Bow anchoring.

Discussion in 'Multihulls' started by fallguy, Oct 10, 2020.

  1. fallguy
    Joined: Dec 2016
    Posts: 3,491
    Likes: 476, Points: 93, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Has anyone ever used two anchors off the bows of a cat? Or am I missing an obvious problem.

    Are they still sized for one or can they be sized down?
     
  2. tevake118
    Joined: Jan 2013
    Posts: 19
    Likes: 1, Points: 3, Legacy Rep: 10
    Location: Goodland, Fl.

    tevake118 Junior Member

    Hi Fallguy;
    There are some cruising cats with double bow anchor rollers, but what happens ( when both anchors are set, say at 60-90 degrees to each other) if the wind changes 180 degrees? Or worse, goes around the clock? One rode gets wrapped around the other... Also, as we know now, cats need anchor bridles to reduce yawing, which (see Practical Sailor - several articles) frequently dislodges a well-seated anchor by causing the surrounding solidly packed substrate to become looser. Are you going to have two bridles, too? Are you going to have both rodes going to a big swivel, and then on up to the bow roller? Are you going to be ok with unwrapping one (chain) from around the other? Oh, and, what about that windlass; how is it going to manage two rodes? It seems to me that the only feasible solution would be to have the second anchor about one half the weight, and on a short length of chain, so you could then disconnect the nylon, and untangle it from the main rode. But then that second anchor cant be expected to take over the function of the main anchor, if needed...
    And bow and stern anchors create their own problems, too. Especially when the wind goes abeam...
    So, some have tried going to tandem anchors - in train, one ahead of the other, but on the same rode. This has been shown to not work, as there is alternating loading, causing less than the sum of the parts.
    Also, catamarans shouldnt have a lot of weight up near the bows, you know..
    So, I believe today we multihullers usually put our security in one extra heavy. modern anchor design, like a Rocha, Mantus Supreme, Spade, Fortress, etc.. And keep a second anchor as back up; ready to dump in an emergency; and a third - maybe - to serve as a lunch hook, and for kedging off from the dinghy.
     
    fallguy likes this.
  3. fallguy
    Joined: Dec 2016
    Posts: 3,491
    Likes: 476, Points: 93, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    How about a single anchor on a bow? I am heavy to starboard, so I could put an anchor on the port bow. Or does this get wild in a wind?


    I want my netting area clear. This is a powercat. I can probably run an anchor out the bottom of the forward lockers, but access then is physically harder for a grassed up anchor; and the hawse is in the wet zone in any heavy stuff.
     
  4. fallguy
    Joined: Dec 2016
    Posts: 3,491
    Likes: 476, Points: 93, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Also, at the current time, I foresee limited need for the stone. I don't even plan to buy a windlass. Just plan to spot the location. I have a place for a conventional anchor hung on the middle of the netting beam.
     
  5. bajansailor
    Joined: Oct 2007
    Posts: 1,303
    Likes: 374, Points: 83, Legacy Rep: 37
    Location: Barbados

    bajansailor Marine Surveyor

    You could keep your anchor mounted on a roller on the port bow, or inside the locker if you want to get the weight a wee bit further aft.
    Once you have deployed it, assuming you are using a rope cable with a short length of chain, then you can attach another rope on to the anchor rope with a rolling hitch and take this other rope to a cleat on the starboard bow so that the boat is sitting to a bridle.
     
    fallguy and hoytedow like this.
  6. fallguy
    Joined: Dec 2016
    Posts: 3,491
    Likes: 476, Points: 93, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    This is good stuff. I want some weight on the port bow. Pretty sure I am stern heavy to starboard. All my rode and roller and anchor can go up on the port bow, which, by happenstance, is also not yet painted.

    I will need to determine how/where to bridle and how to tie this rolling hitch.

    Thanks.

    I have a picture on the way.
     
  7. fallguy
    Joined: Dec 2016
    Posts: 3,491
    Likes: 476, Points: 93, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Instead of a picture, a question.

    if I were to bridle off the roller on one side; then does the other side also need to come stright off the bow?

    or am I entirely confused about bridle ropes

    U dun't know wat ur doin James; ur gonna destroy the ship!
     
  8. Blueknarr
    Joined: Aug 2017
    Posts: 980
    Likes: 200, Points: 43
    Location: Colorado

    Blueknarr Senior Member

    I drew twin bridles. They could attach anywhere on the inside of the bows. Avoid the chaffing of attaching to the outside.
    Make the bridle lines longer than the boat's width. Then all of the tying can occur from a single bow. It's a bit lubberly but when not in use the bridle can be left stretched from bow to bow.
    If the points of attachment are not even, then uneven bridle lengths can offset the difference. BUT it is far trickier!
    I use twin bridles on monohulls to avoid chaffing on the pulpit roller. The anchor rhode is slack from the bridle to the roller.
     

    Attached Files:

    Last edited: Oct 10, 2020
  9. fallguy
    Joined: Dec 2016
    Posts: 3,491
    Likes: 476, Points: 93, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Can I bridle from the bow eye? I don't care about lubbery. I might even keep the boat on the tide line.
     
  10. Blueknarr
    Joined: Aug 2017
    Posts: 980
    Likes: 200, Points: 43
    Location: Colorado

    Blueknarr Senior Member

    Bow eyes work OK.
    Using a deck cleat allows for some adjustments and are usually easier to reach than most bow eyes.
     
  11. fallguy
    Joined: Dec 2016
    Posts: 3,491
    Likes: 476, Points: 93, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    I have them up there as well, but I think I'd need some chafing guards.
     
  12. fallguy
    Joined: Dec 2016
    Posts: 3,491
    Likes: 476, Points: 93, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    your picture would not be a rolling hitch; how do you connect the bridle to the deployed anchorline?
     
  13. Blueknarr
    Joined: Aug 2017
    Posts: 980
    Likes: 200, Points: 43
    Location: Colorado

    Blueknarr Senior Member

  14. bajansailor
    Joined: Oct 2007
    Posts: 1,303
    Likes: 374, Points: 83, Legacy Rep: 37
    Location: Barbados

    bajansailor Marine Surveyor

    Regarding the rolling hitch on the animated knots site - I see that they only do one round turn before the locking hitch.
    I always do two turns.
    And if the rope is new and slippery, then you could even do an extra turn - they do mention that the knot can slip (especially so I would think if you only use one round turn).
    Rolling Hitch https://www.animatedknots.com/rolling-hitch-knot

    You could use an existing bridle, but you can just as easily make a bridle with two equal lengths of rope using the anchor cable and the rope going to the starboard cleat.
     

  15. Blueknarr
    Joined: Aug 2017
    Posts: 980
    Likes: 200, Points: 43
    Location: Colorado

    Blueknarr Senior Member

    Yes only one additional line is nessicary. It should have the same stretch as the anchor rhode.

    The premade bridle allows:
    - slack in anchor rhode to prevent chaff at roller
    - use of all chain rhode
    - position of bridle at more convenient location
    - bridle can be of smaller diameter with two lines carrying the load
     
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.