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Old 07-23-2015, 08:30 PM   #21
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Old 07-23-2015, 10:37 PM   #22
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Op, I owned a 36 gulf star for 8 years and put a lot of miles under its keel. It's a good boat, but would roll the peanut butter out of the jar. We loved it anyway. Idon't believe there is cost effective solution considering the boat is worth $50, 000 or less.

If you plan open water travel trade up to a different boat. Seriously.
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Old 07-24-2015, 03:03 AM   #23
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The snap-back roll is typical of a semi-planing hull with a fairly flat after-section and hard chines. This configuration does a good job of minimizing roll but only up to a point.

We dont mind the snap-back roll but from what I read a lot of people really hate it.

The effctiveness of steady sails seems to be very dependent on the type of boat. We contemplated having one made, not for roll dampening but for reducing hunting on a mooring or at anchor. We first talked to a number of owners of our brand of boat who had steady sails and the almost universal consensus was that they do a good job of reducing hunting while moored or anchored but are almost totally ineffective at reducing roll while underway in a beam sea. That's for this particular make; I have no idea how effective they are or aren't on other makes and configurations.

Another consideration that owners brought up was the risk that a steady sail could overpower the mast stay fasteners if the wind was strong enough. This, of course, is totally dependent on the strength of the mast's standing rigging setup. Our older boat has only two stays for the mast, and their anchoring system on the flying bridge, while sufficient for boom loads not to exceed 200 pounds, is not the strongest on the planet. Newer versions of the same model boat have four stays although I don't know if their anchoring system is any better.

In the end we decided not to bother with having a steady sail made and setting up the mast and boom with track and running rigging. The hunting issue on a mooring we deal with by deploying a Fortress off the stern which, with its light weight and effctive design, is a fairly quick and easy process.

If we had a boat with roll chacteristics we really didn't like, I think we would go for the passive paravane method of roll dampening if the boat could be properly set up for it. I have nothing against active stabilizers in terms of their effectiveness or ease of use. I simply have an inherent reluctance to make something like a boat any more complex than I think it needs to be to accomplish what we want it to accomplish. I'm not anti-technology, I'm anti-having-to-pay-to-fix-technology when it breaks. If somebody else is going to pay to fix it, well then, the sky's the limit, right?
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Old 07-24-2015, 06:24 AM   #24
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Paravanes work , but have some expense , a learning curve and the downside of increased air height , more bridges will be come obstructions.

If the boat is sea kindly , the roll is slow ,esp when it changes direction , its not hard to live with .

A change of course of 5deg only puts you off 5 miles every 60 , and costs little .
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Old 07-24-2015, 08:07 AM   #25
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With our Gulfstar 36 a course change or "tacking" made very little, if any, difference. The roll was uncomfortable, even dangerous in any sea over 2 feet in any direction except right on the nose (which it loved) or right aft. Anything on the beam or any quarter would cause a massive roll. Tacking just meant we were out there in open water rolling our guts out that much longer.
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Old 07-24-2015, 09:27 AM   #26
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Originally Posted by Dougcole View Post
With our Gulfstar 36 a course change or "tacking" made very little, if any, difference. The roll was uncomfortable, even dangerous in any sea over 2 feet in any direction except right on the nose (which it loved) or right aft. Anything on the beam or any quarter would cause a massive roll. Tacking just meant we were out there in open water rolling our guts out that much longer.
I agree that in many instances the amount of tack would either make the crossing time prohibitive or just makes the misery a tad less but much longer.

I will some time tack towards or head straight for a lee.....but those seem to be rare opportunities.

Most of the time I just wait out the worst days which for the last three round trips to FL via the ICW and Chesapeake have only been a handful...and I travel a lot in December and March...2 of the worst months for wind.
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Old 07-24-2015, 09:39 AM   #27
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[QUOTE=ranger42c;351425]Beebe describes an anti-roll tank thing, I think water-filled IIRC. Might be the same as what Kasten mentions, but I seem to remember Beebe's book had some illustrations...
/QUOTE]


Found it: Beebe, 4th edition (at least), Chapter 8: "Passive Anti Roll Tanks" (ARTs). Illustrations included.

Tacking sometimes works for us when we're puttering along at trawler speed. But sometimes not.

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Old 07-24-2015, 01:04 PM   #28
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Adding ballast gets into static and dynamic stability as well as seakindliness. I think the concepts are sorta simple, the math IS simple but I don't find the subject to be obvious nor intuitive. Doing it wrong can be a very bad thing.

