Thoughts on sea anchors and drogues for Cape Dory's

[rtbates]

What pins?

I'd tie you there w/o fear!

[Neil Gordon]

No, the mast base is not as strong as it appears.

Probably not a good idea to use the halyard winches for anchor retrieval, then?

[Didereaux]

Not a problem as mine are now mounted on the cabin roof(well one is and the spare is still on the mast.

...and no I wouldn't use a mast mounted winch to bring up an anchor, to high up, too small and not the backing to handle a really heavy load. Although it's quite possible to put a half ton on a halyard...if you like to see things buckle and snap! heh

The primary jib winches are about the strongest points on the smaller boats after the chainplates and stemhead.

Yeah, yeah, I know you knew all that, but how the hell can I keep my word count up if I don't throw some baksheesh at the word gods?

heh

[Didereaux]

Randy rote>"
What pins?

I'd tie you there w/o fear!"

Okay that skinny bolt!

Oh yeah? Hell if I fell against a 25D mast the sucker is history. (ask Geo Shaunfield lol)

[s.v. LaVida]

With my limited knowledge of the forces, I would tend to agree that the mast isn't the place to apply those forces.

Except for the extended lengths of bridle, I'd agree, with OJ, that the samson post on the bow is the logical choice.

However, going forward with two parts of a bridle in heavy seas does not have much appeal to me.

My thougthts are leaning to making fast to the midships cleat and the stern cleats or a padeye( installed somewhere in the middle), while safely operating from the cockpit or very near the cockpit.

JMHO,
Mike

[s.v. LaVida]

4 years..... commerical diving and working the oil rigs in the Red Sea taught me the value of "baksheesh".

thanks for bringing a memory back to life.

Mike

[Tod Mills]

....essentially, deployment backwards, to reduce the initial forces and minimize the risk of damage in the event the lines don't run free?

Personally, the so-called sampson posts I see in the catalogs look to me almost like decorative pieces, with small, thin bases to carry what could be considerable bending moment in addition to the shear load, which could tend to cause the deck to ~. It is a quite different loading situation than where a post penetrates the deck and ties into structure below.

Just thinking out loud,

Tod

[img]http://www.todspages.net/images/LF-Pcrk.jpg[/img]

[Oswego John]

Hi Tod,

My thought is that your thinking out loud hits the nail square on the head. Those so called, bolt on sampson posts are toys when compared to a real post.

A true Sampson post is like an iceberg. The little bit of it that protrudes above the deck is a small fraction of the inherent strength and support that remains unseen below.

Whether it is made of metal or wood, the properly designed and installed post is one of, if not the strongest parts of the yacht. There is no concern that it will buckle, bend or shear under heavy load. The post is an integral part of the boat, itself.

Depending upon the size of the boat and the anticipated working load that it will be subjected to, plus an extra margin for safety, a 5" or 6" oak post will withstand a tremendous load. Some people prefer to use a 3", 3 1/2" or 4" schedule 40 or stronger pipe for the post

There is an interesting point that might be worth mentioning at this time.There are times when skippers opt to drag the sea anchor, drogue, etc, off the stern to slow the ship down. Doing this could expose the cockpit to following seas and possibly getting pooped.

At other times, some skippers may elect to drag the sea anchor off the bow. This method keeps the cutwater dead on into the wind and waves. On some craft with a cut away keel, the bow deployed anchor helps prevent the ship's bow from meandering back and forth and being quarter broadsided. This will probably reduce to some degree, violent rolling and yawing FWIW.

Best regards,
O J

[s.v. LaVida]

OJ,

Well I need to ----- or get off the pot, so I'm going with using the midship and stern cleats, increase their backing plates and pray!

I think the 4 legged bridle will suffice, if it doesn't, hopefully, you'll have a good time at the wake!

Off to break some ice and pull a prop shaft.

sea u,
rit

[Oswego John]

Hi Mike and all,

After reading Leo's post this afternoon, I just spent the last hour or so on this snowy afternoon going through the USCG report on the use and effect of sea anchors, parachutes and series drogues. There is some eye opening reading in it.

First of all, don't even give a second thought to deploying a sea anchor off the bow. Although we have heard of it being an alternate method in rough seas, don't do it. I respect the results of the controlled experiments conducted by the USCG and now have a new appreciation for what they recommend.

The series drogue is probably the way to go. They point out that the use of a bridle is advised. One of the weakest links in the tow assembly is line abrasion and fraying of the bridle from continued use for a long period of stormy conditions. When using a bridle, stainless steel blocks are advised as well as using reinforced thimbles for eyesplices, avoiding the use of common galvanized sheet metal thimbles.

One of the suggestions that intrigued me was the recommendation to use a specially made car on your genoa track for a point of attachment of the bridle. Go figure that out.

Lake effect for yesterday, today and all next week.
Whatever

Good luck,
O J

[s.v. LaVida]

I came to the same conclusions after reading the report as you did, OJ.

