Acquiring A Ready Made Series Drogue

[alctel]

The emergency rudder thing bothered me a lot as well, with no real good solutions. In the end I ditched my existing windvane and got a different one with an auxiliary rudder - basically a ready-to-go emergency rudder.

I would say at least half of the abandoned boats over the last few years were due to losing the rudder so it is a fairly important thing.

[thinwater]

If you chose an emergency rudder instead of a drogue for emergency rudder, you may still want to have some sort of plan for stabilizing the boat while you install it. You won't be hove to, since the rudder is either gone or jammed over, and the boat will be out of control. Any simple drogue will help.

(I learned this while testing steering drogues in rough weather--it's not dangerous but it is hateful working on an out of control boat.)

Sizing. This is going to vary with the boat, sail balance, design, and conditions, and is thus a long story. However, unlike speed limiting drogues, they are adjusted during use; when the drag is too much you pull it in tight behind the boat until it begins to lift out of the water. Unless the weather is severe, the drogue is attached right to the bridle and is not far behind the boat, no more than 40 feet and sometimes only 10 feet.

(For the amount of money you are spending, subscriptions are cheap. The internet has bred the unfortunate assumption that information should be free, decimating research and editorial budgets. Advertising only pays for infomercials.)

[thinwater]

Originally Posted by alctel

The emergency rudder thing bothered me a lot as well, with no real good solutions. In the end I ditched my existing windvane and got a different one with an auxiliary rudder - basically a ready-to-go emergency rudder.

I would say at least half of the abandoned boats over the last few years were due to losing the rudder so it is a fairly important thing.

Can the vane rudder steer the boat with the main rudder gone? My understanding is that they still rely on the main rudder for lateral plane and trim. I would research that.

[Matt Johnson]

]I can't find the photos of the cassette, but here is the emergency rudder bracket we built for our Sabre. The cassette and bracket were hooked up when heading offshore and a rudder blank could be just dropped in place and tied down. The rudder was controlled via a set of pulleys to the stern quarters. I never actually built the rudder itself, but carried a board that could work if needed. Even without a elliptical profile, the 2"x12" board could steer the boat.

Maybe you can mount an emergency rudder offset and outside your stern platform.

Matt

[Dockhead]

Originally Posted by thinwater

Can the vane rudder steer the boat with the main rudder gone? My understanding is that they still rely on the main rudder for lateral plane and trim. I would research that.

Some wind vanes are specifically designed to be used also for emergency steering -- IIRC Hydrovane, and perhaps some others. I have heard that they work well for this.

[Dockhead]

Originally Posted by funjohnson

]I can't find the photos of the cassette, but here is the emergency rudder bracket we built for our Sabre. The cassette and bracket were hooked up when heading offshore and a rudder blank could be just dropped in place and tied down. The rudder was controlled via a set of pulleys to the stern quarters. I never actually built the rudder itself, but carried a board that could work if needed. Even without a elliptical profile, the 2"x12" board could steer the boat.

Maybe you can mount an emergency rudder offset and outside your stern platform.

Matt

A nice setup

[Fuss]

Originally Posted by thinwater

If you chose an emergency rudder instead of a drogue for emergency rudder, you may still want to have some sort of plan for stabilizing the boat while you install it. You won't be hove to, since the rudder is either gone or jammed over, and the boat will be out of control. Any simple drogue will help.

(I learned this while testing steering drogues in rough weather--it's not dangerous but it is hateful working on an out of control boat.)

Sizing. This is going to vary with the boat, sail balance, design, and conditions, and is thus a long story. However, unlike speed limiting drogues, they are adjusted during use; when the drag is too much you pull it in tight behind the boat until it begins to lift out of the water. Unless the weather is severe, the drogue is attached right to the bridle and is not far behind the boat, no more than 40 feet and sometimes only 10 feet.

(For the amount of money you are spending, subscriptions are cheap. The internet has bred the unfortunate assumption that information should be free, decimating research and editorial budgets. Advertising only pays for infomercials.)

Dockhead, can you explain to me why you would want to spend so much of your time on this forum asking questions related to your Greenland expedition, but are not prepared to subscribe to the morganscloud website for 20 euros a year and have access to one of the best information sources from people with the most experience with exactly what you want to do.
You are a lawyer which means you should be familiar with what good advice costs. But somehow when it comes to your hobby, you seem to prefer free, often incorrect information.
I don't understand this logic.

[Pete7]

Originally Posted by Fuss

subscribe to the morganscloud website for 20 euros a year and have access to one of the best information sources from people with the most experience with exactly what you want to do.

Yes any of us could spend E20, but half the fun is in the chase; as Keats describes in his Ode to a Grecian Urn. Also the real value is bringing together dozens of people with different ideas and experiences to find the best compromise between available time, cost, effort and efficiency.

Pete

[kmacdonald]

Originally Posted by Pete7

Yes any of us could spend E20, but half the fun is in the chase; as Keats describes in his Ode to a Grecian Urn. Also the real value is bringing together dozens of people with different ideas and experiences to find the best compromise between available time, cost, effort and efficiency.

