Use of drogue/parachute anchor on Catamaran

[Pieter]

Hello friends,

Recently i saw on youtube a film of a Cat in a major force wind (i have to guess around 40-45 knots).. they didnt have any sails up, going with the wind and the waves, and they had this drogue/parachute type ancor deployed. For this first time i finaly had a visual of how this ancor actualy works, and i could also imagine how this would work if you would deploy it from the bow and keep the bow into the wind as if your anchor would be dragging. We already sailed the coast of Brazil, spend a year in the Caribbean, went across to Europe and via Africa back to Brazil on board of our FP40ft.. During this voyage we never were in rough weather so i never thought of it. Now we are planning to go to the Pacific and i plan to prepare to have this item on board. Questions i have for now:
1. What is the difference between a drogue and a parachute?
2. Having read Eric Taberly.. he was always against using those kind of "breaks" especial deployed from the stern..
3. It depends on the situation at hand if you want to deploy from the stern or the bow?
4. Is this a must have on board item?

Thanks for your remarks and insights.

[thinwater]

^^ please post the you tube link to help us understand what you are referring to.

You know, of course, that the answer is complicated with many opinions.

[Pieter]

Thanks for yr msg. Here is the link i was refering to :

https://www.youtube.com/watch?v=hQ-svmgOxqw

I know there will be diferent opinions on this issue, so that will be great to first hand experiences etc.

Thanks again, and best rgds
Pieter
SV Lumina
Lumina Charters – Brazilian Coastal Catamaran Sailing

[AD28]

Victor Shane: Drag Device Database. Nothing but anecdotes:

Drogues on Catamarans | Victor Shane's Drag Device Data Base

Sea Anchors on Catamarans | Victor Shane's Drag Device Data Base

[Pieter]

Ok, thanks for the links... Will do the reading, but are there multihull cruising sailors who have first hand experiences (incl. what adaptations need to be done on the boat so you can deploy rather easily.. if that exists anyway...).
Thanks again.
Best rgds
Pieter

[AD28]

Um,

the DDDB... is COMPLETELY first-hand experiences - that is what the DDDB is, a compendium of same.

[Steadman Uhlich]

Originally Posted by Pieter

Hello friends,

Recently i saw on youtube a film of a Cat in a major force wind (i have to guess around 40-45 knots).. they didnt have any sails up, going with the wind and the waves, and they had this drogue/parachute type ancor deployed. For this first time i finaly had a visual of how this ancor actualy works, and i could also imagine how this would work if you would deploy it from the bow and keep the bow into the wind as if your anchor would be dragging. We already sailed the coast of Brazil, spend a year in the Caribbean, went across to Europe and via Africa back to Brazil on board of our FP40ft.. During this voyage we never were in rough weather so i never thought of it. Now we are planning to go to the Pacific and i plan to prepare to have this item on board. Questions i have for now:
1. What is the difference between a drogue and a parachute?
2. Having read Eric Taberly.. he was always against using those kind of "breaks" especial deployed from the stern..
3. It depends on the situation at hand if you want to deploy from the stern or the bow?
4. Is this a must have on board item?

Thanks for your remarks and insights.

The most informative site and best info related to drogues I have found is a site devoted to the Jordan Series Drogues (JSD). It contains numerous pages describing the science of waves, the technical design of drogues, anecdotes about use, links to specs so you can make one yourself (simple to do) and a source where you can buy ready made ones too.

The description of sea anchors and drogues is there on the pages of that site too.

Jordan Series Drogue

I also encourage you to see the link on that page for the USCG Report of the lab and field testing of the JSD compared to parachute style drogues and sea anchors. Especially read the concluding paragraphs of that report, found near its end. It is a PDF file document. When you open the PDF, look down near the end to find page 68 of the PDF which is page 59 of the the Report. Look for the section 6.4 "Boat Design" and begin reading there. The PDF pages 68, 69, 70 should give you some of your answers. Here is a link to the Coast a Guard Test Report:

http://jordanseriesdrogue.com/pdf/dr...uardreport.pdf

My Summary: Based on what I have read on the topic, I would get a JSD if concerned about surviving a "survival storm" at sea.

Also, the JSD design and specifications to make one using cloth and rope is open source info. The designer, Mr. Jordan, wanted all sailors to have access to the design, so they could make their own. It requires the use of a sewing machine and simple materials and some hours. Some cruisers have made their own while on a voyage.

--------

Note! I do not own a catamaran or big mono. But, I have read comments by cat owners and mono owners that have differences of opinion on what they would use or do in a storm. Everyone has an opinion. The USCG Test Report and several other things I have read on this topic (testimony by highly experienced sailors who chose the JSD), are more convincing to me.

[Pieter]

Thanks Steady Hand.... will do for some good reading...

[Moontide]

Suggest that you look into the Jordan Series Drouge. Didn't see report on one in Victor's database, but can find reports on line. If you like sewing you can make one yourself. The design concept seems to be perfect for a cat. The key is keeping your speed down so you are not surfing on the waves, which raises the possibility of broaching. Broaching a cat in survival conditions can result in flipping it.

The series drouge operates to increase drag resistance as speed picks up and reduces drag as speed slows down. Prevents surfing but allows steerage speed to be maintained which is critical in keeping the boat headed down swell.

Have heard, and agree, that lying to a sea anchor is not good strategy for a cat in survival conditions as they can allow the cat to slide down a wave backwards, greatly increasing the chances of flipping.

I do not have first hand experience in any of these but have down lots of research after buying my Lagoon 470 11 yearts ago. Am a long time monohull sailor with 10's of thousands of sea miles, and another 15,000+ on this cat.

Number one rule for me is stay with the boat. A cat is a giant liferaft, right side up or upside down.

Bill

[svrevelations]

Originally Posted by Pieter

Ok, thanks for the links... Will do the reading, but are there multihull cruising sailors who have first hand experiences (incl. what adaptations need to be done on the boat so you can deploy rather easily.. if that exists anyway...).
Thanks again.
Best rgds
Pieter

We have 2 x Shark Drogue (model L Shark) devices on board our 50' catamaran. Although we have never used these devices in a true high wind situation, we did test them whilst sailing from St. Helena to Brazil.

The drogues were pre-rigged to specially constructed stainless steel attachments bolted onto the aft of the yacht (port and starboard respectively) with 140 meters of rode each. Each rode consisted of 1" x 50 meters Polyester joined with 90 meters of 1/2" Dyneema. The deployment and later retrieval was really easy. We also attached about 2 meters of 1/2" chain behind each drogue to help keep it submerged.

With 18 knots of wind from the aft port quarter, spinnaker flying, the yacht was doing 13 knots. We first deployed one of the Shark Drogues and when the rode was fully extended, the yacht slowed down to an average of 9.4 knots. After a couple of minutes, we deployed the second Shark drogue and the yacht further slowed down to an average of 6.2 knots.

[Steadman Uhlich]

What follows is written in a friendly tone of voice, and intended to provide a different point of view to this discussion.

Another few points I would like to make, because a forum like this is usually full of opinions (like mine) from people who have never used an item (e.g. a drogue in a real survival storm where the boat is threatened by breaking waves).

Everyone has an opinion. And if you know sailors like I do, each sailor is always sure they have the made the right or best choices for their boat and the gear they use.

For many years the sailing literature (and by this I mean books that are still in print, read, and recommended by many) has featured suggestions of what to do in a storm, based on traditional methods such as using warps, chains, tires, oil, sea anchors, and parachute drogues, etc.

Anecdotes (like those in the database that has been mentioned) are useful and interesting reading, but I think anecdotes have a weakness that is often overlooked.

Anecdotes about using warps, tires, chains, and such are usually accompanied by statements like "it worked for me."

There is a problem with anecdotes; they are personal observations, NOT rigorous scientific controlled tests and comparisons of gear.

Also, few sailors will experience "survival storms" at sea. And, if they do, it is unlikely they will try testing different forms of drogues, warps, or sea anchors to see which is most effective at that time in breaking waves or that their observations are made with any kind of objectivity. At the time of their use, they will be stressed, worried about their survival, and clinging to hope.

They will just use what they have at hand on their boat at the time. And they may only use that once and never use anything other than that again, if ever again. This is why I think the USCG Test Report and the science behind it is more rational than just anecdotes about towing tires, using a parachute sea anchor, or using oil for a slick, etc.

The USCG Test Report (see link I posted above) is most convincing to me. That is my opinion, and I am sure others will see it differently.
_______________

Finally, this is not to say I don't enjoy reading the opinions and anecdotes of others on this forum or in books. They are always appreciated and usually enjoyed.

But, I like to keep them in perspective, if there are actual scientific or engineering test results that contradict the anecdotes. That is all.

[thinwater]

I know Practical Sailor has a 2-part article in the works (I was there for the gale testing of many brands). Although there are a lot of variations, they all work by creating drag, and proper sizing and rigging seemed to be FAR more important than the brand.

