Sunday, December 30, 2012

An Update to our 32 foot Proa Design

In the last few weeks the 32 foot proa that we have been working on with proapist Russell Brown   (more on Russ)  has evolved to the point where we are ready to enter the detail design stage. Significant development has been made in the steering system as well as refinement of the beam/connective arrangements and cockpit layout.  It looks like the lightship weight of the craft will be under 800kg, even when built primarily from marine plywood!  This is possible due to the moderate surface area and low structural loading of a proa compared to other types of multihulls.

One of the interesting characteristics of the pacific proa as compared to most multihulls is that they excel upwind.  This can be seen in the attached VPP output for the boat:

Congratulations to Wild Oats XI on their 2012 Sydney Hobart triple crown win!

New course Record
Line Honours
1st on Corrected Time

Bieker Boats is proud to have done the structural engineering and detail design of the asymmetrical daggerboard and centerline light air daggerboard used for the race.  These survived the strenuous offshore conditions, including a high force impact to one of the daggerboards.  In addition, Bieker Boats conceived the concept and supervised the engineering study of fins mounted to the tail of Wild Oats' bulb to prevent keel flutter at the top end of the yachts speed range.

Monday, November 26, 2012

32 foot proa

Paul is having fun designing a 32 foot offshore proa with long time proapist Russell Brown. It is designed for ease of construction using mostly plywood and constant camber foam cored panels (shown in green).  See the attached pics of the preliminary design:

Friday, November 16, 2012

Retracting Drive Unit

The retracting drive unit in the 35 MKII is a little different from others that have been built.  Where others have employed single or multiple constant-velocity joints to keep the angular velocity constant, we can use a simple universal or Cardan type joint.  This works because the tail shaft is in alignment with the stub shaft coming from the gear when the unit is deployed.  The universal joint also functions as the hinge point for the strut.

Monday, November 5, 2012

Riptide 35 MkII Launch Day

The new Riptide 35 MkII Longboard hit the water for the first time today in Anacortes. It was a beautiful November day, the boat trimmed well, and the retracting drive unit we designed for the boat performed better than our expectations (9 knots with an 18 HP engine and zero vibration).  Thanks and congratulations go to new owners Peter & Mary Salusbury and Jim Betts Enterprises for their hard work and dedication.

Monday, October 29, 2012

Two New Boats

Here's some recent pictures from Jim Betts Enterprises in Anacortes of the Riptide 35 MkII and the Riptide 41 build progress.  It's good to see them together!