A turbine blade is provided comprising: an airfoil including upper and lower ends; a root coupled to the airfoil lower end; a shroud coupled to the airfoil upper end; and at least one sealing rail extending radially outwardly from an upper surface of the shroud and extending generally along a circumferential length of the shroud. The sealing rail may comprise a mid-section, opposing end sections and at least one intermediate section located between the mid-section and one of the opposing end sections. An axial thickness of the rail may vary.