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Started by atomvoyager, October 17, 2008, 08:51:51 PM

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dobrodaddy

Don't know much about Albergs, but on the Rawsons its common to add a  bowsprit  to get better balance. then a inner forestay is usually added. I'll be doing this soon.

Captain Smollett

I would not say the Alberg 30 (or any other Alberg design?) has 'improper' balance.  It's just that the main is relatively large (compared to the foretriangle) and has a low aspect ratio, so needs to be reefed 'earlier' than other, more 'modern' designs.

If the boat is going hull speed and sailing well with a reefed main at 15-18-ish knots, adding a sprit so one can balance a full main will gain nothing, and MAY hurt handling due to increased leeway.  Over-canvassing a boat is a pretty big negative.

Hull speed is hull speed, no matter the sail plan that gets you there.

My two cents...
S/V Gaelic Sea
Alberg 30
North Carolina

Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover.  -Mark Twain

s/v necessity

I've read many discussions on this subject (Alberg boats and weather helm)  Many people claim that a new mainsail is in order if it's a problem.  Considering most of these boats are pretty old, and I've seen many/most of them sporting pretty old sails too...  I have wondered if old mainsails are the culprit.  I suspect the newest Alberg boat is still over 20 years old, and some of them are using their original sails.  I' haven't had a chance to sail my CD28 yet, so I have no personal knowledge, but I have a friend who sails a Triton, and claims it is surprisingly well balanced.  Finger tip control and all that jazz.

Cmdr Pete

My Commander has the same hull as the Ariel.

I have a 135 roller furling genoa, and try to avoid sailing with a partially furled genoa. I'll go with one or even two reefs before rolling up some genoa.

The boat loves this configuration. I get my highest recorded speeds that way

The wind looks a little light in this picture, but what the heck

1965 Pearson Commander "Grace"

Melonseed Skiff "Molly"

CharlieJ

Talked to Laura just yesterday.She's out singlehand for a few days. She had to reef the main around noon, and said that the boat practically sailed itself for a few hours in that configuration.

Then the winds got up more, she reefed the jib and finished the day that way.

She was anchored last night in 26 gusting 30. The forecast, of course, was for 10 to 15. She's SUPPOSED to come home this afternoon, but just may stay anchored, since it's SUPPOSED to be 10-15 tomorrow.

Of course, Tehani sails with finger tip control, even with the rail down. In fact I once sailed for an hour and wondered why the boat was occasionally wandering ( under tiller pilot) THEN realized I had the unit in stand by rather than turned on ;)
Charlie J

Lindsey 21 Necessity


On Matagorda Bay
On the Redneck Riviera

TJim

It seems to me that the problem of balance is where the power is centered and if the power is mainly after there would be two possible solutions.  The first would be to reduce the power on the main by reefing.  That will lower your "possible" speed because you have less power but you go faster because you also reduce your weather helm by bringing the boat more into balance.  However, it seems to me that if you move your Forestay forward (a sprite) you have moved your center of power forward and should have reduced weather helm and therefore have more power to sail faster.  I mean the reason for reefing really had nothing to do with wind velocity, only with weather helm and rudder drag which  was corrected by reducing power rather than moving the power forward to balance
the power without sacrificing power.   Am I making sense?? I'm not advocating more sail forward, just the same power moved farther forward, which seems reasonable tome would result in better balance and less weather helm, hence more speed..... I'm not trying to argue with anyone,,,, because I'm not sure of the answer.   Just throwing something out there  to activate thought processes..
TJ

CharlieJ

On some boats that would probably be beneficial.

On a boat like our Meridian, which is SO well balanced as is, I would really hesitate to change things. I feel Phil Rhodes did a great job with the boat.

On of the things the previous owner wanted to do, and had planned, was to increase the rudder size. I'm VERY happy he didn't- it's near perfect as is.

We can often steer just like this-
Charlie J

Lindsey 21 Necessity


On Matagorda Bay
On the Redneck Riviera

Captain Smollett

Quote from: TJim on May 13, 2009, 11:41:31 AM

It seems to me that the problem of balance


Is there a problem of balance with your Triton?  I guess this is where I'm confused.  Are we having two different discussions?

I don't notice a 'problem' with the A-30's balance.  That the design of the rig favors an early reef to keep the boat on her feet (and yes, balanced) does not mean there is a problem to be corrected.  If she's doing her max speed at 15 knots with the sail plan that balances the rig, I don't see that as a problem.

It seems that all of Alberg's CCA era boats have this characteristic, but that is not necessarily a problem, right?

So, my question at this point, asked in all honesty (not flaming and certainly not defensive though I own an Alberg designed boat): is it being asserted that the Alberg boats being discussed have some inherent design "issue" that can/should be corrected, and this inherent problem manifests itself as an early reef requirement?  Or, has the discussion of a 'correcting a helm balance problem' arisen as a side topic to the OP's observation that he reef's early (for whatever reason)?

Asked another way: is there some unspoken "rule" that states that: If you must reef at 15 knots to get the best possible performance from your boat, that implies an inferior design parameter compared to a boat that gets *ITS* best performance from full sail at 15 knots, even though neither could possibly sail ANY faster or with less leeway (my working definition of 'best possible performance') with increased sail area in those conditions.

S/V Gaelic Sea
Alberg 30
North Carolina

Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover.  -Mark Twain

TJim

One of the problems is that there is no such thing as a "Triton" per say... they were all built from the same basic Alberg design but they weigh any where from just over 7000# up to around 10000# or more.  I believe mine is the heaviest at 9660 empty but she holds over 500# of water in the keel tank plus another 160 in a forward tank and another 160 in the holding tank.  That's not to mention all the equipment and supplies that go aboard.  And yes I feel like I have a weather helm problem caused by an out of balance boat.  And when I talk to feel Alberg design owners who sail in the San Francisco bay, most of them feel the same way.  This may be because we routinely sail in winds that are 20 to 35 knots.  This is not the exception but rather the rule and maybe we experience weather helm that most of you just don't sail in.  I do believe that most of the Alberg designs are pretty much different sizes of the same boat and design characteristics, the West Coast boats built by Aero marine being possible exceptions. Both the lightest and the heaviest Tritons were both built by Aero marine and....the fastest and the slowest both were built by Aero marine, but that changes considerable with wind speed.  The stronger the wind the faster the heavy boats run because they have a longer water line.  In light air they are dogs.  The more power you can use, the faster they go.  When you reef, you give up power.  If you can move your center of power forward, it seems to me you can maintain balance (less weather helm) and increase speed.  You can reduce the size of the foot on your main and accomplish the same thing but, again, you are giving up power that would move you faster if it were balanced, or moved forward.  Another thing, hull varies directly in relation
to the power available.  My (theoretical) hull speed on my Triton is 6.8 knots, The spec'd hull speed is 6.4 knots The extra speed is derived by the extra weight
increasing the water line by 2.5 feet. However I carry the same sail plan as the boat that  I'm giving as much as 3000# to.   If I have good wind and can use it, I can run .4 knots faster than the light Tritons.  I think that's almost 10 miles a day.
This is only true if I can balance the boat and avoid weather held.  So the above is why I'm all hung up on.  By the way I have averaged 7.4 knots on a downwind run in 15 ft seas and 35 knots of wind.  That was with 2 reefs and a 35 sq ft storm sail.  So the boat will do it if I can just get it balanced .  However, I bought a Ranger 33 and the Triton must be sold... I really hate to give her up but it's a matter of living aboard with more comfort and leisure Things like hot water, showers, a range with an oven, 6" cushions that are both wider and longer and
on and on....etc.... Any way this line of thinking, I'd like to know that it would work or it wouldn't work, who knows, I might have an Alberg 35 or 37 some day. Tjim

Bluenose

#49
Quote from: Captain Smollett on May 13, 2009, 10:17:01 AM
I would not say the Alberg 30 (or any other Alberg design?) has 'improper' balance.  It's just that the main is relatively large (compared to the foretriangle) and has a low aspect ratio, so needs to be reefed 'earlier' than other, more 'modern' designs.

If the boat is going hull speed and sailing well with a reefed main at 15-18-ish knots, adding a sprit so one can balance a full main will gain nothing, and MAY hurt handling due to increased leeway.  Over-canvassing a boat is a pretty big negative.

Hull speed is hull speed, no matter the sail plan that gets you there.

My two cents...

Okay, my four cents.

If by "Over-canvassing a boat is a pretty big negative" you mean carrying too much sail for the conditions I would agree. But I would argue that few sailboats are burdened with an over canvassed sail plan. Especially many of the CCA era boats when the rules didn't count overlapping jibs so they were deliberately under canvased to enhance their ratings and the overlapping genoa was added back in on race day to make up the missing sail area.

The Triton is a great example. As one person mention they can range in displacement from 7,000 lbs to 10,000 lbs. That is a Sail Area to Displacement ratio of around 16 at 7,000 lbs and 13 at 10,000 lbs. These numbers are a long way from being over canvassed.

And even though hull speed is hull speed, the wind required to reach it makes a huge difference in how often you can actually sail. And the ability to reach hull speed with the wind at, say, 7 kts is pretty nice.

One of my favorite discussions on sail plans is from  "The Proper Yacht" by Arthur Beiser

QuoteI believe that the majority of cruising boats today carry rigs that are too small for both performance and convenience. No sailboat should need half a gale or some absurd expedients as oversized genoas and spinnakers in order to really go, yet that is precisely the case far too often. Most weather in most parts of the world contains a good percentage of light winds, and it is simply a crime to design and build a sailboat unable to move well under such conditions. It is not just the that one of the keener joys of sailing is to ghost along in a zephyr; on a long trip, proficiency in light airs usually means days saved.

    The shrunken rigs typical of cruising boats have their origins in a number of misconceptions. One is that argument that a large rig is more fragile than a small one and also puts too much stress on the hull. This was certainly true in the past but modern material permits a rig of any size to have any safety margin desired without compromising performance (except in racing, which is not our concern here). And the hull of a properly built modern cruising boat is well able to take all the loads imposed by whatever rig is chosen. An extension of the same train of thought rejects large sails because once upon a time they were heavy and hard to control. Again today's technology comes to the rescue, with soft, lightweight synthetic cloth, strong but supple synthetic line, and powerful multi-speed winches that can incorporate electric drives if desired. Roller furling for jibs, and even for mains, is available to provide further help. So a generous rig need not be any harder to manage than a skimpy one. In fact, experience show that a sizable rig actually makes coping with the sails easier. The point is that with area to spare, one can arrange matters in a seamanlike manner - a well-divided rig, headsails with only moderate overlaps (or none at all), no spinnakers - without worrying about maximum efficiency.

    When a person interested in a cruising boat of certain sizes sees a racing boat of that size go by with her army of gorillas all working their tails off, it is natural for him to think, "My God, the rig is too big," and to seek a smaller rig for himself. This reaction does not survive close scrutiny. The basic sail area of a racing boat is heavily taxed by the measurement rule. Accordingly such a boat is obliged to have a rig not larger that absolutely necessary and to rely upon exploiting it to the utmost. Two flukes of the racing rule provide the means the racing boat uses to augment here basic sail area; that part of a jib aft of the mainmast is not counted in the sail area unless it exceeds a generous limit, and spinnakers are also "free" up to a point. Over lapping genoas and huge spinnakers are labor-intensive expedients, which is no handicap since racing boats are the better for plenty of live ballast anyway. There is no reason for a cruising sailor to let the vagaries of a measurement rule govern his life on the water. With sails large enough in area to provide the push required and sensible enough in design to be servants and not masters, a proper cruiser should be able to sail circles around any racing boats with a crew of the same strength. One wants speed and convenience in a cruiser, pleasure for the few instead of work for the many, and an ample rig is necessary to achieve this goal.

    Another argument against enough area for light conditions is that, if the wind picks up sail with have to be shortened. Absolutely correct - but it is not compulsory to carry the largest sails if prudence dictates otherwise on a particular day. Most cruising is done in regions where winds of no more than about 15 knots predominate, and it seems silly to have a boat just right from the Roaring Forties anywhere else.

And a little latter in his discussion:

QuoteSince the wetted surface of a boat is rarely stated and is tedious to establish from a lines plan (itself seldom published), the sail area-displacement ratio is the more practical one for comparing different designs. This ratio for the designs in Part Two of this book is platted in the first graph on page 44, and the sail areas themselves against in the second. The average ratio is 16.0, which is greater that the figure of 15.5 often quoted as optimum for cruising yachts and that I consider unduly small.

I guess I can understand if someone wanted to add a bowsprit and or a taller mast to enhance their sailing performance.

Cheers, Bill


CharlieJ

AH yes- "The Proper Yacht" by Arthur Beiser

One of my all time favorite books. My copy has lived by my bed, or at least within arms reach for as long as I can recall. In fact, it is within reach of me as I type this.

I still often read through and drool at the lovely lines of the yachts he chose, small to large. To me, the lines of the newer generation of sailboats just don't qualify as "yachts". I just cannot call a Catalina 27 a yacht, sorry.

Our Rhodes Meridian DOES fill that definition in my mind however. Of course I'm not in the least prejudiced ya unnerstand ;D ;D

Even if we do have to reef early :D
Charlie J

Lindsey 21 Necessity


On Matagorda Bay
On the Redneck Riviera

Amgine

One of the reasons moving the center of effort forward will not 'solve' the balance issue is the assymetry of the boat's waterline when it heels, one of the factors which develops weather helm. This is why no matter what the sail layout is it will eventually need to be reefed as the wind picks up - and why the Alberg's relatively narrow waterlines don't get as unbalanced as big-bummed designs at similar angles of heel.

As someone who has recently purchased new sails for an Alberg design, baggy older sails do develop much more heel, so more weather helm. The boat is definitely easier to balance now, but *off* the wind I'm having more trouble getting the autopilot to steer. I hope it's just learning curve.

TJim

I think the more significant thing is the fact that the farther aft the center of power is the more it causes the boat to head up with increased wind and the more you have to stand on the tiller to  keep her on course.  Or the earlier you have to reef. I  get weather helm at 20 or 25 degrees, if I drop a reef in the weather helm drops off but it doesn't necessarily change the degree of heel.  In fact I can run up past 30 or 35 degrees of heel with no significant weather helm by reefing.  But I believe the boat would be going faster at the same degree of heel if I didn't have to reduce power because the center of power was to far aft.......causing the boat to head up....  I have a hard time seeing it another way until someone can explain why ...that makes sense to me...  As most of you guys can tell, I'm pretty thick and hard headed......  but when I get it, I get it.... TJim

Amgine

Well, think of it in a slightly different way: when you reef the sail, usually the center of effort (COE) does not actually move forward more than a few inches. When you find the center of effort of the reefed sail, you'll find it mostly moved down, not forward, and moving down means it will heel the boat less. (The distance from the center of buoyancy is reduced, reducing the lever arm of the force heeling the boat.)

When you look at the COE in three dimensions, though, you see that not only is the unreefed COE somewhat higher, it is also several to many feet to leeward depending on the angle of heel. The more heel, the more feet to leeward. And, as I'm sure you're aware, every foot to leeward means every pound of effort gets a multiplier for foot pounds of force trying to spin the boat up into the wind. So if you can lower that COE, you do two things: reduce heel, and reduce how far the COE is to leeward. This combined effect is actually greater than moving the COE forward.

And, of course, there's the hydrodynamic force of the heeled waterline. With less distance to travel, the water to windward has greater pressure giving a slight twisting force to windward but reducing the windward lift effect of the keel (doesn't affect the righting effect of the keel, which is a factor of its lever arm, just the amount of 'gain' on VMG to windward.) This isn't all that great a force, but it's still something to keep in mind and narrower beam-to-length ratios will tend to have the lowest amount.

For my boat, an Alberg-designed Cape Dory 25D with a modified full-keel shape of shallow draft, the designer suggested the boat be sailed quite flat, preferably less 21°. Looking into this I learned that about 25° the lateral resistance will drop substantially, meaning the boat starts making leeway much more rapidly, plus the effective sail area curve falls off pretty fast, the COE being way out to leeward results in rudder angles of more than 5° so it's acting more as a brake. By reefing earlier I can often increase my speed over the ground and point a little higher, so my VMG to weather is better.

But I admit that last week I was sailing with the inclinometer maxed (40°.) Too much sail for the breeze, but it was sure exciting! Only the second time I've actually had water over the toe rail.

TJim