Pete

Yea, and many new ideas on old issues will come to light. New materials and designs can improve reliability to the point failures are virtually eliminated. Think titanium rudder stock and frame. Eliminate the potential for corrosion failures in the rudder. Unfortunately change happens slowly and with great resistance.

[Dockhead]

Originally Posted by Fuss

Dockhead, can you explain to me why you would want to spend so much of your time on this forum asking questions related to your Greenland expedition, but are not prepared to subscribe to the morganscloud website for 20 euros a year and have access to one of the best information sources from people with the most experience with exactly what you want to do.
You are a lawyer which means you should be familiar with what good advice costs. But somehow when it comes to your hobby, you seem to prefer free, often incorrect information.
I don't understand this logic.

It's an interesting question, and I will indeed explain my logic.

My budget for preparing for this trip is over $30k and out of that I have $2k for cartography, pilot books, etc. I have also spent a lot of time in the Cruising Association library in London.

I AM a subscriber to Morgan's Cloud, but Practical Sailor is one more sailing magazine and I already subscribe to YM and PBO and I'm not going to have any more.

As to this: "You are a lawyer which means you should be familiar with what good advice costs. But somehow when it comes to your hobby, you seem to prefer free, often incorrect information" I'm going to give you the benefit of the doubt and assume you just don't realize how rude that sounds -- the idea that I take in "incorrect information" just because I'm too cheap to pay for a sailing magazine, and don't have the judgement to discern that the free information I take in is incorrect -- give me a break!!

Getting good information on very complex subjects is a serious task, requiring work and judgement, which cannot be solved just by throwing money at it in any case. One of the most powerful tools there is, probably the single most powerful tool, actually, and how much it costs is irrelevant, is discussion with a wide range of people with wide experience and expertise -- done here and on GCaptain and YBW. Of course you have to exercise judgement, because you have people making bold statements who don't actually understand anything, right next to people like Evans Starzinger, Snowy Petrel, Thinwater, and many others, who are among the most knowledgeable people in the world on a number of subjects. On CF, you get to ask questions and develop themes and dig deep when you need to -- this is generally a much more powerful learning tool than simply reading something in a magazine where a given article is generally the point of view of just a single person, the writer.


As to posting links behind paywalls -- it's bad form on here in any case. I'm thinking not so much about myself, as I am the hundreds and sometimes thousands of people who read these threads. If the link contains information essential to the discussion, then the plot is lost by the majority of people who are unwilling to spend $30 just to keep up with a single thread in a single discussion. The gist of the article, within the limits of fair use, should be posted, so that those reading the thread but with no other need for the resource, can keep up with the discussion.

[MartinR]

Originally Posted by kmacdonald

Sea buoys don't support that but they are very limited in location. That may be true in isolated locations but aren't reported buy merchant mariners on a regular basis. I'd like to know ESA's definition of rogue wave is.

I think at the moment the definition is a wave height of 25m. They measured waves that were almost 3 times the significant wave height. This I would definitely call rogue.

Actually sea buoys support this. I think the maximum significant wave height measured by sea buoys is now at 18 or 19m, meaning the maximum waves will be around 35m. Once upon a time nobody believed these figures, so extreme readings were filtered out as faulty. Then only linear wave theory was accepted.
Now we can clearly see that recent predictions from chaos theory seem to be correct.

[thinwater]

I post a lot of material outside of paywalls. For example, this short post on steering drogues is on my blog.

Sail Delmarva: Mexican Navy Tows Disabled Sailboat for 1 1/2 Days.



However, I'm also making a living as a journalist, which limits how much I can post for free. I've been scolded by publishers for being too free with information, and yet sharing information is what writers do. It's our nature. I'm striking the best compromise I know how.

It costs money to collect equipment and to test it. PS is like Consumer Reports in that there is no advertising and thus no commercial bias. The down side is that only subscribers can pay for the work. For example, I tested a lot of drogues in shitty weather for a series of articles. Yes, I found it interesting, but it wasn't free, I got thrown against my tether many times, and I went well beyond my personal interests in order to truly learn the topic and develop meaningful comparisons. I didn't just steer with a Seabrake. I steered with the Seabrake in calm weather, in force 7, then repeated both under sail, then switched to a Galerider, Delta Drogue, and Small Shark and repeated all that. It was quite time consuming.

I also made a lot of mistakes, which I can tell you aren't very fun in rough weather and might be unrecoverable in a storm. Some of them will be boat-specific. So the very best advice may be to practice with a drogue in force 7. In those conditions she'll teach you things without hurting you (assuming you watch your feet and hands).

[kmacdonald]

Originally Posted by MartinR

I think at the moment the definition is a wave height of 25m. They measured waves that were almost 3 times the significant wave height. This I would definitely call rogue.

Actually sea buoys support this. I think the maximum significant wave height measured by sea buoys is now at 18 or 19m, meaning the maximum waves will be around 35m. Once upon a time nobody believed these figures, so extreme readings were filtered out as faulty. Then only linear wave theory was accepted.
Now we can clearly see that recent predictions from chaos theory seem to be correct.

Hummmmm.... that varies significantly from the previous definition of a rogue wave being twice the significant wave height. 25m makes a lot more sense. The twice the significant wave height could label a 1cm wave a rogue wave and that's exactly what some of the studies claim when saying rogue waves exist and "more research needs to be done"----please send money. Some are calling for a "rogue wave prediction center" sort of like the "hurricane center".

[Dockhead]

Originally Posted by thinwater

I post a lot of material outside of paywalls. For example, this short post on steering drogues is on my blog.

Sail Delmarva: Mexican Navy Tows Disabled Sailboat for 1 1/2 Days.



However, I'm also making a living as a journalist, which limits how much I can post for free. I've been scolded by publishers for being too free with information, and yet sharing information is what writers do. It's our nature. I'm striking the best compromise I know how.

It costs money to collect equipment and to test it. PS is like Consumer Reports in that there is no advertising and thus no commercial bias. The down side is that only subscribers can pay for the work. For example, I tested a lot of drogues in shitty weather for a series of articles. Yes, I found it interesting, but it wasn't free, I got thrown against my tether many times, and I went well beyond my personal interests in order to truly learn the topic and develop meaningful comparisons. I didn't just steer with a Seabrake. I steered with the Seabrake in calm weather, in force 7, then repeated both under sail, then switched to a Galerider, Delta Drogue, and Small Shark and repeated all that. It was quite time consuming.

I also made a lot of mistakes, which I can tell you aren't very fun in rough weather and might be unrecoverable in a storm. Some of them will be boat-specific. So the very best advice may be to practice with a drogue in force 7. In those conditions she'll teach you things without hurting you (assuming you watch your feet and hands).

No one is against your earning money from your work -- least of all me, who gets money from writing and speaking and teaching from time to time myself.

Just keep in mind that some people will be following the conversation and won't be willing to pay $30 just to read one article, if they don't otherwise need a subscription to PS. If you just post the gist so that people can at least follow your point, then that gives people of choice, while at the same time attracting some people behind the paywall -- so everyone wins.

Cheers.

[Snowpetrel]

Originally Posted by MartinR

I think at the moment the definition is a wave height of 25m. They measured waves that were almost 3 times the significant wave height. This I would definitely call rogue.

Actually sea buoys support this. I think the maximum significant wave height measured by sea buoys is now at 18 or 19m, meaning the maximum waves will be around 35m. Once upon a time nobody believed these figures, so extreme readings were filtered out as faulty. Then only linear wave theory was accepted.
Now we can clearly see that recent predictions from chaos theory seem to be correct.

"Unusually steep waves are classified as rogues if either: (a) the height (crest from preceding trough), H is greater than twice the significant height, Hs (Hs = 4 times the standard deviation of the wave record); or (b) the crest height, Crx, above mean sea level (MSL) is greater than 1.25 times Hs2. Rogue waves are not necessarily huge, but they are much bigger than the surrounding waves." https://www.nature.com/articles/srep44124

Also see here https://www.nature.com/articles/srep...ink-section-61.

So in a 1 ft chop a 2 ft wave is considered a rogue event, and it's possible (but statistically very unlikely) for a 3 ft wave to exist somewhere in a 1 foot wavetrain. Of course 1.5 foot waves will be reasonably frequent in this 1 foot sea. These wave heights are not an issue for our boats, but maybe they are rogue event for a kid in a small kayak, especially since these rogue waves tend to have a much higher steepness ratio and are more likely to break violently.

I generally plan for a 2x sig wave height wave when deciding things like what hatches to close. Realising that significant wave height is only the average of the highest third of the waves, so you will often see waves much higher than the sig wave height anyway.

The Draupner wave was one of the first electronic readings and was reliably recorded at 25 meters in a 12 meter sig wave height. But plenty of earlier accurate scentific observations had been made of larger waves (eg the '69 obs by scrips reasearch station FLIP) plus numerous seafarers accounts.

https://en.m.wikipedia.org/wiki/Draupner_wave

Wave statistics were pretty well understood before the Draupner wave. My old 93 copy of Van Dorns excellant book 'Oceanography and Seamanship' has a very good discussion of large waves and and the wave spectrum. I think what the modern research is finding is that they tend to be more clumped together in certain areas and conditions rather than evenly distributed, and extra large storm rogue waves are more common deep sea than had prevously been supposed by scientists.

Wave energy increases ^4 to wind speed so if we double the windspeed the wave energy in a fully developed sea goes up 16 times. Wave height goes up by ^2 of windspeed, and wave energy goes up ^2 of wave height.

This CSS Diagram is pretty useful. Handy to have a laminated copy at your chart table for reference.

Here is a good example of its use
http://davidburchnavigation.blogspot...-aleutian.html