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Old 04-05-2011, 10:13   #16
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Re: Multihulls: Heavy Weather (passive) Handling

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Originally Posted by Multitalent View Post
Sailing a catana 47 who carbon mast failed in 60 kts. we ran downwind and slightly cross the waves at about 10 kts for 8 hours, both engines running in idle as safety, after a few hours we rigged a 300 rode in a stern to stern loop with the 45" CQR in the center, this was quite effective and allowed the autopilot to maintain control though we kept a man lashed to the helm at all times. Seas were 10 meter but regular with crests that only rarely broke at the stern and only once of twice in the cockpit.
Which is the biggest drawback to the Catana. I like the simple and effective solution for a drogue.
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Old 04-05-2011, 14:29   #17
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Re: Multihulls: Heavy Weather (Passive) Handling

Palarran, the fact that your friend was able to surf down a 30 foot wave at 30 knots on autopilot without pitchpoling says to me only that miracles do sometimes happen (although admittedly, we do not know the size or design of the boat). Burying a bow/pitchpoling is probably a greater risk for most catamarans than capsize and at a certain point, I think that most people agree that you have to slow your boat down in order to minimize that risk. A series drogue will not only achieve this, it will tend to keep the stern towards the waves and, since the pull remains more constant than with a chute style drogue (that can occasionally collapse), the strains on the mounting points are also substantially reduced.

When to deploy a drogue will depend not only upon wind and sea state, but also upon the design of your boat. All else being equal, boats with a higher BOA/LOA ratio will have greater resistance to capsize, but less resistance to burying a bow/pitchpoling; furthermore, they will not track as well as narrower boats and hence, will be at greater risk of skewing sideways in a following sea. Furthermore, while slender bows will tend to increase speed, the increased speed and reduced forward bouyancy will also increase the risk of burying a bow/pitchpoling. When running before a storm in such a boat (BOA/LOA significantly in excess of 50%, slender bows) I would think it wise to deply a drogue well in advance of reaching survival conditions or extreme speeds.

The decision as to whether to employ a para anchor or a series drogue in survival conditions has already inspired considerable debate. In making that determination, IMO one should consider the literature (including the Coast Guard study posted on the Jordan site), anecdotal reports (especially for your type of boat), the amount of sea room and, as already mentioned, the design of the boat including the amount of bouyancy both fore and aft, the location/design/construction of the companionway doors and the cockpit, especially cockpit drainage. Finally, if you choose to go with a para-anchor, you must have confidence that the model you have chosen will hold your boat virtually stationary against the onslaught of wind and waves (so as to avoid damage to the rudders/steering mechanisms that may occur if you are driven backwards).

Brad
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Old 04-05-2011, 15:28   #18
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Re: Multihulls: Heavy Weather (Passive) Handling

Brad,
The boat was a 75' Tahiti day charter cat he was delivering to New Caladonia from France. I'm not sure he considered it a miracle but it was the scariest moment he has had. FWIW, he has 200,000 bluewater miles and another 200,000 inter-island delivery or captained charter miles.

In regard to pitchpoling, it is his opinion that almost all new designs of catamarans have enough reserve bouyancy to avoid it. Can it happen, yes.

I have also read all the info on series droges vs chutes and IMO, the series is not the way to go with a catamaran. They are designed to reduce your forward speed to 2 or 3 knots vs 6 to 8 with a chute. With the slow foreward speed, it increases your chances of being pooped (which is really my biggest fear). Ultimately it won't be my choice on the way over as he will be the captain and needs to make that decision.

Not having the experience that Christophe has but an opinion, I have to agree with him that on a catamaran there really isn't ever a time for a parachute sea anchor. What function do they perform that is different from using your motors keeping you in place? Brad, have you ever read a first hand account where one was used sucessfully in a sea condition that without it, the boat would have been lost? I think cat sailors need to realize they are different animals from mono's.

Yeloya's intent (I think) of this thread is to question if your better to do nothing. I think we all can agree that in extreme conditions, that's not an option. Most would also agree that it's usually the crew that breaks before the boat. Of all the video that has been posted on cat capsizes or failures and observing the seas at that time, I have to agree with him.
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Old 04-05-2011, 15:39   #19
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Re: Multihulls: Heavy Weather (passive) Handling

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AllezCat -- As a St F 44 owner, I'm interested in some details. We've never encountered anything over the low to mid 30's with seas that didn't worry me. Ours also has the bow padeyes for a sea anchor. I'm curious about the drogue you rigged and what you found problematic. I had pretty much assumed that if we had plenty of sea room, I'd go with a drogue and use a chute if we didn't have much sea room. Your thoughts?

Thanks!

ID
The drogue was a bunch of stuff chucked on a loop of rope from stern to stern - little anchor etc...No swivel.
became a big twisted mess - cut it away. I have the bought one now with rode and swivels.
You do use the pad-eyes for your regular anchor bridle?

