Rail-transportable wind turbine tower

Abstract

A tower is provided having a plurality of axial substantially tubular sections with an outer diameter no greater than a designated maximum diameter. At least one of the sections includes at least one reverse taper portion located near a base of the tower. The reverse taper portion has a first end, located near the base, having a first diameter. The reverse taper portion has a second end, opposed to the first end, having a second diameter. The first diameter is smaller than the second diameter.

1 . A tower comprising:
 a plurality of axial substantially tubular sections, the sections including an outer diameter no greater than a designated maximum diameter;   wherein at least one of said plurality of axial substantially tubular sections includes at least one reverse taper portion located near a base of said tower, the at least one reverse taper portion having a first end, located near said base, having a first diameter and a second end opposed to the first end having a second diameter, where the first diameter is smaller than the second diameter.   
     
     
         2 . The tower according to  claim 1 , the at least one reverse taper portion having a profile that is at least one of straight, stepped, curved, and compound curved. 
     
     
         3 . The tower according to  claim 1 , the designated maximum diameter being a maximum diameter permitted for rail transport, and wherein the designated maximum diameter is equal to or less than about 13 feet 6 inches. 
     
     
         4 . The tower according to  claim 1 , each of said plurality of axial substantially tubular sections having a weight no greater than a designated maximum weight, and wherein, the designated maximum weight is equal to or less than a weight permitted for rail transport. 
     
     
         5 . The tower according to  claim 4 , wherein the designated maximum weight is equal to or less than about 140,000 pounds. 
     
     
         6 . The tower according to  claim 1 , wherein each of said plurality of axial substantially tubular sections have a length no greater than a designated maximum length, and wherein, the designated maximum length is equal to or less than a length permitted for rail transport. 
     
     
         7 . The tower according to  claim 6 , wherein the designated maximum length is equal to or less than about 89 feet. 
     
     
         8 . The tower according to  claim 1 , wherein the at least one reverse taper portion is angled off of vertical by an angle θ, wherein θ is between about one and about five degrees. 
     
     
         9 . The tower according to  claim 1 , wherein said plurality of axial substantially tubular sections include a bottom section, at least a portion of said bottom section having said at least one reverse taper portion. 
     
     
         10 . The tower according to  claim 9 , said bottom section comprising:
 a plurality of substantially cylindrical stacked cans; and   at least one can having a reverse taper disposed at or near a bottom of said tower.   
     
     
         11 . The tower according to  claim 10 , said bottom section comprising two cans having a reverse taper disposed at or near a bottom of said tower. 
     
     
         12 . The tower according to  claim 10 , wherein the at least one can having a reverse taper has a taper that is angled off of vertical by an angle θ, wherein θ is between about one and about five degrees. 
     
     
         13 . The tower according to  claim 1 , the at least one reverse taper portion comprising a stepped portion having a smaller diameter near the first end and a larger diameter near the second end. 
     
     
         14 . The tower according to  claim 1 , wherein the tower is a wind turbine tower. 
     
     
         15 . A wind turbine tower comprising:
 a plurality of axial sections, the sections including an outer diameter no greater than a designated maximum diameter, the designated maximum diameter being a maximum diameter permitted for rail transport; and   wherein at least one of said plurality of axial sections includes at least one reverse taper portion located near a base of said wind turbine tower, the at least one reverse taper portion having a first end, located near said base, having a first diameter and a second end opposed to the first end having a second diameter, where the first diameter is smaller than the second diameter.   
     
     
         16 . The wind turbine tower according to  claim 15 , wherein the designated maximum diameter is equal to or less than about 13 feet 6 inches. 
     
     
         17 . The wind turbine tower according to  claim 15 , wherein each of the axial sections has a weight no greater than a designated maximum weight, the designated maximum weight being equal to or less than a weight permitted for rail transport; and
 wherein each of the axial sections have a length no greater than a designated maximum length, the designated maximum length being equal to or less than a length permitted for rail transport.   
     
     
         18 . The wind turbine tower according to  claim 15 , wherein the plurality of axial sections include a bottom section, at least a portion of said bottom section having the at least one reverse taper portion, and wherein the at least one reverse taper portion is angled off of vertical by an angle θ, wherein θ is between about one and about five degrees. 
     
     
         19 . The wind turbine tower according to  claim 18 , said bottom section comprising:
 a plurality of substantially cylindrical stacked cans; and   at least one reverse taper can having a diameter that increases with increasing height, the at least one reverse taper can disposed at or near a bottom of said wind turbine tower.   
     
     
         20 . The wind turbine tower according to  claim 19 , said bottom section comprising at least two reverse taper cans disposed at or near a bottom of said wind turbine tower.