View Single Post
  #10 (permalink)  
Old 09-11-2009
Jeff_H's Avatar
Jeff_H Jeff_H is offline
Super Moderator
 
Join Date: Feb 2000
Location: Annapolis, Md
Posts: 5,478
Rep Power: 14
Jeff_H has a spectacular aura about Jeff_H has a spectacular aura about
Jon:
There are designers who for a nominal fee will review proposed modifications to one of their prior designs and make recommendations as to the feasibility and modifications required to successfully alter the design. Not all designers will do this and not all boats that list a particular designer were actually engineered by that designer. It is one of those 'your results at home may vary' sort of a thing.

There are a whole range of issues in fitting a bulb, such as will the boat trim properly with the added weight placed where it is, was the rig designed for the increased loads implicit when you increase stability and adding a bulb to an unshortened keel will increase the load on the keel bolts, but more to the point will increase the loads on your boat's internal structural system and so proper engineering is important.


John Shasteen,

At least from the research that I have encountered, conversations with designers, and from conversations with towboat operators, while wings may complicate getting a boat unstuck, bulbs at the bottom of keels apparently tend to make getting unstuck easier than a simple fin and should not add to the stress on the keel bolts 'as you wiggle out of the muck'. As noted above, bulbs do add to the sailing loads to the bolts, rig and surrounding supporting structure.

Respectfully,
Jeff
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Curmudgeon at Large- sailing my Farr 11.6 on the Chesapeake Bay

Last edited by Jeff_H; 09-11-2009 at 12:48 PM.
Reply With Quote Share with Facebook