Shank shape for a turbine blade and turbine incorporating the same

A turbine includes a turbine wheel having a plurality of buckets, each of the buckets including a bucket airfoil, a bucket dovetail to connect the bucket to a turbine wheel and a shank shape to connect the airfoil to the bucket dovetail, the shank having an uncoated nominal profile including a concave, pressure side, substantially in accordance with Cartesian values of X, Y and Z′ set forth in Table I wherein the Z′ values are non-dimensional values in a range from 0 to 1 convertible to Z distances in inches by multiplying the Z′ values by shank height in inches, and a convex, suction side, substantially in accordance with Cartesian values of X, Y and Z′ set forth in Table II wherein the Z′ values are non-dimensional values in a range from 0 to 1 convertible to Z distances in inches by multiplying the Z′ values by the shank height in inches. The X and Y are distances in inches which, when connected by smooth continuing arcs, define a shank profile section at each distance Z, the profile sections being joined smoothly with one another to form a complete shank shape.