SailNet Community - View Single Post - Bukh engines
Thread: Bukh engines
View Single Post
  #14  
Old 10-30-2007
JimsCAL's Avatar
JimsCAL JimsCAL is offline
Senior Member
 
Join Date: May 2007
Location: Glen Cove, NY
Posts: 2,343
Thanks: 0
Thanked 27 Times in 26 Posts
Rep Power: 8
JimsCAL is on a distinguished road
I am sure Robert (as a Naval Architect) can explain this much better than I can (being a Marine Engineer), but I suspect he calculated the hull speed using an equation like:

Hull Speed (kts) = 1.3 to 1.4 X Square Roof of Waterline Length (in feet)

Hull speed in a displacement (non-planing) hull is when the resistance due to wavemaking basically limits further speed increases. Below that speed, the frictional resistance dominates. The very rough rule of 2 Hp per 1000 lbs generally provides sufficient power to get to hull speed plus a little margin.
Reply With Quote Share with Facebook