Paravanes F/S

I am considering installing paravanes on my trawler. Read Beebee's chapter on Stabilization and have an engineer looking at load factors etc. Perused the internet/forums and information regarding rigging and parts is fairly sketchy. Kolstrand has the fish and holders. If anyone has installed these passive stabilizers I would be most appreciative of any information.
Thanks
Ian
Miss Marian
43' Trawler

You might want to send a PM to Wxx3 who I believe had them installed on his KK42.

I always thought Pilgrims were coastal cruisers until I read that Papillon had stabilizers.

I agree search on Wxx3, he did a nice research documentation of passive stabilizers. He might even have it on his blog.

Thx

Thx...mine is the 43...the 40 is the most popular. Only made 3 of these

Have you thought where you're going to mount the poles? Ours are mounted just below the cap rail but we have walk-around side decks. A few 40' Nordhavn's have the mounting for the poles at the edge of the boat deck.

The loading is huge when the paravanes are deployed and the engineering and design is critical. Our design has A-frame that helps distribute the load and helps manage the compression.

A Navel architect could help since paravanes are pretty much a custom fit per boat.

I have installed on a pilot house trawler. Additionally I have fished on several commercial trollers that use this system. In general there are several things you may wish to consider in designing the system. Generally the poles and supports are located very close to the area of maximum beam. For example is the beam is 12 feet then the in the water fish should be 12 feet from the boat so that the the distance are 12 feet port fish to boat, boat beam, 12 feet starboard fish to boat. It is very important the the boat have adequate hard points in order to carry the load of in the fish in the water. I have seen under engineered boats suffer structural damage to roof tops and other areas from this load. There are several other considerations that you will need to explore such as haul back system, forward stay design, use of grasshopper legs and stowing of equipment. As always, work with folks that have experience in design and installation.

Yes he did.

Additionally, this is truly not a passive system and is probably miss named in that the load on the boat is a dynamic load.

I have looked at installing several times. I have the fish poles and a basic design idea for installing. However the modification of the mast super strecture is required. I did install a new thick wall aluminum mast with install them. There are several commercial trawlers that have them, that I can have used as a reference. Finding a qualified engineer or person is hard to find. So if I were to install it would be basically copying an existing set up

Also it would be a some what reduced hybrid, in that the poles would be short about 10 ft. The reason is to keep the angle of support more of a straight on pull. The larger the angle the more the pull. A sail boat rigger is a good reference as to angles and mounting. The small angle of a sail boat rigging is to keep the stress as low as possible.

Also you might want to look at the boats roll ride. A comfort roll is 4 to 8 seconds. Shorter roll make the roll snappy and to long makes it feel unstable. So before you do anything avaluate the ride and other methods of stabalizing. Besides they make the boat uglier.

Wxx3 had his installed while docked behind my store so I got to watch. He used high tech rope for the rigging. That looked like a good idea to me as it made it easier to adjust than if he had used cable rigging.

Figure your roll period first then go from there. Longer poles equal smaller fish, shorter (thicker) poles-bigger fish. Same load on the boat. Needs to be on a major structural bulkhead. Very easy to calculate the roll moment (speed) of the paravane square inch/weight thru the water if you know the roll speed and then you can calculate the forces transfered to the hull/boat. Not simple. Err on the big side. Your boat probably cant handle really good paravanes.

HopCar said:

Wxx3 had his installed while docked behind my store so I got to watch. He used high tech rope for the rigging. That looked like a good idea to me as it made it easier to adjust than if he had used cable rigging.

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I didn't. The rigger did. One of the top sail boat riggers in Miami.

Love what he designed and installed.

I owned a P-40 for several years on east coast and did not think it was suited for big open water for several reasons including significant roll. If It were me I would go with a gyroscopic stabilizer there the engineering and load characteristics are more clear cut. You don't need the poles and increased weight aloft which might increase roll when not deployed. For coastal use the fish are a problem in shallow congested areas and where there are traps a gyro no problem.

Thanks Larry...seen Hobo on numerous occasions. I have to locate the poles on the upper deck because I have no walk-around. Engineer looking at loading factors etc. I have a substantial mast so a lot of the work is already there. You wouldn't happen to have created a parts list, design, or cost analysis?
Ian

Ian said:

...I have a substantial mast so a lot of the work is already there. You wouldn't happen to have created a parts list, design, or cost analysis?
Ian

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Scott on Sealife (who's cruising out side the US) did an almost exact duplicate of what we have. Complete and installed was less than $10K. He did the purchasing/installation and had a fabricator weld all the aluminum. Everything was off the shelf. The 2 poles are 20' of 3" schedule 80 Al and the A-frame is 3.5" schedule Al.

Your biggest issue will be reinforcing the boat deck and how to deal with the compression on the mast. Most of the masts on our boats, do not carry all the way to the keel and/or have compression posts. As Old Deckhand mentioned, you can do some damage to the boat deck and other areas if you skimp on design.

Sorry no parts list or design. They were all lost in a fire when the original designers boat burned. If you go through the archives I've posted of pictures of the design.

Thanks Larry...we are being very careful and diligent with the load on the mast which is quite significant. I was hoping it would be much less than 10K!! What is the search parameters in the archives for your diagrams?
Ian

Ian: Sorry, no diagrams, just some pictures and discussions. Try using the "search" tab at the top of the page and "advanced search". Put in paravanes and try putting in my user name.

Might take a walk down a commercial dock to get some ideas. I bought the fish and poles from a commercial for scrap value. Since most commercial do not have super structure mid ship they are mounted to the gunnel which is 3 to 5 ft off the water so I would mount to the hull just under the gunnels as the super structure is not strong enough. So only the mast support would have to be strengthened

Wire rope would be used for the pole rigging so adjustments could be made so a sail boat rigger could be used. So its the mast support is the primary concern, not the side support. Since the Eagle roll ride is comfortable para vanes would only be added if we decided to go down the coast, which is not in our plans. However the Eagle was designed to be a coastal cruiser and been up down the coast several times.

Rather than fish I have also looked at fixed bilge keels which would also dampen the roll since the Eagle is round soft chine. Some commercial also have them. I almost had them installed several years ago. I would install them before the fish.

Thanks Phil

I think the location of the poles fore and aft is important. If the boat pitches around a point well aft of amidships poles fwd of that point would put a much greater load on the system. Fish should go up and down as little as possible.

In Prince Rupert I talked to several paravane users both commercial and R trawler. They were more concerned about how deep the fish ran than the span width. Twenty feet deep and using chain was the consensus there.

Old deckhand ... I can't remember if the fishermen in SE used wood poles for paravanes. Many do for fishing gear ... do they use wood for paravane poles too?

From my memory, the location for the paravane poles is to mount them 27% forward of the stern, using LWL as your 100% number.

manyboats said:

I think the location of the poles fore and aft is important. If the boat pitches around a point well aft of amidships poles fwd of that point would put a much greater load on the system. Fish should go up and down as little as possible.

In Prince Rupert I talked to several paravane users both commercial and R trawler. They were more concerned about how deep the fish ran than the span width. Twenty feet deep and using chain was the consensus there.

Old deckhand ... I can't remember if the fishermen in SE used wood poles for paravanes. Many do for fishing gear ... do they use wood for paravane poles too?

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Yes Eric, we rigged the paravanes (chicken irons) off the same poles we used for trolling. I only had wood poles, never aluminum.

Ted

Ted how many others did/do use wood poles for paravanes?

It would be of value to know deployment and retrieval factoring with the paravanes. There seems to be a wide range of opinion on either relative ease or pure hell. Of course, the position/location of the boat when doing this is paramount. Sometimes we can't choose the timing or location, but the methodology is of great interest.
Ian
Miss Marian 43'
New Smyrna Beach,FL

Eric

Before they started using aluminium trolling poles we all used wood.
I don't think many still use wood. The fleet has been severely
down-sized and it seem harder to find good wood poles so most use the
aluminium ones.
It's not only the trollers, but the long-liners, some of the seiners, packers etc.

Ted

manyboats said:

...they were more concerned about how deep the fish ran than the span width. Twenty feet deep and using chain was the consensus there...

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I think that depends. The commercial guy ours were copied from ran at 15' deep.

Diesel Duck 492 said:

From my memory, the location for the paravane poles is to mount them 27% forward of the stern, using LWL as your 100% number.

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Your memory's pretty good. I've been told about a 1/3 the length from the stern so you're right there.

Ted said:

...rigged the paravanes (chicken irons)...

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Ours have been referred to as "sissy bars".

Hi
Some of us have grab handles in various places.
Even this big, heavy old girl has an overhead thwartship bar
just behind the wheelhouse windows. Could be called a "sissy bar",
but more likely an "OH SH*T!!!" bar.

We usually ran our fish about 18 feet down. You don't want them to
come out of the water when you're on the crest of a big wave. They
have been known to go over the boom or through the side of the
deckhouse.

Ted

Ted said:

...You don't want them to come out of the water when you're on the crest of a big wave. They have been known to go over the boom or through the side of the deckhouse...Ted

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I can't imagine the seas that the vessel would be in to cause the fish to shoot forward after coming out of the water, toward the boat and over the boom or through the side of the deck house.

Ours have come out of the water. The exit and reentry is a little unsettling because of the unloading and reloading of the poles, but never even close to boat. Underway the fish are tracking pretty much parallel to our travel line so when they exit the water they pretty much follow the same track. I'm not saying it hasn't happened but again I find it hard to imagine those sea conditions and we have been in some real ****.

Don't know what wild seas off the North-west coast up here. Heard about it sitting
around like this talking (verbally), not typing, with some of the old-timers.
Also hard to believe but true, father and two sons on a halibut trip, father died, sons radioed, asked, and got permission to ice him down and bring him in at the end of the
trip.

Ted