Galerider. Very easy to handle.


The real motivation for the research was not so much storms as emergency steering. I believe if you follow reports of rescues of sailboats at sea, loss of sterling is one of the most common failures, more common than taking on water. The boat may remain perfectly seaworthy, but if you can't sail in any useful direction, you're done in. To investigate this we spent days sailing around with the rudders intentionally locked, either straight or 2 one side. Slow, but we could at least head in any direction we wanted. The most important factors were size and rigging. And that is a good reason to take a drogue, IMHO. And neither a JSD or parachute are very useful for this (parachute is a boat stopper, and the JSD does weird things in the lulls, when the tail goes deep--it is really a boat stopper too, just a different sort).

Seabrake rigged for steering, rudder jammed over.


Does the steering application apply to cats? Most have a means of sailing on one rudder. But in the case of the Alpha 42, the rudder was jammed to one side, overpowering the remaining rudder. A drogue might well have made the difference (we did considerable testing with rudders over to test this hypothesis).

Steering using the winch instead of the wheel.

[Don C L]

As you may have discovered in the reading, the drogue and the para-anchor have different purposes and so are designed differently. The drogue is to slow the boat down and maintain positive control in steering and (hopefully) reduce the tendency to broach (and thus reduce strain on a rudder that is trying to fight the broach) and is deployed from the stern. The parachute is intended to stop the boat's motion and is deployed from the bow. If you deploy a drogue from the bow and the boat is allowed to be thrown back, there is a very good chance you'll damage/break/snap off the rudder. You cold deploy the parachute from the stern but you'll get a lot of sea water in your coffee if you get pooped!

[Don C L]

Originally Posted by thinwater

I know Practical Sailor has a 2-part article in the works (I was there for the gale testing of many brands). Although there are a lot of variations, they all work by creating drag, and proper sizing and rigging seemed to be FAR more important than the brand.

Galerider. Very easy to handle.


The real motivation for the research was not so much storms as emergency steering. I believe if you follow reports of rescues of sailboats at sea, loss of sterling is one of the most common failures, more common than taking on water. The boat may remain perfectly seaworthy, but if you can't sail in any useful direction, you're done in. To investigate this we spent days sailing around with the rudders intentionally locked, either straight or 2 one side. Slow, but we could at least head in any direction we wanted. The most important factors were size and rigging. And that is a good reason to take a drogue, IMHO. And neither a JSD or parachute are very useful for this (parachute is a boat stopper, and the JSD does weird things in the lulls, when the tail goes deep--it is really a boat stopper too, just a different sort).

Seabrake rigged for steering, rudder jammed over.


Does the steering application apply to cats? Most have a means of sailing on one rudder. But in the case of the Alpha 42, the rudder was jammed to one side, overpowering the remaining rudder. A drogue might well have made the difference (we did considerable testing with rudders over to test this hypothesis).

Steering using the winch instead of the wheel.

Actually, nothing against these techniques, but you CAN steer a sailboat without a rudder by a combination of the right areas in the headsail and main and with sheeting. It is something fun to experiment with on any boat. On a 65' boat I crewed on that lost its rudder we found that we could maintain and steer fairly well between a close reach and broad reach in about 15 kts of wind. The problem was neither tack took us to a very friendly shore! We tried rigging, well, no, thought about rigging, the spinnaker pole athwartships aft to hold out line and bridle for a drogue steering, but it was just too much boat for that and way too dangerous.

[Steadman Uhlich]

Originally Posted by Don C L

As you may have discovered in the reading, the drogue and the para-anchor have different purposes and so are designed differently. The drogue is to slow the boat down and maintain positive control in steering and (hopefully) reduce the tendency to broach (and thus reduce strain on a rudder that is trying to fight the broach) and is deployed from the stern. The parachute is intended to stop the boat's motion and is deployed from the bow. If you deploy a drogue from the bow and the boat is allowed to be thrown back, there is a very good chance you'll damage/break/snap off the rudder. You cold deploy the parachute from the stern but you'll get a lot of sea water in your coffee if you get pooped!

Good post.

But, I think the line that says "If you deploy a drogue from the bow and the boat is allowed to be thrown back, there is a very good chance you'll damage/break/snap off the rudder" could also include "sea anchor or parachute" in addition to the "drogue."

My point? Any boat thrown backwards on its rudder from a wave from the bow is likely to suffer damage, regardless of what kind of device is hanging off the bow.