# more on old IOR boats



## TSOJOURNER (Dec 16, 1999)

I own a S&S designed 25 ft ''73 IOR boat, have sailed her all over and lived aboard over 25 years now. I can say that not all boats of this era are the same. This boat is very well found, and with the deep heavy lead fin keel, deep full skeg rudder, and low freeboard, she never gets squirrely in any conditions. I can carry the big light air spinnaker with such a small amount of wind you can barley feel it, and she is responsive enough to keep it flying, but if the wind picks up, you can get the ''chute down with one person without ever getting out of control. She has a fairly quick motion, other than that is comfortable in bluewater, much more comfy than many more ''modern'' designs I''ve sailed on! Don''t forget, S&S were noted to be conservative and put the boat first and rules second. I have a big 496 sg ft gennacker I use attached to the anchor roller as a ''sprit, the boat is plenty stiff enough to carry it, and it makes her roll along in the mid sevens all day and night even with a full cruising load. Yee hah! I do use a sock with it, bringing it down at 2am without one would be no fun. We have sailed upwind in 70 kts and 30-35 ft seas with panache. She is a powerfull performer, upwind and down, as long as the right sails are used. There are dis-advantages, of course,...not much headroom, can get wet upwind, not much room on the foredeck with the narrow bow, too much draft for the Bahamas, no vee berth (that is not such a disadvantage, I have a fully enclosed shower under the sail hatch there, so if I put a wet sail down, so what?)but these are really pretty minor quibbles mostly.
Webb Chiles also favours old IOR boats...remember him? 
She is beamy in the mid sections, it makes her look like a fat old duck from behind. But that beam is part of what gives her so much power. And with the deep draft and plenty of ballest, she is very safe. We just survived Ivan ''on the hook'', and she was un-fazed, as always.
So don''t discount a boat just because it is an old IOR boat, some of them are really great bluewater cruisers in their old age!-Ken


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## Jeff_H (Feb 26, 2000)

I also have owned a 1973 S&S 25 foot IOR era design. Mine was a Northstar 500 quarter tonner. The description of your boat very much matched the Northstar that I owned. Both your boat and the one that I owned were very early IOR-1 boats, which tended to produce reasonably good boats compared to later, more modern IOR-II and IOR-III. (Webb Chiles''s Heritage One Ton is also an IOR-1 boat as well. I would also like to point out that Webb Chiles would not exactly be a good role model of a sailor chosing sensible offshore cruising boats given his track record of choices in the past.) 

In any event, while I somewhat agree that smaller early IOR-1 era boats were generally more robust and more seaworthy than later IOR boats, my experience with my quarter tonner was somewhat different than yours. On the Quarter tonner that I owned, there was a tendancy to aerate the rudder at moderately flat heel angles (somewhere around 35-40 degrees) and for the boat to round up at that point. While the boat was nicely balanced a flatter heel angles (say under 20 degrees) leading up to the wipe out, the boat would rapidly develop higher weather helm loads. 

Downwind the Northstar had a tendancy to roll wildly under the chute if there was any seas running. So much so that it was possible to roll the spinnaker pole end into the water. Power reaching under the chute was pretty much of a white knuckle experience as the huge chute tended to depress the bow and make the boat want to round up and yet the huge overlap of the chute made diving down in a gust a bit of a risky activity if you were short handed.

Probably my biggest gripe with boats of this era is their sail plan proportions. On my Northstar, like most of the IOR boats that I have sailed, the mainsail was tiny and the jibs were huge. This meant frequent sail changes. To get any light air reaching or beating performance on the Northstar, we used a light #1 genoa (170%). This was a wonderful sail for those conditions but somewhere around 6-8 knots of wind was beginning to overpower the boat and we would have to switch to a heavy #1 genoa (150%). That sail was overpowered at roughly 12 knots and so we would either shift down to a #2 (140%) or else a reef in the main was required, which was slow and gave the boat a little bit of initial lee helm. The #2 was a good sail in winds from roughly 10 knots up to the high teens and then we shifted to a working jib that was just a tick below a 100%. With better sail cloths perhaps each of these sails would have had a wider wind range but to sail the boat with any kind of reasonable performance at all, expecially when loaded to go cruising meant a very large sail inventory or else a lot more motoring than I would prefer. 

And that brings me to my final point on these boats. Because of the IOR rule, these boats tended to be very sensitive to the amount of weight carried aboard. A 25 foot IOR 1 boat was made to be sailed by five or six crew members, somewhere around 1000-1200 lbs of crew weight and when going up wind that crew was expected to be on the rail. Fully loaded to go racing these boats would tolerate roughly a ton of live load (crew and supplies) after which they became harder to handle. That is a comparatively small payload for a 25 foot cruising boat.

I guess my point here is that while you have successfully proven that you can cruise and live aboard a small IOR-1 era boat, I would suggest that I strongly agree that there is quite a bit of variablility in the suitability of even S&S designed IOR-1 boats to being used as cruising boats. I will also suggest that some of the designs from that era that emerged based on the MORC rule, and from the later MHS (IMS) rule produced boats that are easier to short hand and perhaps more seaworthy as well.

