T&T: Hull Speed 20% faster and more economical, by new

[Arild Jensen]

bill wrote:
> His comment was regarding viking ship replicas.
>
> I'd suggest the lapstake planked hull would have a major effect in flow separation.  Whilst lovely and fair when done properly, the laps don't necessarily or always follow flow lines and will create interference with laminar flow and introduce air, lessening surface tension allowing the hull to break free and exceed theoretical hull speed when enough power is applied or surfing conditions exist.
>
>
> regards,
> Bill 
REPLY
I agree.  But as to what  percentage  is attributable to  the slight 
convex form and how muhc to th elapstrake  construction, who knows. 
If anyone is aware of  any studies of this aspect, I would be very 
interested. 

Maybe  the old times were not so dumb after all.  These hulls evolved  
over centuries following a tried and true  method  of sea faring  across 
the seas.
It seems to me the Cris Craft  Sea Skiff was also  lapstrake planked.  
Even  though the last models might have been  molded on FRP.
Could it be the lapstrake  design  contributed to the  boats  overal 
performance.  As I recall from driving a couple at the marina I worked 
in  they were fast and sea kindly.
Maybe the fin effect of a lapstrake  does in fact contribute something.


regards
Arild