Parachute Anchors, Para-Anchor, Sea Anchor

Discussion in 'Boat Design' started by brian eiland, Feb 12, 2006.

  1. brian eiland
    Joined: Jun 2002
    Posts: 5,067
    Likes: 216, Points: 73, Legacy Rep: 1903
    Location: St Augustine Fl, Thailand

    brian eiland Senior Member

    Photo of that Book Cover

    I've long ago lost that book I mentioned as having a profound influence on my way of thinking about ultimate storm survival at sea. I just found a photo of the cover of that book (and a few copies on Amazon).
     

    Attached Files:

  2. tspeer
    Joined: Feb 2002
    Posts: 2,319
    Likes: 303, Points: 83, Legacy Rep: 1673
    Location: Port Gamble, Washington, USA

    tspeer Senior Member

  3. bntii
    Joined: Jun 2006
    Posts: 731
    Likes: 97, Points: 28, Legacy Rep: 1324
    Location: MD

    bntii Senior Member

    Brian- I was very impressed with the Jordan series drogue:

    http://www.jordanseriesdrogue.com/

    I assume you have looked into the gear?
    If I ever get my butt out to sea again I will be bringing one without question.
     
  4. brian eiland
    Joined: Jun 2002
    Posts: 5,067
    Likes: 216, Points: 73, Legacy Rep: 1903
    Location: St Augustine Fl, Thailand

    brian eiland Senior Member

    To me it is sort of equivalent to carrying that full battened mainsail for too long as the wind and seas really rise. Now its pinned against the mast and spreaders with little hope of getting it down without considerable other help,...or find a way to get turned back upwind in order to get the sail either down or at least reefed. Now you've got trouble.

    Relying on a drogue device can lull you into a somewhat similar false sense of security. Now how do you get it reeled in as things get progressively worst? And what do you put out next?

    Don't get me wrong, drogues work (very well in many instances), they are just not my answer to the ultimate case.
     
  5. bntii
    Joined: Jun 2006
    Posts: 731
    Likes: 97, Points: 28, Legacy Rep: 1324
    Location: MD

    bntii Senior Member

    I would defer to the work done on the series drogue as being just that- the answer for the 'ultimate case' and find the Jordan gear to be a separate case from the family of drogue tactics:

    http://www.oceanbrake.com/Resources/CG-D-20-87.pdf


    It is my belief that a parachute will not deal adequately with large breaking seas and will leave the vessel vulnerable and in need of the next layer of defense.

    Vessels have been lost when shock loads overcame the bridles and attachments for vessels using chutes.
     
  6. Frosty

    Frosty Previous Member

    Sea anchors and droges are two different things,-- Conversation seems to be overlapping a bit. A drogue can be made from anything being dragged out the back even a deck chair or some tires, ---anything. Even a sunken dinghy.

    A chute is a frightening thing to handle , advertisements make it look easy. Imagine fighting a spinaker on deck in force 9. getting it out is another, youlle probably have to cut the line.
     
  7. brian eiland
    Joined: Jun 2002
    Posts: 5,067
    Likes: 216, Points: 73, Legacy Rep: 1903
    Location: St Augustine Fl, Thailand

    brian eiland Senior Member

    I read rather quickly thru this document you referenced, and I was not impressed. In first place there is much talk about the cyclic loading that will take place with drogue systems....many cycles in a full blown storm. Then there is the fact that you will likely have to abandon the cockpit (at least aft ones) on most vessels when the seas start to get really big. And you would have to have a waterproof companionway hatch to keep those following seas out while you are stuck down below.

    I spent 3 days surfing BIG seas one time in my old wood ketch. There were times I wanted to go faster and times I wanted to slow down. There was a time when I slowed down to much (took down all sail), and the wave tops were breaking into the cockpit floor and splashing down the companionway, and flooding my engine room (brand new Perkins I'd just installed!). I became unhappy with this situation and rehosted my small staysail to gain a little speed. I don't see this amount of speed adjustment with a drogue situation, unless you have had very considerable testing of the specific size and style drogue (per that document) for the particular vessel size and displacement. And even then your speed is not that controllable.

