This is one of the most frustrating objects I have yet drawn in TurboCAD.  This model was created using the "lofting" command.  A tremendous amount of trail and error was done before the locations and proper shapes of the cross section profiles were achieved for the lofting to be successful.

 

TurboCAD creates solid objects by interpolating object boundries using profiles and their shapes, orientations and positions.  The program creates the boundries much as a splined curve is made between various points.