Respectfully,
Jeff


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## Silmaril (Feb 22, 2003)

I too am the owner of one of the older IOR I designs. In fact, a Heritage 1 Ton that the afore mentioned author of dubious common sense is using for his latest escapades. I tend to agree with much of what Jeff offers in his critique of the designs, in general. 

I will add a few of my own observations: We were out on our last day-sail of the year on Sunday, 11/7. True winds in the upper teens to low twenties, seas 3 - 5 feet, steaming along at about 8 kts, beam reaching with a full main and heavy #1 (150%), rail not even close to the water, moderate helm. Two couples enjoying a lovely fall afternoon with Long Island Sound to ourselves. A wonderful afternoon to set me up for the long winter months ahead.

Within limits and understanding her foibles, these are the conditions that make Silmaril a joy to sail. HOWEVER.... turning into the wind to drop sails, set her up for the usual wave peircing, bow into the next wave, everybody gets wet, experience that one has to deal with when sailing a boat with such a slender bow section. No pounding like the later IOR II and III designs, just a wet ride in very moderate conditions.

Then turn her down wind for the motor into the harbor, and you are chasing her all over as she sashays from side to side on the following seas. I have done it with the chute up in these conditions, and well, you had better be on the ball 100% or be ready to be bitten. Does the term "Death Roll" come to anyone''s mind? For cruising, the ''chute, pole, and strut just aren''t part of the inventory! I use my drifter, (170%) my heavy #1, and the reefable #3/4 genny, along with slab reefing the main.

A lot of the boats from that early era exhibited even worse behavior (the Nautor 44 & 47 S&S designs were notorious for their wild broaches) I chose mine very carefully from experience with the particular design. Knowing her bad points, I avoid them as best I can. But the designer (Charlie Morgan) pushed the envelope of the era in many ways. For a 37'' boat of that era to weigh in at 13,000# with 6,500# in a deep 6''6" fin, deep balanced rudder, and still be going strong today after MANY hard racing and cruising miles, testifies to the construction techniques he used in the design. It was built tough, not pretty below, but very funtional.

There are boats today that I feel are still built with the same "Sailing First, Cruising Second" approach: The Seaquest 36 Reichel-Pugh design comes to mind, a fast balanced design, taking advantage of the latest in modern design, the J-109 also is an excellent performing racer/cruiser, the Cape Fear 38 by Bruce Marek can be had in all-out race trim or more cruising oriented. The C&C 110, while taking a bashing from some, is a really well built high performance boat with a nod towards more cruising comfort, but still able to "make tracks" when raced.

The good, high performance designs are out there, you may have to look beyond the mass producers to find em, but todays boats have come a L O N G way from the early IOR designs.

Because I haven''t hit the lotto or had any better mousetrap ideas come my way, I am happy with my old IOR desgn, familiar with her strengths and her weaknesses, and enjoy those days when she really shines on the water.


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## TSOJOURNER (Dec 16, 1999)

Yes, she is a NorthStar 500. And yes, I have had the rudder break free a few times...but I wouldn''t consider 40 degrees ''flat'' for that, many modern cruising boats will have the rudder lose its grip well before the angle this boat does, I say that based on relativly little experiance with other boats but also by comparing the underwater designs.

As for yawing, yep, that can be a workout, but I have a Sailomat windvane, and it can steer with the big chute better than I can. So no workout. Haven''t noticed the bow go down as much as she tucks into her bow wave...seems to me she actualy will try to climb up it to some extent. 

I have had a couple of broaches with the spinnaker, but with the size of that chute, given the same conditions any boat would broach, and to her credit she got right back on her feet with no damage. Never actualy got the pole in the water, close a time or two. 
But nowdays I rarely use the light air chute, as I find the gennaker a better cruising sail.

Changing sails can be, or I should say is, a chore. But if the main was a lot larger, then there would be a lot of changing sail area there, to. Not as much I''m sure. But you would then have a much larger boom that could make gibing tougher, and might get in the water. However, I do agree that the need for relatively frequent sail changes are a disadvantage here, you don''t know how many times I have cursed that in an early morning squall!

I very much agree she is sensiteve to her weight...most racing boats are. That is not so much of a problem with one or two people, or as in my case one person and two Schiperkes, as we can do fine without five tons of extra weight. 
And if you loaded down a boat of about the same size with 1500 lbs, you might not notice the difference in handeling as much, but it would still make a difference...such as capzie resistance. Very likely even more of a difference considering the way the 500 is made. But here also, I agree that this design is more sensitve to extra weight.

However my point still is, that for a small very capable bluewater boat, one that can do very well without the engie being run at all and one that can handle any weather, this boat would be hard to beat. As an example, two years ago in Aug. I did an ''out and back'' in the Gulf of Mexico, 22 hours, 5.45 kt average with the wind on the nose coming back, and a full cruising load of 1000-1500 lbs aboard. Very comfortable ride. I used the gennaker going out, the boat was pushing 7.5-7.7 kts by GPS for a long time...not too many other boats 20 ft on the water could do that with all the equipment and resources aboard needed for cruising. Heck, quite a few of the boats in the marina that are much longer couldn''t do that! 
Don''t forget, when these were made was the time, even though it was the last of it, it was the time when these boats were supposed to be "racer/cruisers".
Most of the modern designs I see are purely for costal sailing, the market having apparently determinded that folks don''t much want very small ocean capable cruising boats. I wouldn''t trade a well designed and built old IOR boat for a dozen such modern boats for passagmaking, even though the modern designs are better on the hook or with a cockpit full of guests.
Webb Chiles? Well, he made it didn''t he? That says as much about his guts as his judgement, and presumabley he has learned quite a bit from those times.

I agree that designs have changed, and we do progress, but sometimes there is a false presumption that just because soemthing is not new it is not as good, when often the old stuff can be better than the new stuff. A lot of the newer designs for boats have increased the comfort factor in many ways...that doesn''t mean they have not comprimised in others, or that the fundemental design is better overall.-Ken


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## Jeff_H (Feb 26, 2000)

Great Response, Ken! Thanks. Just on the off chance that this is my old boat. My boat was black and sold to an airline pilot who lived up in Atlanta. I called her ''Midnight Express''. She had an atomic 4 with a Vee drive. Neat boats for their day. I raced mine out in the Atlantic. 

Jeff


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## owenmccall (Feb 10, 2004)

Ok, so these old IOR boats have a lot of design flaws, which you guys have clearly enumerated. But please tell me (since I just bought one) do they have any special strengths, other than their low price? For instance, I have heard that (at least the S&S boats) go to weather exceptionally well.


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## TSOJOURNER (Dec 16, 1999)

Well, I''ve owned sailed and lived aboard mine for over 25 years, and the guy I bought it from was the original owner, in his 70''s then, now dead it seems. But she does have the A-4 with vee drive. I want to change that to a diesel electric hybrid. Nothing against the A-4, it has served well, but it is not very fuel efficient and is heavy...and now that the oil pan has rusted out it seems an opportunity.
She is a fun boat to sail. 
Regarding a couple of other notes, about the yawing downwind in big seas, it yaws with or without big sails but less than some other boats I''ve been on. Much less than some of the modern designs with the spade rudders. The full skeg helps with that as well as helps the rudder keep it grip. 
And about weight carring, I have sailed on the Flicka and the Catalina 27 and a Grampion (SP?) about the same size, the all did worse performance wise than my boat when fully loaded. Of course, I never had four 250 lbs guys sitting on the rail! But I think any smaller boat will show it when you add cruising weight. -Ken


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## Jeff_H (Feb 26, 2000)

Compared to boats that preceeded them they go to windward quite well but compared to the boats that followed them they really are not all that weatherly. They also tend to be a little bit wet compared to a IMS typeform for example. 

The thing about the IOR was that it narrowly defined the measurement points on a boat in a way that made it easy for designers to distort the boats to beat the rule. The problem was that it produced boats that were comparatively slow and generally not especially seaworthy. Some of the really early boats like the one we are discussing were still very good boats for their day but a lot happened in the years that followed. 

What did you buy?

Jeff


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## TSOJOURNER (Dec 16, 1999)

Yes, most S&S boats at any rate were noted to be upwind witches and the NorthStar 500 is indeed close winded and powerful. Also wet, if you insist on putting your nose into the blow. But I have no qualms at all pointing her into 40 kts and big seas...just shut the hatch and clamp the potholders down on the stove, it''s gonna be a ride! When really into it, I have seen her roar down the front side of a sea and then stick her bow into the next sea all the way to the mast, then lift up and throw all that water into the cockpit. Urgh! But it doesn''t seem to slow her down much.
These boats can be very solidly built. When I last crossed lake Okeechobee (SP?) several years back, the keel hit a submerged log that stopped us instantly from 6.5 kts. No visible damage. (I did not dive and look at the time, too many alligators around! But I did a few weeks later.) 
There are NO stress cracks...none, anywhere on this well used hard sailed boat of 31 years. And there were no blisters for the first 18 years, then I sanded and re-painted, and now I have had a few small ones at the waterline. 
But, the stb. toe rail DOES leak (when the present batch of goop fails once again), has done so forever, such a PITA to fix I never have. 
The only other thing I intend to address someday is adding an inner forestay and running backs, so I can hang the storm jib inboard and also to prevent mast pump in some conditions. That is caused by the shrouds not being any fore and aft. -Ken


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## owenmccall (Feb 10, 2004)

A 1971 Palmer-Johnson 30 "P-J 30", aka "S&S 30". These were sold in the UK (where they were built by Aquafibre) as the "Aqua 30". P-Js imported them and added an extra 3 feet to the (keel-stepped) mast. The 34 footer is very similar but better known (e.g. "Morning Cloud" owned by Prime Minister Edward Heath). There is also an "S&S 30" that was built in Australia, but this is the same hull as our Yankee 30. My boat disp. 7000#, 3400# ballast, 9 ft. beam, 21 ft. LWL, with a recently rebuilt Albin 2-cyl. gas engine. This is our first keelboat, after having raced a Buccaneer 18 (centerboard sloop) for 17 years. We don''t plan to race this boat.


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## TSOJOURNER (Dec 16, 1999)

We sailed a San Juan 28 for years, a cut-down version of 1970''s Bruce Kirby designed IOR half-tonner, the SJ30. I remember Dennis Clark telling me how they modified the SJ30 mold with a 55 gallon drum of polyester filler to make the 28. It was a classic IOR boat, dinky main, big foretriangle, pinched ends, squirrely as hell with the chute up in a breeze but fast up and down in light air. Per the brochure it had a 50% ballast ratio and despite the very rounded sections stiffened up and was powerful upwind in a big wind and sea. I remember getting caught in the Gulf of Alaska 20 years ago in a 40 knot northerly while traveling in company with a J-30. We had no problem going upwind into this to beat into a sheltered bay, after trying for a while he gave up and cracked off. When we met up the next day he had seaweed hanging from his lifelines, we never took more than spray.

The interesting thing about this boat was how well it sailed under just main. Clearly the power was in the foretriangle but you could sail it around like a dinghy with just the main up. It held up OK in some tough use although we blew the rig off it in Typhoon Holly, but that was asking a lot of a boat that is really a coastal cruiser. 

Bottom line is I think at least some IOR boats are under-rated; they can sail very well, especially in lighter air where the pinched ends reduce wetted surface and the big foretriangles provide power. Given that, we now sail a boat based on the typical IMS type-form (before the latest slab-sided weirdo''s) and love it. We had the chute up in 20-25 this summer in good sized seas 100 miles off-shore and it was effortless. In the IOR boats I''ve sailed it would have been a white knuckle deal. Time does move on.


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## owenmccall (Feb 10, 2004)

cpa, 

I do have a few questions for you. If you would, please contact me [email protected] [email protected] Thanks.

Owen McCall


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## TSOJOURNER (Dec 16, 1999)

Is the discussion solely related to IOR boats designed solely for racing? If not...

I think that for most sailors who would like a performance boat, IOR boats are a fact of life. The IOR existed from roughly 1970 to 1990, correct? Thus, If you are looking for a boat of any significant size at a reasonable price....welll..... I think you are getting an IOR boat.

But that is not a bad thing. I too think many IOR boats are under rated. The sheer number alone that have circumnavigated indicate that there are robust and seaworthy designs that a good sailor can be happy with.

Yes, by today''s standards IOR designs are somewhat of an artifact based on a rule. But then, was the rule such that it was impossible to create a good sea boat? I don''t share that view (though you might make that case for the CCA rule). 

In my opinion, there are a plethora of "IOR" boats that are not at all alike. Like any design field, there seems to be a range of designs that went from one extreme (perhaps light, pinched and wet) to the other (heavier, less extreme, moderate and seakindly). Pure racers to boats more suitable for cruising. Thus, I am not sure we can dismiss all boats of that era under the rubric of the IOR rule. There are certainly IOR boats that sail well, have a sea kindly motion and are not at all wet.

I also think there are some advantages to IOR boats. The overhangs for one. Less extreme than those of CCA boats but offering greater reserve bouyancy forward than many of the plumb bow designs popular today. This attribute is important to cruisers who might carry more ground tackle forward and also do not wish to spend long tacks ''submarining'' the boat. IOR sailplans that have modest mains and large genoa jibs are not as easy to handle as more recent plans with fractional jibs and large mains, but, this type of rig is simple and robust, roller furling and large winches can mitigate jib management to a significant degree. 

IOR boats can be fun to sail and a thing of pride to own. And they are affordable. There is plenty of upside for us :O)

Best to all

John
s/v Invictus
Hood 38


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## Jeff_H (Feb 26, 2000)

John

I look at this differently, while there were a lot of IOR boats built during the period 1970 through the late 1980''s, most boats built during that period, that are suitable for cruising, especially aimed at coastal cruising or specifically aimed at offshore cruising, were built with little or no regard for the IOR rule except perhaps for the fad of tiny mainsails and huge genoas which really was a carry over from earier race rules as well.

I think that most IOR boats are overrated rather than under rated as cruising boats. They are tender, wet and a bear to sail without an army of gorillas. While I am sure that there are a number of IOR boats that have sailed around the world, I doubt that they represent a very large portion of the cruising population and in most cases they certainly do not represent a reasonable decision for a distance cruiser without an enormous amounts of heavy modification and a certain willing to take risks and live uncomfortably while doing so.

By the very nature of the rule anything built after IOR-1 was anything but "heavier, less extreme, moderate and seakindly". The rule explicitly discouraged that so a boat built that way was by definition not an IOR boat.

I also disagree with your statement, "The overhangs.....[were] Less extreme than those of CCA boats but offering greater reserve bouyancy forward than many of the plumb bow designs popular today." Actually one of the advantages of the plumb bows of today is that they actually have more reserve buoyancy forward than bows with overhangs and they use that reserve buoyancy sooner and more gently than a boat without a more plumb bow. That is the reason that traditional working watercraft in areas with rough conditions typically have plumb or near plumb bows. Plumb bows are less likely rather than more likely to submarine as they start to lift the bow sooner.

Respectfully,
Jeff


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## TSOJOURNER (Dec 16, 1999)

Hi Jeff,

It is great to chat with you again. I take your point that boats that were designed to be heavier and more sea kindly departed from the IOR rule. Perhaps they are better termed IOR era boats? 

