The criteria of "blue"

[paulanthony]

Originally Posted by Jon Eisberg

[COLOR=Blue][COLOR=Blue]




Absolutely mind-boggling, the extent to which this cluster-f impeded the utility of the cockpit... And at night, fuggeddabouddit, the only solution when you actually wanted to be able to see, would be to simply drape a beach towel over the whole stoopid thing :-)


But again, based on what I'm seeing out there these days, that's probably just me...

Or, perhaps the distortion of a wide angle lens... :-)

Why have one when you can have two?



Seems silly to me also. Why pay a lot of money for a 360 vista of the deep blue and then spoil it. There would seem a perfect spot for a screen on the end of that table in the shot. Why would they not use that to position a monitor?

[jwcolby54]

Originally Posted by paulanthony

We will listen Ken. Don't worry. Splain it to us please. Would love to see your take on fluid dynamic theory.... Here is a reference page on hydrostatics to help you but not sure you will need it with your wealth of knowledge. Fundamentals

Can't wait for this.. So excited.

And then get out your copy of "Characteristics" and "splain" what specifically is wrong in there.

Can't wait for this.. So excited.

[jwcolby54]

Originally Posted by Jon Eisberg

Absolutely mind-boggling, the extent to which this cluster-f impeded the utility of the cockpit... And at night, fuggeddabouddit, the only solution when you actually wanted to be able to see, would be to simply drape a beach towel over the whole stoopid thing :-)

Maybe not. I have never seen any of this gear but in mapping widgets for land use, the display can often be switched to red light and dimmed down a lot.

Still and all, I get your point.

I have to say, the point of sailing is supposed to be to get out and enjoy the sea. It seems unlikely that the skipper can even see the sea on that rig.

[Steadman Uhlich]

Originally Posted by Pelagic

I am sure we are all aware that in order for 'Criteria' to be meaningful, .....testing conditions must be very well defined.

If we make high quality build materials, execution, systems and good seamanship ALL assumed constants, ......then the design decisions on "scantlings, hull form, weather deck, rigging and static stability become the major testing Criteria.

But what about the testing Conditions?

If we tested for 'Survivability' then that might favor the design with the heaviest scantling for a given material's use ..... But how does that weight penalty affect weather deck dryness in normal trade wind conditions?

If we tested for stability then what about dangerous G-forces with excessive beam on a given hull design or a design that produces high speeds?

Also the dynamics of ocean passages and wave forms makes this an even tougher criteria decision as does the reality that those blue water passages represent a relatively small percentage of your enjoyment onboard and you will prioritize creature comforts into the mix.

For those searching for the Holy Grail...it is what makes our chosen craft so personal and distinctly human.

We fall in love with that lady...warts and all.... and learn to keep our boat and all on board within their designed comfort level.

The enthusiastic research and hunting for that special lady is a trait we all have in common and should not become a judgmental weapon.

Thank you for posting your comments above. I found them thoughtful and interesting to see in this thread.

Regarding the characteristics, I liked what you wrote about the issues regarding choices made in boat design.

As with most things in life, I consider it a matter of "balance."

And I like to read comments in a discussion like this that show balance, and an understanding of human nature, as yours do.

I particularly like your last point.

[jwcolby54]

Originally Posted by Jon Eisberg

When you're done with DESIRABLE & UNDESIRABLE CHARACTERISTICS..., you really owe it to yourself to get Bob Perry's book... A wealth of information conveyed in Bob's typical straightforward fashion, not to mention a very entertaining read...

I have it. Bought it the day it was mentioned way back in this (or some) thread.

And it is a fascinating read, though a lot of "story" to wade through. I am just getting to the part where he goes into hull lines (as in the drawings and slices in the various directions). Now it is getting interesting.

[NevisDog]

Originally Posted by jwcolby54

And BTW they discuss how a following sea crashing on a boat can put gigantic pressure on the rudder, causing it to slam sideways. ...

And of course, "laying up" entirely removes the problems of the rudders since the boat is no longer moving (twitching) and the seas aren't slamming against the rudders sideways.

OK, so if modern physics, materials or design make any or all of that stuff above moot, please feel free to discuss, in technical terms, how so.

Part of the problem I notice is that it's mainly the racing community that end up in strife due to adverse weather combined with poor hull configuration. Many cruising folks will avoid the worst weather conditions their entire cruising lives (very sensibly), so they don't actually have the experience of the Pardey's, or the racing community, so when you or I bang on about strength/safety/survivability, many will happily tell you to just buy a boat and get out there - nothing to fear, nothing to worry about, every rudder is strong enough. They don't mean to be disparaging - it's just their personal experience can be very different from much of what we read in books.

A couple of quick points:
1. Lying ahull, whether to a sea anchor or not, doesn't mean your rudder is safe. It's when the yacht is driven backwards (by an extra large wave) that the rudder is most vulnerable, as it flies off to maximum stop angle and has maximum side loading.

2. Steve Dashew does seem to have solved most of the spade rudder problems.

3. The joy of handling a yacht with spade rudder, compared to the sometimes ponderous control offered by, and heavy tiller loads imposed by the 'barn door' keel-hung rudder is enough to convert most sailors (just not me).

[Steadman Uhlich]

Originally Posted by barnakiel

I do not buy the argument that people without boats or people who do not sail are lacking anything when it comes to discussing things blue and offshore.

Imagination is of paramount importance. And there does not seem to be any unjust distribution of imagination between the landlubber and the one who sees (himself/herself) as an old salt.

Experience may count, BUT experience is formed while sailing specific boats on specific waters.

So I say I am 100% fine with blue/offshore whatever visions and prejudices made by each party.

Cheers,
b.

Barnakiel,

I was surprised to read your comments above.

Pleasantly surprised.

I found them brave and insightful.

And, coming from someone like yourself who has sailed a lot further on blue water than most and in a smaller boat than most, I found them particularly valuable in a forum like this that attracts all kinds of sailors, of varying levels of experience, who have their own biases for their own boat or brand or type of boats.

Thank you for adding your voice and views to this forum and this discussion.

[paulanthony]

Originally Posted by NevisDog

A couple of quick points:
1. Lying ahull, whether to a sea anchor or not, doesn't mean your rudder is safe. It's when the yacht is driven backwards (by an extra large wave) that the rudder is most vulnerable, as it flies off to maximum stop angle and has maximum side loading.

Very true... I read about a 42 foot cat. New design(will try to remember the name - American one I think) which had to be abandoned because it got pushed backwards in a heavy sea and both rudders were lost in the way you describe above. They were at maximum stop angles and for a moment were being used to part the ocean until they structurally failed in a big way.

Found it... Alpha 42 http://www.practical-sailor.com/blog...t-11328-1.html

[jwcolby54]

Originally Posted by Jon Eisberg

When you're done with DESIRABLE & UNDESIRABLE CHARACTERISTICS..., you really owe it to yourself to get Bob Perry's book... A wealth of information conveyed in Bob's typical straightforward fashion, not to mention a very entertaining read...

I have it. Bought it the day it was mentioned way back in this (or some) thread.

And it is a fascinating read, though a lot of "story" to wade through. I am just getting to the part where he goes into hull lines (as in the drawings and slices in the various directions). Now it is getting interesting.

[FastCruiser]

Originally Posted by jwcolby54

Cool pictures. Having no boat, nor even an hour of sailing, and having been told to "shut the ... up" (more or less) because of that, I hesitate to open my mouth again. All I can claim is that I am reading voraciously about this and many other subjects. The reading, contrary to popular opinion, does not appear to be the "opinion" of the author, but rather what is understood about the issue.

So a spade, being entirely free hanging can have the shaft offset into the interior of the rudder. This allows the spade to be balanced such that the water flowing over it does not push it to one side or the other. This allows the full spade to be very light to steer, even when turning hard.

That "push" is one of the problems of the keel hung rudder. When the rudder turns either direction, the water flowing against it pushes back, making steering hard. A skeg hung rudder doesn't have the shaft offset either, so it cannot be balanced either. So it is harder to steer than the spade IF the spade has an offset shaft, though (apparently?) not as hard as the keel hung rudder.

All of that, btw came from a 25 year old worthless book that I made the mistake of buying before asking the considered opinion of the old salts on this forum. Complete with diagrams and pictures showing how and why each of those things are true (according to that 25 year old book at least).

So the full spade rudder OTOH has a weakness, that large seas pushing sideways on the boat will apply enormous lateral pressure on that spade rudder. Since the rudder is "hung" on a shaft coming through the hull astern, if the lateral pressure is high enough the shaft bends at the point where the shaft exits the hull and enters the spade. If the pressure is large enough, and the shaft is strong enough, the entire ass end can be ripped open. Something has to give. Both of these things have occurred apparently. Given that this was mentioned in my 25 year old worthless book, it is impossible (for me) to say whether modern materials and engineering has entirely fixed this problem.

The ONE large benefit of the keel hung rudder is that it can have a bushing at the very end of the rudder shaft, at the bottom of the keel. This makes the likelihood of the shaft bending remote, and the likelihood of the aft end being ripped open remote. Furthermore, the lateral pressure simply causes the rudder to swing sideways, and said pressure simply slips past.

OK so someone just a few posts back validated (or at least concurred) with what I had read in my 25 year old book about the steering issues that can occur with the skeg hung and spade rudders.

With drawings and diagrams, the book discussed how, when a boat keels over, the shape of the hull changes. The rudder comes up, and in fact (apparently) the fin keel and the skeg / spade start to "fly" aerodynamically (or hydro-dynamically), which together with the keel shape change causes the nose to point windward. This can cause the boat to literally dump the sails and come to a halt if not actively managed. With no forward motion, no water flowing over it, now the rudder is useless, you can't steer until you adjust the sails to get back under way. So specifically in bad weather, the spade and skeg hung rudders both make the boat more skittish at certain angles of attack. This seems to be a problem mostly when the boat is sailing up wind and keeled over.

The full keel (not fin) has an enormous area relative to the fin keel and tries to keep the boat on course. This is precisely why the fin became so popular, because it "steers better" - in most cases. But not all.

OK, so that is all book knowledge. AFAICT it is not "opinion" but an explanation of the physics behind what actually can and does happen. Of course, I will stress again that I don't own a boat, nor even have any sailing time so who am I to try to bring this information to the table eh?

I also assume that everyone here already knows this since I have been told that there was nothing I could say that anyone on this forum didn't already know. I suspect however that some of us junior types might enjoy this discussion.

I am also reading the Pardey's "storm tactics handbook". I fear recommending it too highly since I also failed to get the approval of the salts on the forum before buying this book. However at least the Pardeys do appear to have enough experience that maybe their "opinion" will be looked upon favorably?

And BTW they discuss how a following sea crashing on a boat can put gigantic pressure on the rudder, causing it to slam sideways. Of course their solution is to "Lay up early, Lay up often" to paraphrase. I am still trying to wrap my mind around that whole "following slick" thing but they swear by it. A fascinating book for me. The idea of dragging a parachute through the water to slow the boat down when laid up is cool.

And of course, "laying up" entirely removes the problems of the rudders since the boat is no longer moving (twitching) and the seas aren't slamming against the rudders sideways.

OK, so if modern physics, materials or design make any or all of that stuff above moot, please feel free to discuss, in technical terms, how so. This truly is just my understanding of a rather complicated set of ideas, which I am trying hard to assimilate, so that I may become (willingly) one of the Borg.

You're not going to like what I say here, and NO, I'm not using the "Skipper" word here, at least not yet.
Yes, many old salts, as myself, (Randy here) have read these books but have also found that as true as they are, they are also false.
There is to much grey area to be exact in any of the information you mention and when someone states its FACT, many "Old Salts" just set back, have another drink of beer and roll their eyes a bit.
Keel hung and skeg rudders can be balanced and I've seen it. By adding more mass to the leading edge of the rudder.
You bring up the Pardeys, and they have a mass amount of knbowledge but I for one know, A newer performance hull will almost always run from its slick and its harder to get it to set still, than take another option.. Its a grey area.
The effects of a hull when healed.. different designes are built based on how the boat sails or is designed to sail..
Our boat is designed to sail at about 12 to 15 degrees, sailing flat on its bottom is like trying to drive a skate board, but at 12 degrees, she locks in solid and screames. its all grey area.
anything you read, take it with a grain of salt, but dont state its fact as someone will prove you wrong.

Now I'll use that skipper word, as after a time sailing different boats, you as a skipper will find a motion you like in a boat along with everything else that and make your own decisions..

[jwcolby54]

Originally Posted by NevisDog

A couple of quick points:
1. Lying ahull, whether to a sea anchor or not, doesn't mean your rudder is safe. It's when the yacht is driven backwards (by an extra large wave) that the rudder is most vulnerable, as it flies off to maximum stop angle and has maximum side loading.

I have only the Pardee book to go on, but it seems that "laying ahull" means taking down all sail and turning the boat loose to survive, which is mostly does but... as you describe...

What the Pardeys are trying to teach is something called laying lying "hove to" which is a process of getting the boat into a specific sail state and pointed into the wind such that the boat is not moving forward. It is drifting sideways now but it is under sail. This can be done with or without a device (parasail).

Apparently this process, this method of handling the boat has been done for as long as there is records about sailing. So it is not new.

if a parasail is used, it is put in the water and ends up "upwind" of the boat, acting as an anchor if you will but not a metal object hooked to the bottom.

So the Pardeys are trying to demonstrate is that using this technique, the boat casts a shadow down wind, similar to a wake. This area is calm(er) and the boat is sailing (drifting sideways) down into that calmer water. They show how to get the boat headed at a 60 degree heading "into" the wind, which maximizes the "shadow". The sea anchor does nothing more than slow the drift down wind into that shadow. So instead of drifting one or more knots per hour, you drift well under one knot per hour, because the anchor is dragging through the water (up wind) resisting the boat drift.

And they claim that when you get your boat into this attitude and sail state, the seas, no matter how violent, "calm" behind the boat and makes the waves die down in the immediate vicinity of the boat. You create your own little island of stability.

OK, so I am not a sailor, do not own a boat (yet), I just have read a book. It seems that this strategy is well understood by commercial boats of all types and used extensively by everyone but yachts. Big freighters even, fishing boats, etc.

So I recommend the book. It can explain much better.

"Storm Tactics" by the Pardeys.

[leftbrainstuff]

Originally Posted by Greenhand

So, if it is that important to you, and it is up to you, create the website as resource. There. Done.

The boatbuilding industry has no reason to pursue this. As long as rescues don't exceed mandatory training days, the average government has no reason to pursue it...to paraphrase your comments, only the consumer cares and there are so few consumers who care that it is up to the consumers to figure it out for themselves. Which is pretty much the system already in place, just without your fancy equalizer.

Nicely summarized.

At the end of the day its up to you how much risk you are prepared to accept and how you manage that risk.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[paulanthony]

Originally Posted by FastCruiser

You're not going to like what I say here, and NO, I'm not using the "Skipper" word here, at least not yet.
Yes, many old salts, as myself, (Randy here) have read these books but have also found that as true as they are, they are also false.
There is to much grey area to be exact in any of the information you mention and when someone states its FACT, many "Old Salts" just set back, have another drink of beer and roll their eyes a bit.
Keel hung and skeg rudders can be balanced and I've seen it. By adding more mass to the leading edge of the rudder.
You bring up the Pardeys, and they have a mass amount of knbowledge but I for one know, A newer performance hull will almost always run from its slick and its harder to get it to set still, than take another option.. Its a grey area.
The effects of a hull when healed.. different designes are built based on how the boat sails or is designed to sail..
Our boat is designed to sail at about 12 to 15 degrees, sailing flat on its bottom is like trying to drive a skate board, but at 12 degrees, she locks in solid and screames. its all grey area.
anything you read, take it with a grain of salt, but dont state its fact as someone will prove you wrong.

Now I'll use that skipper word, as after a time sailing different boats, you as a skipper will find a motion you like in a boat along with everything else that and make your own decisions..

That's true Randy but what he is doing is testing his learnt theoretical knowledge base within the theatre of experience(people like you) to get feed back as to the value/accuracy of what he has leant and of course for the simple sake of enjoyable dialogue about an interesting subject. Effectively, you are his tester and the way you have responded to him was kind, respectful and informative with out condescension which is great. That's what us less knowledgeable members want from old salty's

[K_V_B]

Originally Posted by jwcolby54

Cool pictures. Having no boat, nor even an hour of sailing, and having been told to "shut the ... up" (more or less) because of that, I hesitate to open my mouth again. All I can claim is that I am reading voraciously about this and many other subjects. The reading, contrary to popular opinion, does not appear to be the "opinion" of the author, but rather what is understood about the issue.

And personally I have no issue with you posting here what you read. I find it quite interesting...

So a spade, being entirely free hanging can have the shaft offset into the interior of the rudder. This allows the spade to be balanced such that the water flowing over it does not push it to one side or the other. This allows the full spade to be very light to steer, even when turning hard.

The other thing about a spade rudder is that it is hydrodynamical more efficient. So you can get the same steering forces from a smaller rudder.

So the full spade rudder OTOH has a weakness, that large seas pushing sideways on the boat will apply enormous lateral pressure on that spade rudder. Since the rudder is "hung" on a shaft coming through the hull astern, if the lateral pressure is high enough the shaft bends at the point where the shaft exits the hull and enters the spade. If the pressure is large enough, and the shaft is strong enough, the entire ass end can be ripped open. Something has to give. Both of these things have occurred apparently.

Spade rudders do need to be properly engineered. But as far as I can see the consensus amongst NA's is that this can be done, and that this is the way to go. It's for example interesting what Steve Dashew writes on the subject. Here you have someone who has lots of experience and knowledge, and who does like to make things bulletproof.
One of the things one can do with a spade rudders is design it so that part of it will break away under heavy load. That way you can dissipate forces, but still keep some steering.
SetSail » Blog Archive » What is the Best Rudder Configuration – Spade, or Skeg Mounted?

[FastCruiser]

Originally Posted by jwcolby54

I have only the Pardee book to go on, but it seems that "laying ahull" means taking down all sail and turning the boat loose to survive, which is mostly does but... as you describe...

What the Pardeys are trying to teach is something called laying lying "hove to" which is a process of getting the boat into a specific sail state and pointed into the wind such that the boat is not moving forward. It is drifting sideways now but it is under sail. This can be done with or without a device (parasail).

Apparently this process, this method of handling the boat has been done for as long as there is records about sailing. So it is not new.

if a parasail is used, it is put in the water and ends up "upwind" of the boat, acting as an anchor if you will but not a metal object hooked to the bottom.

So the Pardeys are trying to demonstrate is that using this technique, the boat casts a shadow down wind, similar to a wake. This area is calm(er) and the boat is sailing (drifting sideways) down into that calmer water. They show how to get the boat headed at a 60 degree heading "into" the wind, which maximizes the "shadow". The sea anchor does nothing more than slow the drift down wind into that shadow. So instead of drifting one or more knots per hour, you drift well under one knot per hour, because the anchor is dragging through the water (up wind) resisting the boat drift.

And they claim that when you get your boat into this attitude and sail state, the seas, no matter how violent, "calm" behind the boat and makes the waves die down in the immediate vicinity of the boat. You create your own little island of stability.

OK, so I am not a sailor, do not own a boat (yet), I just have read a book. It seems that this strategy is well understood by commercial boats of all types and used extensively by everyone but yachts. Big freighters even, fishing boats, etc.

So I recommend the book. It can explain much better.

"Storm Tactics" by the Pardeys.

Another grey area, as a performance yacht will NOT lay a-hull.. the underwater design makes the boat want to sail off the slick. without the sails up.
you see it mentioned often on the forum as folks as how to keep their boat in one place while at anchor in a current.
Let me re-phrase that, its hard as hell to get a performance hull to "hove-to" as it wants to sail out of its slick.. and another grey area, you can do it, but as the conditions change, you have to change the way the boat sets against the para-anchor.