Welcome, Guest. Please login or register.
March 17, 2018, 01:05:57 pm
Home Help Search Login CONTACT Register
News: http://sailboatdata.com/bbs/index.php?type=rss;action=.xml;sa=news;board=11.0;limit=20

+  SailboatData.com - Forum
|-+  Main
| |-+  General Discussion
| | |-+  L/B vs B/L
« previous next »
Pages: [1] Go Down Print
Author Topic: L/B vs B/L  (Read 2311 times)
Member Emeritus

Karma: +0/-0
Posts: 158
Boat Type: Dread Pirate ship RADIO FLYER


« on: December 27, 2011, 11:13:16 pm »

A 'narrower' boat has a HIGHER number than a fatter one? Correct.

And a longer boat for that same beam has a higher number.  Same physical change but a different cognitive way of thinking about it.

A boat with a 50' LOA and a 10' Beam should be displayed as a what? 5.0

So I just checked a number of sources looking for what is the most common way to express the ratio between length and beam.

Of the 5 design books that I have only one, Larsson & Eliasson, discusses the ratio and uses the form Length/Beam (>1).

In the magazine Good Old Boat, Ted Brewer, regularly compares 3 boats and he uses the B/L form (<1).

Doing google search for "beam to length ratio"  seemed to favor L/B (>1) by 6:1 or better, academic articles more so.

For monohull sailboats the typical ratios tend to fall into a range of 2.4 to 5 or so.  But for other vessels such as catamarans or military vessels the ratio can go much higher.  Catamarans can be into the 20's, military vessels over 10.

When comparing ratios for very long  and narrow vessels, it is easier to visualize a change from 10:1 to 11:1 than .10 to .09.

I expect that L/B is easier to use when dealing with these sort of vessels so that is the form that is used for most design work for consistencies sake.

A house is but a boat so poorly built and so firmly run aground that no one would think to try and refloat it.

Karma: +2/-0
Posts: 1882

« Reply #1 on: December 31, 2011, 11:19:37 am »

Sounds like that's the way to do it.
Have a great New Year.
Pages: [1] Go Up Print 
« previous next »

Login with username, password and session length

Powered by MySQL Powered by PHP Powered by SMF 2.0 Beta 4 | SMF © 2006–2008, Simple Machines LLC Valid XHTML 1.0! Valid CSS!