Surfing down waves is pretty hairy in your house. There is an unknown point where it would/could trip and flip.
Waves tend to lift the stern and twist the boat off course(according to the auto-pilot) which reacts and swings back on course.
We, however, can anticipate and steer for efficiency on the wave.
But, surfing/downwind steering is very tedious. the question is how much you trust the pilot and how much energy you have(you can only drink so many red-bulls).
At some point the drogue is very useful to help stop the out-of-control surfing. In someone else's house it may be fun. I don't agree with "bare-poles until running out of sea-room and then motoring" until you run out of gas - then what?
The chute is for really extreme, or to stop and rest - and stays put on the sea(mostly moves with the current).
It is imperative that there is mucho stretchy rode - and it streeeeetches!!! Plus all the other stuff they advise:
Sea Anchors, Boat Brakes, Delta Drogue & Accessories by PARA-TECH
cheers
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Old 04-05-2011, 16:26   #20
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Re: Multihulls: Heavy Weather (Passive) Handling

If you're running in large seas in a catamaran, do you really have the choice to head into the seas and use a parachute?

I would guess that, at times, your boat heading determines what device you would use to slow the boat down.
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Old 04-05-2011, 16:36   #21
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Re: Multihulls: Heavy Weather (Passive) Handling

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Originally Posted by Palarran View Post
I have also read all the info on series droges vs chutes and IMO, the series is not the way to go with a catamaran. They are designed to reduce your forward speed to 2 or 3 knots vs 6 to 8 with a chute. .
A chute hangs off the front and pretty much stops the boat dead, bow on to weather.
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Old 04-05-2011, 16:43   #22
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Re: Multihulls: Heavy Weather (Passive) Handling

he was talking about a chute style drogue versus a series drogue( many little chutes).
There was a better drogue available some years ago that solved all problems.
It was a solid cone shaped unit. And had venturi "things" on the side that opened at speed. So, in theory it would slow the boat to a reasonable cruising speed(say 7 knots) but then on steeper waves if it began to surf the venturi things would open up creating more resistance and maintaining the slower speed.
But was rapidly off the market - so maybe not so good in practice???
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Old 04-05-2011, 16:53   #23
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Re: Multihulls: Heavy Weather (Passive) Handling

They say that an old tire dragged from the stern works pretty well as a drogue in both monohulls and multihulls. Never tried it myself, but the price is right.
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Old 04-05-2011, 17:34   #24
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Re: Multihulls: Heavy Weather (Passive) Handling

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Originally Posted by AllezCat View Post
he was talking about a chute style drogue versus a series drogue( many little chutes).
There was a better drogue available some years ago that solved all problems.
It was a solid cone shaped unit. And had venturi "things" on the side that opened at speed. So, in theory it would slow the boat to a reasonable cruising speed(say 7 knots) but then on steeper waves if it began to surf the venturi things would open up creating more resistance and maintaining the slower speed.
But was rapidly off the market - so maybe not so good in practice???
Interesting conversation... I have studied this a bit, and although I don't yet have one, I favor the Jordan Series drogue, as my Gale Rider can be pulled out of the face of a large wave.

One point... A drogue IS NOT a parachute "sea anchor". A parachute sea anchor is normally deployed off of the bow, and other than the stretch of the VERY long rode, the boat only moves backwards at a fraction of a knot. The loads are astronomical in a survival storm!

A drogue, is normally deployed off of the stern, and allows the boat to move with the seaway at 6 or more knots...

M.
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Old 04-05-2011, 17:39   #25
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Re: Multihulls: Heavy Weather (Passive) Handling

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One point... A drogue IS NOT a parachute "sea anchor". A parachute sea anchor is normally deployed off of the bow, and other than the stretch of the VERY long rode, the boat only moves backwards at a fraction of a knot. The loads are astronomical in a survival storm!

A drogue, is normally deployed off of the stern, and allows the boat to move with the seaway at 6 or more knots...

M.
I know - was not implying that.
But the drogue is parachute "shaped" just much smaller than the parachute sea anchor
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Old 04-05-2011, 17:40   #26
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Re: Multihulls: Heavy Weather (Passive) Handling

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I know - was not implying that.
But the drogue is parachute "shaped" just much smaller than the parachute sea anchor
actually its not.
I think it is cone shaped.
perhaps I should test deploy it, or at least look at it.
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Old 04-05-2011, 18:02   #27
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Re: Multihulls: Heavy Weather (Passive) Handling

While we're on this discussion, a thought I don't recall being addressed: If you start out running, or using a drogue (I'm thinking Jordan series drogue, just to be specific), but run out of sea room and conditions deteriorate even more to the point where a sea anchor is needed -- how the heck do you do a 180 in those conditions? And, maintain it long enough to deploy the sea anchor? My boat surfs just fine, with the pointy ends going forward, but the thought of surfing backwards? To quote Mr. Bill -- "Oh, noooooo!"

I am very appreciative of you folks who have actually faced such situations. Thank you so much for your willingness to share.

ID
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Old 05-05-2011, 03:36   #28
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Re: Multihulls: Heavy Weather (passive) Handling

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My friend Christophe is a delivery captain that specializes in catamarans. He has done 15 Atlantic crossings and 2 Pacific crossings in cats ranging in size from 40' to 82'. I've asked him multiple times about this after reading opinions on CF and his answer is simple - you go bare poles down wind until you run out of ocean. Then, you turn into the waves and hold position using your motors. He has never used a drogue and wouldn't even consider a parachute an option.
The skipper who brought my boat from La Rochelle was exactly saying the same things..

These quotes are from the famous Queen's birthday storm in 1994:

"Ramtha, a 38-foot Roger Simpson designed modern-style catamaran from
Australia, with a husband and wife crew with five years of coastal cruising
experience and some offshore experience: The crew had set a drogue several days before the storm to fix her steering, but had to cut it loose when they were unable to pull it back up. Ultimately, they found themselves in 70 knots of wind and 40 foot seas, conditions so bad that the 4,000-ton ship Monowai, coming to their rescue, rolled as much as 48º in each direction,injuring three of her crew. Despite four reefs, Ramtha's main blew to shreds and her steering system became inoperable. With nothing but her twin engines available for maneuvering, being aboard her was like "going down a mountain in a wooden box" or being on a "roller coaster that never stopped." The boat slid down waves forward, sideways, and backwards. Several times it seemed as though she might flip, but she never did"

Another one

"Heart Light, a 41-foot Catalac U.S.-based catamaran with a crew of four; a husband and wife couple with 16,000 ocean miles, and two crew with no
offshore experience: Despite having 16,000 miles ocean experience, the
captain and wife claimed to have not steered the boat except near the dock and to have never jibed between the States and New Zealand. Heart Light was a heavy, solid fiberglass, narrow catamaran. Nevertheless, she did reasonably well, surfing at between 6 and 13 knots while dragging a drogue. When the autopilot couldn't handle it any longer, the skipper finally learned how to steer, working desperately to prevent waves from slewing the stern in front of the bow. Eventually, both engines went down and lines fouled both rudders. They tied off the helm to port and slid sideways down waves. Despite being "captapulted" through the air on many occasions and being knocked onto one hull several other times, she endured. When the rescue ship arrived, her captain noted that the boat "appeared seaworthy and was riding comfortably in the improved weather." "

And the conclusion of the author, Bob Austin:

"There are several interesting things about the two catamarans in the core
area of the storm: 1) Neither of them pitchpoled; 2) Neither of them flipped ÷ although the crews thought they came close; 3) Neither of them were dismasted; 4) Both of them apparently would have survived ÷ by surfing forwards, sideways, and backwards ÷ had they just been left alone."

Add to that, the Catana 45 (much seaworthy than any of these boats) that was filipped over killing 3 people 10 years ago in much moderate conditions than this in the Med, because of the erratically rigged chute..

Cheers

Yeloya
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Old 05-05-2011, 04:29   #29
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Re: Multihulls: Heavy Weather (Passive) Handling

I don't see how you could hold station with the motors - in extreme conditions. Expending finite amounts of fuel and crew energy.
The sea anchor achieves exactly that. With no use of fuel. Just like at "ground" anchor.
Taking the waves on the bows is preferred.
A lot can be said for just lying a-hull though...
And as others have mentioned going from drogue with much equipment out to turning into the seas and deploying a sea anchor - how to do in extreme conditions?
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Old 05-05-2011, 06:06   #30
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Re: Multihulls: Heavy Weather (Passive) Handling

A few comments:

1. It is better to have the bows going through the water...... Agreed and that is precisely what happens with a series drogue, which only slows the boats forward progress. Until a sea-anchor is properly set, the boat moves backward quickly; even after it is set, as I said earlier, how confident are you that it will completely stop reverse motion in changing conditions and with the anchor on different positions on the wave train?

2. Mulithulls are different from monohulls.... Again, agreed. However, both monohulls and mulithulls can be pooped from breaking seas approaching from astern. Even though the USCG test showed that it was extremely rare with the series drogue, that is nevertheless why I suggest that one must consider the design and drainage of the cockpit and the design/strength of the companionway doors on your particular cat. What seems clear, however, is that most cats have much more bouyancy aft than most monohulls and hence, have a far greater tendancy to lift the transoms in following seas.

The series drogue slows the boat too much and increases the risk of pooping..... Increased flooding of the cockpit over standard drogues was not shown by USCG tests, but if you would rather go faster, then you could always deploy a smaller than recommended series drogue. Yes, this would be contrary to Jordan's recommendations and the test results, but if you would prefer your intuitive beliefs, it should still be better than a chute or cone-style drogue, which can collapse and be thrown forward by the seas behind the boat.

The fact that so many delivery skippers of cats just drop sail and run before a storm on autopilot tends to confirm that, if you have sea room, the boat is better off running with the storm. Indeed, I would suggest that the reduced tendancy to broach and the increased bouyancy aft, as compared to monohulls, is preciesely why this is a more viable option for cats than it is for monos. The series drogue maintains this approach, while slowing the boat in extreme conditions so as to minimize, if not eliminate, the risk of pitchpoling - and it does so by putting a much more constant (and hence less violent) strain on the boat and the attachment points for the drogue.

Brad
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