Lets talk sea anchors and drogues - SailNet Community
Seamanship & Navigation Forum devoted to seamanship and navigation topics, including paper and electronic charting tools.

 4Likes
Reply
 
LinkBack Thread Tools
post #1 of 12 Old 10-16-2015 Thread Starter
Senior Member
 
davidpm's Avatar
 
Join Date: Oct 2007
Location: Madison
Posts: 5,092
Thanks: 530
Thanked 91 Times in 81 Posts
Rep Power: 13
 
Lets talk sea anchors and drogues

I been reading up on the subject in preparation for a class.

This is what I think I know:
Please comment or correct as you see fit.

Neither are likely to be aboard a rental boat.
They need to be bought and sized for a specific boat.
They need to be tested so you know how they work.

Sea Anchor.
Is deployed from the bow.
Slows the boat down to 1 to two knots hopefully
You may not need too much sea room as your speed will be low.
Probably should not be tied to bow cleats, use Samson post if available or bridle to primary winches.
Can be hard to retrieve, trip line may help.
Can fail if bow blows off enough so boat lays beam to the wind.
May not need active steering.
Chafe has to be watched carefully
May cause hunting and violent fetching up.
Pardey bridle may work for some boats.
Motion can be uncomfortable.


Drogue
Is deployed from the stern.
Is supposed to slow the boat down to 5 to 7 knots.
You will need a lot of room to run off
Probably requires active steering
Chafe has to be watched carefully.
If too much drag is caused, the cockpit may be pooped.
May catch and release causing acceleration and fetching up.
Jordan series drogue may help with this.
Improvised warps may help
May be hard to retrieve, may have trip line.
Motion may be better than with sea anchor until it isn't'
Stern cleats will probably not hold. Use bridle from primary winches.

Did I hit all the high point accurately and completely?

The lesson from the Icarus story is not about human failing.
It is a lesson about the limitations of wax as an adhesive.
If you have an engineering problem solve it.
davidpm is offline  
Sponsored Links
Advertisement
 
post #2 of 12 Old 10-16-2015
Senior Member
 
Join Date: Feb 2010
Location: Narragansett Bay
Posts: 21,035
Thanks: 82
Thanked 591 Times in 567 Posts
Rep Power: 12
   
Re: Lets talk sea anchors and drogues

Moving from properly backed cleats to the primary winches is new to me. You may need to have sail up with a drogue. If a storm tri-sail, perhaps the primaries are free.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Jeanneau 54DS

In the harsh marine environment, something is always in need of repair. Margaritas fix everything.
Minnewaska is offline  
post #3 of 12 Old 10-17-2015
Senior Member
 
outbound's Avatar
 
Join Date: Dec 2012
Location: NE & Windwards
Posts: 6,678
Thanks: 140
Thanked 200 Times in 190 Posts
Rep Power: 8
 
Re: Lets talk sea anchors and drogues

Went with JSD. Had massive backing plates put under stern cleats and had them moved aft when building boat. Have SS plate on deck over small segment of deck under cleats to end of stern. All done to eliminate issue of chafe. Run is free as lines touch nothing leaving the boat.
Have never used the JSD in anger. But so far biggest draw back is the damn thing is heavy. Weighs maybe 60 lbs.with all the attachments. Comes in special roll out carrier so it deploys correctly. Very awkward to move or store. When on passage it is placed on top of everything in the lazerette to be rapidly available. Chain and anchor from spare ground tackle next to it as end needs to be weighed down to work correctly. Only hope I have ate my Wheaties and heart is pumping from adrenaline if need to deploy for real.
Upsides are:
I can do it myself even though I'm in my 60s.
All literature of actual storm occurances suggest it's the most effective technique.
It is truly passive if rigged as a stern bridle. I have my storm boards in the stern to partially close the walkthrough but allow drainage. Then boards to fully secure the companion way beyond just the doors. With helm lashed that's it. Lie on the sole and pray.
I had the thing built in two segments. Can use the short segment to steer or just slow the boat a bit. Know the full thing slows us to 2-3kts in 30-45. Don't know what it will do in a storm.
Minnesail likes this.

s/v Hippocampus
Outbound 46
outbound is online now  
The Following User Says Thank You to outbound For This Useful Post:
davidpm (10-17-2015)
 
post #4 of 12 Old 10-17-2015
Bristol 45.5 - AiniA
 
Join Date: May 2006
Posts: 4,526
Thanks: 5
Thanked 124 Times in 112 Posts
Rep Power: 14
 
Re: Lets talk sea anchors and drogues

I have a Fiorentino parachute anchor (big sucker 18' diameter). I have never used it and in fact have never come close to using it. I have it rigged up following the Pardey's approach where it is used to help you heave-to with minimum head-reaching. This involves having a second line with a very large snatch block to a bite on the main warp so the boat lies at an angle to the parachute. It is quite an involved setup including some chain, a big swivel, heavy lines, etc. I would tie the warp to two very large, heavy bow cleats and run the secondary line through a mid-deck fairlead to a large cockpit winch. Even with a trip-line I wonder how easy it would be to retrieve, even if the wind dropped from say 60 knots to 25 knots. Chafe would also be a huge concern.

