Page 2 of 2 FirstFirst 12
Results 36 to 37 of 37

Thread: Anchor Kit

  1. #36
    Join Date
    May 2016
    Location
    Ottawa, Canada
    Posts
    529

    Default Re: Anchor Kit

    Quote Originally Posted by Peerie Maa View Post
    Generally anchors scale geometrically. Foe 1/8th of the mass, halve all the dimensions. It is the pull on the rode that sets the anchor, which is why the geometry must be just so.
    Hey Nick,
    I've been thinking a bit about this scaling thing, and my hypothesis is based on some sort of analogy to a "Reynolds Number". The "fluid" (sand / mud / gravel) size doesn't also scale with the anchor size, so a bigger anchor has an easier time setting. Maybe we need some smart PHD student to do a study !
    Cheers,
    Mark

  2. #37
    Join Date
    Oct 2008
    Location
    Walney, near Cumbria UK
    Posts
    55,378

    Default Re: Anchor Kit

    Quote Originally Posted by Mark0 View Post
    Hey Nick,
    I've been thinking a bit about this scaling thing, and my hypothesis is based on some sort of analogy to a "Reynolds Number". The "fluid" (sand / mud / gravel) size doesn't also scale with the anchor size, so a bigger anchor has an easier time setting. Maybe we need some smart PHD student to do a study !
    Cheers,
    Mark

    Fishermens style anchors have been found from the Viking era, so there is shed loads of empirical data for them. THere was research carried out in the era of flying boats that resulted in the lightweight designs. Bruce built on this work when developing his range of crows foot boat anchors and the big anchors used by the oil industry. Big ship stockless are another issue. HHP anchors are not bad, but the other patterns like Halls are more or less clump weights used to lay out enough chain for the friction of the chain on the bottom to hold the ship.
    The key issue was found to be fluke angle, which needed to be adjusted for a soft mud bottom or a harder sand, gravel, cobble bottm.
    In additiion to fluke angle, big palms, and sharpening leading edges to allow theem to cut into the bottom are important. It is always going to be broad brush engineering as bottom mechanics are so variable, from soft mud through to hard bolder clay
    It really is quite difficult to build an ugly wooden boat.

    The power of the web: Anyone can post anything on the web
    The weakness of the web: Anyone can post anything on the web.

Posting Permissions

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