    I also see the vessel itself covering a lot of ground during the storm (with a drogue), unlike the parachute situation. This might be a problem considering proximity to land masses or other vessels out on the ocean at the time (and I'm hiding out down below because the cockpit is unusable?)

    I had two other problems with that paper.
    1) It devoted a total of ONLY one paragraph to the deployment off the bow of a storm device.
    2) It contained NO references to actual real life deployments.

    I would recommend you get some sort of access to that DragDeviceData book mentioned by Tom Speer above
    DragDevice Data Base, using parachutes, sea anchors, and drogues to cope with heavy weather. 70 documented case histories
    http://www.amazon.com/Victor-Shane/e/B001K8BSAM/ref=ntt_athr_dp_pel_1

    If i remember correctly many of those real life experiences were also in that book I wrote about. And a number of those were from all walks of life, including commerical fishing vessels and multihulls, in severe conditions. That documentation is what made a believer of me.
     
  8. bntii
    Joined: Jun 2006
    Posts: 731
    Likes: 97, Points: 28, Legacy Rep: 1324
    Location: MD

    bntii Senior Member

    Both devices (a series drogue or chute), are essentially stopping the vessel and both must be sized correctly to be of use.

    The important point of departure between the two approaches to my mind lies in the response of the vessel to a large breaking sea. I prefer the elastic response of the Jordan gear to the chute.
    This point is the important one when considering the "ultimate case" and less so for all the sundry uses where exhaustion or other factors may make one chose to quit active sailing.
    Of the various secondary tradeoffs I rank the ease of deployment, total elimination of chafe and shock loads, and protection of rudder over having the cockpit exposed to boarding seas.

    I think this passage is perfectly ideal for the use of a series drogue and may have made you a sworn advocate had you been carrying one:

    "I’m sailing from the Chesapeake Bay down to St.Thomas, USVI on Christmas eve in a heavy full-keel 47 wood cutter staysail ketch. I know there is a storm approaching, but I figure if I can get out past the Gulf stream (avoid the northerly wind against the north flowing current) before it hits, then I will ‘run’ with the wind and waves in the open ocean. It turns out to be a much more intense storm than predicted with a very intense center that moves just north of Bermuda. I experience 60-70 knots of wind for two and a half days. I am surfing BIG but organized seas using a hankerchief-size staysail. It’s reported that two other vessels nearer the center of the low pressure are sunk in the same storm. I have two other inexperienced crew onboard and we are doing 3 hour shifts, as that is as long as you can concentrate on avoiding a broach. I decide the wind is high enough to run under bare poles and save the staysail from gibing itself to death, and maybe keep my bowsprit out of the backface of the wave at the bottom of the trough. We slow down all right, but now the crest of the waves are breaking over my stern and completely filling my cockpit. Tons of water is captured in the cockpit floor space and spills thru the engine hatch seams located there. It’s drowning my brand new diesel engine, and the slower surfing speed has aggravated our broaching tendency. Bilges getting full of water. Back up with the staysail until we are all so tired, I decided to heave to with a rudder forcing her to windward and a backed staysail forcing her off wind. Finally some much needed rest for all of us. I cannot think of a drogue arrangement that I could have left UNATTENDED in this situation, either in reference to broaching tendencies caused by the opposite rotation of the surface waters at the crest of the wave as opposed to that in the trough...."


    Did you swear off going to sea in old wooden vessels with leaking hatches after your experience Brian?


    The paper is dated at the time of initial research and introduction of the device.
    Some years of use have shown its value in real life deployments.
     
  9. brian eiland
    Joined: Jun 2002
    Posts: 5,067
    Likes: 216, Points: 73, Legacy Rep: 1903
    Location: St Augustine Fl, Thailand

    brian eiland Senior Member

    Didn't swear off of it, but never had the occassion to be in anything worst, or near as bad.

    I went to this page of that other reference you sited, and it does have a few compelling supporters for drogues. So I will have to keep an open mind about this subject until I get a chance to review it further.
    http://www.jordanseriesdrogue.com/D_2.htm
     
  10. Petros
    Joined: Oct 2007
    Posts: 2,934
    Likes: 148, Points: 63, Legacy Rep: 1593
    Location: Arlington, WA-USA

    Petros Senior Member

    I went to a talk over the weekend at the Port Townend wooden boat festival. Jeannine Socrates is the oldest woman to circumnavigate the earth and she talked about her sea anchor experience.

    She has used the large single cute ones and did not have a good experience, very difficult to handle. On her last voyage (just completed this july 2012), she used one that was a series of small chutes on a long line. It worked much better, was easy for her to winch in (they would pass right through her winch), and was easier to control. It seems to me a series of small chutes would be much Superior, you have redundancy, you can pay out more or less line to adjust the amount of drag you want, easier to handle and will not suffer the cyclic collapse of one large cute anchor. IT seems it would be easier to stow as well.

    I have never used a any such device, but a lot of small cutes deployed seems like a much better solution to me.
     
  11. Submarine Tom

    Submarine Tom Previous Member

    Drogue, wharp, sea anchor, whatever you want to call it, they work great!
     
  12. brian eiland
    Joined: Jun 2002
    Posts: 5,067
    Likes: 216, Points: 73, Legacy Rep: 1903
    Location: St Augustine Fl, Thailand

    brian eiland Senior Member

    Can you please clarify if she deployed that series of small chutes from her bow as you hinted that she had done the large single chute, or from the stern??
     
  13. Submarine Tom

    Submarine Tom Previous Member

    From the bow I would think, unless you particulary like following seas... rough, following seas, pitch-poling following seas...
     
  14. Petros
    Joined: Oct 2007
    Posts: 2,934
    Likes: 148, Points: 63, Legacy Rep: 1593
    Location: Arlington, WA-USA

    Petros Senior Member

    she did not state if from bow or stern, she was in a monohull. the incident occurred after a knock down (wave broadside when hove to near the cape, it did severe damage to her rigging and she needed to motor to port for repairs).

    I thought it was off the stearn, but now that you ask I can not be sure. She may have been talking about here anchor winch that she used to haul it in.
     

  15. bntii
    Joined: Jun 2006
    Posts: 731
    Likes: 97, Points: 28, Legacy Rep: 1324
    Location: MD

    bntii Senior Member

    Given D. Jordans ideals on how a modern vessel lies to cables:

    "To conclude this discussion we might ask why, over thousands of
    years of sailing experience, did sailors not realize that a sailing yacht should
    be moored from the stern, not the bow. The answer lies in the difference
    between the design of traditional vessels from the age of sail and the design
    of modern sailing yachts. Traditional vessels had long, straight keels running
    all the way to the stern. The rudder was small and did not extend below
    the keel. They were mostly schooner or square-rigged, and they were heavy
    and deep in the water. The resultant wind force on the masts and rigging
    was abaft the center of the boat. As a result, they came about slowly and
    often with some difficulty.
    Conversely, modern sailing yachts have short, deep keels and a cutaway
    forefoot. They also have powerful rudders and are lightweight. The single
    mast is tall and located forward of the center of the boat. These features are
    necessary to obtain good upwind performance and agility when coming
    about. However, they make the boat highly unstable when tethered from
    the bow in a strong wind. Fortunately, the more unstable a boat is when tethered
    from the bow, the more stable it will be when tethered from the stern.
    Fifteen years of experience with the series drogue tethered at the stern has
    demonstrated that, with hurricane-force winds and even when buffeted by large,
    breaking storm waves, the boat will ride quietly and will quickly adjust to wind
    shifts and random wave strikes.."

    http://www.jordanseriesdrogue.com/pdf/AnchorJordan52006.pdf

    And the fact that a vessel makes 1 to 1 1/2 knots under the series drogue, I would think always used from stern.

    The gear is designed to be use chain plates installed on each quarter to take the bridle attachments which makes the installation chafe free in use:

    [​IMG]

    [​IMG]

    http://www.boatdesign.net/forums/boat-design/calculation-chainplate-series-drogue-40064.html
     
Loading...
Similar Threads
  1. JCaprani
    Replies:
    37
    Views:
    8,355
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.