Hull Shapes and Behaviour in Heavy Seas

[Mr B]

Originally Posted by boatman61

The Titanic sank because the watertight bulkheads had no roofs so they flooded one overflowing into the other and cascading till she sank..
No one calculated the multiple watertight areas could be affected at the same time.. I think it was 3 or 4 watertight sections were exposed by the gash..
Will google n come back..

Those bulkheads they removed, Saved the company 10,000 pounds at the time, A 2 inch hole in the bottom of the Titanic would have sunk it,

The Titanics sister ship steamed into New York at full speed, with a hole in the bottom three times the size of the Titanics, But it had the full bulkheads, only the crew knew about the hole, It didnt sink,
If they hadnt cheated on the Iron Bulkheads in the Titanic, It would not have sunk either,

[Training Wheels]

When you make broad, negative generalizations about boat types, that can be seen as a personal attack to some. What you have espoused is your opinion, yet you say it is as fact.

[NevisDog]

Originally Posted by Training Wheels

When you make broad, negative generalizations about boat types, that can be seen as a personal attack to some. ..

??? If that's the case then any discussion of boat types and their relative behaviour is futile. Each type is loved by someone, but that shouldn't prevent discussion of the type, whether in broad terms or specifics.

Does no one on CF have experience of these downwind racing sleds? I'd love to hear what it's like aboard one in heavy seas. Does the off-watch get strapped into their bunks or is that an urban myth?

[Icarus]

Originally Posted by daletournier

Oh c'mon, let's see some numbers, how many keels have fallen off vs how many are out there?? It's not even close to be statistically significant, if fact I doubt there's been enough to make any real argument at all.

While boats go to sea there will be mishaps, it's just the way it is BUT to suggest this is the norm or anything but rare is just being prejudice.

I saw a encapsulated keel crack due to internal rusting thus causing the tayana 37 to take on water, all tayana's are bad?
According to the previous posts my above tayana statement is only lodgical?

Keels should not fall off, simple.

[NevisDog]

Originally Posted by Paul L

... The only time the rudder came loose was when it was way over canvassed- ...

Then you have never encountered waves out of proportion in steepness and size to your hull size. Read the Fastnet report for better insight.

[Paul L]

Originally Posted by NevisDog

Then you have never encountered waves out of proportion in steepness and size to your hull size. Read the Fastnet report for better insight.

You can make bold statements like that and keep pushing to the absolute survival storm area if you want. No small boat is comfortable and safe in all extreme storms. Its interesting that there was a J/30, very similar to my J/37, that went through the Fastnet storm with little trouble. Probably kept their rudder in the water the whole time. They were not racing.
http://www.jboats.com/j30-articles-r...-fastnet-storm

[NevisDog]

Paul: "I’ve got to tell you that the J/30 is the best goddamned sailboat in the world for its intended purpose. Only once did I get rolled down by a huge wave. And, I’ve got coffee stains on the cabin overhead to show that it was 120 degrees..."

Yet he went through the Fastnet storm "with little trouble"? Not many rudders stay in the water when rolled to 120. Sure a J-boat is tough and withstood the hammering without damage - not so pleasant for the crew though, perhaps, as a full-keel, heavy displacement yacht? Or did I miss something?

There are two issues here - (1) structural strength is #1, always; (2) seakindliness comes a close second, at least for those of us who gave up racing and punishing ourselves a lifetime ago.

[Paul L]

Originally Posted by NevisDog

Paul: "I’ve got to tell you that the J/30 is the best goddamned sailboat in the world for its intended purpose. Only once did I get rolled down by a huge wave. And, I’ve got coffee stains on the cabin overhead to show that it was 120 degrees..."

Yet he went through the Fastnet storm "with little trouble"? Not many rudders stay in the water when rolled to 120. Sure a J-boat is tough and withstood the hammering without damage - not so pleasant for the crew though, perhaps, as a full-keel, heavy displacement yacht? Or did I miss something?

There are two issues here - (1) structural strength is #1, always; (2) seakindliness comes a close second, at least for those of us who gave up racing and punishing ourselves a lifetime ago.

Well not bad considering the carnage of the fleet.
Do you think the rudders on the full keel boats that got knocked down were functioning?
The point being that a modern under body is not less safe than a full keel. Arguing that one is somehow superior over the other is just not supported by experience.

[NevisDog]

I don't believe any of the few full-keeled yachts out there ('79 Fastnet) got knocked down. It would take more than a force 10 to knock down any full-keeler I've sailed on. And arguing that one type is as sea-kindly as the other, just because they each survive, from my experience, seems utterly ridiculous.

[Paul L]

Originally Posted by NevisDog

I don't believe any of the few full-keeled yachts out there ('79 Fastnet) got knocked down. It would take more than a force 10 to knock down any full-keeler I've sailed on. And arguing that one type is as sea-kindly as the other, just because they each survive, from my experience, seems utterly ridiculous.

OK you win. You gotta have a full keel boat to be safe. Happy?

Are you really serious that you think full keel boats somehow are immune to knockdowns - which are seas driven far more than any wind force?

[NevisDog]

Originally Posted by Paul L

(1) OK you win. You gotta have a full keel boat to be safe. Happy?

(2) Are you really serious that you think full keel boats somehow are immune to knockdowns - which are seas driven far more than any wind force?

Briefly:
(1) Vessel safety depends on structural strength, as mentioned above. Try not to confuse these two issues.
(2) It's not what I think - it's the findings of the report into the '79 disaster - folks lost their lives due to the then-current trend towards excessively wide, excessively-shallow, tender hulls that were/are, beyond any question, seriously at risk of knockdown in storm waves, due to their hull shape.

[Paul L]

ND
#1 no confusion. Try not confuse an extreme IOR design with other designs
#2 style boats are the extreme IOR style boats of the era. I don't think they are are good offshore designs and they had a very poor record in the Fastnet storm, except perhaps for the ver large ones. This doesn't say anything about more modern underbodies vs full keels, so why try and conflate it?

Either way, truce, I'm done with this silly argument.

[daletournier]

Originally Posted by NevisDog

Good point, well made... but Pat has been attacked rather mercilessly for his 'traditionalist' views by the 'modernist' camp, so let's cut him some slack for his retaliation on this occasion. Somewhere between the two extremes lies the truth?

Pat has not been attacked. His strong biases and generalisations have been called out. You have a guy called Jim here that has 250k nm under his belt that has sailed the same waters Pat claims are regularly unsuitable for anything but his style boat, this is obviously not true as Jim has sailed those waters on fin keelers as just one eg.

He says that only a full keeler will survive a heavy grounding, yet I give you a real world recent case of a fin keeler bashing on a reef for five days and surviving intact, another eg of Pats bias dismissed.

As for comfort at sea there are other mistruths here, some need to have things black and white and that just isn't how it is, so many variables. The full keel boat I had which was a similar length as Pats was by far the most uncomfortable downwind boat I'd ever had, rolled like a pig!

I'm not the most experienced here BUT I'm definitely more experienced than many and aren't getting my opinions from numbers and books. As someone that has a reasonably modern hull design with a big bum and a pointy nose and has sailed it across an ocean, beaten into heavy weather, run downwind in a strong gale under bare polls I'm here to say that Nevisdogs view of modern hull designs being incredibly uncomfortable is INCORRECT.

The problem with Pats writing is he presents the Newbie with a bias view as ifs its 100% fact, and in doing so is painting a poor picture of modern designed boats, propelling myths through bias that suit "HIS" view of the world.

Also most will never ever see waves an sea state so steep that the rudder is coming out of the water other than crossing bars etc, which I've done many times and crossing in such conditions is bad seamanship.

Regarding southern ocean going sleds, the young lady in GGR wasn't on an ocean going sled she was on an old full keeler yet she end to end pitch poled in the southern ocean. As pointed out in another post, the Winston Churchill was a big heavy displacement yacht that sunk in the 98 Sydney to hobart, not just fin keelers, just a couple of examples where Pats theory falls down. I know a RYA instructor that was in that sydney to hobart (he's done many) and asked him what they could have done differently, he said "not gone" he laughed at the suggestion made by some that heavy cruising boats would of faired better. He's sailed many boats.

My point is so many variables come into play in heavy weather, just making statements like "full keelers are better" when things get tough is ignoring all those variables....... it dosent work like that.

[daletournier]

Only six of the original 17 starters in the GGR are still sailing and there have been five Southern Ocean dismasting. Some may think this is because the boats are too small, too slow and cannot outrun Southern Ocean storms.*History does not support this assumption.

I don't know why so many have dropped out BUT I do question the authors view that history does not support this assumption. The participants of the current race that have dropped out are "history" not assumptions but fact! Is it because of size or speed? I don't know why exactly they have failed BUT fail they have. You can't cherry pick, the fact is 6 remain out of 17, these are boats that some are arguing are more robust and better suited for ocean sailing. I repeat 6 out of 17 remain.

Regarding a wind vane being better on a full keel vs a fin keel, well this depends! I have a strong autopilot and a Hydrovane on my current boat and had both on my previous boat, both were fin keelers. I use both regularly, have done 12,000nm in last two years using both, ddw, heavy wind 50°forward of the beam, light wind etc., and many more miles in the previous 7 years on my last boat.

Once against people are making assumptions that can not be made as there are so many variables, boats vary in design, size and captains experience, it dosent just come down to hull shape, keel shape.

On my previous smaller fin keel boat the Hydrovane performed 100% perfectly in a variety of conditions, needed very little attention, performed better than my autopilot, and I repeat this was a bolt on fin keel boat with a spade rudder.

The Hydrovane on my current fin keel, bigger faster boat dosent do quite as well, it still performs great but needs more adjustment to fine tune it and more attention to sails. Speed and weight seem to be more determining factors than full keel vs fin keel.

Now here's another variable, what wind vane is the author talking about? There are quite a few. Once again a big broad statement, like others are making in this thread.

Also I've found some just seem to be able to get Windvanes (or at least Hydrovanes) to function better than others. Let's take the GGR as an example. In the GGR thread someone recently posted a video of a participant that dropped out early (sorry, can't remember his name .) One of his issues was he couldn't get the Hydrovane to perform properly YET the race leader and the guy coming third (when I looked a week back) are both successfully using Hydrovanes on the same or similar boats as the guy that couldn't get his to work well.

In fairness I definitely would not say modern hull design is better in heavy conditions than a full keeler, I do not have enough experience to make such a statement, there's just to many variables to say either way, no two captains are the same, there's so many different types of boats in both categories, the condition of individual boats vary considerably, sea conditions vary etc etc, so when I hear blanket "this is how it is" statements like some on this thread make it leads me to question their experience at sea and why they are so sure they are correct.

Regarding the fast net yachts, 1979!!!! these boats a so far removed from what myself and others cruise on that the comparison is laughable.

[daletournier]

And for the record I just sailed across the Mozambique channel and down the South African coast on my 47 foot modern hulled yacht primarily using a Hydrovane. My autopilot failed twice on this trip, the belt and then the brushes, the Hydrovane didn't fail at all and handled all that was thrown at it.

The below picture is the speed at which we were sailing at for many many hours due to current assistance while being steered 100% by the Hydrovane. I was reefed (furled) quite heavily here trying to keep the speed under 12 knots.