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Power righting pole on NA 6.0 #9725
08/20/02 07:17 AM
08/20/02 07:17 AM

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I bought a righting pole from Murrays for my Na 6.0. I installed it under my main bean with the 3/16 stainless steel rivet provided.



When I tried it my rivets head almost pass trough the holes of the pole mounting gear. I was not able to right my boat even if I "hung" myself as far as possible from the boat.



Ps : I weigh nearly 180 lbs



Any suggestions !!!








Last edited by PRobert; 08/20/02 07:18 AM.
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Re: Power righting pole on NA 6.0 #9726
08/20/02 09:13 AM
08/20/02 09:13 AM
Joined: Jul 2001
Posts: 2,844
42.904444 N; 88.008586 W
Todd_Sails Offline
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I don't use one of these, but, was any of your body in the water? If so, you didn't get the weight of your body. Was wind pushing on the underside of the tramp? Just some helpful thoughts.


F-18 Infusion
#626- SOLD it!

'Long Live the Legend of Chris Kyle'
Re: Power righting pole on NA 6.0 #9727
08/20/02 11:48 AM
08/20/02 11:48 AM
Joined: Aug 2001
Posts: 190
Long Island, NY
Steven Bellavia Offline
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Long Island, NY
Hi,

I too (at 150 lbs) have tried to rgiht my cat (Hobie FX-One) by myself with a righting pole, and have failed. I was hanging on the end with my hands AND feet around the very end (like a monkey, nothing in the water), bows to the wind, etc and couldn't budge it.

Since then, I have modifed it slightly by adding a pulley at the end and a line to hoist the Murray's water bag (which holds 88 lbs of water) first, then my weight. I haven't tried it yet. Somehow I feel like flipping my boat on purpose to try the new and improved righting system is like setting your house on fire to test the fire extinguisher (So I exaggerate a little).

An image of this proposed system can be found at:

http://images.ofoto.com/photos246/5/74/20/93/17/0/17932074503_0_ALB.jpg



Or, I will try inserting it here, (but it usually doesn't work from the free OFOTO site)



[Linked Image]



Let me know what you think.

Good luck!



Steve



.
physics strikes again! #9728
08/20/02 01:03 PM
08/20/02 01:03 PM
Joined: Jun 2001
Posts: 160
Connecticut
Eric Anderson Offline
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If your feet are on the hull of the boat a righting pole has no larger lever arm then if you were using a righting line.



YOur righting moment is about 180 lbs X ~ 4 ft or 720 ftlbs



The mast and sails weight about 65 lbs the midpoint is 16 ft from the hull or 16*65= ~1040 ft lbs. If you are 180 lbs you would need to get your center of effort at least 6 feet from the hull to work. If you had some what to stabilize the pole fore and aft you couild just climb out and it would right it self.



IF you used steve's righting bag and an 8 ft pole,

you would have 180 lbs X ~ 4 ft + 88lbs * 8 ft = 1424 lbs. This would be plenty to right the boat.



Alternatively you could sail the boat with around 280 lbs total crew weight and you would be able to right it in all conditions.



Good Luck

eric Anderson

Re: Power righting pole on NA 6.0 [Re: Steven Bellavia] #9729
08/20/02 01:10 PM
08/20/02 01:10 PM

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hi Steve



I can't see your photo but I understand what you have in mind. I'm not sure that this will work because at the moment your water bag will touch the water, you will lose all the added weight.



I'm sure somebody out there have a solution for us. Do you have problems with rivets that holds your pole to your beam ? If not. how did you installed it ?

Re: physics strikes again! Revised somewhat ;-} [Re: Eric Anderson] #9730
08/20/02 04:22 PM
08/20/02 04:22 PM
Joined: Jun 2001
Posts: 292
Long Island, NY
Ed Norris Offline
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The first clue I had suggesting that your analysis needs revision comes from the contributor to this forum wo said his I20(?) came up so quick the high daggerboard slid down into his harness, pinning him under the hull. Fortunately for the rest of us (not to mention him), he survived to write a warning.



Second, my dry weight, 150 lbs, is sufficient to raise my 5.0 on land. Without going to the end of the pole. I'm with Steve on the fire extinguisher thingy.



So I took a second look at your analysis, to see where it's... um.... imprecisely alligned with the real-world system. [Linked Image]



For one thing, while the halfway point for mast length is maybe 16 ft, or 14 on mine, you know well that half the sail's area isn't halfway up the pole! I don't now how to do the math, but let's guess (gasp!) a third of the mast's height = 1/2 of the combined mast/sial weight. Certainly, the top third twists off and dumps the wet stuff much faster than the bottom, and the jib doesnt get above the middle third, or very little. Sure it's got moer moment, but there's so little of it... I dunno, I took a wild guess at a third.



Thus, heeling moment while flat over is 65 X 11 = 715 lbs. So 4 feet of pole should just do it for a 180# guy. Absent other considerations. And at 65X10=650, my 150 only needs to be a smidgen over 4 feet of pole out, and that's what I experienced. This in non-wind conditions; ie, no aero - righting, no wind on the tramp trying to turtle etc etc.



This suggest to me that it's dynamic factors at work here, like wind load, water weight, etc.



As for the rivets, I told Steve at Murray's the attachment plate was a near-infinite force multiplier for popping the rivets as soon as I opened my kit. HIs reply "Nobody's complained of any attachment failures, though the pole will knock off the striker and cause the occasional mast failure." I ignored his advice to just "rivet it on, you'll be fine" and built up a platform with epoxy, and used 4 rivets instead of 2.



Done the way Steve suggested it, the assembly has the same force multiple as a claw hammer pulling nails, and for precisely the same structural reasons. Except this claw's got a compound handle with a 6 foot long business end and rigging to put over a thousand lbs of force into the claw, which then applies a 200x multiplier of it's own. .



Pop go the rivets!



Murray's should admit their falw and suplly a curved plate to replace the current flat one. Monel rivets and an insulating sheet for galvanic protection wouldn't hurt either.





Sail Fast, Ed Norris
Re: physics strikes again! Revised somewhat ;-} [Re: Ed Norris] #9731
08/20/02 05:10 PM
08/20/02 05:10 PM
Joined: Apr 2002
Posts: 602
Wilmington,NC
Dlennard Offline
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A Friend of mine got one for his Tiger and the rivets pulled out the first time he used it.



David

Re: Can't Get It Up #9732
08/20/02 05:26 PM
08/20/02 05:26 PM
Joined: Jul 2001
Posts: 851
US Western Continental Shelf
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L O L ! [img]/forums/images/icons/laugh.gif[/img]


Santa Monica Bay
Mystere 6.0 "Whisk" <--- R.I.P.
Murray's takes a reasonable, responsible position [Re: Dlennard] #9733
08/20/02 05:38 PM
08/20/02 05:38 PM
Joined: Jun 2001
Posts: 292
Long Island, NY
Ed Norris Offline
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Ed Norris  Offline
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I just spoke with Stan at Murray's. I'm impressed.



First, buyers of this product from Murrays enjoy an unconditional money back guarantee. "We stand behind everything we sell, and not just for 10-15 days. If you've got a person out there 6 months and he's not happy; we don't want that."



Whew! Refreshing attitude.



Second, the trouble seems to lie in trying to make a kit that fits all boats - a near hopeless task. Nobody except me has called them to report any trouble, but when I described this thread, Stan became quite concerned and said they'd investigate appropriate shims and instructions.



Stan was patient, concerned, polite and not in the slightest way defensive or dismissive.



The issue of corrosion was also addressed, albeit, with somewhat less urgency than "first-use failure" engineering concerns.



I'm sorry I was a tad harsh.


Sail Fast, Ed Norris
Re: Power righting pole on NA 6.0 [Re: Steven Bellavia] #9734
08/20/02 07:39 PM
08/20/02 07:39 PM
Joined: Jul 2001
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Steve,



I liked your post on the FX-1....I bought the big water bag,....not the pole for my I-17.......I had a spare 7:1 block set up from another boat to use to pull up the 250 pound water bag,...this is what happened..





First, under full load, the seams leak,...every one of them,...when I called Murray's...they said,..' oh yeah, we heard that happens, let me send you some seam sealer, no charge"......so check you water bag at home first,....see if half of the water leaks out the seam...



Next,..you will find,..that the fully hoisted bag blocks out just 10-12 inches above the water,...if you have waves,...it touch water all the time......





So,.I got the boat up,...a local fisherman lifted up my mast tip......up goes the boat,.....you throw yourself on board,....and now you have a 150 pound( or so) anchor hanging 8 feet below your boat between your rudders and d- boards....try lifting that up!!!



anyone else??



Bruce



St. Croix


Re: Power righting pole on NA 6.0 #9735
08/20/02 08:57 PM
08/20/02 08:57 PM
Joined: Mar 2002
Posts: 3,355
Key Largo, FL and Put-in-Bay, ...
RickWhite Offline

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First of all the righting poles are made to right a two-person boat with two people. When designing it, the idea was not to single-handedly right a big boat like the Nacra. So, you may need a water bag system as well, if you are going to single-hand the boat.

As an aside, however, I would recommend you do not sail the Nacra 6.0 by yourself -- you could be asking for a lot more than a righting problem.

That is the reason I sold my Nacra -- lost a good crew when she fell in love, got married and had a baby. Now I sail a Wave and Taipan 4.9 (and it easily rights single-handed, as did the Taipan 5.7)



On the rivets, the pole should have not ve pulling on them, if you installed them properly. All the load on the rivets would be a side load and that would not pull rivet heads out.



I am not exactly sure how the Murray System works, but the idea is to cant the lever up, slip the knot through the loop so the bar is on an upward angle. Once set perpendicular to the boat, hand over hand to the end of the bar and right the boat.



If you cannot right the boat with your weight alone (test this on land) then you can possibly sleeve in an extension until you get the length you need to single hand.

Good luck,

Rick


Rick White
Catsailor Magazine & OnLineMarineStore.com
www.onlinemarinestore.com
Re: Power righting pole on NA 6.0 [Re: RickWhite] #9736
08/21/02 07:33 AM
08/21/02 07:33 AM

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Thanks Rick



I'm riding my 6.0 along because I just lost my crew too.



I can't imagine that the designer of that pole hope 2 people would use it to right a cat. First why would they spend 200$ when they can right their boat with a 5$ line. Second, the attachment is not made for this pressure (a flat attatchment fit on a round beam). Third, the pole itself bent dangerously only with 1 pers, imagine with 2.



It is not possible to sleeve an extension because lines are strating at the end of the pole and reach the join of the main beam an the hulls.



I still think that it is a conception problem.

1) You cant get enoug leverage for big boats (at least, this should be mentionned by the conceptor)

2) The attachement.


Re: Murray's takes a reasonable, responsible position [Re: Ed Norris] #9737
08/21/02 07:36 AM
08/21/02 07:36 AM

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Do you have the email adress of that guy at Murrays ?

Re: Power righting pole on NA 6.0 #9738
08/21/02 08:21 AM
08/21/02 08:21 AM
Joined: Mar 2002
Posts: 3,355
Key Largo, FL and Put-in-Bay, ...
RickWhite Offline

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Key Largo, FL and Put-in-Bay, ...
The reason for the concept in the first place was because my crew and I could NOT right the Nacra 6.0 with line. Even when I had her crawl up on my shoulders and hike from there -- which caused some bad kinks in my neck for quite some time.

We lost the Hogs-Keys 100 because of that. We had a great lead on the entire fleet with the Hooter on the N6.0 when the turning block for the Hooter at the top of the mast blew apart. So, I turned the boat on its side and just used a shackle.

But, then we could not right the boat, even in shallow water. Finally, a fisherman helped us right the boat and we DSQed ourselves for getting outside help.

After installing the pole, we had no problem righting the boat with two people.

And I must say, there is no better marine supplier than Murrays -- they are the best!

Rick


Rick White
Catsailor Magazine & OnLineMarineStore.com
www.onlinemarinestore.com
Re: Pole: Ten - - attachment: Zero [Re: RickWhite] #9739
08/21/02 09:18 AM
08/21/02 09:18 AM
Joined: Jun 2001
Posts: 292
Long Island, NY
Ed Norris Offline
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Here's a post from a guy who righted an Inter 20, with his wife *sitting astride the lower hull*



Inter 20 righting story



From the context, I honestly don't believe he was writing to advertise the pole in any way. Maybe having his wife on the hull kept it pointing up longer?



Or look at the photos - those two are less than 80% of way to the end of the pole.(second pix, starting to lift the boat, she's at half way, he's just past 3/4) The pix demonstrates that there's reserve leverage.



So much for leverage. It simply *can* be done. Figure out how, instead of "proving" it's impossible. Maybe somebody should ask the guy with the inter 20. I think Tami's said she's got one she built herself.



As to the attachment, I'm sorry to differ with Rick, but I do stand by my analysis. To elaborate.



The plate in the Murrays version demands to be mounted about half way between the striker and the tramp. This so the base of the pole is sufficiently out from under the D-striker so that you can aim the pole perpendicular to the hulls. Mounting closer to the tramp will only aggravate the following problem:



The plate is flat (except for a recess into which a 2 inch long universal joint is bolted) The two rivet holes are inline with the centerline of the plate.



So the Uni-joint sticks out, pointing aft and somewhat away from the tramp, *but not perpendicular to the hulls* The Pole, while in use, *must* be perpendicular to the hulls. So the poll is pushing on the U joint at an angle!! This is critical because it means that the force expressed on the plate by the U-joint is a 'rocking' or 'tipping' motion, *not* sideways at all!! The closer you mount the plate to the tramp, the greater the angle, and the stronger the 'rocking' force.



And if you 'rock' a flat plane against a curved surface, with a fastener between them at the point of contact, you've just duplicated the physics of a claw hammer pulling a nail. In this system, the Fulcrum is right next to the load, virtually in the same place, meaning when you do the math, it's a near infinite force multiplier, which neatly overwhelms the 'mere' 2 inch moment of the U-joint - especially when you convert a 150 lb sailor's weight with the help of the pole's rig into at least 3 or 4 times that amount of force pushing in on the pole.



For durability, you must build up a platform and rivet at the corners of that plate, not the middle of the short ends.



But hey, I could be wrong.







Sail Fast, Ed Norris
Re: Power righting pole on NA 6.0 [Re: RickWhite] #9740
08/21/02 10:17 PM
08/21/02 10:17 PM
Joined: May 2002
Posts: 217
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jcasto1 Offline
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I made a righting pole myself in 96, based on a design I saw on a N5.5 uni.

After a while spent sideways on Tres Palacios Bay between races "testing" the first version unsuccesfully, my second version was successful because of two important improvements.

1. Stronger attachment point of pole to front beam between dolphin striker & tramp. I used two pieces angle-iron (aluminum) of fairly thick stock mounted to beam, with 3/16 diam clevis pin as swivel joint through the pole.

2. Second set of lines/wires to midpoint of pole. With lines only at end of pole, the middle of pole bends down when you're in the middle of it, or upwards when you're at end, past line that keeps pole in place. lines to middle of pole prevent excess bend, allow lighter x-section to be used successfully


Jim Casto
NACRA 5.5 & NACRA 5.7
Austin TX
Lake Travis
Re: Power righting pole on NA 6.0 [Re: RickWhite] #9741
08/21/02 11:52 PM
08/21/02 11:52 PM
Joined: Jul 2001
Posts: 851
US Western Continental Shelf
hobiegary Offline
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You guys are all just cracking me up! LOL! [Linked Image]



Rick, is the Murray's righting pole any different than yours? Does Murray's sell the Rick White Signature Power Righter? Do they sell another, somewhat similar righter?



Solo~Righting a Mystere 6.0 (that means, by myself)



[Linked Image]



Santa Monica Bay
Mystere 6.0 "Whisk" <--- R.I.P.
Re: Power righting pole on NA 6.0 [Re: hobiegary] #9742
08/22/02 08:03 AM
08/22/02 08:03 AM
Joined: Mar 2002
Posts: 3,355
Key Largo, FL and Put-in-Bay, ...
RickWhite Offline

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It was originally my idea and the manager at Calvert Sails had a side biz of making them. Then he quit Calverts and went on his own and then quit producing them. He was also supplying Murray, but after he quit the job, Murray found another supplier.

So, I am no longer associated with the product, but still very willing to help.

By the way, due to some of the posts on this thread, I have made some modifications on the use and installation page on this website.

Rick


Rick White
Catsailor Magazine & OnLineMarineStore.com
www.onlinemarinestore.com
Re: Power righting pole on NA 6.0 #9743
08/22/02 08:44 AM
08/22/02 08:44 AM
Joined: Jun 2001
Posts: 778
Houston
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Let comment on what I know from personal experience.



N6.0NA

I found it takes about 300-320 lbs at 4 ft (1200-1280 ft lbs) to right them reliably with everything else right

This implies the rig is about 75 lbs with a center of mass about 16 ft from the pivot point

This implies that 150 lbs hanging from the end of an 8 ft righting bar should be able to right the boat



Righting bars:

I built one before they were available commercially for a 5.5uni

I found to right a 5.5 uni, I needed my weight (180) hanging from a rope about 7-8 ft out.

Curled around the bar like a monkey didn't work.

Attaching your trap harness to a loop at the end will find you 8 ft under water when the boat comes up.

I finally put a knotted rope on the end of the bar and climbed the rope until the boat came up



Righting bags

I found if you are strong enough to manage one of those things, you are big enough not to needed it

They leak

They make great wash down buckets

They make great sea anchors, when they fall off during a race

They make ok sea anchors when the boat finally comes up, you lose your grip and the boat tries to sail off without you

They make good padding when you get blown against a dock because you couldn't right the boat

Trying to right your boat with one in 3 ft seas gives you something to do while waiting on the rescue boat

I last saw my righting bag floating toward LaPorte TX, if someone finds it, please keep it


Re: Power righting pole on NA 6.0 [Re: RickWhite] #9744
08/22/02 11:39 AM
08/22/02 11:39 AM
Joined: Jul 2002
Posts: 25
W. MICHIGAN
DAVEY Offline
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I'm not an engineer, just a car salesman...after all this intellectual discussion have we determined a: if this thing works? and 2: is there a reason nobody is using the screws that come with the righting system?

I just bought one of these things, thought it looked "cleaner"

than the righting line around my neighbors hobie, BUT if the jury is still out on the merit of this thing I'm not going to mess around installing it.

Another thought...if I understand Ed's post, part of the problem is mounting it aft of the dolphin striker instead of to either side of it... as my 17 supercat doesn't have a d/s, I'm thinking I won't have that problem.

Any thoughts ?


You can't drink all day if you don't start in the morning !
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