I have no personal experience with Jordan drogues but know a person who used his twice between Easter Island and southern Chile in boisterous, but far from survival conditions, say 45 knots. He thought it did a great job and did not find it hard to retrieve. Might get those for any future ocean crossings (if we decide to do that).

After the refit we have decided to sell Ainia. We want something smaller that would be could for the light summer winds of Lake Ontario, although we plan to spend at least a couple of winters in the Caribbean before heading north.
killarney_sailor is offline  
post #5 of 12 Old 10-17-2015
Senior Member
 
pdqaltair's Avatar
 
Join Date: Nov 2008
Location: Deale, MD
Posts: 3,719
Thanks: 4
Thanked 131 Times in 129 Posts
Rep Power: 12
 
Re: Lets talk sea anchors and drogues

Chutes: The failures to lie bow-to-wind have one basic cause; the chute was too small. If the keel is big, then the chute needs to be bigger, often to the point of impractical. Additionally, there will be rode stretch, which can cause the boat to rotate, if the keel is deep. Multihulls tend to work better, since the keels, if not retractable, more easily slew sideways in big surf. I've used on on a cat with dagger boards in strong squalls, and it rode like a raft, easily sliding around to face the wind.

Whether bow-to-wind is the right answer is a separate question.

Drogues: Too many maybes to make much sense of it, primarily because a towed warp and a JSD have practically nothing in common. In fact, drogues need to be divided into 2 groups: those that seriously limit speed, and those that do not. The methods, intend, and results are thus very different.

Remember that there are 2 cases: wind drag, which will commonly be in the 500- to 1000-pound range, and break wave forces, which can be 4000 pounds and up. And remember that the rode is going to stretch considerably at peak force (less with the JSD, because the load is distributed) (some makers, like Seabrake, suggest low-stretch rodes to reduce the delaying effect of stretch).

Real world experience? Little. I've deployed these in 25-30 knots to collect data, but I hardly needed them. In those conditions, none were too difficult to retrieve using engines and watching out for lines. They all worked in moderate conditions, depending on what you wanted to accomplish. In a real storm, I'm sure "it depends."




Writing full-time since 2014
Author--Rigging Modern Anchors

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

"Keeping a Cruising Boat for Peanuts"
"Faster Cruising for the Coastal Sailor"
"Singlehanded Sailing for the Coastal Sailor"

Last edited by pdqaltair; 10-17-2015 at 12:09 PM.
pdqaltair is online now  
post #6 of 12 Old 10-17-2015
Senior Member
 
Join Date: Dec 2010
Posts: 5,111
Thanks: 1
Thanked 226 Times in 186 Posts
Rep Power: 10
 
Re: Lets talk sea anchors and drogues

Quote:
Originally Posted by outbound View Post
Have never used the JSD in anger. But so far biggest draw back is the damn thing is heavy. Weighs maybe 60 lbs.with all the attachments. Comes in special roll out carrier so it deploys correctly. Very awkward to move or store. When on passage it is placed on top of everything in the lazerette to be rapidly available. Chain and anchor from spare ground tackle next to it as end needs to be weighed down to work correctly. Only hope I have ate my Wheaties and heart is pumping from adrenaline if need to deploy for real.
Next time, have it made using Amsteel... :-)

That's one of the beauties of Don Jordan's design, it doesn't rely on any elasticity in the rode itself, to achieve the desired "bungee effect". Using a rope like Amsteel, you can significantly reduce the size and weight of the drogue, and stow it in a much more compact and manageable package...





Quote:
Originally Posted by killarney_sailor View Post
I have a Fiorentino parachute anchor (big sucker 18' diameter). I have never used it and in fact have never come close to using it. I have it rigged up following the Pardey's approach where it is used to help you heave-to with minimum head-reaching. This involves having a second line with a very large snatch block to a bite on the main warp so the boat lies at an angle to the parachute. It is quite an involved setup including some chain, a big swivel, heavy lines, etc. I would tie the warp to two very large, heavy bow cleats and run the secondary line through a mid-deck fairlead to a large cockpit winch. Even with a trip-line I wonder how easy it would be to retrieve, even if the wind dropped from say 60 knots to 25 knots. Chafe would also be a huge concern.
I'd be very reluctant to try the Pardey's method with a boat the size of yours in extreme conditions, the loads could be monstrous... I'd be much more inclined to try an alternative method described by John Harries - who sails a boat rather similar to yours - of simply heaving-to while streaming a Galerider drogue from the bow...

https://www.morganscloud.com/2013/06...ile-heaved-to/





I'm certainly not about to call BS on the Pardeys, but I have NEVER heard another first hand account of anyone using it as successfully as they have ;-) And, people like Steve Dashew and Evans Starzinger, if memory serves, have said the same thing...

