. #2
    Join Date
    Jul 2009
    Location
    'Estrella del Sur' is currently on the hard in Fort Pierce, Florida for hurricane season.
    Posts
    675

    Default Re: Radical Bay 8000

    Thanks Roger, I expect that Bigcat (who is building a similar rig) will be interested in both your experiences, as well as your description of the procedure in tacking.

    Brad

  3. #3
    Join Date
    Oct 2008
    Location
    near Seattle
    Posts
    1,116

    Default Re: Radical Bay 8000

    Quote Originally Posted by Southern Star View Post
    Thanks Roger, I expect that Bigcat (who is building a similar rig) will be interested in both your experiences, as well as your description of the procedure in tacking.

    Brad
    Indeed, I am. I have read this somewhere else, as well. I think it was in an account of a junkrigged biplane catamaran:

    http://www.duckworksmagazine.com/04/...ulls/index.cfm

    Of course, this is an example of the old style Hasler rig. The new style has camber, either through cutting rounds between the battens or through hinging the battens. The new cambered style junk rig sails to windward much better than the flat ones. There are lots of links about all this on my website.

    http://www.flickr.com/photos/25569561@N08/
    Currently concentrating on http://earthnurture.com .

  4. #4
    Join Date
    Dec 2008
    Location
    Now cruising in the SUN! In Malta.
    Posts
    1,055

    Default Re: Radical Bay 8000

    We went sailing today on "Smart One", the original bi-rig Radical Bay 8000, in winds from 3- 20 kts and seas up to lumpy 2m.

    After stuffing two tacks in 1m lumpy wave as per the above described method, a discussion and new ideas followed.

    We have now tried with success the following in flat seas:

    Upon the command of "tacking now" leave the sails as they are, once they are starting to flap release the sheets to both sails.

    After the boat has gone through the wind enough, start with slowly hauling in the new windward sail, then after she picks up speed and steering control haul in the leeward sail.
    Last edited by multihullsailor6; 15th November 2009 at 07:05 AM.
    Roger

    ------------------
    I look to the future, because that's where I am going to spend the rest of my life - George Burns

  5. #5
    Join Date
    Oct 2008
    Location
    near Seattle
    Posts
    1,116

    Default Re: Radical Bay 8000

    Quote Originally Posted by multihullsailor6 View Post
    We went sailing today on "Smart One", the original bi-rig Radical Bay 8000, in winds from 3- 20 kts and seas up to lumpy 2m.

    After stuffing two tacks in 1m lumpy wave as per the above described method, a discussion and new ideas followed.

    We have now tried with success the following in flat seas:

    Upon the command of "tacking now" leave the sails as they are, once they ae starting to flap release the sheets to both sails.

    After the boat has gone through the wind enough, start with slowly hauling in the new windward sail, then after she picks up speed and steering control haul in the leeward sail.
    I think that on all his boats Schionning doesn't design big enough rudders. Outboard rudders should be bigger than inboard rudders, as well, all else being the same, because they can suck down more air and lose some efficiency.
    Currently concentrating on http://earthnurture.com .

  6. #6
    Join Date
    Dec 2008
    Location
    Now cruising in the SUN! In Malta.
    Posts
    1,055

    Default Re: Radical Bay 8000

    Last weekend, on the Radical Bay 8000 "SmartOne" we participated in the Mykonos Race, a two-fold race:
    1) A coastal regatta from Cape Town to Langebaan / Saldanha Bay with a distance of 65mls
    2) On the next day a 26mls round-the-bay regatta within Saldanha Bay.
    We came first in class, with a GPS top speed of 21ks. Together with the delivery trip from Simon's Town round the Cape of Good Hope a one-way distance of 130mls.

    But more to the issue, we have refined the tacking issue:
    1) The rudders have been enlarged by about 10-15%
    2) We now tack this way:
    - Upon the "tacking now" command, release the windward mainsheet whilst keeping the leeward sheet tight
    - Once the boat has turned through the wind and the new windward sail has filled, release this sail for approx. 3 sec. to prevent stalling and let the bows move further downwind
    - Tighten the windward sheet
    - Once the boat has built up speed and the helmsperson has rudder control slowly pull in the leeward sheet.
    Doing it this way we didn't mess up a single tack.
    Roger

    ------------------
    I look to the future, because that's where I am going to spend the rest of my life - George Burns

  7. #7
    Join Date
    Oct 2008
    Location
    near Seattle
    Posts
    1,116

    Default Re: Radical Bay 8000

    Quote Originally Posted by multihullsailor6 View Post
    We came first in class...
    But more to the issue, we have refined the tacking issue:
    1) The rudders have been enlarged by about 10-15%
    2) We now tack this way:
    - Upon the "tacking now" command, release the windward mainsheet whilst keeping the leeward sheet tight
    - Once the boat has turned through the wind and the new windward sail has filled, release this sail for approx. 3 sec. to prevent stalling and let the bows move further downwind
    - Tighten the windward sheet
    - Once the boat has built up speed and the helmsperson has rudder control slowly pull in the leeward sheet.
    Doing it this way we didn't mess up a single tack.
    Congrats on your victory! I'm sure your boat is very light, and that may be why you have to adjust the sheets to tack. Heavier biplane rigs haven't reported needing to adjust the sheets when tacking. I wonder if even larger rudders would make the sheet adjustments unnecessary? How is the helm once you are properly on your new tack?
    Currently concentrating on http://earthnurture.com .