The best Internet write up on the subject that I know of is, again, Kasten, http://www.kastenmarine.com/beam_vs_ballast.htm. There is more to the link than beam vs ballast so don't let that title run one off. If one really wants to dig into the subject read C. A. Marchaj, "Seaworthiness: The Forgotten Factor"

Later,
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Old 07-24-2015, 07:39 PM   #29
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Back to the Gulfstar. I tend to agree with Dougcole. His description of our gulfstar roll is extremely accurate. Of course the 2 ft beam sea is dificult only when the frequency is small, 4 sec etc. I seem to find that a 4 ft beam with 8 sec frequency is no problem. Now, I believe this is because of the round bottom. I also believe a semi displacment or planing hull would possibly be a problem in a large beam sea with large frequency since it would tend to float parrellel to the face of the sea. I do feal that tacking makes some difference but not much. I am told only 36 gulfstar 36 boats were made so consequently not much effort has been put into solving the problem. Now to the issue of finding another more appropriate vessel. Oh, and I also agree the idea of picking your days is smart no matter what the vessel, smart for many reasons and is a factor to good seamanship but, what those days, and there are many that change unpredictably and quickly? Back to another boat, what vessel? Even the out of price range "Passagemakers" have rolling issues and add sails, paravanes, gyros and tanks per Beebes book. Albin not a passage maker but looks good and still has some rolling. Willard, one mentioned in Beebes book added bildge keels with supposedly great results. Size is not a factor look at Kristens 25 ft passagemaker. Of course it has paravanes. Back to basic physics, a body at rest tends to remain at rest. This would tend to support ballest. But where is the cg of the vessel and righting moment and when is it exceeded. The roolig we are talking about is due to very poor initial stability. Although extremely uncomfortable it does not mean the vessel is dangerous. But until a righting moment is determined it would be foolish to assume the veesel has a fantastic righting moment. A gulfstar does not have a lot of weight located high of the deck. The flybridge is very small compared to most trawlers. I have also minimized as much high weight as possible. Ok, now assuming I decide it is time to look at another vessel which make and model? Trawler or do I become a sailor?
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Old 07-24-2015, 07:57 PM   #30
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I also have a 36' Gulfstar trawler, bought her ten years ago. Travel mostly the Florida Gulf coast and the Keys. Regarding Rolly Polly, for me it is mostly how, when and where I drive the boat. I do believe in altering course if it gets too rough and since I am an ex sailor I am used to this. Tacking works for me. Also, I stay out of the ICW as much as possible because I dislike getting waked by other boats, which can cause much rolling. I don't boat on weekends either because this is when the crazies are out. I go offshore down the coast of Florida and to the Keys (and back) and I find this ride to be very pleasant, so maybe being in this part of the world also diminishes the rolling. Also, I watch the weather and only go when it is 'nice' out.

The 36' Gulfstar trawler is an inexpensive, coastal boat. If you shop you can buy them for less than $25,000 in decent enough shape such that you could use them immediately without a lot of additional expense. With this in mind I would never invest a lot of money in anti-roll devices.

But if I could not tack, and if I could not choose where and when to go boating, and if I REALLY wanted to seriously dampen roll, then I would pay attention to what has already been written and proven on this subject by Bob Phillips, Another Asylum, Tortola, BVI, by Dave Cooper of Swan Song and by Professor Don Bass, at the Marine Institute in St. John, Newfoundland. This problem can be fairly easily and inexpensively solved without a lot of high dollar, add-on equipment. The answer is ROLL TANKS.
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Old 07-24-2015, 11:48 PM   #31
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Thank you, I did in deed read the article. I assume you read my more detailed response to Martin regarding why, how, how much and where we placed our ballast.
Had I read this article before doing what we did, I suspect that I would hesitate and quandary a bit more prior to making a move. Yet, the results we obtained with what we did are amazing in terms of settling the boat down. Honest, were I to be occupied in the boat and unannounced you stepped on the gunnels, the action would throw me off my feet! In a beam sea, ;you could not sit on the helm chair without rotating 90 degrees with the sharp rolling motion. We have a FD hull, not a SD or flat bottom. I agree with the conclusions of actions apparent with sharp chine boats, I have had several. In our FD hull the roll was a roll, a very quick roll, not the snap roll as described. Yes, I in adversely used the term “Snap” in my response where it should have been “Quick”. In a head sea due to the shortness of the hull (27’ WL) our local sea distance cap to cap, are more suited for a 36 foot boat or longer. So we “Hobby Horse” to a degree,
Prior to the adding of ballast that action would throw you out of the helm chair, back and forth. Let me say that at that point I wondered if the purchase of the boat was a huge mistake. I wondered back if the prior owners became dissatisfied with the action and did sell the boat to move it along as there had never been any effort to address in the format we invested.

The bottom line is with the majority of the 1100# weight added, dead center over the already built in 1500# led cast in the keel when constructed, with remaining ingots located abeam of the engine stringers and 100# located under the anchor chain. In addition, we shifted our three bank of batteries from mid-ship port side of the engine stringer to forward center line engine compartment bulkhead (90#?) the boat now lifts and falls with a noted softness over the original harshness.
The boat handles beam seas in a almost vertical position with the waves running under the boat and not slapping the boat over. Yes, on the stern wave action we are still looking much the drunken sailor but not with the added quick roll, more the reaction is a lighter slower heeling. More a rudder battle over a hull swerving action. Does that seem a clear picture? Our roll is soft, our hobby horse is reduced and the boat is a more pleasant motion in our common 2 foot seas. (Note: when the seas exceed 2 feet, in any case we are looking for a hidey hole.

As to the effects of adding weight per the article, we recently increased the hp of the engine with a repower, noted in several recent post. Our hull seed is 6.9 knots and with the calculated weight of the boat including all ballast and such, only 34 hp are required to reach hull speed. So the power sector of the article as it relates to our small boat is nil.
WE don’t push much water as we are about maxed out for efficiency at 1400 RPM and at hull speed so the concerns of extra weight are again in my opinion nil.
Please understand that I am wanting to be argumentative in the discussion rather I draw a different conclusion in light of actual physical application that runs contrary to the article in so many ways.

As I type this response, sitting in the Wrangell boat harbor, I am witnessing several commercial fishing boats that have installed tanks to accommodate fish quality. The boat tanks are flooded to the point that the water is flowing over the decks and off. Can you imagine what a say 20 foot long hold, say 15 feet wide and say, 8 feet deep water contained weighs and what does that do for the discussion of ballast placement? And yes, these boats are running in heavy seas at times in full tank conditions. Don’t want to change the thread, but those conditions I described run contrary to the authors article I would think.
Perhaps Tad Roberts being a marine architect would present a response to why I am having success in face of the article and the conclusions of having commercial boats tanked affecting stability rules
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Old 07-25-2015, 01:50 AM   #32
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Back to the Gulfstar. I tend to agree with Dougcole. His description of our gulfstar roll is extremely accurate. Of course the 2 ft beam sea is dificult only when the frequency is small, 4 sec etc. I seem to find that a 4 ft beam with 8 sec frequency is no problem. Now, I believe this is because of the round bottom. I also believe a semi displacment or planing hull would possibly be a problem in a large beam sea with large frequency since it would tend to float parrellel to the face of the sea. I do feal that tacking makes some difference but not much. I am told only 36 gulfstar 36 boats were made so consequently not much effort has been put into solving the problem. Now to the issue of finding another more appropriate vessel. Oh, and I also agree the idea of picking your days is smart no matter what the vessel, smart for many reasons and is a factor to good seamanship but, what those days, and there are many that change unpredictably and quickly? Back to another boat, what vessel? Even the out of price range "Passagemakers" have rolling issues and add sails, paravanes, gyros and tanks per Beebes book. Albin not a passage maker but looks good and still has some rolling. Willard, one mentioned in Beebes book added bildge keels with supposedly great results. Size is not a factor look at Kristens 25 ft passagemaker. Of course it has paravanes. Back to basic physics, a body at rest tends to remain at rest. This would tend to support ballest. But where is the cg of the vessel and righting moment and when is it exceeded. The roolig we are talking about is due to very poor initial stability. Although extremely uncomfortable it does not mean the vessel is dangerous. But until a righting moment is determined it would be foolish to assume the veesel has a fantastic righting moment. A gulfstar does not have a lot of weight located high of the deck. The flybridge is very small compared to most trawlers. I have also minimized as much high weight as possible. Ok, now assuming I decide it is time to look at another vessel which make and model? Trawler or do I become a sailor?
Cat, make and model unimportant?
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Old 07-25-2015, 05:14 AM   #33
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I read that the Gulfstar is a low priced vessel, which it is. From this one would assume it to be low quality, which in some years was. But, at the same time the manufacture, around 1975, contracted with a marine architect to fix some of the manufacturing problems. They did just that. May I suggest that the low price of boats and aircraft are simply due to lack of demand and popularity. (There are excellent low priced bargain aircraft in the used market.) Yes that can be due to quality concerns but also simply due to not what was wanted at the time. I believe only 36 of the gulfstar 36 vessels were built. Not very popular,and maybe a lot of boat for the money. In our vessel I do not see what I would call low quality and maneuverability is fantastic. So far even in 6 to 8 ft following seas the vessel handles well. In consistent following seas the autopilot works perfectly. In head seas, short square 3 to 4 ft chop it can be rough, but nothing like a vessel with chines. Many more in demand vessel have to the untrained eye the same or at least similar hull shape. The so called "better" vessels (more costly) have got paravanes and other devices to stop beam sea roll. Still waiting for the answer to trade up to what? Regarding tanks, according to Beebe the tanks should be high. This architecture would be using leverage to steady the vessel. Low ballast would be using inertia to steady. If you were able to bring the CG below the water line would the vessel be almost uncapsizable. But, how does this effect righting moment. I would have to draw a diagram to determine the general effects of this condition. I am not a marine engineer although I am an engineer. I proceed cautiously because as thay say, "a little bit of knowledge can be dangerous".
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Old 07-25-2015, 06:54 AM   #34
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As an experiment I would put a number of large plastic garbage bags on the cabin top , filled with water.

Start with 500lbs , go higher as the experiment progresses.

It might slow the roll and a quick slash with your knife would unburden the boat in seconds if it became a danger .

Garbage bags are cheap, sea water free , Knowledge is GOLD!
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Old 07-25-2015, 07:20 AM   #35
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Actually Al...the way you spread the weight around was exactly what I was talking about. So I can see it working based on my readings.

Weight centered down low doesn't solve all stability issues as many think.
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Old 07-25-2015, 08:06 AM   #36
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kpinnn is correct, i believe, about the quality of the build of the gulfstar 36' trawler. if they are taken care of they can be great, lifetime vessels. all boats need care. don't know why they were not more popular but i am very pleased with mine. lots of bang for the buck and i very much like being under the radar in the gosh-look-at-me-and-how-wonderful-and-expensive-my-boat-is department. i am transitioning from a 50' hatteras to this 36' gulfstar so i am familiar with some of this mentality. all in all, the 36' gulfstar trawler is a terrific boat and i look forward to many more years with her.

and what FF said about using water filled plastic trash bags up high to see if maybe this pseudo style of roll tank might be helpful is just brilliant. wish i had thought of that.
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Old 07-25-2015, 08:16 AM   #37
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I liked many things about the Gulfstars...just not the layout and accommodations for a lliveaboard.

Nothing technical...just preference....and I think it is what hurt their popularity more than anything.
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Old 07-25-2015, 08:29 AM   #38
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yes, psneeld, i understand what you are saying about the layout of the 36' gulfstar trawler. it was a trade-off. for example, the interior layout works well for me but i really love and miss the idea of a large back porch on a boat. my gulfstar does not have that. my previous boat did, and that is where i spent most of my leisure time. can't have everything.
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Old 07-25-2015, 09:32 AM   #39
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The layout works great for us and we do have the full back deck as well as a mast. I believe there was a mark I and Mark II style. One of the vessels has a mast without full deck and the other no mast but full deck. Surprisingly out has both. If I can reduce the initial roll along with some real teak and fiberglass uplifiting we will have a great economical classis looking trawler. We have put on about 2000 miles in a year. Here in the Northeast get many comments regarding it looking like a boat should. Last week while docking in Portsmouth NH we were told by somone watching us enter that it was the best looking trawler in the harbor. Well this is all a matter of opinion and personal preferance. I also need to differenciate between initial roll and stability or safety. I believe these are different subjects. Well, with one exception if the roll is so violent the people are thrown around that is dangerous but still does not indicate capsize tendencies. Of course I have no idea what the center of gravity (CG) is or center of boyancy (CB). I do know that typically a low center of gravity and round bottom hull should give the best righting torque. The gulfstar or at least ours does not have a lot of high structure compared to other trawlers. The round bottom should offer a more consistant CB compared to a chined or flatter bottom boat. These two characteristics should afford a greated angle of heel before the metacenter and CG line up, resulting in capsize. Now that is seaworthiness but sea kindlyness (roll) is another story. The tank idea is great. I think I will try the water bags. The original tanks were designed with baffels that allowed water to move from one side to the other in a restricted fashion that would have to correspond to the natural roll frequency of the hull. Actually I would suspect the goal was to create a rolling force at 180 degrees to the roll. It was also supposedly mounted high to get the most effect. Now I have moved my CG upward. This move would definately reduce safe heeling angle. I liken this to flying theory regarding spins. At one time spins and spin recovery was taught now the theory is teach spin recognition and we will not have to deal with spin recovery problems. As an acro pilot I think spin recovery is more important. With the boat if roll can be stopped then you will never heel to the capsize angle, or will you. I guess I would like to reduce roll to an acceptable level without sacrificing safe heel angle. Maybe due to the relative small size of the vessel and small beam a lower water tank could work and if low enough possibly lower the CG increasing heeling safety. Bags on the deck may show something that dictates more testing.
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Old 07-25-2015, 10:02 AM   #40
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with that back porch, kpinnn, you might have the perfect boat. i think i might be jealous.
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