Most likely it's cheaper to ship to Duluth by ship, then on rail from Duluth to Canada. Could be that the problems with lack of rain in the Panama Canal area, forcing long delays was a deciding factor.
The skinny ends of the blades rest in a saddle that will allow them to move fore and aft to allow for buff/slack in couplers and draft gears and rotate for traversing curves. Really nothing the railroads haven't been doing for many years. I believe BN has been shipping Boeing aircraft fuselages from Washington to Kansas on special rail cars for quite a while.