The thing that mystifies me about the technique as they describe it, is how on earth they get the snatch block that rides on the primary rode, to stay in one place... I've attempted to configure that sort of bridle while simply lying at anchor, for the purpose of lying head-to a swell at odds with the wind direction... Baracoa, Cuba, is a harbor notorious for a wraparound surge... If you look closely, you might see my rode streaming aft from the bow, as one of legs of a bridle adjusted from a cockpit winch...





And yet even in such benign conditions, it would just be a matter of time before the snatch block would start either riding up the rode towards the bow - resulting in the boat simply lying head to wind - or riding down the rode towards the anchor, which has the effect of the boat becoming anchored more from the attachment point of the aft leg of the bridle, typically a cockpit winch...

I just don't see how a snatch block can work in this scenario, the only way I've ever managed to get a bridle to work, is to have it fixed to a particular point on the primary rode, and then adjust the legs to suit from there...

Then again, perhaps it's just me... ;-) But I'd sure appreciate hearing from anyone who's managed to configure a stable bridle by the use of a snatch block, as they'd be the first...

;-)
mbianka likes this.
JonEisberg is offline  
post #7 of 12 Old 10-17-2015
Senior Member
 
outbound's Avatar
 
Join Date: Dec 2012
Location: NE & Windwards
Posts: 6,678
Thanks: 140
Thanked 200 Times in 190 Posts
Rep Power: 8
 
Re: Lets talk sea anchors and drogues

Thanks Jon. Live and learn. It's on the list :-)

s/v Hippocampus
Outbound 46
outbound is online now  
post #8 of 12 Old 10-17-2015
Bristol 45.5 - AiniA
 
Join Date: May 2006
Posts: 4,526
Thanks: 5
Thanked 124 Times in 112 Posts
Rep Power: 14
 
Re: Lets talk sea anchors and drogues

Jon, I agree that the loads would be incredibly high. One of the biggest differences between mid 30s boat and a mid 40s boat (or should I say between 15,000 pounds of displacement and 35,000+ pounds are the loads that are generated. We have hove-to, with fore reaching so we certainly did not lie in our generated slick in 50 to 55 knots. Not sure in what conditions I would use the parachute. I guess it would be something close to survival conditions and I wonder how long it would last. The JSD seems to make a lot more sense and would be something you could use in much less serious conditions - and hence use it more often.

After the refit we have decided to sell Ainia. We want something smaller that would be could for the light summer winds of Lake Ontario, although we plan to spend at least a couple of winters in the Caribbean before heading north.
killarney_sailor is offline  
post #9 of 12 Old 10-18-2015
Senior Member
 
Argyle38's Avatar
 
Join Date: Oct 2010
Location: Connecticut
Posts: 267
Thanks: 15
Thanked 9 Times in 9 Posts
Rep Power: 10
 
Dock
Re: Lets talk sea anchors and drogues

Quote:
Originally Posted by outbound View Post
Went with JSD....
I can do it myself even though I'm in my 60s.

It is truly passive if rigged as a stern bridle.
How exactly does this work? If you are running before the wind with a JSD, do you not have to continually steer to keep from broaching?

I've always thought that is a weakness of a stern-rigged drogue. If you have enough crew to hand steer for the duration of the storm, then great, but not so good for being short handed.

Related question, does your boat surf? I could imaging a flat bottomed boat would handle running under drogue much better than a displacement boat. Conversely, a displacement boat will likely heave-to better than a flat bottomed boat, so a heave-to+sea anchor might work better.
mbianka likes this.

S/V Argyle
Downeaster 38 #40

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Argyle38 is offline  
post #10 of 12 Old 10-18-2015
Senior Member
 
Join Date: Feb 2010
Location: Narragansett Bay
Posts: 21,035
Thanks: 82
Thanked 591 Times in 567 Posts
Rep Power: 12
   
Re: Lets talk sea anchors and drogues

I wouldn't expect to have to steer too much downwind in a survival storm. That's where you'll be going, like it or not, and the drogue is keeping your stern to wind. Lash the wheel.
outbound likes this.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Jeanneau 54DS

In the harsh marine environment, something is always in need of repair. Margaritas fix everything.
Minnewaska is offline  
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Drogues and Sea Anchors Ajax_MD Seamanship & Navigation 36 09-22-2014 08:20 AM
Lets talk about dinghies y'all alctel Gear & Maintenance 55 09-17-2014 06:14 PM
Drogues & Sea Anchors onboard SoOkay Gear & Maintenance 8 03-25-2014 02:54 PM
lets talk dinghies mikieg General Discussion (sailing related) 39 01-31-2012 09:52 AM
Lets talk about trailer tires! Lancer28 Gear & Maintenance 29 08-16-2007 11:14 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome