🚀 go-pugleaf

In article <13797@grayt> grayt@Software.Mitel.COM (Tom Gray) writes:
>
>Why are ship port holes round?
  
Ship port holes are round in order to avoid cracks in the hull that would 
start from sharp corners due to the stresses that appear in bad weather.

The constant diameter triangels as found in Wankel motors have one 
serious disadvantage that make them useless as manhole covers. 
If they are moved in wrong direction of some reason, they will turn 
into a vertical position because of the placement of the center of 
gravity. This will not happen with a circular cover. 
As manhole covers often are used in streets, I wouldn't like to be
the one driving into one hanging vertically in the manhole.

Kurt (klundqvi@ra.abo.fi)