Adding weight

[sailhmb]

To make minimum class weight I will need to add weight.  Where is the best location; bottom of the keel or center of mass?

 

[Monkey]

What do the class rules say?  Some classes are very specific as to corrector weight locations. 

 

[TeamFugu]

The "best" place would be as close to the center of mass as possible. That will dampen or at least not increase the rocking and pitching moment. That being said, some more modern classes, like the ISSA require the weight to be distributed so the boat passes a "swing" test where when the boat is swung or twisted while suspended maintains a certain amount of momentum. I can't remember the physics but if a good percentage of the weight is centralized, the boat will not swing or spin as much as it would with the weight spread out.

Many put the weight at the base of the mast because it is easy to do so.

 

[xonk1]

What kind of boat? How much do you need to add? Could make a big difference in just where the corrective weight is placed.

 

[neuronz]

How much weight are we talking? Center of mass has benefits concerning dynamic motion, low center of gravity usually helps with stability. It could also be used to change static trim or heel if there is need/desire for it.

 

[fastyacht]

This is 100% a class rules issue! Find out tje rules!

 

[sailhmb]

Sorry I should have stated no actual boat, therefore no class rule weight placement restriction.  This is just a "what if" question; if you had to add weight, where would you put it, center of mass or righting moment?  if you need some specificity then a 200kg boat and 10kg of weight.

 

[Major Tom]

What about centre of pitching, that means the placement of the weight has zero impact on pitching moment?

 

[fastyacht]

Sorry I should have stated no actual boat, therefore no class rule weight placement restriction.  This is just a "what if" question; if you had to add weight, where would you put it, center of mass or righting moment?  if you need some specificity then a 200kg boat and 10kg of weight.

Keelolboat put at bortom of keel. Centerboarded put wjere tom says

 

[slug zitski]

Don’t know your project 

but when adding trim ballast I find that molding the lead into Triangle shaped bars is the most efficient way to lay the ballast into the curved inner hull between frames

the lead bars are commonly called Toblerones after the chocolate bar 

use a length of the appropriate size steel angle iron as a mold , then cut the lead bars to length with a hand saw 

 

[Zonker]

Just eat a lot of donuts. Moveable ballast is far more effective.

 

[Liquid]

It's been a while for me but some 14ers put correctors on the transom bulkhead.

 

[Justaquickone]

I always thought that in a dingy you put it just behind the centre of balance to dampen any pitching.

 

[Xeon]

If it’s a centreboard boat , at the back of the centreboard case . 

 

[Gouvernail]

How you enjoy The Weight depends  on the boat:

E Scow: Bring the Band 

Snipe- Turntable

Ensign—— Reel to reel

Laser-  Eight Track 

J-24-  Cassette

 Melges 24–  CD

RS AERO- Bluetooth 

 

[sailhmb]

I prefer live.

 

[Gouvernail]

I prefer live.

Me too

 

[JimC]

Sorry I should have stated no actual boat, therefore no class rule weight placement restriction.  This is just a "what if" question; if you had to add weight, where would you put it, center of mass or righting moment?  if you need some specificity then a 200kg boat and 10kg of weight.

If its a ballasted boat then add it to the ballast, if its an unballasted boat then don't add weight unless class rules force you to, in which case as close to the centre of pitching as the rules permit.

 

[European Bloke]

If it's a dinghy you sail it flat, so adding weight the board has no righting benefit and causes all sorts of issues with fitting and managing the board.