The issue of reserve bouyancy is one of great interest. I am not an NA nor expert in any way but as I view watercraft, both power and sail and watch how they move through the water (in real life and in pics), I see more plumb bow boats going bow down than I do boats with overhangs. When I look at the design of major ships like deep ocean work boats and ships such as Aegis class cruisers, the design trend is the "plow sheild" bow....which is essentially an overhang. I may be quite mistaken but I think this type of bow, either on a sailboat or powerboat or ship serves two functions: that of creating a drier ride through the waves and reserve bouayancy. I understand your point about a plumb bow boat using its reserve bouyancy sooner...and as I look at some of the new Bene''s and Dehler''s I might see how a higher bow might do that. But...intuitively...if you have a broad bow with its overhang, you have a hull area of light displacement. Thus under Bernoulli’s principle it is bouyant and it is bouyancy not being used by the boat at its static waterline...thus it is reserve bouyancy. No? Remember, I am no expert so this is what I come up with thinking in the simplest terms.

All the best

John
s/v Invictus


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## jack_patricia (May 20, 2001)

John, Jeff and the Group:

I''m coming to the party a bit late on this thread, but find it a pretty interesting discussion after John''s initial observations.

First, I''d agree with Jeff that many boats out cruising and that were built during the ''IOR era'' are not direct descendents of the IOR rule; or at least, that''s not what I''ve been seeing. I''d also agree that there has been some ''bleed over'' between IOR design trends and more generic cruising boat designs, one good example being the large foretriangles that exist on many 80''s and 90''s cruising boats. Personally, I think that''s helpful because most often a cruising boat (or at least, one used for long distance cruising) will end up - sooner or later - with an inner stay, and the utility of that stay is aided by the larger foretriangle. (I''m sure I''m destroying lots of nuance and design sublety with that statement but, in general, I think it''s a valid one).

Second, I think you''re basically on target with your comments about bow designs and reserve buoyance, John. I''m troubled by Jeff''s comment that, in general, a plumb bow is going to produce more reserve buoyancy than one with an overhang because a) the plumb bow is most likely present in the design to extend the static waterline length and improve hull speed, not because of its reserve buoyancy benefits, and b) because reserve buoyancy is going to depend on the lines of the boat''s forward sections, not just on a single line we see in profile of the hull shape but on the three-dimensional form of the bow section. Intuitively (tho'' perhaps also in ignorance on my part), logic suggests that with identical hull forms and with one hull offering more overhang than the other, greater reserve buoyancy will exist in the lines with greater overhang. To the extent that designers include a fuller bow section with a more plumb bow (as seen in profile) in order to provide equal or greater reserve buoyancy, there''s going to be more weight and also cost introduced by those fuller lines, so it''s not a free lunch. I mention this because there''s almost the implication in Jeff''s comments that the greater reserve buoyancy of a plumb bow comes from the plumb bow itself (as seen in profile), which I don''t believe to be close to true.

So Jeff...and few more words to knit together John''s and my views with your own, if you please. And BTW, Happy Thanksgiving to you both if I don''t have a chance to see this thread until late in the week.

Jack


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## owenmccall (Feb 10, 2004)

What I think is confusing to me is that we are not specifying "a fuller bow GIVEN (1) A FIXED DECK LENGTH OR (2) A FIXED WATERLINE LENGTH." If we are talking about a fixed waterline length, then a overhanging bow will have more reserve bouyancy than a plumb bow. If we mean per a fixed deck length, then a plumb bow will have more reserve bouyancy and a submerged "ramming prow" (reverse overhang, like on a Roman trireme) will have the MOST reserve bouyancy.


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## TSOJOURNER (Dec 16, 1999)

Neither am I trained in the esoteric art of maritime design, but I have my own intuitive notion about this subject. The phrase “reserve buoyancy” must be understood in a broader sense than it is normally thought of. It is not simply load carrying capacity. 

Think of the differences in the entire hull form, not the bow alone. From above, the waterline shape of earlier IOR influenced boats appears much like a diamond, especially in comparison to more recent plumb bow hull types which tend more toward a triangle shape. IOR boats with larger bow overhangs typically have broader beams which occur further forward then taper more to the stern, relative to plumb bow boats which typically have somewhat narrower beams farther aft forming a fuller stern section. 

Simply imagine a block of wood cut to these waterline shapes. With the IOR diamond shape, the center of flotation is near mid-ship and the boat tends to rock (pitch) from this central axis. Lifting the bow tends to depress the stern and visa versa. With the triangle archetype, the bow waterline is sharper and narrower and center of flotation is moved aft. Lifting the bow depresses the stern much less and pitching motion is dampened. 

While it is true that sailboats with plumb bows are likely to be more sensitive to excess weight forward, it seems reasonable to assume that with properly distributed ballast and gear stowed aft they will rise more easily and with gentler motion to oncoming seas given the longer lever arm between bow and beam and reduced pitching energy to be overcome. This is functionally the same thing as reserve buoyancy.

Many other well understood benefits also accrue, such as waterline length as mentioned plus downwind stability resulting from a more stable three point stance, so long as proper ballast trim is maintained. If ultimate storage capacity is the goal then fuller bow sections will be beneficial, but at a cost. As in all boat design decisions, some compromises are made, moderation is best and more is not necessarily better. 

This simplistic perspective does not address the extensive overhangs of older, slimmer designs which grew out of far different circumstances. I’ll leave historical context, technical corrections and terminology to the better qualified among us. Am I misunderstanding completely, Jeff?


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## Silmaril (Feb 22, 2003)

Well, I''m no navel "artichoke" but some of my observations may be revalant.

Back in the 70''s when I was doing a lot of sailing on IOR boats, 1 Tonners, 2 Tonners, "Grand Prix" boats, I spent a couple of weeks campaigning on a "Thistle" one design sloop. I was particularly impressed one weekend in Buzzards Bay, 25+ kts, lots of steep chop, and the Thistle just flew... If you know the Thistle, it has a plumb bow and a very full forward section and carried it''s beam well aft. Almost a cylinder with one end shaped to go through waves. Not to mention the fractional rig, large main, small jib and ''chute. After that weekend, I always wondered why you could not design a "big" boat the same way. When I saw my first Riechle-Pugh (sp) maxi, I said to myself, "Hmmmm looks like somebody finally saw the light!"

One of the things about the IOR designs was yes, they have overhang, but they carry a narrow entry well aft before they baloon out to their maximum beam. Yes, by definition, a boat with overhang would have more reserve boyancy, but that would assume a similar beam profile. Modern designs carry their beam farther forward and farther aft, so as the bow goes down, a much greater area is being pressed into the water, and as a result, there is more boyancy. 

Now, I will have to agree, that by dismissing all IOR designs as "bad", you may be throwing the baby out with the bathwater. My trusty old IOR designed Heritage 1 Ton has many of the bad design traits of the IOR era, but the whole is way more than the parts. I show my transom to most boats in my size range, regardless of when they were built. But I have to "shift gears" much more often than newer boats, and that is when they can get me. Unless I have a full crew, who really know what they are doing, I am forced on a race course to make compromises that will ultimately affect my boat speed. 

As far as cruising goes, I don''t carry the comforts of home with me, think "camping with sails", but I am WAY faster than any modern non-racing design. I can remember a brisk fall day, 20 - 25+ kts. I was having a blast with full main, no genny. Steaming along at 7kts, enjoying the sun and weather, and the occasional wave rolling aft, while most of the cruisers were huddled behind their dodgers, full fowlies, and struggling. But that is just the way I sail. For some, that day was work, for me it was playtime. I think that if you are into the look of the IOR boats, and I certainly am, they can be a good value. I would steer clear of the post "Celebration" (Bill Cook designed 1 Ton from 1978) era IOR boats, with their funky rule cheating flat section down the center of the hull. They will rattle your teeth in a chop. But I like the look of the early designs and best of all Silmaril is PAID FOR!!!!!


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## TSOJOURNER (Dec 16, 1999)

Nice discussions and always great to hear from Jack (not just because he agreed with me :O)

I think for the purposes of discussion we will have to stipulate that either beam carried forward and angle of V in the hull have perhaps more to do with how dry a boat is and/or that comparisons need to be made on a standard LWL or LOD. 

But lets take the case of two similar boats meeting the same wave:

When a boat with a plumb bow say 5 ft above the static waterline meets a 6 ft wave, at the moment of impact there is little opportunity for the hull to be bouyed at this point to overcome the motion of the wave and the wave washes over the bow. 

When a similar boat with some overhang approaches the same wave....the angle of the face of the wave carries to the angle of the bow and thus a portion of the boat not already directly involved with bouyancy is used to provide more (read addional or reserve) displacement (read bouyancy) before the portion of the boat above the static waterline is carried to the wave. Thus the boat is carried over the wave rather than through it. 


I also have a question. If it true that a plumb bow boat has a longer lever arm ...then that arm (LWL) creates more torque and (as mentioned above) it takes less pitching energy to overcome and thus it has a greater ability to float forward (bouyancy). BUT....this runs counter to statements made here that boats with longer waterlines (same LOA) pitch LESS. SO...we have a theory that runs counter to an observation. 

So...the related observation that has been made about boats with longer overhangs is that they pitch more. If that observation is true, then either these boats must have a reduced pitching energy to overcome...or lever arm has little to do with pitch. I submit that what accounts for the discrepancy in these observations is that boats (with overhangs) in fact have appendages that contribute downward force when above the water (due to gravity) and upward force with meeting water...reserve bouyancy! 

My best to all

John
s/v Invictus 
Hood 38 (searching for its identity as an ''IOR era" boat :O)


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## Jeff_H (Feb 26, 2000)

I want to start by saying that I am finding this to be a great discussion, and in many ways I think that, at least to me, this represents what is the best of what a discussion group should be. I do think that my comments were not as defined as they probably should have been and that has to the very interesting kind of grappling for a definition that seems to be taking place here. 

I would like to start with my comment about plumb bows having more reserve buoyancy than a raked bow. Let me try to explain this with an example. I am suggesting that we visualize two boats with the identical deck plans, and the identical static buoyancy forward of the point of maximum beam, but one boat has a plumb bow and the other a ''destroyer bow'' (by which I mean the straight raked stems found on most IOR era boats). Both bows hit an identical wave. On the boat with the plumb stem, the forefoot of the stem will be in contact with the rising portion of the wave and will begin to feel upward forces causing it to start to rise at a point several feet before the stem at the deck is in contact with wave. The stem of the destroyer bow will only feel the lift of the wave several feet later, somewhere around the point that the waterline contacts the wave and it is only at that point that the bow starts to lift. 

In the case of the plumb bow, as the boat''s momentum carries it into the wave, the buoyant volume represented by the flare of the topsides between waterline and the deck would represent the reserve buoyancy and that volume is beginning to lift the bow several feet before the volume of the topsides on the destroyer bow would come in contact with the wave. It is that difference in location of the reserve volume that gives the plumb bow its increased reserve buoyancy. 

What complicates this discussion are a number of other factors which I think Jack alluded to. Modern race boats often have not only plumb stems, but also have minimal flare to their topsides. When you have a plumb stem and a plumb topsides there is less reserve bouyancy than is ideal. When you further couple that with the very fine bows on the more extreme racing types, you end up with a bow that is very intolerant of weight forward. That said, old IOR boats were far less tolerant of weight forward than any other type of boat that I have ever sailed. 

Which brings us to other pieces of the puzzle. If we go back to our original example, the plumb stem would tend to have a sharper entry angle. This means a much more gentle collision with waves because while the bow starts to feel the lift of the wave sooner, the actual upliftinf force is acting over a smaller surface area, so instead of slamming into each wave the plumb bow tends to start to slice into the wave. That feeling of slicing into the wave at first gives the feeling of ''submarining'' into the wave, but the deck is less likely to slice through the top of the wave because ultimately there is more reserve buoyancy to prevent that per the above. To some extent it is that softer impact that gives the newer plumb bowed boats a more comfortable ride. 

Here is where I need to abandon the model described above because as has been noted, newer boats have their center of buoyancy further aft than was popular during the IOR. When combined with a plumb stem angle of rotation when passing through a wave is reduced. I know this sounds a bit counter intuitive if you think that a plumb bow has greater reserve buoyancy but I can explain it this way. I think that we can assume that all other things being equal, the bow of a boat with greater reserve buoyancy would rise further out of a wave than a boat with less reserve buoyancy. (This is somewhat mitigated in our discussion because the reduced impact of the finer stem imparts less impact energy to push the upward than the fuller bow of the destroyer bow.) So while the bow might rise higher, the angle of rotation would be measured to an axis of rotation that is further away and so the actual angle of rotation is reduced. And because of the greater damping of the longer waterline length (mentioned by Phil I think), there is less of a tendancy for the pitch to continue as the pitching energy is disipated.

Anyway, those are my thoughts.

Jeff


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## TSOJOURNER (Dec 16, 1999)

Jeff''s description matches our experience. One thing we have noticed with our fine bowed new boat is how much drier the cockpit is sailing upwind. The entry slices into the water instead of hammering into it like older boats with shorter waterlines and a lot of topsides flare. Waves will slop onto the foredeck but run off before they get far aft of the shrouds and there is much less spray flying around. So not only is the motion gentle but you stay drier.

This is a complex issue though as mentioned. Weight forward makes a boat wet. I raced on a Hood 38 that was set up for serious cruising. They carried 300''+ feet of 3/8" chain in the anchor locker. That boat pulverized every wave it met and they would end up in the cockpit. In a chop though you could stand below without holding on, the motion was so easy. Getting back to the earlier point, a Hood 38 is a good example of a boat that was designed in the IOR era that exhibits few of the trademark characteristics such as pinched ends, distorted run and bumping at measurement points.


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## TSOJOURNER (Dec 16, 1999)

Really great discussion. Another reason to come here more often. 

Jeff, that was a terrific explanation, thank you. Very worthwhile and instructive. I can see now how a plumb bow boat can have reserve bouyancy. 

That and Jon''s point lead me to conclude that the overall design of the boat also contributes to her bouyancy and dry ride. I would agree that in either case bow flare is important in giving either boat greater reserve bouyancy and be able to produce a drier ride. Also, as Jon points out, balancing the boat is cruicial. 

I keep my boat well balanced and do not carry as much weight in the two bow lockers as the one Jon was on (do you recall the name?...we are a small community). I don''t find much pounding or get water in my cockpit. I do love the ride on this boat (another thread perhaps). I have heard from a couple who cruise a Passport 37 (you probably know them, very nice people) and report that they are sailing somewhat bow down due to carrying a tremendoud amount of ground tackle forward. Still, they love the ride they get with that boat and its performance.

I can certainly see the value in plumb bow boats now. Although...I have seen a few models that do not seem to have much flare forward and look to be wet. Clearly, I need to sail more of these boats...any offer? Will to trade stints at the helm.

Not to detract from the true IOR boat discussion (and apologize if this is a hijack), your points regarding that design are well taken. I think it useful to discuss "IOR Era" boat designs that were influenced by the IOR rule, but departed from it....as these boats tend (IMHO) to be the majority of well sized boats being sold at reasonable prices. Perhaps another useful discussion in this thread is the difference and contrast between true IOR rule boats and those that were competitive under the rule but departed from it.

All the above said, it still appears to me that boats with overhangs at least still have a very good amount of reserve bouyancy forward...I am not sure which design would have more...to me at least I am not certain we can state which has more. I can see the point about the plumb bow boat with adequate flare meeting the wave and being carried up. But...the same would be true of a boat with moderate overhangs and adequate flare (like my Hood and your Farr 11.6). As I think about the bow of these boats meeting a wave, I still see the overhang touching the wave face and providing life and or bouyancy as the bow entry at the static waterline approaches and then rides the wave face up on its bouyancy. I still see a very good if not high amount of reserve bouyancy in this design. 

As for pounding when meeting the wave, I am convinced by your model of a finer entry cutting through and thus reducing the counter force of the elastic collision. That does make sense.

But still on the question of reserve bouyancy, I guess I still want to throw into the mix the fact that again, modern deep sea vessals such as warships have overhangs...I see this perhaps producing some pounding (having been there) but also greating reserve bouyancy on those boats and helping with a drier ride. Add to this that AC boats have overhangs and the overhang design of the bow of Alinghi was said to contribute to her speed. 

Nice to chat with all of you. 

My best

John
s/v Invictus
Hood 38


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## TSOJOURNER (Dec 16, 1999)

Hello John. The Hood 38 I''ve sailed and raced on was "Ghostrider". Last I heard the boat was in Southern California somewhere. Recall two complete sets of heavy ground tackle (all chain) in the bow. I was impressed how the boat could lug all that weight without being seriously bow down. They also had the full kit on the stern such as wind pilot, wind generator on a pole etc. so it probably helped balance things out. With lots of weight in the ends the boat would not rise easily to a sea but smash through. A lighter boat would have been stopped hitting waves that hard but a lighter boat with weight more amidships would slide over waves without banging into them.

I''ve raced a Saga 43 which has a fine entry but lots of flare to provide the reserve bouyancy you mention. Its nice having the deck space forward to work on but the flare seemed counter-productive in terms of keeping spray down. Intuitively you''d think flare forward (and overhangs) would make a boat drier. I''ve started thinking they make the foredeck drier but the cockpit wetter. Boats with fine entries, short overhangs and not much flare have wet foredecks but don''t generate a lot of spray to end up in the cockpit when sailing upwind.

As to AC boats having overhang, that''s all about rating rules. They measure the length just above the waterline. They are trying to get unmeasured sailing length. Look at "box rule" boats like the TP 52''s where there are no constraints other than length, width, beam, displacement etc. They all have virtually no overhangs. 

Have a great Thanksgiving.


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## Jeff_H (Feb 26, 2000)

JohnDrake

I would be honored and delighted have you sail with me on Synergy. I must say for the record that Synergy is 25 year old design and so does not have a plumb bow. Boats have really evolved a lot since she was designed. Synergy (a Farr 11.6 for those tuning in late) is a kind of missing link in the evolution towards the IMS typeform that has replaced the IOR typeform. 

While she has a very fine bow for her era and her center of buoyancy is quite far aft, she also has a destroyer stem and a fair amount of flair. She has extremely low freeboard. Similar to the descriptions offered above, she does not collide with a chop but knifes through. When I first bought her and was sailing in a steep chop, I would find myself bracing for the impact with each wave only to be surprised at the gentleness. She does not go bow down when heeled as was typical of IOR era boats but when she is at high speed beating into a chop she will slice off the top of the wave and send it flowing aft. Slowing down a little stops that problem (dropping from 8 knots to somewhere in the mid-7''s).
Similar to the description above, while she takes some water over the deck, it does not make it aft of the shrouds. I think that she would be improved by slightly more freeboard, a more vertical stem and less buoyancy aft.

The following is a link to a picture of Synergy heeled over which pretty much shows how she sits on her lines at a compartatively high heel angle....

http://cruisersforum.com/photopost//showphoto.php?photo=441&password=&sort=7&thecat=998

The following is a link to another picture that shows her heeled from astern:
http://cruisersforum.com/photopost//showphoto.php?photo=438&password=&sort=1&thecat=500

So while she does not represent the best of modern design, she certainly reflects some of the better attributes of a modern thinking. I would be honored to sail with you when convenient. Please email me at [email protected] so that we can set something up.

Best wishes,
Jeff


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## TSOJOURNER (Dec 16, 1999)

Jeff

You are very kind and I have always appreciated your words and advice here and elsewhere. I would love to take you up on your offer and sail aboard that fine boat. I know I would enjoy the sail, company and conversation greatly. 

I would like to offer you a place at the helm of Invictus as well. She is being hauled this week, so next season certainly. I think you would find she sails much the same, moderate, dry and sea kindly in most respects. As you know, I got her as much for her cabin as her hullform. I hope you can come by to see her sometime. 

Let''s make it a point to get together. I will email directly. Are you sailing through the winter? I will be spending 3 weeks in FLA helping a friend double hand his HC 38 from StA to the Keys. Other than that, will be around and working on the boat.

Jon - you have some nice friends with some very nice boats. I knew about the box rule, it wasn''t that, it was something in a comment Gary Jobson made after the race that there was something about Alignhi''s bow that made her knife through the waves faster. Not sure what it was...

Best to all, hope all has a good holiday.

John


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## TSOJOURNER (Dec 16, 1999)

Hi John:

The knuckle bow exploits the way that rated length is taken at 200mm above the measurement waterline in the Americas Cup class. The knuckled stem profile is designed so that a rated length equal to that of a conventional bow provides a 200- to 300-mm longer effective sailing length. If you type "Alinghi knuckle bow" into Google you can learn more about this than you probably care to know. My point about the box rule is that when rating games such as described above are removed, plumb bows result.

Plumb bows have their own issues, like raising the anchor without banging it into the stem. The Saga we''ve sailed on solves this with a substantial bowsprit / anchor handling fabrication. Had a nice holiday weekend - spent it on the boat.


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