A knot question - SailNet Community
Seamanship & Navigation Forum devoted to seamanship and navigation topics, including paper and electronic charting tools.

Reply
 
LinkBack Thread Tools
post #1 of 21 Old 04-11-2011 Thread Starter
Senior Member
 
Kiltmadoc's Avatar
 
Join Date: Nov 2009
Location: Danvers, ma
Posts: 279
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 6
 
Question A knot question

I am taking a USCG boat safety course and they were discussing knot strengths. Bowline came in at 60% strength. For my genoa sheets I have been using bowline knots.
But, I remember from my climbing days that a figure-8 follow through is 80% strength. So, why not use this knot instead of the bowline? Or do people use a totally different knot for their genoa sheets?
Kiltmadoc is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 21 Old 04-11-2011
Member
 
Join Date: Apr 2010
Location: near San Jose, CA
Posts: 32
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 0
 
Sheets on most boats are oversize for ease of handling and/or reduced stretch. The strength reduction of a bowline still leaves a huge amount of reserve strength.
scotthenry is offline  
Quote Quick Reply Share with Facebook
post #3 of 21 Old 04-11-2011
Senior Member
 
jackdale's Avatar
 
Join Date: Dec 2008
Location: Calgary, AB, Canada
Posts: 9,035
Thanks: 27
Thanked 59 Times in 56 Posts
Rep Power: 7
 
The bowline is easier to untie.

Some folks use a cow hitch / lark's head in the middle of one long line serving as a sheet to both winches.

__________________
ISPA Yachtmaster Offshore Instructor Evaluator
Sail Canada Advanced Cruising Instructor
IYT Yachtmaster Coastal Instructor
ASA 201, 203, 204, 205, 206, 214
As I sail, I praise God, and care not. (Luke Foxe)
jackdale is offline  
Quote Quick Reply Share with Facebook
post #4 of 21 Old 04-11-2011
Senior Member
 
RichH's Avatar
 
Join Date: Jul 2000
Location: Pennsylvania
Posts: 3,467
Thanks: 24
Thanked 155 Times in 144 Posts
Rep Power: 16
 
Fig. 8 'middled' in a single continuous jib line is probably the best. Next would be the 'strangler' - of course middled, then clove hitch or larks head.
If removable is important, then add a stainless locking caribiner/shackle.

For use of two jib sheets the buntline is far superior to the bowline, just add a few feet to the lines as you'll need to cut off a buntline.

If you want bombproof 'security' and 'small', then consider to eye-splice the lines onto the clew.

If you HAVE to untie a jammed knot .... thats what knives are for. Cutting 6" from a jib line is no big deal.

I only use jam-ing knots or splices on jib lines. I do not want my knots to capsize in F8 and above - been there, too dangerous.

Last edited by RichH; 04-11-2011 at 10:19 PM.
RichH is online now  
Quote Quick Reply Share with Facebook
post #5 of 21 Old 04-12-2011
Senior Member
 
dnf777's Avatar
 
Join Date: Jun 2007
Posts: 320
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
 
Quote:
Originally Posted by RichH View Post
If you HAVE to untie a jammed knot .... thats what knives are for. Cutting 6" from a jib line is no big deal.

.

Can I post that on a placard in my boat?

I forget that all too often. Or maybe I just have poor knotmanship.
dnf777 is offline  
Quote Quick Reply Share with Facebook
post #6 of 21 Old 04-18-2011
Senior Member
 
QuickMick's Avatar
 
Join Date: Oct 2009
Location: California
Posts: 1,381
Thanks: 0
Thanked 3 Times in 3 Posts
Rep Power: 6
 
to clew, i use the larks head. figure 8 follow-thru w/stopper for the backstay. only a guess, but if it got really willy nilly, im thinking your genoa would rip before a fig 8 failed? i think id rather deal with a broken knot and a flapping sail. in any case as mentioned above, lines are generally strong enough to compensate for being overloaded with a large margin of safety...

How inappropriate to call this planet Earth when it is quite clearly Ocean ~ Arthur C. Clarke

Quinn McColly
Macgregor Venture
QuickMick is offline  
Quote Quick Reply Share with Facebook
post #7 of 21 Old 04-18-2011
Senior Member
 
MarkofSeaLife's Avatar
 
Join Date: Nov 2010
Posts: 2,968
Thanks: 43
Thanked 122 Times in 103 Posts
Rep Power: 5
 
Dock
In the 'old days' prior to furling genoas a sailor would forever be switching headsails: Genoa No1, 2 and 3, Jib, Storm Jib. So you had to whip the sheets off fast, and on fast!

Bowline is great for that.

In the modern world of cruising the bowline is undone off the Genny about once per year if lucky. So it does tighten up and become a pain to get off.

However I still use them because I think its best to keep the number of knots used on a boat to a bare (bear?) minimum. Otherwise the big furry thing can bite ya on the bum in the middle of the night.

Some folks have started using a single line for their sheets with some knot forming a loop through the clew. But this ain't such a good idea because if the sheet breaks you can't tack and have one good sheet remaining. You have a sail flapping and when furled the clew is too high to thread a new sheet! (Sheets break most often at the knot, of course cos it 50% or 60% strength as you've pointed out)

So I keep bowlines, and I keep few as possable knots used on board.


Just as an aside: When sending someone up the mast professional pullers... actually 'pullees' are told to use a snap shackle instead of a bowline. This sends shivers up my spinless as a snap shackle can unsnap! But Occupational Health and Safety mobs want to know the breaking and safe working loads and they can work that out with a snap shackle but NOT with a knot. Of course you can put in both and have a safety line too.

Sea Life
Notes on a Circumnavigation:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by MarkofSeaLife; 04-18-2011 at 03:54 PM.
MarkofSeaLife is offline  
Quote Quick Reply Share with Facebook
post #8 of 21 Old 04-18-2011
Senior in age only!!!
 
centaursailor's Avatar
 
Join Date: Nov 2010
Location: Balbriggan
Posts: 554
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 5
 
I striped down my 4 to 1 main sheet system earlier this year.
Couldn't believe how the bowline had cut into itself were it anchored to the block. It was real neatly tied and showed no sign of wear on the visible surface, only when opened up.
I,ve left it a bit longer for future inspection.
Safe sailing

The great appear great because you are on your knees. James Larkin, Irish Labour Movement.
centaursailor is offline  
Quote Quick Reply Share with Facebook
post #9 of 21 Old 04-19-2011
Senior Member
 
SVPrairieRose's Avatar
 
Join Date: Oct 2009
Location: Vancouver BC
Posts: 227
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 6
 
Quote:
Originally Posted by RichH View Post
Fig. 8 'middled' in a single continuous jib line is probably the best. Next would be the 'strangler' - of course middled, then clove hitch or larks head.
If removable is important, then add a stainless locking caribiner/shackle.

.
NOOOOOOOOO!!!!!!

One of the reasons for using a small knot is that when a sheet is lost on a tack or dropping a sail when it is luffing like crazy and hits you it won't kill you. A shackle or locking stainless caribeaner turns a whip into a mace! that would thrash your deck, shatter a carbon fibre mast or break a bone!
SVPrairieRose is offline  
Quote Quick Reply Share with Facebook
post #10 of 21 Old 04-21-2011
Barquito
 
Barquito's Avatar
 
Join Date: Dec 2007
Location: Madison, WI
Posts: 2,262
Thanks: 0
Thanked 27 Times in 27 Posts
Rep Power: 8
 
Quote:
thrash your deck, shatter a carbon fibre mast or break a bone!
Why... is there something wrong with that?
Barquito is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Frayed Knot Coldwater Gear & Maintenance 10 09-23-2009 10:11 AM
More Knot ??'s offline2004 Gear & Maintenance 4 04-29-2007 09:15 PM
What is the name of that knot...? vissepo Seamanship & Navigation 37 04-02-2007 03:05 PM
Knot log? Nereus32 General Discussion (sailing related) 1 05-15-2005 06:09 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome