Hobie Forums
http://www.hobie.com/forums/

Righting Bag Test
http://www.hobie.com/forums/viewtopic.php?f=14&t=9728		 Page 1 of 3
Author:  skipper0802 [ Fri Jun 13, 2008 3:03 am ]
Post subject:  Righting Bag Test
Hello All,
Today had the right conditions to go out and test the righting bag I built last season. Little wind, calm water and some sunshine. I wanted the knowledge that I could right my 16 by myself under any conditions with no problems.

The bag: sewed from cordura with four-point, grommeted suspension at the opening, all connected to a simple ratcheting block and a spring-loaded carabiner.

Test: with mast (or bows) to windward, flip the boat (had to trap-out with the bag over my shoulder). "Will be easy to right" I thought, thinking I'd designed sufficient counter-balance weight. OK ... over goes the boat. I clamber onto the lower hull at the balance point, un-hook my bungee from the righting line, toss the righting line over the upper hull, attach the bag lead line (carabiner) to the righting line, filled the bag with water, pulled the bag out of the water using the ratchet block, placed the lead line over my shoulder and pushed-out with my legs.
"Cool, this should do it". The bag and I are leaned out just over the water. I watched the mast and ... nothing!

Alright, double-check ... mast to wind? Yep. All sheets clear and uncleated? Yeah. Bag full? NOPE.

Turns out that my design for 2.5 cubic feet of water (~62 lb/ft3) was barely 1/2 full. This only gave me ~60 lbs. Added to my weight (163 lbs) = about 223 lbs. Simply not enough. I should have had near 318 lbs. When I tested the bag for leaks on my patio with my garden hose, it held the 2.5 cu.ft. However, when you drag it through the lake to fill it then pull it up, the opening collapses and a lot of water escapes. No way it held the 2.5 x 62 = 155 lbs I expected it to.

Fix: Option 1- install a stiff lip to the bag opening to keep it from collapsing when lifted from the water surface and therefore filling to capacity. Option 2- install a mast bob to compensate for the lesser counter ballast of the righting bag.

I'll get some pics for clarity soon. What did I miss? Anyone see something I didn't? Thanks for your opinion in advance!
Author:  localizer [ Fri Jun 13, 2008 7:54 am ]
Post subject: 
Quote:
Bag full? NOPE.


This is exactly the issue I had when I tested mine. I'm now trying to figure out how to make it full. Yes, I'm considering a stiff lip, but it also must be foldable or twistable. I'm still researching.

I don't think mast bob will be of any help in this case. on the contrary - you are adding weight you will need to counter weight. mast bob helps keep your mast afloat, not to right the boat.
Author:  skipper0802 [ Fri Jun 13, 2008 8:26 am ]
Post subject: 
True, the mast bob does add some weight. I thought of it as adding bouyancy to offset the missing counter-weight. More importantly, it would help keep the mast out of the water AND reduce the angle by which I must right the boat (mast towards horizontal initially).

During yesterdays test, a passerby helped by lifting the mast, maybe 10 - 15 lbs worth of lift (his estimate), once the mast was moving upwards past the horizontal, my cat continued to its normal orientation. The key counter-weight amount in this case seems to be the value that would bring the mast to horizontal. (The rest is momentum). I think I'm close to the answer.

I'm also brainstorming the idea of a bag ring that can collapse when stored in my tramp pocket (underneath), and also deploy to support the bag's capacity. I'll publish my findings as soon as I can.

Thanks for your thoughts!
Author:  rattle 'n hum [ Fri Jun 13, 2008 11:21 am ]
Post subject: 
I've had similar issues with the large Murray's righting bag....hard to fill and leaks at the seams. I'm about 5' 7" and weigh around 180 lbs. I can right my H-16 solo with no wind helping and the bag less than full....maybe two-thirds. Help from the wind makes it much easier, but you can't always count on that.

For these reasons, I'd recommend that anyone under about 200 lbs. whose looking to buy a righting bag should not get the small one.

I've been meaning to seal the seams on my bag, but it hasn't been a priority since I can make it work.

Kudos to you for seeking to be able to right solo in all conditions and for taking the time to test!

Jerome Vaughan
Hobie 16
Clinton, Mississippi
Author:  mmadge [ Fri Jun 13, 2008 11:29 am ]
Post subject: 
I think the one made by hobie is rated at 150lbs.I am hoping that is big enough for me at 160lbs
Author:  Rex [ Fri Jun 13, 2008 3:19 pm ]
Post subject:  One idea
Think: "small tent pole"

A sleave on the bag opening, open at one end at the top of the sleave. A piece of fiberglass tent pole (thin) a bit longer than the sleave. Place "pole" in sleave flexing it to fit into pocket. Should hold bag lip open at least in smile shape.....

Bag will roll up on pole...alternatively you could have a sectioned pole.

Just thinking....
Author:  vinnynniv [ Sat Jun 14, 2008 6:23 pm ]
Post subject: 
carry a mug and fill up your bag by hand
Author:  Birdlaw [ Tue Jun 17, 2008 8:31 am ]
Post subject: 
I had the thought of using a BIG dry bag.....Its versatile and could be closed when full. I use a small dry bag as a paddle float for my kayak and as an emergency bailing device.

At 4 pounld per gallon, it would have to be a big honkin bag, but it is just an idea......

I am all about versatility. I heard about a guy useing a cooler tied to part of the mainsheet trying to right a boat he was single handing. THAT IS TOO MUCH versatility and "redneck" engineering.
Author:  skipper0802 [ Tue Jun 17, 2008 9:06 am ]
Post subject: 
Birdlaw,
Wow. Read about the cooler/sheet method. I prefer using a bit more cognitive forethought when out for a sail.

My latest thought on creating a flex-resistant lip on my righting bag: use a width of material that is non-metallic, can be formed into a circle, and that will not take a set. Like the characteristics of a sail batten. I thought of shock-cord poles like those used in small tents but I think the poles would yield under the weight of the water in the bag. If I could bend a batten into this radius ~14" then pop-rivet it in place ... it might work.

Stay tuned. I'll post pics on my results,
Author:  IndyWave [ Tue Jun 17, 2008 9:52 am ]
Post subject: 
If you go to Ace Hardware, they sell plastic rings to hold open leaf bags. They're adjustable with wing nuts, but could be modified as needed.
Author:  skipper0802 [ Tue Jun 17, 2008 9:57 am ]
Post subject: 
Thanks for the lead Indy. I'll check it out!
Author:  bullsnake [ Tue Jun 17, 2008 4:17 pm ]
Post subject: 
Why not just use a bigger bag, that way when some of the water leaks out, the amount that is still in it will be correct?
Since you said you made the bag yourself, could you just sew a top strip around it to effectively make the bag taller? I know it would cause there to be more seams, but they might be above the point where most of the water would escape from when it is "taller".
The seams might not leak enough to make a difference anyway.
Author:  skipper0802 [ Thu Jun 19, 2008 4:20 pm ]
Post subject:  Righting Bag Test - Initital Success!!!
Here's some good news -

I went to Ace just as Indywave suggested. I found 1/2" diameter sprinkler tube, made of black PVC (or PVsomething). I bought a tube remnant ($2.76) and a splice (0.69 cents). I opened the lip seam, inserted the proper circumference of tube, and spliced it with the coupler. I replaced the quarter point supports with regular nylon line pieces I had in my scrap bin.
Test:
I filled a large trash bin of water, dunked the bag, filled it and tried to lift it out/up. I couldn't. It was too heavy!! The lip held with no problem! An added plus is that it fits (collapsed) into the pocket I sewed underneath my mesh tramp.
Here's a pic -

Image

You can see the bag just out of the dunk test, its quarter-point support lines, the ratchet lead, and the carabiner that I clip onto the righting line.

I am very much looking forward to getting the boat out this weekend and doing a functional test. I am going to feel real good when this thing works like I think it should!

Thanks for all your thoughts and ideas!
Author:  skipper0802 [ Tue Jun 24, 2008 6:34 pm ]
Post subject: 
I have great news! The functional test worked without a problem! Please see the sequence of photos:

- Just after I intentionally capsized her.
Image

- I have un-hooked the righting line and thrown it over the upper hull.
Image

- I have pulled the righting bag from tramp pocket, and clipped it to righting line. Next, I fill the bag. The bag lip does not collapse and spill water like before. Note my left hand on the ratchet block line.
Image

- The bag is full, the line is over my shoulder, and I am ready to push out.
Image

- The counter-weight in effect, mast is out of the water and moving up.
Image

- The Mast is gaining momentum.
Image

- My cat is back on her feet. As the hull came down, I moved to the dolphin striker to prevent over-rotation. Note that my starboard-side bungee clip gave way and let my portside trapline fly.
Image

- My bag works and I declare victory!
Image

- I back at the house. I have no more trepidation about sailing hard and needing someone there to lift the mast for me. My thanks to my wife for her patience while I futzed around.
Image
Author:  ET Hobie guy [ Tue Jun 24, 2008 7:07 pm ]
Post subject: 
hey Eric, Thanks for the photos. Very nice. Tell the wife she did a great job. I think I must get a bag to right by myself. I am around 170 - 175 and was unable to begin to get upright when I capsized a few weeks ago. BTW, beautiful area where you live.
Page 1 of 3 All times are UTC - 8 hours [ DST ]
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/