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  #76  
Old 05-11-2011, 11:50 AM
ImaginaryNumber ImaginaryNumber is offline
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Chris,

The hull and topsides of Hogfish Maximus extend beyond the transom. It appears that design #36 also does that. What is the purpose of that?

What are the major differences between HFM and design #36? I can see it's a little shorter, the aft end/cockpit is different, and you're going with a junk rig?

Could your designs be built of heavy aluminum plate, perhaps using the Strongall method?

To what extent do the chine runners contribute to leeway prevention? I'm sure you've tried sailing without the centerboard down, but for comparison do you have any idea of HFM would sail with only a centerboard and not the chine runners? How high does HFM point in significant seas?

Because sharpies don't have a ballasted keel, and because they are shoal draft, the ballast has to be high in the boat compared to more conventional keel boats. I would think that this would make a sharpie tender. However, the squarish hull shape may provide more outboard buoyancy, counteracting the higher center of gravity. So I'm curious how this all plays out in actual practice.
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  #77  
Old 05-11-2011, 05:18 PM
BriggsMonteith BriggsMonteith is offline
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Chris is the only one who can say for sure, but if I had to guess the extension of the hull is 2 fold. The first being it increases the water line aft without excessive weight especially when healed and the second might just be a cleaver step to help get on deck...
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  #78  
Old 05-12-2011, 10:29 AM
frank smith frank smith is offline
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ballast in a sharpie is for righting more than initial stability . A wide bottom with deck weight kept to minimum is the key with a self righting sharpie. Also a relatively high degree of rocker to get ballast as low as possible and help reduce the Cp with what is a bluff bowed boat . This all changes if the board is ballasted , as with most modern sharpies.
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  #79  
Old 05-12-2011, 10:46 AM
frank smith frank smith is offline
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Here is an interesting comparison between a ballasted and unballasted box sharpie . http://www.boatdesign.com/postings/p...comparison.htm
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  #80  
Old 05-12-2011, 01:29 PM
ImaginaryNumber ImaginaryNumber is offline
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Frank,
Interesting comparison between ballasted and unballasted sharpies. Would be nice if the diagrams had also included some different styles of ballasted keels. Do the Hogfishes have ballasted boards, and are they self-righting?
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  #81  
Old 05-15-2011, 09:00 AM
frank smith frank smith is offline
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IN , Chris is the one to answer those questions. But I have thought that it would be interesting to due a stability study on flat bottomed boats with and with out internal ballast, and shapes from the box sharpie to the dory.
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  #82  
Old 05-15-2011, 09:55 AM
Steve W Steve W is offline
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There is something very appealling about this type of boat but one thing that has always puzzled me about all extreme shoal draft boats such as HFM etc, how the hell do you paint the bottom? I used to paint the bottom of my keelboats between tides dried out leaning against a couple of pilings. Careen perhaps, somehow having to use a travelift takes away something.
Steve.
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  #83  
Old 05-16-2011, 11:46 AM
frank smith frank smith is offline
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I like the stub keel and twin rudder set up of the LIS43, I think that is the direction I would go . Of course it is a different idea from HFM , sort of like apples and oranges .
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  #84  
Old 05-17-2011, 03:31 PM
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philSweet philSweet is offline
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That stability comparison posted above is nonsense (post 79). The CG arrow might be ok, But the boyancy vector is obviously wrong. Also, the CG doesn't appear to change with the addition of ballast, so I'm thinking its pulled out of the hat. The second case ought to show considerable improvement under all circumstances for any practical boat CG.
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  #85  
Old 05-17-2011, 09:39 PM
chris morejohn chris morejohn is offline
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Sharpie ballast, chine runners,etc.

Hello
To answer some questions,the extended tramsoms are as Briggs has described but mainly as a step out of the water.I like the vee stern as it gets the bottom run alot smoother than having to draw a flat bottom out of the water.All of my centerboards are ballasted just enough to get them down fully,as in about 75 lbs.the daggerboard I use in HFM is hollow so it has to be pulled down with a line to a winch. it is 3x8 feet and will float 3 men.A life boat!The chine runners on HFM work great when the boat is heeled over about 12degrees or more.They do not work so well in light winds.I can tack and sail the boat to windward in 3to 4 feet of water with the board and rudder up if she is heeled over and the chine is dragging.I normaly pull the board up as soon as I start to ease the sheets.Do not need the drag although on the GPS it is minimal.When we are tacking into a new harbor we pull the board up to 4 draft and untie the rudder pulldown line and then can pretty much sail where we want.The chine runners work for the HFM as built.I would not have them bigger or longer.My idea originally was just following Henry Sheels keel idea but using the chine edge as a long low aspect keel. It does not matter how wide the keel is.To not have them on a flat bottom boat is a missed oppurtunity.The HFM and sister ships are very stiff sailors both fully loaded and just launched with only ballast.I hope this helps.
Chris morejohn
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  #86  
Old 05-17-2011, 09:51 PM
chris morejohn chris morejohn is offline
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other stuff

I have never worked in aluminum but if someone had those skills than go with them.I like plywood constuction as you only build the boat once whereas in metal boats you do it twice in that you have to insulate and cover the whole thing inside. And dont loose those pennys.
As to painting the bottom i can get 80% sitting up right and the rest gets polished as we go exploring shallow areas.
In the HFM going to weather in 6-8 foot seas in 18-20 knots she does 5.5 knots tacking 100 to 110 degrees to weather heeling about 18 degrees.
Chris
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  #87  
Old 05-28-2011, 10:23 AM
ImaginaryNumber ImaginaryNumber is offline
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aluminum vs plywood/epoxy

Quote:
Originally Posted by chris morejohn View Post
I have never worked in aluminum but if someone had those skills than go with them.I like plywood construction as you only build the boat once whereas in metal boats you do it twice in that you have to insulate and cover the whole thing inside. And don't loose those pennys.
Chris
You are correct that building in aluminum is in some ways more involved than building with plywood/epoxy, and initially it may be more expensive. However, there are certain advantages as well:

*not necessary to paint the topsides/deck
*less need to protect raw material from rain
*can build in colder temperatures
*no concern about scratched epoxy allowing water to soak plywood
*can have more abrasion and impact resistance than plywood
*aluminum can be worked with common carbide woodworking tools
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  #88  
Old 06-01-2011, 10:54 AM
frank smith frank smith is offline
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Hogfish is not a good design for aluminum . Best to be built out of plywood , IMO .
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  #89  
Old 07-29-2011, 10:14 PM
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souljour2000 souljour2000 is offline
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Hogfish maximus et al...

Chris..your Hogfish boats are very cool and obviously born from alot of water-time in different boats...if you could ever build them to your standards in production and I had the money..I'd be your first customer...hope you'll continue to tell us about these boats and the ideas behind their various design attributes.
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  #90  
Old 09-06-2011, 07:56 AM
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DennisRB DennisRB is offline
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Just thought I would bump this by showing a pic a stumbled upon here http://www.microcruising.com/pictures.htm

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