Tender or Stiff - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > General Interest > General Discussion (sailing related)
 Not a Member? 


Like Tree2Likes
Reply
 
LinkBack Thread Tools
  #1  
Old 04-13-2006
Junior Member
 
Join Date: Nov 2005
Posts: 14
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
ricccccc is on a distinguished road
Tender or Stiff

What makes a boat tender or stiff
Reply With Quote Quick reply to this message Share with Facebook
  #2  
Old 04-13-2006
TrueBlue's Avatar
Señor Member
 
Join Date: Oct 2004
Location: Narragansett Bay
Posts: 4,853
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 13
TrueBlue is a jewel in the rough TrueBlue is a jewel in the rough TrueBlue is a jewel in the rough
A sailboat is tender when it is unbalanced, heeling excessively in breezy conditions and requiring adjustment by crew to sheets and trim. In keel boats, insufficent keel weight, lead or otherwise, will cause the boat to heel. Conversely, too much sail area in proportion to ballast, or an unusually high center of balance, will create the same effect.

The reverse applies when a boat is stiff.
__________________
True Blue . . .
sold the Nauticat
Reply With Quote Quick reply to this message Share with Facebook
  #3  
Old 04-13-2006
Member
 
Join Date: Mar 2006
Location: Merritt Island
Posts: 87
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
LaLeLu is on a distinguished road
Tender = Light displacement, shallow keel and/or too much sail. Our previous boat, a Hunter 30, was tender. However, it was also quite fast for it's length - so it can be a tradeoff.
__________________
Susan
LaLeLu 40' Caliber
Merritt Island, FL
Reply With Quote Quick reply to this message Share with Facebook
  #4  
Old 04-13-2006
Faster's Avatar
Just another Moderator
 
Join Date: Sep 2005
Location: New Westminster, BC
Posts: 15,149
Thanks: 83
Thanked 233 Times in 225 Posts
Rep Power: 10
Faster has a spectacular aura about Faster has a spectacular aura about Faster has a spectacular aura about
Hull form is a factor also. Many round-bilged boats are initially tender, heeling easily in light breezes, but firm up as the righting arm of the ballast increases.

Flat bottomed boats with hard turns (or possible chines) in the bilges provide what is known as "form stability" and initially resist heeling due to the bouyancy of the hull sections. These types of boats, if insufficiently ballasted, are particularily tender once the form stability has been overcome, and rely heavily on crew weight & placement for righting moment.
SchockT likes this.
Reply With Quote Quick reply to this message Share with Facebook
  #5  
Old 04-13-2006
SailorMitch's Avatar
Senior Moment
 
Join Date: Nov 2005
Location: MD
Posts: 1,931
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 10
SailorMitch will become famous soon enough
It's also a subjective thing. What one person considers to be a tender boat may not be to someone else. For example, to my wife anything that heels more than 5 degrees is tender. To some folks, you don't start really sailing until the boat is heeled over 15-20 degrees.

Most designers have a target range for their boats to heel, so some boats will heel more than others in the normal course of things. It's good to know the designer's intent because you don't want to push the boat beyond that amount of heel or the boat will want to round up. To prevent that, you have to turn the wheel to keep the boat going straight and then the rudder starts to act as a brake slowing you down.
Reply With Quote Quick reply to this message Share with Facebook
  #6  
Old 04-13-2006
Jeff_H's Avatar
Moderator
 
Join Date: Feb 2000
Location: Annapolis, Md
Posts: 6,632
Thanks: 5
Thanked 101 Times in 77 Posts
Rep Power: 10
Jeff_H has a spectacular aura about Jeff_H has a spectacular aura about Jeff_H has a spectacular aura about
Although 'Faster' was closest, so far you have not gotten an answer that reflects the traditional naval architectural definitions of tender and stiff. These terms are strictly used in reference to initial stability (form stability) and generally are not thought to include other forms of stability. A boat that is said to be stiff has a lot of form stability. (Stability that comes strictly from the shape of the boat.) Tender refers to a boat without much form stability.

Faster explained quite well the shape of a boat that produces lots of form stability, but in a general sense, as they heel, boats with lots of form stability shift their center of buoyancy to leeward more quickly than tender boats. Since the center of gravity does not shift relative to the boat itself, as a boat with a lot of form stability (a stiff boat) heels, initially, the lever arm between the center of gravity and the center of buoyancy increases rapidly, creating a lot of initial stability. The problem occurs at steeper heel angles, Unless the boat has a very low center of gravity, as a stiff boat heels the center of buoyancy rapidly moves back toward the center of gravity. As this occurs the stability of the stiff boat can rapidly decrease.

Stiff boats tend to have very quick motions but rock through smaller roll angles. They also tend to have a smaller angle of ultimate stability and so are more prone to be able to capsize and stay over longer.

Under the traditional definition of tender or stiff, neither term has anything to do with the overall displacement of the boat, the depth of its keel, or the amount of sail area that it carries. Traditional heavy displacement boats tend to be tender (lacking form stability). Modern race boats tend to be a bit on the stiff side and 70's era race boats tended to be excessively stiff.

What confuses people is the frequent coloquial missuse of the terms. People assume that tender means that a boat heels easily. That really opens a whole can of worms because at that point, a boat that appears stabile may be so for a lot of reasons varying from a low center of gravity (which is good for performance, seaworthiness and motion comfort) to a lot of form stability, (which is not bad for performance but comes at the price of motion comfort and seaworthiness) or simply short of sail area (which does nothing good for the boat in the long run).

Respectfully,
Jeff
Marcel D likes this.
Reply With Quote Quick reply to this message Share with Facebook
  #7  
Old 04-14-2006
Senior Member
 
Join Date: Jun 2001
Location: Wilson, NY
Posts: 562
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 14
Irwin32 is on a distinguished road
Good explanation, Jeff. Tender boats are not bad or unseaworthy. For years I owned a Paceship Eastwind that was pretty tender, but the nicest sailing boat I have ever been on. The helmsmen had to be dead not to be able to feel when this boat was in the groove.
Reply With Quote Quick reply to this message Share with Facebook
  #8  
Old 04-18-2006
Faster's Avatar
Just another Moderator
 
Join Date: Sep 2005
Location: New Westminster, BC
Posts: 15,149
Thanks: 83
Thanked 233 Times in 225 Posts
Rep Power: 10
Faster has a spectacular aura about Faster has a spectacular aura about Faster has a spectacular aura about
Thanks, Jeff, for the excellent clarification.
Reply With Quote Quick reply to this message Share with Facebook
  #9  
Old 04-19-2006
Senior Member
 
Join Date: Jun 2005
Location: New Orleans
Posts: 1,907
Thanks: 7
Thanked 28 Times in 25 Posts
Rep Power: 10
nolatom will become famous soon enough
In ships, tender and stiff tend to refer to rolling periods, with the former having a long rolling period and the latter a short (quick) one.

If you're carrying cargo, tender may be better, the ship rolls more slowly and gently, the movement is easier on the cargo. Tender here means having a low metacentric height (vertical distance between buoyancy and gravity);

Stiff ships tend to snap back upright quickly, with a short rolling period. Lots of military ships are stiff, since the quick rolling period brings the decks (meaning gun decks) back level in a hurry. That 'snappish' motion is hard on cargo and passengers, though, it beath you up.
Reply With Quote Quick reply to this message Share with Facebook
  #10  
Old 09-06-2012
Junior Member
 
Join Date: Apr 2005
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
davidlaing is on a distinguished road
Re: Tender or Stiff

Light displacement is not, in itself, a cause of tenderness. A low ballast/displacement ratio is, but the distribution of the ballast matters, too. A boat with a given B/D ratio and a deeply-positioned ballast will be stiffer than a boat with the same B/D ratio but with a more shallowly-positioned ballast.
Reply With Quote Quick reply to this message 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:

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

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Water Tender Dingy 9.4 gunnyman1 General Discussion (sailing related) 5 07-11-2008 07:39 PM
Tender marking requirements joub General Discussion (sailing related) 1 02-20-2004 09:15 AM
Fixing wood tender bert2 Gear & Maintenance 3 09-18-2003 08:05 PM
Tank Tender wannasail Gear & Maintenance 1 09-22-2002 07:31 PM
Tender: inflatable or folding? Lucian General Discussion (sailing related) 10 09-02-2002 01:38 AM


All times are GMT -4. The time now is 05:49 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.