Saturday, February 13, 2021

Class 40.

 - Original Model year 2008. TYD#282.

- A new commission for a Class 40.

- This one from Hawaii. Unlikely place for the Class, nevertheless a boat with a program of distance travels.

- Long observer of the 40's, I started in 2008 with the first study; a simplified version to get my feet wet; as seen above and below.







- This Model, 2009 is further improved with more stability and with harder chines.





- Very basic, until 2011 when I introduced what I believe the first so called "Scow Bow". Granted, largely inspired by David Raison's Mini Transat of that year with a round nose and a winner. Adopted to a 40, the volume is enormous and soon the Class Association put a dent to the size, by placing limits in terms of measurements.





- The next step of course was to address the bow correction imposed by the Class 40 organization.
It was felt that unlimited or close to be, as seen on the sample above was too dramatic. Therefore  a couple of dimensions brought the animal under control. 

- This 2013 version is the first attempt at interpretation of the new ruling. If you observe carefully, while I kept the maximum beam forward athwartship as allowed by the rule, I projected the point on deck down to the waterline, introducing a side knuckle at the waterline, a chine to complete by a circle below the waterline. The idea at the time was to keep a waterline as long as possible but with the benefit of fuller bow. I think this configuration is still valid. And ought to produce a good all around boat, up and down the spectrum of wind directions.







- In retrospective because of the taste of the day, I would show a livet inclined to inboard within the limit of 120mm. vertically from the sheer line. The hull is very smooth,  with a chine positioned from the middle of the boat and going aft to the transom.




- The roof as designed offers protection, but missing is the possibility to see forward and therefore I would modify the width to include a visibility forward.


- Now, 2021. With this new commission I started with 3 different Rhino Models to assess the possibilities offered by the tendencies currently being pursued. The thing in common is obviously the adoption of a scow stem, limited in width at the bow, but with different interpretations. From very rounded to a little finer and something in between.



- Model X. With a slightly longer and therefore finer bow entry at the waterline. For a given displacement the hull is a little shallower in the middle and with straight buttocks.



- Model Z. With the shorter of the models on the waterline, the bow is therefore more blunt leading to more rounded sections for the rest of the boat with the emphasize to cut down on the wetted surface.


- Model Y. Chosen for all around performance with the logic to present as few holes as possible in consideration to the overall program for the boat. This is the model we will pursue for the rest of this essay in reality. It must be noted that the boat is presently under construction and questions, inquiries are welcome.










    1 comment:

    1. Very interesting bow shape. Kind of look like a bulbuous bow!

      ReplyDelete

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