Were these reverse three-pointers simply built too light?

Discussion in 'Boat Design' started by RatliffFranklin, Jan 30, 2007.

  1. RatliffFranklin

    RatliffFranklin Previous Member

    The reverse three-pointers of John Cobb and Lee Taylor seemed to have solved the problem of blowover.

    John Cobb clocked 204 mph through the kilo on his last run with Crusader.

    http://www.boatdesign.net/forums/showthread.php?t=15460

    Lee Taylor clocked 269 mph through the kilo on his last run with Discovery II.

    http://www.boatdesign.net/forums/showthread.php?t=15461

    The crashes occurred after the boats left the kilo.

    Crusader was about 30 feet long and weighed around 5,000 lbs, but about 3,000 lbs of that was jet engine.

    Discovery II was forty feet long and had an empty weight of only 2,500 lbs.

    The designers had cautioned Cobb that the front planing surface needed reinforcement but Cobb believed if he ran conservatively enough the existing hull structure would be adequate. The consensus is structural failure of the forward planing surface caused the crash.

    Aside from the fact Discovery II was being run in conditions too rough for the hull, the designers believe the rudder locked and submerged the left sponson enough for the stress to rip it apart.
     
  2. Pericles
    Joined: Sep 2006
    Posts: 1,948
    Likes: 106, Points: 63, Legacy Rep: 1307
    Location: The heights of High Wycombe, not too far from Rive

    Pericles Senior Member

    Built by trial and error.

    Pericles
     
  3. Dan Ellison
    Joined: Dec 2006
    Posts: 59
    Likes: 7, Points: 0, Legacy Rep: 86
    Location: pheonix az.

    Dan Ellison Junior Member

    Why aren't ATV's made as 3 wheelers any more? Because it is an unstable platform.
     
  4. balsaboatmodels
    Joined: Jan 2007
    Posts: 43
    Likes: 1, Points: 0, Legacy Rep: 17
    Location: Boonville, MO, pop.8700; & 415 buildings on Nation

    balsaboatmodels Junior Member

    Built by Trial and Error

    Is it just me, or does it some days seem more like "Error And Trial"?

    FSW
     
  5. FranklinRatliff

    FranklinRatliff Previous Member

    Bluebird

    I don't think it's quite that simple, but the fact Campbell's Bluebird achieved 200 mph not only with less effort than Cobb's Crusader but on less power and without destroying itself in the process probably says something about conventional three-pointers versus reverse three-pointers.
     

  6. FranklinRatliff

    FranklinRatliff Previous Member

    WSR Boats

    I think with WSR boats most days are more error than trial.
     
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.