That extra height might be welcome in rough seas to secure “bodies” in the cockpit. As far as water removal, that should be a set of large, through transom scuppers. In a number of small offshore designs the transom resembles Swiss cheese to ensure water vacates quickly. That would be my approach to addressing water in the cockpit.
The build looks good.
VG23 New Build
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Jaysen
- * Bateau Builder *
- Posts: 6520
- Joined: Wed Aug 05, 2015 7:59 am
- Location: St Helena Island, SC
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Re: VG23 New Build
Re: VG23 New Build
Thanks Jaysen,
I've dithered on cutting down the cockpit sides slightly. I decided to reduce height by a couple of inches. This will (a) make the cockpit-coaming-to-deck transition easier and (b) will make the sheer-line look better (in my subjective opinion). I'll make the cut tomorrow on the starboard side. Very large drains in the transom are indeed planned.
Some more progress attached. Cockpit seat rounded over and glassed. Cabin seats rounded over and glassed in. First coat of paint on the seat locker lids. I've been preparing to fit the shelves in the cabin too and have prepared the framing for this. Need to get some more 1"x1" to finish it. Also preparing to fit cockpit coaming on the starboard side. Storage will be for light stuff, mooring lines, etc. There will be a manual bilge pump on this side too. Two 24"x12" hatches on each side of the boat.
I've practically finished all the stability calcluations for this VG23 now. I didn't have Jacques' actual lines for the boat, so measured my own. Jacques commented on stability: "Build as designed, the VG23 has positive stability up to 130 degrees with CB keel, 145 degrees with the deep keel. With the various changes I've made (e.g. increasing cabin roof height slightly, etc.) my calculations show vanishing stability at ~142 degrees. The VG23 is an excellent safe, stable design. I have absolutely no regrets we decided to build the boat.
I do want to emphasise that this is my calculation only, based on measurement from my own build. No responsibilty will be accepted for those of you who build a VG23 and find it acually rolls at 135.78 degrees
Jacques never published (as far as I've been able to figure out) a full stability curve for the VG23. I've plotted up my own and it is similar to that for the VG26. I'll stick it on here in a future post as it may be of interest to some of you, and potential future builders. Based on the lines, I've also my own spreadsheet of dozens of parameters that any boat designer would calculate for their designs. Maybe I'll share in a future post. The one thing I haven't calculated yet is VCG - I used a value Jacques gave in a previous post. I intend to finish that calculation at some point also.
Cheers,
Mick
I've dithered on cutting down the cockpit sides slightly. I decided to reduce height by a couple of inches. This will (a) make the cockpit-coaming-to-deck transition easier and (b) will make the sheer-line look better (in my subjective opinion). I'll make the cut tomorrow on the starboard side. Very large drains in the transom are indeed planned.
Some more progress attached. Cockpit seat rounded over and glassed. Cabin seats rounded over and glassed in. First coat of paint on the seat locker lids. I've been preparing to fit the shelves in the cabin too and have prepared the framing for this. Need to get some more 1"x1" to finish it. Also preparing to fit cockpit coaming on the starboard side. Storage will be for light stuff, mooring lines, etc. There will be a manual bilge pump on this side too. Two 24"x12" hatches on each side of the boat.
I've practically finished all the stability calcluations for this VG23 now. I didn't have Jacques' actual lines for the boat, so measured my own. Jacques commented on stability: "Build as designed, the VG23 has positive stability up to 130 degrees with CB keel, 145 degrees with the deep keel. With the various changes I've made (e.g. increasing cabin roof height slightly, etc.) my calculations show vanishing stability at ~142 degrees. The VG23 is an excellent safe, stable design. I have absolutely no regrets we decided to build the boat.
I do want to emphasise that this is my calculation only, based on measurement from my own build. No responsibilty will be accepted for those of you who build a VG23 and find it acually rolls at 135.78 degrees
Jacques never published (as far as I've been able to figure out) a full stability curve for the VG23. I've plotted up my own and it is similar to that for the VG26. I'll stick it on here in a future post as it may be of interest to some of you, and potential future builders. Based on the lines, I've also my own spreadsheet of dozens of parameters that any boat designer would calculate for their designs. Maybe I'll share in a future post. The one thing I haven't calculated yet is VCG - I used a value Jacques gave in a previous post. I intend to finish that calculation at some point also.
Cheers,
Mick
FB11 (Designer Evan Gatehouse)
VG23 (Designer Jacques Mertens)
A human being should be able to change a diaper, plan an invasion, butcher a hog, con a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects. Robert A. Heinlein.
VG23 (Designer Jacques Mertens)
A human being should be able to change a diaper, plan an invasion, butcher a hog, con a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects. Robert A. Heinlein.
Re: VG23 New Build
Stability curve for VG26 from the study plans...
My calculated stability curve from the lines of my own build of the VG23.
The stability "curve" was drawn freehand. Manual planimeter and scale ruler and everything worked out pencil and paper as it might have been 50 years ago or more. Of course, these days I could do some nice polynomial or cubic-spline curve-fitting to cover up any of my own points that don't lie on a smooth line. Probably due to inaccurate measurements on my part, or bad data entry with the calculator. But, even with the inaccuracies that might remain, it is "good enough" for me.
Mick
My calculated stability curve from the lines of my own build of the VG23.
The stability "curve" was drawn freehand. Manual planimeter and scale ruler and everything worked out pencil and paper as it might have been 50 years ago or more. Of course, these days I could do some nice polynomial or cubic-spline curve-fitting to cover up any of my own points that don't lie on a smooth line. Probably due to inaccurate measurements on my part, or bad data entry with the calculator. But, even with the inaccuracies that might remain, it is "good enough" for me.
Mick
FB11 (Designer Evan Gatehouse)
VG23 (Designer Jacques Mertens)
A human being should be able to change a diaper, plan an invasion, butcher a hog, con a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects. Robert A. Heinlein.
VG23 (Designer Jacques Mertens)
A human being should be able to change a diaper, plan an invasion, butcher a hog, con a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects. Robert A. Heinlein.
Re: VG23 New Build
An AVS above 140° for a small boat with a short keel is impressive ! Is that for the hull alone, or the fully rigged boat, with mast etc ?
Built C17 (app.php/gallery/album/262), GF14, Devlin Bella 16. Sails a 30ft Biloup 89 sailboat.
Re: VG23 New Build
Hi,
Yep, bare hull alone with boat at the DWL as designed - as per the normally quoted static stability curves.
My main aim was to try and get somewhere near the value Jacques quoted "Build as designed, the VG23 has positive stability up to 130 degrees with CB keel, 145 degrees with the deep keel". I agree that for a small boat, anything above 130 is great and "good enough" at least for me. The rig and ultimate weight distribution on board will change everything of course, but that is true of any boat. I read somewhere that calculations showed some off-the-shelf design reduced their stability from >120 degrees to something like 98 degrees simply by adding a roller-furling jib...
My own values probably should be interpreted with (at least) an error of ±10 degrees given hand measurement and calculation and hand-sketching the curve. Doing a full error analysis would be possible of course but more work
To reduce error I could calculate every 5 degrees (or every 1 degree!). Or, more sensibly get the lines in a proper design program and get the computer to do the work. But regardless of that, there are approximations in all such calculations, even if the numbers are done by computer 100% accurately and nicely presented. The entire methodology has assumptions.I was simply looking to demonstrate to myself that I could do the calcs and confirm to myself Jacques quote. The "stability" quoted for boats is always 'static stability" so just a starting point. No account of rig, or weight distribution. It is a guide - nothing more. But I'd rather have static stability as high as possible, and for a small boat, as you say, the numbers look decent. I'm happy enough with that!
Cheers,
Mick
FB11 (Designer Evan Gatehouse)
VG23 (Designer Jacques Mertens)
A human being should be able to change a diaper, plan an invasion, butcher a hog, con a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects. Robert A. Heinlein.
VG23 (Designer Jacques Mertens)
A human being should be able to change a diaper, plan an invasion, butcher a hog, con a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects. Robert A. Heinlein.
Re: VG23 New Build
Ok, thanks for the information, I was not aware that stability curves were published for bare hulls without rigging, I'm curious to know what the "real" AVS would be with a fully rigged boat.
Built C17 (app.php/gallery/album/262), GF14, Devlin Bella 16. Sails a 30ft Biloup 89 sailboat.
Re: VG23 New Build
Sorry for not being clear - my fault. When I say "bare hull" I should have said "as designed". Meaning with the rig and stores onboard as specified by the designer. I used Jacques VCG which takes everything he envisaged onboard into account. So, included the designed rig, but not any changes I've made on my own build - and there are a few. The one calculation I've not done yet is to calculate my own build VCG (via moments) to see how much difference it will make. I'm estimating my build will be ~500 lbs heavier than designed with some change in VCG that will alter the stability curve to some degree.
Sorry for the confusion. Hope that makes sense.
Mick
FB11 (Designer Evan Gatehouse)
VG23 (Designer Jacques Mertens)
A human being should be able to change a diaper, plan an invasion, butcher a hog, con a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects. Robert A. Heinlein.
VG23 (Designer Jacques Mertens)
A human being should be able to change a diaper, plan an invasion, butcher a hog, con a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects. Robert A. Heinlein.
Re: VG23 New Build
Progress over the last few days. More work on the seatbacks in the cabin, port and starboard. Rounded the cut-outs and seatback locker lids. Also dry-fitted the starboard seatback in the cockpit, the narrow deck portion on top, and cut the holes for the hatches. Glassed on the port skirt top too.
Mick.
Mick.
FB11 (Designer Evan Gatehouse)
VG23 (Designer Jacques Mertens)
A human being should be able to change a diaper, plan an invasion, butcher a hog, con a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects. Robert A. Heinlein.
VG23 (Designer Jacques Mertens)
A human being should be able to change a diaper, plan an invasion, butcher a hog, con a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects. Robert A. Heinlein.
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rick berrey
- Active Poster
- Posts: 384
- Joined: Sat Jun 20, 2009 2:16 pm
Re: VG23 New Build
Looking very much like a boat now
Re: VG23 New Build
Nice work Mick!! Jeff
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