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Old 04-08-2005, 08:19   #61
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I guess we'll just have agree to disagree. I'll stick with what I wrote. And yes I have sailed on many of these early '60s boats and find them to be quite delightful.

Do you really think these boats were poorly built?? Have you really looked at these boats. For the first thing, the hulls were thicker than necessary because the bean counters and engineers hadn't been turned loose. Though thicker layup is not the most efficient way to build a really strong hull it does make up for a whole host of other possible sins and gives much higher penetration resistance. Don't know exactly why, but blisters weren't nearly as much of a problem as they have been after after 1973 or so. Interiors were relatively simple and may not have been glassed into the hull as well as they could have been but they were at least tabbed into the hull.. With the thicker hulls, it wasn't that big a deal, in any case.

I have had the displeasure of owning and sailing some of the later fin keeled, aft rudder boats and wasn't impressed. Had one come apart at sea and other had floppy bulkheads after only a year. Neither handled for crap, they didn't track well and one was downright dangerous as it was uncontrollable in gusty conditions. Layups were barely thick enough to keep water out and furniture was a molded affair that wasn't even attached to the hull. There were some quality boats and designs, I just didn't happen to come across any.

The fin keel, aft rudder configuration became de riguer largely because of the success of the Cal 40. I would be hard pressed to think of a design that dominated the racing scene like it did. The reduced wetted surface and flat run aft made them surfing demons. The aft rudder being a long way away from the Center of Effort gave good control. It did have relatively full bows and pounded mercilessly hard on the wind but hey, that's not the reason you owned a Cal 40.

Things went down hill from there, unfortunately. The IOR rule favored some really bad design parameters that made for a lot of really squirrely boats off the wind. That was despite having the rudders way aft. Yes there were some fine IOR boats at the beginning but by the end of the rule, they were designed to beat the rule, not sail well or fast.

In many ways, the current run of non racing cruisers are pretty decent boats. That is if you like fat assed floating condo's. At least they don't have weird bulges and stupid sail plans. They have two things going against them, however. They are butt ugly and grossly expensive.

A 30-40 year old, largely bullet proof, pre weird IOR boat for less than a quarter of what a new boat costs, seems like a pretty good deal. Yes the boat may require some updating but it won't be stuffed full of crappy convenience technology and questionable gew gaws. Just a straight forward simple boat that will safely take you long distances for a reasonable amount of money.

Anyway, hull configurations have as much to do with tracking and handling as keel configuration. What I do know is the boats you seem to have a grudge against are damned good boats for the money. And as Captain Nat said, "A pretty boat always sails well."

Aloha
Peter O.

If fin keels boats were known to be superior by the late 19th century, why didn't we see them become dominant till the latter half of the 20th century.

Aloha
Peter O.
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Old 04-08-2005, 17:38   #62
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I really do think that by and large the 1960's and 70's era boats were poorly built. I base this on a near lifetime of owning, and maintaining boats since they were new, and designing and making repairs on other people's boats from this era but also on such detailed studies as the Insurance Industry study that I posted the link to year or so back.

It is a mistake to think that designers in the 1960's and 1970's did not know just how strong fiberglass was and that somehow engineers and bean counters were the ones that made boats lighter. During WW II and in the years that followed, the US Government had spent a fortune studying fiberglass as a building material. The information was widely available, especially to guys like Carl Alberg, who was working for the government designing composite structures at the time that he designed the Triton.

What was known was that fiberglass had reasonably good tensile stength and was fairly good in bending but was highly flexible and extremely prone to fatigue. Designers of the 1960's and early 1970's knew that they needed to try to limit flexure but the only tool at their immediate disposal was to make the glass thicker. (At some point in the 1970's it became apparent that proper fiberglass engineering required an internal framing system, just as wooden and metal boats do.) It was the marketing people and engineers who initially decided that it was cheaper and easier to make thicker hulls.

The problem came in the method used to thicken the layup. depending one the manufacturer's preference, this was generally done by adding a lot of non-directional (mat and chopped glass) laminates, and resin rich layups. Beyond that, the methods of producing fiberglass fibers and manufacturing reinforcing fabrics and the methods employed in handling the fabrics resulted in a weaker and significantly more fatigue prone reinforcing material than is typically used today. Similarly there was a tendancy to use a lot of accelerators and bulking materials in the resin which also resulted in comparatively weak and fatigue prone resin.

Added to these issues, early fiberglass boats had no internal framing and so tended to flex a lot. This flexure tended to concentrate loads at stiffer portions of the boat and the more highly loaded areas of the boat and, as result, increases the likelihood of a further diminished strength due to fatigue just where the loads are highest.