As I mentioned in one of the other posts about this subject, I've been on work boats, using a sea anchor and it was a terrible struggle, to get it back on board and we had a crane!

Wow, I don't know that I'd want to put that much strain on the cars. What do you do if your having to hoist some storm sail?
the load on the bridles can approach the displacement of the vessel. All on a car? They must have some substantial cars to handle that lot.

Too bad I'm not still in the water, Lake Ontario has had some huge seas this past week, would have been proper proving grounds for the drogue.

sea u,
Mike

[Oswego John]

Mike

I don't intend to beat this thread into the ground but the observations I'm getting as I delve deeper into the subject bear mentioning.

I, too, was suspect of the USCG report suggesting anchoring the bridle ends to the genoa cars. As I see it, very iffy at best. All in all, the report was very illuminating. My personal view was that it was redundant in some areas.

By the Coast Guard's own admission, up to the time period of the tests, the tests didn't go as far as they would have liked them to go. Since that time and now, maybe advanced tests might have been taken, I don't know.

Much of the testing was made on various scale models in test tanks. A 25' and a 28' sailboat were used for open water testing in moderatly rough seas. The 25' boat did great in the test. The 28' boat wound up on a rocky shallow shelf which all but destroyed the series drogue. Because of the inherent danger of loss of life and property, no actual tests were conducted involving sailing craft in the 30' to 40' range in actual storm conditions with up to 20' or 25' waves.

Except for one paragraph or so, there was very little mention of what prevention measures should be taken from cresting waves crashing into the cockpit and smashing through the companionway. It does mention reinforcing the hatchway and doors. Safety straps and harnesses should be securely fastened below decks for the crew, who could be subjected for up to 4 Gs of force.

I saw no mention of locking the steering system perfectly straight ahead in order to minimize the excessive pounding the rudder will receive from following seas for an extended storm period.

Mike, I realize that you have read this report. I guess that I'm trying to make others aware of the conditions that could arise and some of the preventive measures that must be taken to survive these conditions.

I'm still wondering about anyone attaching a drogue harness to genoa cars. Your boat, empty, weighs almost 14,000 lbs. Add to that the weight of the crew , provisions for an extended period plus the added weight of extra safety paraphernalia. It is suggested to use 3/4" nylon towing line, on gennie cars????

Whatever,
Have a good weekend
O J

[Craig LeBlanc]

Hi OJ
Iamb a little late with this but here's my 2 cents.
I read the report and they talked about adding a "SPECIAL EYE" to the genoa tracks. Makes sense to me my tracks are only 4 feet long and end forward of the jib sheet winchs, if I changed these to run all the way back and had a heavy duty eye welded to the aft ends the loads would be spread out along a good portion of the hull and much stronger then the just the deck. I just changed my tracks and cars one size up last summer wish I would have caught this thread earlier.
So much too learn
I guess that's why I love this thing we call sailing.

Mike

I don't intend to beat this thread into the ground but the observations I'm getting as I delve deeper into the subject bear mentioning.

I, too, was suspect of the USCG report suggesting anchoring the bridle ends to the genoa cars. As I see it, very iffy at best. All in all, the report was very illuminating. My personal view was that it was redundant in some areas.

By the Coast Guard's own admission, up to the time period of the tests, the tests didn't go as far as they would have liked them to go. Since that time and now, maybe advanced tests might have been taken, I don't know.

Much of the testing was made on various scale models in test tanks. A 25' and a 28' sailboat were used for open water testing in moderatly rough seas. The 25' boat did great in the test. The 28' boat wound up on a rocky shallow shelf which all but destroyed the series drogue. Because of the inherent danger of loss of life and property, no actual tests were conducted involving sailing craft in the 30' to 40' range in actual storm conditions with up to 20' or 25' waves.

Except for one paragraph or so, there was very little mention of what prevention measures should be taken from cresting waves crashing into the cockpit and smashing through the companionway. It does mention reinforcing the hatchway and doors. Safety straps and harnesses should be securely fastened below decks for the crew, who could be subjected for up to 4 Gs of force.

I saw no mention of locking the steering system perfectly straight ahead in order to minimize the excessive pounding the rudder will receive from following seas for an extended storm period.

Mike, I realize that you have read this report. I guess that I'm trying to make others aware of the conditions that could arise and some of the preventive measures that must be taken to survive these conditions.

I'm still wondering about anyone attaching a drogue harness to genoa cars. Your boat, empty, weighs almost 14,000 lbs. Add to that the weight of the crew , provisions for an extended period plus the added weight of extra safety paraphernalia. It is suggested to use 3/4" nylon towing line, on gennie cars????

Whatever,
Have a good weekend
O J

[Didereaux]

Jordan has added a page on anchoring and mooring(directly tied into drogue deployment).
http://jordanseriesdrogue.com/D_14.htm
Quite a bit more info on stern anchoring as well.

[Dick Barthel]

I haven't read this thread but at the risk of covering something that has already been mentioned, this month's Sail magazine had an article on a lost rudder and how a drogue was deployed to one side to assist in steering.

Dick