Subject: [harryproa] Re: safely using Drogues and Para Anchors
From: Mike Crawford
Date: 2/15/2006, 9:40 PM
To: harryproa@yahoogroups.com.au
Reply-to:
harryproa@yahoogroups.com.au

<<How about with a harry, hanging the parachute off the windward hull, lying beam on to the waves and protecting from wave induced capsize.>>

  It's difficult to tell exactly how this would work without trying it, but there's some \empirical data from the drogue tests that argues for trying what you suggest.

  There were two reasons they chose to mount drogues on the stern in monohulls.  One was because, as the boats were driven leeward through the water by the wind, they could twist and broach.  Putting drogues off the stern and leading with the bow prevented this.  Fortunately there's no issue with directional stability on the proas.

  The other reason was that the bows lacked flotation.  Although it seems to make sense to put the bow into the waves, they said this creates stress because the boat attempts to punch through the waves instead of float over them.  The stern, on the other hand, has plenty of flotation, and actually rises and falls more gently with the wave surface, strange as that may seem.

  I know the data is from monohulls, but the concept of floating up a wave face instead of launching through it really isn't specific to hull type.

  As  you point imply, there's no need for an large sea anchor that yanks the boat through the waves.  All a harryproa would really require is enough force to keep the windward hull on the water as the wave passes.  Given that the boat is stable to 70 degrees, this would not require extreme forces. 

  There would be little worry about the drogues/anchor not being big enough to keep the windward hull to windward because the bare poles all the way to leeward should take care of this.  This setup could also prevent a fast slide down a wave front ending in a pitchpole.

---

  With that said, though, I might just chicken out when faced with big weather and go with a more standard approach of using a bridle that angles the boat to where both hulls hit wave crests at the same time.  Given the difference in hull length, this will still yield some of the benefits of keeping the windward hull to windward, but will also get some help from the longer hulls (versus the shorter beam).

       - Mike

 

nudd@ozemail.com.au wrote:
Drogues go from the stern. Parachute anchors go from the bow.
In a proa using a drogue means you will have to change ends when you shunt.
When anchoring you don't need to change tack.

How about with a harry, hanging the parachute off the windward hull,
lying beam
on to the waves and protecting from wave induced capsize. Perhaps
uncomfortable
but safe?
Paul Nudd



Quoting jerry freedomev <freedomev@yahoo.com>:

>               Hi PC and All,
>                        I see little reason to lay beam to the seas as
> uncomfortable and exposes your sides to the full force of the
> breaking waves, not smart. You will not catch me like that.  Using 2
> at a time, even from different bows/sterns is asking for trouble
> entangling them also.
>                       With multihulls you need to face the/a bow into
> the wind/waves for a comfortable, safe rest while the storm passes. 
> During one hurricane, I had to keep openning the hatch to see if the
> storm was still there it was so peaceful inside despite the 80mph
> winds outside.
>                       Also using too large a drogue/para dia sea
> anchor just puts unnessasary forces on your boat. Around 6-8' on a
> 30' proa should be enough though every boat is different.
>                     If adding up the lengths of proas designed,
> built, I'd be hitting about 120' so far. Cats I'm in the thousand
> feet+ range.
>                    One of the best things about cats, tris and proas
> is you can anchor in open roadsteads in waves and be comfortable
> where in a monohull you will roll your guts out. This along with
> shallow draft makes these craft the best for serious cruising, live
> aboard that I did for 20 yrs.  My last was a proa and probably the
> next one too.
>                    Is there a website with why Harry? does his Proas
> his way? I'm interested why he uses a much longer leward hull and
> would like to see his rudder arrangements.
>                    Intro,   I did Proas many yrs ago before they were
> cool, always admiring the Malibu Outrigger tacking Proa from the
> early 60's and after building many mono's/Cats/tris, seeing Russ
> Brown's first cruising proa just after it was built, I thought I
> could do better as usual and built a series of tacking proas that
> worked great. Steve Brown, Russ' brother and I built cats, tris ,
> proas and other strange boats at the time together, 80's, in Key
> West, Fla, USA.
>                    And yes both Steve and his brother Russ had a
> large advantage growing up with their father and his designing,
> sailing friends as they were like fish in the water, great on
> designing, building boats.
>                                        HTH's,
>                                              Jerry Dycus
> proaconstrictor <proaconstrictor@yahoo.ca> wrote:
>  Anyone have any ideas or experiences (second hand welcome) of drogues
> or para anchors on pros?
>
> The thing I like about the proa platform is that sometimes folks
> carry both drogues and anchors, deploying one off the the stern and
> the other off the bow.  Starting with the drogue and moving to the
> para if conditions worsen.  This can lead to complications with
> reversing the boat to get the para out even as conditions are ramping
> up.  The obvious point being a proa is lonigtudinally symetrical, and
> therefore one can throw the drag device off of either end.  The boats
> and rig are also symetrically placed.
>
> There may be bad news also such as the uneven windage on the hulls
> once streaming the drag device.
>
> Any thoughts about how this could work, broadly from attachment
> points to lights to storage and deployment, all idea welcome?
>
>
>
>
> ---------------------------------
> Relax. Yahoo! Mail virus scanning helps detect nasty viruses!



----------------------------------------------------------------
This message was sent using MyMail


Yahoo! Groups Links