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TJ D · 15-05-2016, 21:31

This is a great thread.

It's interesting to read the different perspectives here. All I can say is that I have been indoctrinated since childhood that heavy boats with small rigs, and lots of overhangs were the real 'sea boats'. Then in 2013, an amazing thing happened. I sold my 43' steel Roberts tank, and switched to the exact opposite end of the spectrum.

We've sailed RS about 11,000 miles since then, in conditions mild and robust, and I can state without reservation that I will never voluntarily embark on a passage on a boat with a waterline substantially shorter than the LOD.

Now, I would also not choose a boat like ours for the kind of expedition sailing that Dock is contemplating. For that, I would incorporate a lot of modern design elements, but would build heavier, out of aluminum, with a lot of watertight compartmentalization and a proper inside watchkeeping station.

For the rest of us, I submit that a well-built modern hull is superior to the older heavy boats in just about every way. (Emphasis on well-built).

TJ

TeddyDiver · 15-05-2016, 22:10

Quote:

Originally Posted by TJ D

This is a great thread.

For the rest of us, I submit that a well-built modern hull is superior to the older heavy boats in just about every way. (Emphasis on well-built).

TJ

Agreed!
The conversation has merely been about some design aspects in modern boat building and their pros and cons.
I'm might sound sometimes speaking against some of these characteristics but that's just to bring some reality to the one sided praisal sometimes seen around. In reality EVERY design feature, how well thought and whatever, has their drawbacks and we should recognize them especially when it's what we choose to have.

BR Teddy

**Dockhead** · 15-05-2016, 23:49

Quote:

Originally Posted by TJ D

This is a great thread.

It's interesting to read the different perspectives here. All I can say is that I have been indoctrinated since childhood that heavy boats with small rigs, and lots of overhangs were the real 'sea boats'. Then in 2013, an amazing thing happened. I sold my 43' steel Roberts tank, and switched to the exact opposite end of the spectrum.

We've sailed RS about 11,000 miles since then, in conditions mild and robust, and I can state without reservation that I will never voluntarily embark on a passage on a boat with a waterline substantially shorter than the LOD.

Now, I would also not choose a boat like ours for the kind of expedition sailing that Dock is contemplating. For that, I would incorporate a lot of modern design elements, but would build heavier, out of aluminum, with a lot of watertight compartmentalization and a proper inside watchkeeping station.

For the rest of us, I submit that a well-built modern hull is superior to the older heavy boats in just about every way. (Emphasis on well-built).

TJ

I agree with all of this, except only one thing -- there is no such thing as a "modern hull". The design tradeoffs have not disappeared.

Some kinds of hull types -- heavy, full keel -- have almost disappeared, but the other choices are very much alive and well, and as hard to make as they ever were.

Only on the pages of glossy magazines is there only one type of "modern" hull type. The advertisers don't want you to think about the tradeoffs, because they want you to get rid of whatever you have which was fashionable last year, and buy and buy and buy, what is fashionable this year, just so that next year you'll repeat the whole cycle. Obviously a real depth of understanding impedes this natural process of commerce.

TJ D · 16-05-2016, 00:02

Quote:

Originally Posted by Dockhead

I agree with all of this, except only one thing -- there is no such thing as a "modern hull". The design tradeoffs have not disappeared.

Some kinds of hull types -- heavy, full keel -- have almost disappeared, but the other choices are very much alive and well, and as hard to make as they ever were.

Only on the pages of glossy magazines is there only one type of "modern" hull type. The advertisers don't want you to think about the tradeoffs, because they want you to get rid of whatever you have which was fashionable last year, and buy and buy and buy, what is fashionable this year, just so that next year you'll repeat the whole cycle. Obviously a real depth of understanding impedes this natural process of commerce.

Yes, I should have been more clear. My definition of a 'modern' hull generally brings a particular shape to mind.

Basically, I'm talking about a long waterline, broader stern sections, and modern materials with a high strength to weight ratio. There isn't much downside to this formula in my experience. The minutiae are all subject to the naval architect and the builder's own vision. I may agree with them or not, but generally, the above is what I meant.

TJ

**Dockhead** · 16-05-2016, 02:07

Quote:

Originally Posted by TJ D

Yes, I should have been more clear. My definition of a 'modern' hull generally brings a particular shape to mind.

Basically, I'm talking about a long waterline, broader stern sections, and modern materials with a high strength to weight ratio. There isn't much downside to this formula in my experience. The minutiae are all subject to the naval architect and the builder's own vision. I may agree with them or not, but generally, the above is what I meant.

TJ

Yes, I understood and don't really disagree, but your own boat contradicts the idea that there is only one approach to hull form -- you have a totally different underbody shape from recent fashion (if I understand the description) with a deep "v" shaped forefoot and without the flat sections (maybe you could post the drawings?).

One thing which puzzles me, however, is "high strength to weight ratio", as part of the "modern formula". I'm not sure there is any such formula. Obviously this is a very desirable quality on just about any boat, but it typically costs money. You certainly don't get it on modern mass produced boats which on the contrary have simply much weaker construction, with extensive use of very thin single skin GRP. This is the result of "value engineering" and is not necessarily bad for the average user -- better engineering and techniques like FEA allow the designers to reduce the weight and cost of different structural elements while maintaining an acceptable level of strength, because they better understand exactly how much strength is typically required. Some boats have gone too far with that probably, like the Benes and Hunters with eggshell bows, but this is a natural evolutionary process IMHO. Really higher strength to weight ratio comes in expensive boats with techniques like coring, and with exotic materials like carbon.

I do agree that there is such a thing as "Progress". There are some concrete improvements which are discovered which have broadly applicable and widely accepted advantages. What I am railing against is confusing Fashion with Progress -- they are different things, which sometimes coincide but often do not.

In my opinion, the biggest change in hull forms of cruising boats since the '70's is simply SIZE. Cruising boats have gotten much larger -- from average 32' to about 45' now.

Don't think that the designers of the '70's didn't know how to build light boats -- by then there were already light cored hulls, very strong using balsa, and other techniques. But you couldn't have a light 32' boat with any degree of seaworthiness, so they built them heavier. There has not been any vast improvements in materials since then, other at the very high end with carbon (still used only in a tiny percentage of total boat production), and more durable coring techniques making cored hulls less risky.

The difference is that when you're designing a 45' boat you can afford to make it far lighter than a 32' with no loss of seaworthiness, or even a net gain.

Some of this is simply better -- lighter may be less expensive (unless you go to exotic materials, and not counting any efficiency gains from robotic assembly, cost of the structure of a boat is nearly constant per kilogram) so the cost of this 45' boat may not be so much greater than the 32' heavier boat of yore, it is no less or even more seaworthy, and vastly much faster -- so that is something like real progress, with hardly any advantage to the old 32' boat. The only problem is that to get the cost down to what the old 32' cost corrected for inflation, you have to greatly cheapen the fitout and other things, and use all the efficiencies of mass production. So that's how we end up with the very cheaply built Bavarias and so forth -- that's the bigger boat at the old price point (which is a better deal than the old 32' boats so probably even that is real progress -- yes, if I had to choose between a Contessa and a 45' Bav, I'd take the Bav, however much I admire the Contessa). Meanwhile, however, the average price of a cruising boat in inflation corrected money has increased as sailors have become more affluent than in the 1970's, so part of the "modern" larger, lighter and faster boat just reflects the deeper pockets of today's sailors.

But there is no consensus around the "wedgie" form with very sharp entry and beam brought all the way back to the transom, and flat bottom aft of the keel, and an extreme high aspect torpedo keel. That is only one of several directions. Your own boat is not like that at all. There is also a lot of variety in current boat designs around fineness ratio, and even Polux claims to like narrow beam boats (he didn't quite drink all his Kool Aid, apparently). So if there is a general movement towards larger and lighter boats, with shorter overhangs (but by no means always NO overhangs), which are (depending on how extreme you go with those) mostly better for most sailors and most conditions, other aspects of hull form -- bow form, beam, shape of forefoot, shape of aft sections -- have no clear "one size fits all" direction, despite what you might gather from reading certain glossy magazines.

Also, not every sailor needs SA/D of 25 or more. One rig size definitely does not fit all uses and latitudes. A larger rig has more weight aloft and more windage -- it's very good in light conditions and very bad in heavy ones, so different sailors, will have different priorities.

Likewise with keels -- ludicrous to suggest, as some have, that the extreme high aspect torpedo keel is the only "modern" one. What is great for a high performance boat in controlled conditions may be terrible for sailing the uncharted rocky coasts of the Eastern Baltic. If we might agree that the ancient full keel is pretty much obsolete (Island Packeters may protest here), and we might agree that some kind of bulb on the keel is good for nearly everyone, that doesn't mean that the ONLY modern keel is a torpedo on a whisp of a whip like on a pure racing boat. Cruising boats made for a wide range of conditions will give up some aspect ratio for sturdiness and tracking, and the torpedo doesn't suit anyone who sails where there are likely to be fishing nets and pot lines about and no towing service for hundreds or thousands of miles.

Few of the boats shown in Polux's posts in this thread have anything to do with normal cruising boats. They are like the Lamborghinis, F1 cars, and fantasy concept hot rods taped to a teenage boy's bedroom wall.

Polux · 16-05-2016, 14:18

Quote:

Originally Posted by Dockhead

I agree with all of this, except only one thing -- there is no such thing as a "modern hull". The design tradeoffs have not disappeared.
...

No, there is not a modern hull (I prefer contemporary or to the state of the art) but there are several modern hulls, from different sailing programs. They share some common characteristics and some differences that can be quite big.

When I talk about modern hulls I mean they are contemporary in design (from different types, as opposed to old designed hulls, meaning hulls that the same designer for the same sail function would have designed 30 years ago but that today would consider obsolete.

The contemporary one is just a gradually improved state of the art version of the old one incorporating all the improvements that sail design development had brought in what concerns the possibility to design a faster, and better sailboat, not only faster but with a better and more comfortable interior.

Let's take for instance a very conservative sailboat brand, Halberg Rassy that has been designed on the last decades by the same design cabinet, German Frers.

German Frers brought contemporary design to Halberg Rassy. Just compare one of the firs H&R designed by them, the 39 (1990) with one of the last designs from the previous designer (Olle Enderlein), the 46 from 1982:

It is not by accident that Olle Enderlein is just a footnote regarding the great designers of the last decades of the XX century while German Frers is a main reference.

So, after 34 years let's have a look of what German Frers is designing now for H &R, the last design, the 44:

Yes, it is still a conservative design for a conservative brand with conservative clients, but a modern design. Certainly German Frers would not dream to purpose today a design along the lines of the 39 (that was a modern design on its days) simply because it would be bad naval Architecture, an obsolete design.

I let you find the differences between those designs and what makes the last one modern and the others obsolete.

Of course, if H&R was a different boat with a different program, another type of hull and NA solutions would be found but certainly none of them obsolete, at least if it was designed by German Frers.

That has nothing to do with magazines or fashion but with the evolution of Yacht Naval Architecture and the (better) solutions it can find today for different boat programs.

TeddyDiver · 17-05-2016, 13:41

Quote:

Originally Posted by Polux

That has nothing to do with magazines or fashion but with the evolution of Yacht Naval Architecture and the (better) solutions it can find today for different boat programs.

Nope, it's about being price competive, key being more cabin space for the beaver (Sorry

couldn't help myself)

reed1v · 17-05-2016, 13:58

Quote:

Originally Posted by TeddyDiver

Nope, it's about being price competive, key being more cabin space for the beaver (Sorry

couldn't help myself)

True, beavers need space. And boats nowadays are becoming vacation condos and of course mid afternoon places to hook up with your favorite pet, beaver or whatever.

Whether it sails or not is not the point. Queen size bed, full bath(without tub), and climate control have become the sine qua non.

Polux · 17-05-2016, 14:01

Quote:

Originally Posted by TeddyDiver

Nope, it's about being price competive, key being more cabin space for the beaver (Sorry

couldn't help myself)

Off course, that applies to the racing boats too, that need a lot of space for the beavers

The fastest monohull is the Comanche and id designed with a big beam and all the beam brought back because beavers need more and more interior space

TeddyDiver · 17-05-2016, 22:08

Quote:

Originally Posted by Polux

Off course, that applies to the racing boats too, that need a lot of space for the beavers

Not for beavers, it's just too much sailing gear and sweat below them to thrive. The thang with racing boats is the testosterone high on the weather railing that makes the thongs to tick, the higher the railing better they tick, thus the wide beam

poiu · 18-05-2016, 02:37

Quote:

Originally Posted by Polux

Off course, that applies to the racing boats too, that need a lot of space for the beavers

The fastest monohull is the Comanche and id designed with a big beam and all the beam brought back because beavers need more and more interior space

The earlier example you gave was such an extreme design it was almost a windsurfer.

This one is nearly a catamaran. So much of the stability comes from the form it might as well turn into one and stop pretending. Just drop the keel, fit boards and remove the unnecessary middle of the hull. It would be lighter and quicker too.

Then there are the foiling boats, which aren't really boats in a sense as their main function is to avoid floating if possible.

As soon as you give up being a liveable displacement monohull then design results in metamorphosis. I don't think the plan is to go that far.

Snowpetrel · 18-05-2016, 04:21

Quote:

Originally Posted by Polux

The fastest monohull is the Comanche and id designed with a big beam and all the beam brought back because... (snip)

Comanche was soundly beaten by the very narrow (and very old) Wild Oats in the Sydney Hobart Race.

Polux · 18-05-2016, 15:31

Quote:

Originally Posted by Snowpetrel

Comanche was soundly beaten by the very narrow (and very old) Wild Oats in the Sydney Hobart Race.

Not on the last one where Wild Oates was way behind till it blew its main sail. Comanche is the one that has the 24 hour speed record too. Besides Wild Oates has been continuously modified, including new bow, new transom and hull upgrade design not to mention the introduction of state of the art systems like DSS.

Not saying that Comanche is faster on all sail conditions but certainly on most of them but that was not the point. The point was that someone was saying that modern boats have only more beam (and the beam brought aft that equates big transoms) only because cruisers want more living space at cost of performance and sailability. Clearly not the case in what regards performance.