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Righting from the daggers? #276555
12/04/14 02:00 PM
12/04/14 02:00 PM
Joined: Aug 2011
Posts: 774
Greenville SC
bacho Offline OP
old hand
bacho  Offline OP
old hand

Joined: Aug 2011
Posts: 774
Greenville SC
So I started on a Hobie 18 not all that long ago and I used to always stand on the daggers to get it righted. When I moved to the I20 I did the same thing. The boards on those boards were solid and hardly moved with my weight.

This fall I capsized the C2 while solo I raised some eyebrows when I stood on the end of the board to get the boat back up.

Is this bad practice? My main concerns are that I might slip and fall on the board and get cut, however is my 230lbs enough to make a board fail?

Last edited by bacho; 12/04/14 02:00 PM.
-- Have You Seen This? --
Re: Righting from the daggers? [Re: bacho] #276568
12/04/14 03:54 PM
12/04/14 03:54 PM
Joined: Jun 2001
Posts: 3,906
Clermont, FL, USA
David Ingram Offline
Carpal Tunnel
David Ingram  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 3,906
Clermont, FL, USA
Originally Posted by bacho
So I started on a Hobie 18 not all that long ago and I used to always stand on the daggers to get it righted. When I moved to the I20 I did the same thing. The boards on those boards were solid and hardly moved with my weight.

This fall I capsized the C2 while solo I raised some eyebrows when I stood on the end of the board to get the boat back up.

Is this bad practice? My main concerns are that I might slip and fall on the board and get cut, however is my 230lbs enough to make a board fail?


It's not worth the $1200 to find out if the board can support my weight so I don't stand on it.


David Ingram
F18 USA 242
http://www.solarwind.solar

"Do or do not. There is no try." - Yoda
"Excuses are the tools of the weak and incompetent" - Two sista's I overheard in the hall
"You don't have to be a brain surgeon to be a complete idiot, but it helps"
Re: Righting from the daggers? [Re: bacho] #276572
12/04/14 04:33 PM
12/04/14 04:33 PM
Joined: Sep 2006
Posts: 586
Hobart, Tasmania, Oz.
Dazz Offline
addict
Dazz  Offline
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Joined: Sep 2006
Posts: 586
Hobart, Tasmania, Oz.
The c2 boards are heavy and very solid pieces of carbon... I would be much more concerned about your dagger wells that are only glass. the boards are quite narrow so there is a lot of pressure in a very small area of support.


C2 AUS 222 by Goodall design
"Darph Bobo"
Re: Righting from the daggers? [Re: bacho] #276573
12/04/14 05:47 PM
12/04/14 05:47 PM
Joined: Jan 2008
Posts: 3,655
Portland, Maine
T
ThunderMuffin Offline
Carpal Tunnel
ThunderMuffin  Offline
Carpal Tunnel
T

Joined: Jan 2008
Posts: 3,655
Portland, Maine
Where's Sam when you need to calculate what the working loads are on the dagger @ 10knots compared to a 230lbs dude?

Re: Righting from the daggers? [Re: ThunderMuffin] #276576
12/04/14 08:27 PM
12/04/14 08:27 PM
Joined: Feb 2005
Posts: 4,118
Northfield Mn
Karl_Brogger Offline
Carpal Tunnel
Karl_Brogger  Offline
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Joined: Feb 2005
Posts: 4,118
Northfield Mn
Originally Posted by Formerly Undecided
Where's Sam when you need to calculate what the working loads are on the dagger @ 10knots compared to a 230lbs dude?


I'll tell you right now. It's a metric fuckton whilst sailing. Unless you're a gigantic fatass, I wouldn't worry about it too much. I don't know how effective it is to do so, vs standing on the hull and laying out flat.

And yeah, where is Sam. I've been meaning to ask him about his DLG project.

Last edited by Karl_Brogger; 12/04/14 08:28 PM.

I'm boatless.
Re: Righting from the daggers? [Re: Karl_Brogger] #276612
12/08/14 01:21 PM
12/08/14 01:21 PM
Joined: Dec 2001
Posts: 5,590
Naples, FL
waterbug_wpb Offline
Carpal Tunnel
waterbug_wpb  Offline
Carpal Tunnel

Joined: Dec 2001
Posts: 5,590
Naples, FL
Hey, did you see that quadra-copter in Boat US magazine that FLOATS?


Jay

Re: Righting from the daggers? [Re: bacho] #276614
12/08/14 02:22 PM
12/08/14 02:22 PM
Joined: Jun 2001
Posts: 3,906
Clermont, FL, USA
David Ingram Offline
Carpal Tunnel
David Ingram  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 3,906
Clermont, FL, USA
For those not familar with the Imperical Measurement Standard "Metric Fuckton"

Metric Fuckton
More properly, "Metric Fucktonne." The Fuckton is the Imperial standard for the measurement of fuckweight, while the Fucktonne, in contrast, constitutes the Metric measure of fuckmass.

Generally used to imply superlative quantity with the Metric standard included to emphasise this point. The inclusion of the term is, however, fundamentally a misuse of that standard, as the Imperial Fuckton (2000 Imperial Fuckpounds) denotes a slightly greater measure of fuckweight within Earth's gravitational pull than does the Metric Fuckton (1000 Metric Fuckilograms).
I've got a Metric Fucktonne of this stuff to finish before Monday, or I'm fucked indeed.


David Ingram
F18 USA 242
http://www.solarwind.solar

"Do or do not. There is no try." - Yoda
"Excuses are the tools of the weak and incompetent" - Two sista's I overheard in the hall
"You don't have to be a brain surgeon to be a complete idiot, but it helps"
Re: Righting from the daggers? [Re: bacho] #276627
12/09/14 02:18 PM
12/09/14 02:18 PM
Joined: Jul 2001
Posts: 1,253
Columbia South Carolina, USA
dave mosley Offline
veteran
dave mosley  Offline
veteran

Joined: Jul 2001
Posts: 1,253
Columbia South Carolina, USA
Dave, you're a fine wordsmith


The men were amazed, and said, "What kind of a man is this, that even the winds and the sea obey Him?" Matthew 8:27





Re: Righting from the daggers? [Re: David Ingram] #276632
12/09/14 10:57 PM
12/09/14 10:57 PM
Joined: Jun 2001
Posts: 493
Minnesota
Jeff Peterson Offline
addict
Jeff Peterson  Offline
addict

Joined: Jun 2001
Posts: 493
Minnesota
You folks need to watch "The Late Late Show" with Craig Fergason, and learn the proper use of foreign country flags!



Jeff Peterson
H-16 Sail #23721
Big Marine Lake, MN
Re: Righting from the daggers? [Re: dave mosley] #276637
12/10/14 07:34 AM
12/10/14 07:34 AM
Joined: Jun 2001
Posts: 3,906
Clermont, FL, USA
David Ingram Offline
Carpal Tunnel
David Ingram  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 3,906
Clermont, FL, USA
Originally Posted by dave mosley
Dave, you're a fine wordsmith


not me... Google, I'm too lazy to come up with that stuff.


David Ingram
F18 USA 242
http://www.solarwind.solar

"Do or do not. There is no try." - Yoda
"Excuses are the tools of the weak and incompetent" - Two sista's I overheard in the hall
"You don't have to be a brain surgeon to be a complete idiot, but it helps"
Re: Righting from the daggers? [Re: bacho] #276638
12/10/14 10:14 AM
12/10/14 10:14 AM
Joined: May 2007
Posts: 127
Rock Hill,SC
KevinRejda Offline
member
KevinRejda  Offline
member

Joined: May 2007
Posts: 127
Rock Hill,SC
Thanks for the clarification Dave. I had some idea what a fuckton was, but now, thanks to you, I know.


Kevin Rejda
Rock Hill, SC

Re: Righting from the daggers? [Re: KevinRejda] #276639
12/10/14 10:25 AM
12/10/14 10:25 AM
Joined: Jun 2001
Posts: 3,906
Clermont, FL, USA
David Ingram Offline
Carpal Tunnel
David Ingram  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 3,906
Clermont, FL, USA
Originally Posted by KevinRejda
Thanks for the clarification Dave. I had some idea what a fuckton was, but now, thanks to you, I know.


Kevin, it is my pleasure to enhance and brighten the days of those around me. I don't care what Jake Kohl says I'm a fuc@king delight to be around.


David Ingram
F18 USA 242
http://www.solarwind.solar

"Do or do not. There is no try." - Yoda
"Excuses are the tools of the weak and incompetent" - Two sista's I overheard in the hall
"You don't have to be a brain surgeon to be a complete idiot, but it helps"
Re: Righting from the daggers? [Re: David Ingram] #276640
12/10/14 03:39 PM
12/10/14 03:39 PM
Joined: Jun 2001
Posts: 12,310
South Carolina
Jake Offline
Carpal Tunnel
Jake  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 12,310
South Carolina
Originally Posted by David Ingram
Originally Posted by KevinRejda
Thanks for the clarification Dave. I had some idea what a fuckton was, but now, thanks to you, I know.


Kevin, it is my pleasure to enhance and brighten the days of those around me. I don't care what Jake Kohl says I'm a fuc@king delight to be around.


I said no such thing! I merely implied that you can be a little grampy at times.


Jake Kohl
Re: Righting from the daggers? [Re: Jeff Peterson] #276643
12/10/14 03:58 PM
12/10/14 03:58 PM
Joined: Sep 2004
Posts: 2,584
+31NL
Tony_F18 Offline
Carpal Tunnel
Tony_F18  Offline
Carpal Tunnel

Joined: Sep 2004
Posts: 2,584
+31NL
Originally Posted by Jeff Peterson
You folks need to watch "The Late Late Show" with Craig Fergason, and learn the proper use of foreign country flags!



Fun with flags...

Re: Righting from the daggers? [Re: Tony_F18] #276644
12/10/14 04:03 PM
12/10/14 04:03 PM
Joined: Dec 2001
Posts: 5,590
Naples, FL
waterbug_wpb Offline
Carpal Tunnel
waterbug_wpb  Offline
Carpal Tunnel

Joined: Dec 2001
Posts: 5,590
Naples, FL
coitus


Jay

Re: Righting from the daggers? [Re: bacho] #276646
12/10/14 06:53 PM
12/10/14 06:53 PM
Joined: Jan 2004
Posts: 330
S
srm Offline
enthusiast
srm  Offline
enthusiast
S

Joined: Jan 2004
Posts: 330
Calculating (or at least approximating) the sailing load on the dagger board is done by analyzing the static forces/moments.

The righting moment of the boat can be approximated by estimating the location of the CG of the boat itself and the crew and multiplying the horizontal distance of the CG from the leeward hull....CG of boat = 400LB x 4ft= 1600 lb-ft. CG crew = 350LB x 12ft = 4,200 lb-ft. Total righting moment = 5,800 lb-ft.

To fly a hull, the rig must generate a heeling moment equal to the righting moment. If you estimate the height of the CE for the rig at 15 ft above the hull, then you can calculate the side force of the rig.
Side force = 5,800 lb-ft / 15 ft = 387 LB.

Since the daggerboard must produce lateral resistance to counter the side force of the rig, the board must be capable of supporting this load at it's CE (of course the hull and rudder also contribute to the lateral resistance, but for the purpose of approximation, one can assume the board supports the entire load). If you assume that the CE of the daggerboard is 2.5 ft below the hull, then the board should be capable of supporting 387 lb at a distance of 2.5 ft from the bottom of the hull. At a distance of 1.25 feet from the bottom of the hull, it would support a load of 770 lb and at a distance of 5 feet from the hull, it would support a load of 193 lb.

sm

Re: Righting from the daggers? [Re: srm] #276650
12/11/14 10:25 AM
12/11/14 10:25 AM
Joined: Dec 2001
Posts: 5,590
Naples, FL
waterbug_wpb Offline
Carpal Tunnel
waterbug_wpb  Offline
Carpal Tunnel

Joined: Dec 2001
Posts: 5,590
Naples, FL
wasn't there a protracted discussion related to forces some time ago in a different thread?

It related to whether it was better to run the righting line over the hull vs. the edge of underside of the beam?

The discussion had stick figures and force diagrams, too...


Jay

Re: Righting from the daggers? [Re: waterbug_wpb] #276651
12/11/14 01:55 PM
12/11/14 01:55 PM

M
MN3
Unregistered
MN3
Unregistered
M



There have been several.

Tami posted this info - Some aspects of structural engineering of dagger boards
Originally Posted by waterbug_wpb
wasn't there a protracted discussion related to forces some time ago in a different thread?

It related to whether it was better to run the righting line over the hull vs. the edge of underside of the beam?

The discussion had stick figures and force diagrams, too...


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