DN NA Class  

DN America Forums

June 01, 2020, 12:23:16 PM *
Welcome, Guest. Please login or register.

Login with username, password and session length
 
   Home   Help Search Login Register  
Pages: [1]
  Print  
Author Topic: Shock absorbers for shrouds  (Read 10127 times)
DN 5449
Class Member
*
Posts: 366


« on: January 17, 2011, 08:39:33 AM »

I was reading an old Ice Sailing book (by Jack Anderson, I think that was his name,book was called Ice Sailing).In the book they mentioned about hooking up the shrouds with a shock absorber that takes up some slack in the leeward shroud so when tacking it does not snap over so hard.Has anybody experimented with this on there DN.
Logged
DN 805
Class Member
*
Posts: 267


« Reply #1 on: January 17, 2011, 09:17:20 AM »

My interpretation is that a shock absorber does not comply with the DN specification H.6 "Devices which adjust stay lengths while the yacht is underway are prohibited."

regards
Jane Pegel
Chair, Technical Committee
Logged
DN 5449
Class Member
*
Posts: 366


« Reply #2 on: January 17, 2011, 09:37:57 AM »

A bunge type connection,(like what we use on a hobie 16 to take up the slack in the forstay) does not change the length of the shroud it would simple take up the slack when it is on the leeward side.Just seems to me when I tack over that leeward shroud snaps over pretty hard putting a lot of stress on it.
Logged
DN 805
Class Member
*
Posts: 267


« Reply #3 on: January 17, 2011, 02:07:27 PM »

My opinion has not changed.  In my dictionary the definition of length is: "...a measured distance".    Any device that is controling the measured distance is not complying with the DN specification. 

The strength of the fittings and wire required in the DN specs far surpass the loads applied.   If your concern were a problem, don't you think that champions who have been racing DNs for 40 years would have brought it to the attention of the Class long ago?   Don't worry about it.   Don't try to reinvent the wheel.   Just enjoy learning how to properly sail the boat.    The biggest gains to made come via improving the "nut on the tiller".

Logged
us5285
Newbie

Posts: 21


« Reply #4 on: January 17, 2011, 10:11:37 PM »

I'm curious, I have seen old school boats use a bungy strap to take up the slack in the flopping leeward shroud. Maybe this is what DN5449 is talking about.  How does this change the length of the shroud?
Logged
Ken Smith
ADMIN

Posts: 290


sail often, travel light


« Reply #5 on: January 18, 2011, 07:13:16 AM »

There is a long history of trying to add stuff to DNs that are automatic like this thread. They are prohibited.

More to the point Jane makes, they are unnecessary and add no value to the boat. What do the advocates think is gained?  The side shrouds attachments to the plank have no requirements except they be non- adjustable during a race. Small pins, and even line attachments have been used. Nothing broke.

I've sheared pins and stripped turnbuckles on the forestay but never heard of a broken side stay. I have seen a dropped mast when a pin came loose, but never anything broken.
Logged

Ken Smith
DN4137US
Ken Smith
ADMIN

Posts: 290


sail often, travel light


« Reply #6 on: January 18, 2011, 10:08:34 PM »

Didn't mean to stifle discussion.  When masts were logs and it was fast to sail with loose shrouds, the mast could bounce off the mast ball.  A bungee could keep enough tension to hold it all moving in the same direction.  Not necessary anymore.

No worries.

Having been about for a while, there is nothing much new.  And we like to evolve slowly.  I saw a runner vintage 1930 or so, designed with a weeping port.  You added glycerine and it dripped down the leading edge of the runner in a little hole I have no idea how they made.

Competition urges formation of advantages.

A typical series goes like this:

Hay, how bout if I did this.
R.  Its not legal.
But it is safer/faster/better/new/different
R.  But its not legal and it won't work.

Try it.  If its great, it'll get adopted and used.

Same series for hollow wood masts, composite masts, wide hounds, fiberglass reinforced balsa boats, Kent chocks, insert runners, bull nose runners, sticks inside masts, etc.  We used to have nylon sails, cotton sails, and a rule that required a wire in the sail to keep the leach from stretching too much.  The wire didn't go away until the late 1980's.  Nylon and cotton both went away much sooner.

We moan about and love the innovations.
Logged

Ken Smith
DN4137US
DN 5449
Class Member
*
Posts: 366


« Reply #7 on: January 19, 2011, 08:36:06 AM »

No worries,just find it a little disconcerning when I tack over and see that leeward shroud snap tight.Then reading about these shock absorbers they use to use got me thinking (which is probably a bad thing).Like a buddy of mine who is a very good soft water sailor use to say,"just sail it like you rented it" or something to that nature.
Unfortunatly I am a long way from a sailing parts dealer so break downs are time lost sailing (usually three weeks by the time I get the part) so I like to eliminate as much stress on the boat as possible.
Logged
Don Williams
Newbie

Posts: 13


« Reply #8 on: January 19, 2011, 08:48:16 AM »

Mike,

Here's a little common sense. Because of you location and your concern, If you feel bungee's may work.  USE them.  Just remember that when sailing in a sanctioned regional or continental regatta, the bungee's would need to be removed to sail within the rules.

Don
Logged
DN 5449
Class Member
*
Posts: 366


« Reply #9 on: January 19, 2011, 01:32:07 PM »

Thanks Don ,that was way to easy for me to figure out.I guess really what I am hearing is that it should not be a concern,or maybe I need to tighten my shrouds.Lots of fun stuff to figure out on these little boats,all good fun.That is the one thing I really like about moving to a new class is learning new skills.
Logged
Pages: [1]
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1 RC3 | SMF © 2001-2006, Lewis Media Valid XHTML 1.0! Valid CSS!