The combination of the above has resulted in hulls that the marine insurance industry report described as being extremely poor in terms of impact resistance. The introduction of the report explained that study was commissioned because the insurance industry was seeing damage on older boats that was disproportionate to the impacts incurred. The study actually described destructive testing on actual portions of older hulls as well as newer boats. Impact resistance on these older thicker hulls was a small fraction of what they were observing on newer boat construction.

When you add in many of the other details of construction on these older boats (skip tabbing, structural plywood bulkheads and flats encased in formica, encapsulated structural wooden elements, poorer quality adhesives and sealants, non-tinned wire, steel wire reinforced natural rubber hoses, encapsulated inaccessible chainplate installations, wooden planked rudders with brazed bronze connections, encapsulated keels, etc.),
I really do think that the boats of this era were very poorly constructed by any objective standard.

For the record, I do not have a grudge against older boats. I grew up sailing them, I have sailed them all my life, and I still enjoy sailing them. There is a very different aesthetic to sailing these older designs and that aesthietic has its merits. That said, I do not see any point in glorifying these old girls beyond their real capabilities either. The reality is that these older designs have some very serious limitations and all I am trying to do is to fairly describe their merits and limitations. There is a lot of missinformation and poor assumptions being made about these older designs. I hate to see them propagated.

To answer your question:
"If fin keels boats were known to be superior by the late 19th century, why didn't we see them become dominant till the latter half of the 20th century?"

Fin keel boats remained dominant in racing, and popular on cruisers throughout much of the 20th century. For example, boats like Dorade and Stormy Weather were ocean racing fin keelers. Many if not most of the CCA era and RORC era race boats were also fin keelers with attached rudders. Separate rudders dropped from favor when they were outlawed on race boats (other than one design boats) in the late 1800's and did not reappear until the rule changes of the early 1950's.

We mostly agree about the IOR rule except that there were predominantly miserable boats at the beginning and middle of the IOR. The late IOR produced boats that were reasonably decent boats (boats like the Garrett 40, Soverel 33 and 39, and Farr 37) considering the contortions that the IOR seemed to require but as a rule, both the CCA and IOR rules really set back yacht design producing comparatively slow and unseaworthy, unseakindly, designs.

Lastly, I am not sure that the quote that you mention actually was from Nat Herreshoff, but I believe that the quote actually was closer to 'If looks fast, it probably is" but I do not think that it was a Herreshoff quote.

Respectfully,
Jeff
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Old 04-08-2005, 17:49   #63
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Fin keels and stuff

Just a few thoughts. When discussing the origin of fin keels the Northern floks usually refer to Hereshoff, and Marchaj refers to the 5.5 metre boat while others point to S&S as the origin of the type. Then the subject goes to the IOR and how bad they were and they had fin keels.
Meanwhile in the real world down South, sensible fin keel boats have been built and sailed for over one hundred years with zero regard to the IOR rule and these types of boats are a joy to sail, and they track well without a skeg in front of the rudder.
They have been crossing oceans while the North has been having enquiries. The Hartley 28 and Westhaven 32 and Auckland 34 and Spencer 37 and many many more. Old fin keel designs that sale the South Pacific.
So I am suggesting that the sailing world does not revolve around a US designer or groups, or European designers or groups. There have been some good designs from this area tho.
And I would not discount many designs that are not the old Albin type nor the IOR type. There are many sensible moderate displacement fin keel boats that sail well. And Jeff has been politely telling us that for some time. No boat is perfect, so everyone has some degree of compromise. These days even the full keel designer types are hacking away at the keel because they know that the full keel is not the final answer. I am thinking of the Crealock 37 and others.
I sail a 1979 fin keel boat that may not track as well as some full keel boats, but it will do a lot of other things that would stop me from buying a full keel boat.
And if I may take a shot at Marchaj his conclusions about fin keel boats are not shared by many others, designers and sailors alike, and a lot of his claims are easy to debunk.
Michael
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Old 04-08-2005, 18:35   #64
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Good points Mike.....I am often amazed at how advanced, both in terms of hull forms and structural design the NZ and Australian boats have tended to be.

I did want to touch on your point about Marchaj. I really think that Marchaj's book really covered a lot of new and previously under appreciated ground. I think that many of his conclusions are on target. If there is a short coming to his work, the research that formed the basis of his book regarding lighter weight boats was largely based on the available samples of what a light boat looked like, which in the late 1970's essentially meant IOR-I and IOR-II derived designs. His conclusions about these particular typeforms remains accurate. The problem arises when the conclusions drawn from the study of IOR boats is broadly applied to all light weight craft. Reading between the lines of marchaj's seminal work, there is a road map for what needs to be done to improve the seaworthiness and seakindliness of light weight offshore boats.

In the late 1970's and early 1980's there is a collision of events that leads to rethinking of light weight boats in the Northern Hemisphere, which to a great extent responds to Marchaj's concerns about designing light weight boats. Of course, you blokes in the Southern Hemisphere had already begun to evolve your design thinking some 5-10 years earlier. In my mind, it is no coincidence that the real breakthrough hull forms, keels, and rigs of the mid to late 1980's came from Southern Hemisphere designers.

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Old 05-08-2005, 02:04   #65
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i really enjoy reading these conversations between sailors that really know something. let me ask a laypersons question. do i understand you to say that newer boats, with thinner hulls, are stronger in collision than older heavy glass boats ? if a beneteau (just to pick one that i hope represents the newer breed - not trying to create heat) and a bristol from the 80's (my boat) hit a partially submerged hazard (log floated off a beach after a storm driven tide) do you have an opinion as to which would do better and sustain less damage based on hull strenght alone ? i do understand that new construction is stronger when dealing with loads from rig and other components on the boat but i have long assumed that thicker was stronger in collisions and your posts really surprise me. capt. lar
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Old 05-08-2005, 03:38   #66
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I am not really precisely sure how to answer your question. First of all, if I remember correctly, the Insurance Industry study focused on boats that were somewhat older than yours from the 1960's and 1970's.

I know from conversations with the production manager at Bristol during this period, that Bristols of the 1960's and 1970's did not have the best quality control. In the early 1980's, Bristol began to upgrade all around, and so I would guess that the 31.1 probably would be better constructed with better glass work than the earlier boats. On the other hand, Bristols of your era did not have much in the way of internal framing and much of the Bristol's excessive weight came from heavy interior appointments rather than from especially sturdy construction.

By the same token, I am not sure that the Beneteau is the best choice for comparison. Boats like the Beneteau 40.7 have close to a state of the art structural system (for a non-cored hull) and seems to be quite robust. If I had to pick a boat between yours and a 40.7 to hit something very hard with, I think it would be a toss of the coin between the 31.1 and the 40.7. On the other hand, I have far less impressed with the construction boats like the Beneteau 423.

By the same token, if you compared the impact resistance of a similar quality modern design to your boat, I would expect that the newer lighter boat would be more impact resistant than your boat.

In any event, all of that is pretty much speculative and only my own best guess.

One other point, it is a mistake to think that newer boats have thinner hulls than late 1970's and 1980's era boats. The weight savings on newer lighter boats do not necessarily come from thinner hulls. Newer boats generally have lighter interiors, rigs and construction details. Weight savings breed weight savings. Lighter boats need lighter rigs and smaller sail plans. Smaller sail plans mean less ballast. Less weight means smaller engines and smaller fuel requirements. The low L/D ratios on newer boats results from comparatively minor weight savings combined with the typically longer waterlines relative to overall length on newer boats.

As to the strength of the new vs old boats to deal with rigging and keel loads, etc, this varies widely with the builder and even by model. But if you compare a upper middle quality boats like the Bristols to newer upper mid-level quality boats, I would expect the newer boats to be substantially stronger.

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Old 05-08-2005, 09:16   #67
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It might also make for a better comparison to examine two boats of similar size (volume), thus comparing similar panel sizes against impact.
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Old 05-08-2005, 14:13   #68
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boy - i will be thinking about that one for a long time. i know this comparison needs to be specific to an individual boat, regardless of when built, but the idea that less can be more in hulls, as with so many other things, is a whole new view. i think i will start a new thread to see what people would consider the "ultimate cruiser". might be fun.
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Old 05-08-2005, 16:08   #69
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This is not all that hard to visualize. Taking this to an extreme, visualize a hull made from a 1/4" of steel vs one made from 2 inches of Balsa wood. It is easy to visualize how a thicker hull may not be stronger since obviously the steel hull would have a lot more resistance to being punctured in an impact.

Fiberglass is not a single homogeneous material that has uniform strength no matter how it is made. Fiberglass reinforced plastics really is a system of components and the choice of components and the way that they are used can really impact the strength of the finished panel. Resin offers nearly no resistance to impact and so the resin rich mixtures of the past started life with substantially lower puncture resistance. This is further exacerbated by the relatively careless mixing of resin in the comparatively recent days before precision metering pumps.