  8. #8
    Join Date
    Oct 2008
    Location
    near Seattle
    Posts
    1,116

    Default Re: Radical Bay 8000

    By the way, I have read that reverse rake, with the rudder bottom forward of the top, eliminates the problem of outboard rudders sucking air down and losing efficiency.
    Currently concentrating on http://earthnurture.com .

  9. #9
    Join Date
    Dec 2008
    Location
    Now cruising in the SUN! In Malta.
    Posts
    1,055

    Default Re: Radical Bay 8000

    Quote Originally Posted by BigCat View Post
    Congrats on your victory! I'm sure your boat is very light, and that may be why you have to adjust the sheets to tack. Heavier biplane rigs haven't reported needing to adjust the sheets when tacking. I wonder if even larger rudders would make the sheet adjustments unnecessary? How is the helm once you are properly on your new tack?
    She weighs only 800kgs empty and I guess 1,100kgs with crew and gear.

    We feel the deeper thus larger rudders are just right now, the loading does not seem to be any higher than before, even when screaming along. Also no air is being sucked in as the rudders are underslung.

    Still want to play around with the depth of the daggerboards, especially when going to windward to possibly decrease the leeway.

    And then maybe a reacher / gennaker flown from the windward mast for light to medium air reaching.
    Roger

    ------------------
    I look to the future, because that's where I am going to spend the rest of my life - George Burns

  10. #10
    Join Date
    Dec 2008
    Location
    Now cruising in the SUN! In Malta.
    Posts
    1,055

    Default Re: Radical Bay 8000

    Here are two pictures of us crossing the finishing line in Langebaan doing 15kts:
    Attached Images Attached Images
    Roger

    ------------------
    I look to the future, because that's where I am going to spend the rest of my life - George Burns

  11. #11
    Join Date
    Dec 2008
    Location
    Now cruising in the SUN! In Malta.
    Posts
    1,055

    Default Re: Radical Bay 8000

    Quote Originally Posted by multihullsailor6 View Post
    Still want to play around with the depth of the daggerboards, especially when going to windward to possibly decrease the leeway.
    Went out on (a fantastic) Sunday after having adjusted the daggerboard downhaul lines to the effect that we now have 30cm more daggerboard in the water. I have the feeling that, above a boat speed of around 6kts, she sits on "rails" and we have far less leeway. So all in all I am happy!
    Roger

    ------------------
    I look to the future, because that's where I am going to spend the rest of my life - George Burns

  12. #12
    Join Date
    Oct 2008
    Location
    near Seattle
    Posts
    1,116

    Default Re: Radical Bay 8000

    Looks like a seriously fun ride!
    Currently concentrating on http://earthnurture.com .

  13. #13
    Join Date
    Dec 2008
    Location
    Now cruising in the SUN! In Malta.
    Posts
    1,055

    Default Re: Radical Bay 8000

    Yep, with a few more tweaks we'll be serious competition for the Dragonflys or Farriers here - going to be fun competition once they stop breaking things!
    Roger

    ------------------
    I look to the future, because that's where I am going to spend the rest of my life - George Burns

  14. #14
    Join Date
    Dec 2008
    Location
    Now cruising in the SUN! In Malta.
    Posts
    1,055

    Default Re: Radical Bay 8000

    Here's another photo of us in this year's pursuit race in Saldanha Bay on the second day when a large flock of birds flew close past us.
    Attached Images Attached Images
    Roger

    ------------------
    I look to the future, because that's where I am going to spend the rest of my life - George Burns

  15. #15
    Join Date
    Oct 2008
    Location
    near Seattle
    Posts
    1,116

    Default Re: Radical Bay 8000

    Pretty photo. Cormorants, maybe?
    Currently concentrating on http://earthnurture.com .

  16. #16
    Join Date
    Dec 2008
    Location
    Now cruising in the SUN! In Malta.
    Posts
    1,055

    Default Re: Radical Bay 8000

    Quote Originally Posted by BigCat View Post
    Pretty photo. Cormorants, maybe?
    Sorry, BigCat, but I flunked my biology classes at school back when and am still not that interested ....
    But it was a strange feeling seeing this enormous flock of birds fly past not more than 10m away. We clearly disturbed their siesta on the water!
    Roger

    ------------------
    I look to the future, because that's where I am going to spend the rest of my life - George Burns

  17. #17
    Join Date
    Dec 2008
    Location
    Now cruising in the SUN! In Malta.
    Posts
    1,055

    Default Re: Radical Bay 8000

    Yesterday we sailed the Radical Bay 8000 back from Langebaan to Cape Town, roughly 70 miles in a S /SSE direction. We chose the day well as a NW wind, 10 - 25 kts, was forecast and it happened like that, though the higher winds only came two hours later than forecast. Sea state was mild for the first 6 hours. We had full sails up all the way. We averaged 8 - 10 kts for the first 3 hours, thereafter in the stronger winds we averaged 13 - 15 kts and completed the trip in just under 7 hours.

    It was a FUN trip, especially the second half, overtaking the 1 - 1.5m waves and surfing down the wave fronts and staying dry. The waves in Table Bay itself, once past Robben Island, were very lumpy, wave height rising to 1.5+ m and becoming much shorter - in fact the skipper remarked he had never seen such a lumpy see in Table Bay after 30 years of sailing here! But this little cat took it all in its stride, even at 15 kts never burrying its lee hull in a wave, lifting when the water reached the deck - very impressive and assuring!
    Roger

    ------------------
    I look to the future, because that's where I am going to spend the rest of my life - George Burns

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •