Boat Design Forums  |  Boat Design Directory  |  Boat Design Gallery  |  Boat Design Book Store  |  Thanks to Our Site Sponsors

Go Back   Boat Design Forums > Design > Boat Design
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 01-18-2005, 04:22 PM
Richard Petersen
Guest
 
Posts: n/a
Bow strength in a storm

Do modern sailboats of all types have a bow cleat, post or strongman to take the strain of riding out a storm by paying out anchor or a seabag?
Reply With Quote
  #2  
Old 01-18-2005, 04:31 PM
D'ARTOIS D'ARTOIS is offline
Senior Member
 
Join Date: Nov 2004
Rep: 311 Posts: 1,069
Location: The Netherlands
Where would you otherwise secure your anchorline, if you doesn't have a strongpoint in your stern section?
Reply With Quote
  #3  
Old 01-18-2005, 04:51 PM
Richard Petersen
Guest
 
Posts: n/a
I am asking about the strength of the anchor point. Not where. To reach over the bow on my boat and then hang upside down in breaking seas would break ribs for sure. I have never pushed it in my boats. I do not know if that shiney eye is going to hold up. It just looks so small. When, if ever, do they pull out. What is the back up procedure, if any.
Reply With Quote
  #4  
Old 01-18-2005, 05:05 PM
D'ARTOIS D'ARTOIS is offline
Senior Member
 
Join Date: Nov 2004
Rep: 311 Posts: 1,069
Location: The Netherlands
Correction: stemsection. If it is for your runabout, Cranchi from Italy had a D bracket mounted through the stem - that is what I remember from my 2nd boat,
long time ago. Not through your thin deck, unless sufficiently reinforced,
Reply With Quote
  #5  
Old 01-18-2005, 05:10 PM
Sean Herron's Avatar
Sean Herron Sean Herron is offline
Senior Member
 
Join Date: May 2004
Rep: 405 Posts: 1,532
Location: Richmond, BC, CA.
This will sound odd...

Hello...

I think I know what you are concerned about here - wave lift and dragging the hook...

If your cleats or other forward deck hardware are not backed up by good non ferrous metal or wood backing plates - this is what I do - cause my little production boat is same...

I throw the hook - pull it snug - let the boat back in the wind to lay the chain - secure a loop in the anchor line and do some half hitches or 'grannie throws' and shackle a 'warp' or 'bungee' chord between these that will take the assumed height of the oncoming waves before making fast to the boat...

I like to think that a good pay of rope plus the 'spring' effect will leave the hook be...

And I would not know if I just made any sense...

SH.
Reply With Quote
  #6  
Old 01-18-2005, 05:16 PM
Richard Petersen
Guest
 
Posts: n/a
It is in the stem section, about 6" above the boat empty, water line. Does any AGENCY ever subject that eye to a sustained test? Or do they say it looks O K. And let it go at that due to cost and diffuculty of the sea test.
Reply With Quote
  #7  
Old 01-18-2005, 05:25 PM
Richard Petersen
Guest
 
Posts: n/a
The larger old woodies use a heavy rubber shock cord when docked. They are the size of my wrist. I will do some calc. of shock loads, and pick up 2, and practice doing your routine in a good chop. Thanks, I appreciate the help, Rich.
Reply With Quote
  #8  
Old 01-19-2005, 12:34 AM
PAR's Avatar
PAR PAR is offline
Yacht Designer & Builder
 
Join Date: Nov 2003
Rep: 2891 Posts: 8,796
Location: Eustis, FL
One of the more tedious jobs for the designer or engineer is calculating the loads on gear and rigging. Compressive, tensional, sheer and elasticity qualities all need come into compliance when sizing the parts and pieces that make up the hardware list on a particular yacht design. There are some guide lines to use, also standards as well as general rules and formulas that apply in these calculations.

Typically, a small runabout bow eye may be able to provide the overall strength to lift several times it's displacement, full up. This isn't the case in larger craft where the size of the piece will be sized for the expected load, plus a fudge margin. As a rule, the individual pieces are sized to the loading of it's assembly or the assembly it will be working with. A large vessel's mooring bit may not tolerate the load of several of the boat's displacement, like the little runabout, but will be sized to be adequate for riding a hook in storm conditions or withstanding the jerks of a much larger tow vessel in a choppy sea. And yes, there are several agency's standards that may come to bear on the application.
Reply With Quote
Reply



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Removing Seats from Aluminum Jon - Strength Issues LarryJ Metal Boat Building 2 08-11-2005 03:33 PM
Lasers mackid068 Sailboats 24 08-09-2005 11:10 PM
Bow modification/redesign on sailboat Burnsy Boat Design 15 05-04-2005 08:29 AM
Bulbous bow design tjrrong Boat Design 4 01-05-2005 05:24 AM
bow alteration Sailboats 9 09-01-2002 01:11 PM


All times are GMT -5. The time now is 02:52 PM.


Powered by: vBulletin Copyright ©2000 - 2012, Jelsoft Enterprises Ltd.
Web Site Design and Content Copyright ©1999 - 2012 Boat Design Net