Too much roll

Bilgewater said:

The Gulfstar is going to roll no matter what.

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Yup. Pretty much the bottom line (pun intended).

Bilgewater said:

The Gulfstar is going to roll no matter what. I would like to have bilge keels to dampen it, but haven't been able to determine if it would be practical or not. The steadying sail helps some, but she still rolls. If the fore cast is for more than 2-4 foot seas, we stay home. If we get caught in it, we slow down and do the best we can. We have "tacked" like a sailboat to keep the seas off the beam for a given course. Flopper stoppers would most likely be the best roll-reducing system, but it would take some serious engineering to do it properly. My concern is how to lower the mast for canal cruising with all the f/s gear installed.

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Yea, it's going to roll, all the trawlers are going to roll to different degrees, and if we want to dampen it something has to be added. Do you think bilge keels on the Gulfstar would be enough to feel a significant difference? what kind of keels or fins are you thinking of? those placed at about the 45 degree angle each side of the keel? What would you consider the best length and depth/width of these? I've seen some that were only a few feet long, about 18" deep and airefoil shaped. And others that were flat like a board, about 12 or 16 inches deep and ran 10 feet or more. I can see your concern about canal cruising if you set up paravane rigs, getting that mess up and down would be major headach. I'm just trying to find out if someone has tried bilge keels/fins, how they were sized, and where they were placed. And of course, was it worth it. I wouldn't want to haul out to have keels installed and discover that they don't work, then have to have the extra expense of installing a mast with a post to the bildge and the Paravane gear.
For me also right now, it's not all about expense, but a lot about time.
Thanks
Bill

In general order of effectiveness.

1) Bilge keels - will reduce rolling 10-20%
2) Steadying sail - will reduce rolling 20-30%, but only with stiff wind from the right direction.
3) Passive tanks (Flume, Fram, U, etc) - will reduce rolling 40-60%
4)Paravanes - will reduce rolling 50-70%
5) Active Fins - will reduce rolling 60-90%
6) Gyro stabilizer - will reduce rolling 60-90%

One way to deal with the paravane poles and folding the rig down is to mount the poles on a universal type base. This allows them to pivot both up and down athwartships, and also fore and aft. Thus they can be pivoted to rest parallel with the rail along the cap or deck, or even along the cabintop.

Here's what Beebe says about bilge keels: "It works out that bilge keels, while effective on large ships, do not suppress roll very much on small craft. Their bilge keels may be expected to suppress roll about five percent or thereabouts."

It all adds weight and/or drag and costs money,

My Willy ((Willard) rolls plenty and for a 30' boat has plenty of ballast at 4000lbs. And it's much stiffer than a round bottom boat. A good balance it seems. Several times I really wished we had some form of stabilizers but those times were few and only a very small part of the day. When the rolling gets pretty bad I frequently stand w my feet fairly close together w my right hand lightly on the helm. That way the boat rolls ... Not me. A mindset of "the boat's rolling, not me" and "let'r roll. But on several occasions it got so bad I was spread eagle gripping the helm w two white knuckle hands. But on reflection those times were almost always of short duration.

But the best inexpensive way to roll far less is to steer a course that forces the boat to roll at a rate that the waves frequency is such that when the boat tries to roll to port a wave at that moment arrives at the port beam and arrests the roll before it begins. Often it's just a few degrees course change to bring this about. You can practice this technique on passing wakes.

Seamanship costs no drag, weight or money.

A lot is known about the paravanes, even how to determine what size for your boat. It may be worth it to have a local marine engineer come by the boat and see if it's possible to install a flume tank on this boat, but I have my doubts about the strength of the pilot house support framing on a lot of these trawlers. That's a lot of weight sloshing around up there.
Bill

My hull although shorter in length is similar to the Gulfstar. I have bilge keels, and although they may help a little, the rolling is still terrible in a 3+ foot beam sea. When I raise the sails, I would estimate the rolling is decreased by about 75%.

I have a 200 square foot gaff rigged mainsail and a 100 sq. ft jib. The boat is only half the displacement of a GS36. I would expect Gulfstar 36 to need a minimum of 500 sq ft of sail area to be effective for minimizing the roll. That requires a substantial mast and rigging. (and cost). I would suggest paravanes might get you equal or better results for less cost.

Tad Roberts said:

Pole length is pretty arbitrary, in this part of the world the beam plus some is usual. Some folks favor really short poles. The longer the pole, the longer it's lever arm and the more force produced. Or longer poles allow smaller "fish", which are easier to handle. We use 20 ft poles on 50' boats, and 14-16' poles (3" sch 40 alu. pipe) on 40' boats with 12' beam. My little 22' Timbercoast troller uses 10' poles of 2" alu. pipe, her beam is 7'4".

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Thanks Tad,

Hadnt seen that before, but it's helpful.
A few thoughts about this.
I am still tweaking my system. I love it, but it can always be better

TO that end, I am going to get two more birds (fish) and actually go one size smaller (I have the medium size now, Larry on hobo has the large size).
I sill see how they work (my guess is that they will be as effective with slightly less drag).

The fish are made my Stano Enterprises, one guy in his garage, I like their design, with wood wings to reduce damage when it hits something as I retrieve it and it's cost, only $125. My fabricatore in miami said he could make that in Al for $400.

You can find these fish at Englung Marine or Murray Pacific Supply.

Lastly, I was told my another KK42 owner that stabilizing sails were not worth the effort.

Also, for the first time in over 7000 nm, I had my tanks totally filled, 720 gallons, coming north from Norfolk to Rhode island. The boat is sitting lower in the water by her stern, and while she seemed a bit more slower in her rolling, it certainly wasn't significant compared to relatively empty tanks. I travelled a lot with just 50 to 100 gallons of fuel.

So the paravanes remain a no brainer for open ocean travel as they are cost effective and don't break down unless you do too many shenanigans.

Wxx3 said:

...I am going to get two more birds (fish) and actually go one size smaller (I have the medium size now, Larry on hobo has the large size).
I sill see how they work (my guess is that they will be as effective with slightly less drag).

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I'm not sure if you go smaller they will be just as affective. Less drag means less roll stabilization. Everything comes at a price?

The smaller fish, as I have been told, when we were in AK and the PNW, were for boats up to about 30-35 feet.

Have you played around with the different speed settings on the fish? If that doesn't work you can add a tab in the front which will decrease the drag even more. Just a thought.

Thanks to Richard and Larry for the comparative commentary. It's that kind of information sharing that can help the rest of us learn from the process. I'm more encouraged about paravanes as a rational investment to reduce roll.

Bill

Check with the Gulfstar owners group to see if a set of plans for paravanes exists. Frequently the marine architects will do that for a trawler they designed. Existing plans would save you a lot of hassle.

Thank Marty,
I've been on Gulf Star owners forum site. Not a lot of activity there. And their asking the same questions. It seems as if nobody has added them to a gulfstar yet, or at least I haven't heard of one, Just the "offshore" trawlers seem to have gone to that expense.
Bill

This is from Beebe's first edition (1975). It gives you an idea of the loading for paravanes. He's was convinced that the fish can generate resisting forces up to 10 lbs. per square inch. Our fish are ~300 square inches each. Proper design is critical.

Hi Larry. Could you snap a couple photos of the attachment points of your poles and cable ends where they attach to your hull? The outrigger poles, are they attached to the hull with backing plates and is the location of the attachment point above the deck through your bulwarks or below deck through hull.
Thanks

No problem. Let me find them.

This would be nice to see Larry. Almost everyone I see with the Paravanes is on the 40' and over boats. Anyone aware of the smaller trawlers rigged with the Paravanes?
Thanks

stevensibs said:

Hi Larry. Could you snap a couple photos of the attachment points of your poles and cable ends where they attach to your hull? The outrigger poles, are they attached to the hull with backing plates and is the location of the attachment point above the deck through your bulwarks or below deck through hull.
Thanks

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No backing plates for the a-frame/pole mount but yes for the forward guy at the bow. The mounting bracket has an access plate, pic 7. The bracket is also vertically attached with SS lag screws to the rub rail. Sounds like you're thinking about it. Are you going to build some? Beebe's book has been spot on for ours.

My Dad invented this during the 60’s and patented it early 1970's. He adapted the concepts from airflows on wing’s while flying Spitfires in WWII.

I spent a few of my mid to latter 1960’s young years building and sea testing it with him. Simple, inexpensive, thorough, no moving part other than flexible curtain; with correct materials it would last indefinitely. Can be affixed to various boat bottom portions and built to various dimensional needs. Works like a charm while moving and standing still. Perfect for displacement cruising trawlers, motor sailors and the like!

I plan to someday reinvigorate this product; after I’m finished with my other inventive ventures having nothing to do with boating... I have improvements in its design and understand all its working features.

Dad tried half heartedly to market this stabilizer but while getting old he never hit the mark. I feel correctly marketed it could become a marine stabilizer winner!

HYDROFOIL-SHAPED STABILIZING OR ATTITUDE-AFFECTING MEANS FOR BOATS


A hydrofoil-shaped stabilizer or attitude-changing means for boats, having an elongated frame assembly adapted to be connected to a submerged portion of the hull of a boat with its longitudinal axis parallel to the fore-to-aft axis of the boat. A flexible curtain assembly extends about the frame assembly and is fixed thereto but free to move laterally and to a more limited extent longitudinally relative to the frame assembly. The interior of the curtain assembly communicates with the surrounding water and is deflected to one side or the other relative to the frame assembly by its displacement relative to the water caused by a change in the attitude of the boat so as to form a hydrofoil having a camber for generating forces to oppose the change in attitude to one side or the other when the boat is underway.

Sure would like to see some sketches.

Larry M said:

No backing plates for the a-frame/pole mount but yes for the forward guy at the bow. The mounting bracket has an access plate, pic 7. The bracket is also vertically attached with SS lag screws to the rub rail. Sounds like you're thinking about it. Are you going to build some? Beebe's book has been spot on for ours.

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Really a good looking rig Larry. Did you have this installed or design and do it yourself?

kawilt said:

This would be nice to see Larry. Almost everyone I see with the Paravanes is on the 40' and over boats. Anyone aware of the smaller trawlers rigged with the Paravanes?
Thanks

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Reading this thread reminded me of a couple of pieces of trivia I saved in my 'Ideas' folder.

One is a photo of a later model Willard 30/4 that as near as I can determine, is the one prepared by Zimmerman for a trip to Bermuda.

The next is a drawing by Rick Etsell, NA who figures prominently in the Willard community. It is for a 32' Trawler, which looks similar to a Willard 30, but since there were no 32' Willards that I am aware of, it could have been a Fales 32, or some other design.

The point is, these are "smaller trawlers rigged with the Paravanes" as requested by kawilt.

kawilt said:

Really a good looking rig Larry. Did you have this installed or design and do it yourself?

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Thanks. Bill Dawes who was a commercial fisherman came up with the original design and Tom Davenport, who owned a KK42, tweaked it to try to make it look cleaner and work better. They were on Hobo when we bought her. We did recently pull all the metal and repainted everything.

A million thanks Larry for all this great information and that photo and rigging layout. What a help this is.
Bill

Thanks so much Larry. And to everyone who answered. Yes I am going to build a set this year. The tanks are going in and then the engine and I want to build the outriggers while the engine room is still wide open.
My friends all say wait till she's in the water see how she rides. One doesn't need to be a naval architect to see how she's going to roll with those big fat round bilges. I'm pretty confident I'm going to need para vanes

kawilt said:

This would be nice to see Larry. Almost everyone I see with the Paravanes is on the 40' and over boats. Anyone aware of the smaller trawlers rigged with the Paravanes?
Thanks

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I've got some pictures of paravanes on a 21' Ranger Tug on my home computer. Took the pictures a few years ago in Tofino, BC. When I get home I'll post them.

Thanks Larry. Those photos are a great help. Very clean installation.

Here's a 1987 Sea Sport that was for sale.

AK and the PNW have more than its fair share of boats, less than 40', with paravanes.

kawilt said:

Sure would like to see some sketches.

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The patent on file has figures: http://www.google.ca/patents/US3753415

QB said:

The patent on file has figures: Patent US3753415 - Hydrofoil-shaped stabilizing or attitude-affecting means for boats - Google Patents

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In comparison to the patent:

Dad and I made improvements on streamlining the stabilizer unit and making it more efficient as well as increasing location/attachment availabilities onto different hull models of different style boats; deep keel sail boats included. Its automatic stabilizing capabilities are remarkable while cruising at displacement speeds or just above or below. Also, depending on placement position(s) it reduces roll while at rest. You can see the resemblance to Dad's Spitfire WWII wing’s cross section. Along with him I worked to complete, improve, and test this stabilizer's design; before and after pantent was issued.

How well I recall... Loved IT ALL!

Happy Stabilized Boating Daze! - Art