Love at 28′; Wanderlust

David Welsford

I think I posted this video on WB TV a few months ago, but it still rings true — in case you missed it the first time around.  (Wait — I wanted to, but I didn’t — It was only available on Vimeo, which our service doesn’t support.)

Imagine being 29 years old again….  Imagine having your own wooden boat, into which you have poured yourself.  David is living our dream, and I applaud him.

What do you think?  Please comment below.

Thanks, Carl

 

Posted in My Wooden Boat of May 2014 | Tagged | 4 Comments

Auto Boats, Number Boats, & The Development of Planing Hulls

Look, in our very own backyard, written by Paul Lazarus, Senior Editor of Professional BoatBuilder (www.ProBoat.com) — second item down, Missing Link:

Auto Boats

 

(Above are plans from Charles Mower for a one-design powerboat, ca. 1910)

This article by Paul discusses the antecedents of round-bilge to hard-chined construction.  I find that particularly fascinating.  One of my great regrets in life has been never to have met nor spoken with Lindsay Lord.  But he’s a topic for another discussion.  Here’s a pdf of his book, not mentioned in Paul’s piece (because Lindsay came much later):  http://e-j-m.com/lord-book.html.

Will Frost Lobsterboat

(Will Frost lobsterboat, ca. 1930)

Paul’s discussion with noted naval architect Donald Blount is particularly fascinating.  Here’s an extract from Donald:

The Number Boat and the Frost lobsterboat have geometric features essential to going much faster than hull speed even though both hulls do not have hard chines. Their essential features are in the list below, in order of importance.

  • Straight buttocks on the aft half of the hull bottom. The combination of bullet points #1 and #2 inhibits the stern from squatting as speed increases above hull speed. In my PBB article “Original Speed,” the steam launch Ellide is essentially double-ended below the water: that is, the stern waterline ending is the same as at the bow; there is no transom as such for flow separation. Note the two photographs depicting this steam launch “sucking down” as her speed increases.
  • Wide hull beam at the transom.
  • Large slenderness ratio. Although boat displacement is not known (but could be calculated from the lines drawings), it is obvious that these boats have shallow draft and must be lightweight. From “Original Speed,” typical values of slenderness ratios before 1900 were around 9.3, varying between 8.3 and 10.3. When the slenderness ratio is greater than 7.0, there is virtually no resistance hump throughout the speed range above hull speed, as is seen for planing hulls and heavy round-bilge vessels.
  • Intersection of the transom and hull bottom is a sharp angle, thereby ensuring flow separation. Hydrodynamic (planing) lift is enhanced when hull geometry has features (chines; a sharp angle to the flow at the transom) causing water to separate from the hull. Chines and transom are preferred; however, either one alone benefits reduced resistance above hull speed.

I believe both of these boat designs were atypical (ahead of their time).”

Read the post yourowngoodselves, and please comment below?

Thanks and sorry to be delayed, Carl

 

 

Posted in My Wooden Boat of April 2014, My Wooden Boat of March 2009 | Tagged , , , , , | Comments Off