Studies of impact failure in fiberglass revealed that the mechanism of failure typically occured in the non-directional fabrics (mat and chopped glass) used in the laminate. Even quality builders of the 1980's used way more mat then is currently employed in modern hulls. The combination of resin rich laminates and larger proportions of non-directional materials also results in a greater propensity for fatique. Fatigue further reduces the strength of the laminate. In other words, while the hulls may only be a small percentage thinner in newer boats, the laminate is substantially stronger.

There is one other odd component in this discussion. Historically boat builders used thicker gelcoat and much thicker veiling laminates (the layup below the gelcoat). Combined these could be something on the order of 20% of the hull thickness on older boats which is nearly double what they would be today. These layers have next to no inherent strength and so reduce the apparent thickness of the hull so that it is closer to that of a modern hull.

I often hear people say "I bought an old boat because they just don't build them that way anymore". They are right that they don't build them that way anymore. Better fabrics, engineering, material handling, precision metering of resin and improved resins have resulted in much stronger layups for less weight.

BTW I like your 'Pogo' sign off.

Jeff
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Old 05-08-2005, 21:24   #70
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Well said Jeff. I was going to chime in with a similar statment, but I could never have said it in the accurate and well worded way you just did.
May I add though,
The resin quality and types of those products available today have far surpassed what was available back then. And we see improvements in that feild every year. Especially in the epoxy ranges and you can add into that err, Mix, the more exotic mat materials available like Kevlar and Carbon Fibre and such. And it's the use of such materials, that is where the greatest leap in hull strength is being seen
The same even applies to the materials like Alloy, Steel and even timber. Althopugh we don't see the same leaps of technology, the production of metals even, has improved in the recent 10 to 20yrs. Timber boats see many more variants in what they are built in as we see timbers from all over the world being used. And how many of those timbers are grown today has resulted in a much superior product to that which was available 20 and 30yras ago.
And if I can just add an angle Jeff did touch on. With a lot of the modern sail boat designs, the main design idea is weight saving so the boat is fast and the ability to fit as much into a boat as possible, so space saving design has become criticle along with the speed. The result are hulls and frames that start to make an egg shell look thick. The downside of designing a boat like that, is to keep the boat stiff. Flex results in wear, fatique and failure. So designers with their modern design programms today, can build a "shape" and flex it and such on the computer and models the stress and then place bulkheads and what have you to maximise the strength of their design. The result is a structure (as Jeff said) that becomes very strong compared to it's weight and thickness. Of course, we see many of those designs in the upper end of the exotic power machines, those speed demons doing the big name races, push those designs to the limit. They sometimes make it to the finish line, sometimes don't.
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Old 06-08-2005, 00:22   #71
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well, that leads nicely to my next question -
which companies are taking advantage of technology and using it to build a really solid cruiser that can be handled by a couple, sails well, goes offshore, has shoal draft capability and is in a price range that sailors that are not wealthy can reach. we would like low maintenance as well, which i think means not a lot of systems that we can live without and quality systems and equipment that hold up. in other words, who is building the almost perfect boat. hopefully we will get several points of view with a range of purchase price. capt. lar
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Old 06-08-2005, 02:15   #72
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I think I would be happy in a new Halberg Rassey 34, but it would cost too much. A Francis 34 or the bigger 38 designed by Chuck Payne would also be nice, but again the cost would be too much. In my price range is the Cascade 36 available from Cascade in Portland OR. In the 28 to 30 foot size range I would settle for the boat I have, a Tanzer 8.5. But for a bigger boat I think I will take another trip to NZ and look again at the Farr 38, a 1980s design available in fibreglass or wood, and the Spencer 37, the Birdsall 36 plus whatever my designer friend down there thinks is worth looking at.
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Old 06-08-2005, 02:17   #73
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interesting you kept the length down. capt. lar
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Old 10-08-2005, 16:23   #74
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Check this out...

Capt. lar,

http://www.shipman.dk/

While it's safe to say it doesn't fall into the affordable category; I think it's just a matter of time - say a decade - before some mainstream production companies make the leap. Indeed, I wonder if the ones already using glass/epoxy won't do it much sooner.
If only the 50 ft. had ten feet less and half the price tag...
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Old 10-08-2005, 16:37   #75
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A couple boats that I think represent a good options in terms of high build quality and good engineering would be the current crop of X-boats, Dehlers and Elans. I am also a very big fan of the Beneteau First 40.7 and 36.7 which are surprisingly well engineered boats.

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