Please suggestion on anchor system

Discussion in 'Boat Design' started by the brain, Jan 3, 2017.

  1. the brain
    Joined: Sep 2016
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    Location: AL

    the brain Senior Member

    Please suggestion on anchor system

    I’m in the process of making a bow anchor holder/roller for my aluimin crusier.

    The holder is a 2 ½’ modified aluimin I-beam w/ trailers bow stop for roller.
    Couple of ?s

    ?1.How wide should the marine 3/4”plywood be under closed bow inbetween securing bolts?

    ?2.will this holder need two rollers?

    ?3.can I get bye w/ securing the chain w/ a heavey duty bunge cord for tension then add small just in case cord?

    I was planning to feed the rode though the hatch.

    ?4. should the aluimin hatch be covered w/
    Plastic to prevent the rope from being ruined?

    I plan to connect rope to shakel to galvanized chain

    ?5.What is used for rope seizing?

    edit I plan to smooth down the corners of I-beam.

    Thanks for advice STB
     

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  2. the brain
    Joined: Sep 2016
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    the brain Senior Member

    I have a threaded rod holding the top bow lifteye connected to the lower bow lifteye will this anchor holder be stronge enough as is or should I add a few stainless bolts toward the front?
    Thanks STB
     

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  3. Nick.K
    Joined: May 2011
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    Location: Ireland

    Nick.K Senior Member

    How long and heavy is your boat?
    Where and for how long do you intend to use the anchor?
    What will the chain/rode be attached to when you anchor?
     
  4. the brain
    Joined: Sep 2016
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    the brain Senior Member

    boat was orginalley 22' long I've added 2' w/ my engine bracket.

    fully loaded w/ gear/fuel/water ect. 2450LBs.

    I plan to anchor for overnight camps in harbors. then next anchorage will be in the Gulf of Mexico Destin, FL right where the wall starts

    (20 miles out where the depth. drops from 90' to 200' I want to anchor in the 90' and adjust the rode so I can bottom fish in the deep blue water.

    The actualle end of the rode will be attached to the top lifteye (that's basicalley holding down the holder.

    I do plan to add a cleat directely behind the holder to tie off at the adjusted desireable spot.

    Thanks STB
     

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  5. Nick.K
    Joined: May 2011
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    Location: Ireland

    Nick.K Senior Member

    It looks from your pictures as if you have cut the flange of the section at the end to widen it out?
    When anchored, the boat will shear from side to side which puts a heavy twisting force on the bow roller, especially one that sticks out as your does. Much of that force is transferred to the flanges which hold the chain on to the roller. If the flange gives way it can fold back and make an effective scissor for a rode...this isn't theory, I cut up a €200k yacht that finished on the rocks exactly this way.
    I can't advise on bolts etc but even for a small boat, to me the fitting looks too light and inadequately fastened especially if you are thinking of spending nights on board.

    How thick is the deck? If it was mine I'd be looking to fit an aluminium backing plate in say 6mm (1/4) under the deck that would go from the bow to say 6inch behind the anchor cleat and I'd bolt all the equip through the backing plate. I'd try to fit it to exclude a water trap between the plate and the deck. I'd remake the roller in heavier material and try to bolt it as close as practical to the bow as well as at the inboard end.
     
  6. the brain
    Joined: Sep 2016
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    the brain Senior Member

    actually I received the I -beam cut like that where you think it was widened abd you correct it doe's look weak.

    the closed bow deck is aluimin a tad less than 1/8" I was concidering adding a plate under the deck however the threaded rod would force me to slot the backing piece weakening it.

    mite be a good idea to add a couple bolts to minimize the twisting.

    if I feel the holder is under to much strain like you say it could twist off

    I will then grab rode in front of the holder and tie directely to either one of my front cleats relieving the preasure on the holder.

    I main objective I wanted to tidie up the deck inside the cuddy and have a dissinated place for the anchor.

    what do you think?

    I usalley get my aluimin from the scrape metal yard so I'll be on the lookout for a stronger I-beam for the next holder.
    STB
     
  7. Nick.K
    Joined: May 2011
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    Location: Ireland

    Nick.K Senior Member

    The anchor is a pain to stow inside,..yes
    Have you got a plan for fixing it in to the roller so it can't come out if you hit a heavy wave? What will you do with the chain / rode...you don't have a pipe fitting? Will you disconnect or leave them through the hatch? Open hatch = wet bunks? A strong cleat mid deck behind the anchor could be a good idea.

    Have you thought of storing the anchor and chain/rode aft? Keeps weight off the bow, no dirt inside, no problem with open hatches and no possibility of anchor or rode being washed overboard and mashing up your prop or worse.
     

  8. the brain
    Joined: Sep 2016
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    the brain Senior Member

    yes I don't like the idea of the rode going though the hatch what is a pipe fitting I'm assuming it's another hole in the bow that's water tight for the rode to go though? do you have any images of said pipe fitting?

    I use two anchors would prefer to keep the #8 dansforth up front.

    the rear anchor I throw at offshore oil rigs// bridges ect. then tie off to the front.

    I basicalley don't want anything on my rear deck that people can trip on I like a clear deck. currentely the rear anchor is well inside the back of transom nicely tucked away.

    My engine makes very good power so I kindof want more bow weight plus I prefer extra tongue weight while towing.

    edit are you concerned the anchor isn't secure in the holder even w/ the strip over it's top?
    STB
     
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