A rotor blade for a gas turbine, the rotor blade being configured for use within a row of samely configured rotor blades attached to and circumferentially spaced about a rotor disc, the rotor blade further including: an airfoil defined between a concave pressure face and a laterally opposed convex suction face, wherein the pressure face and the suction face extend axially between opposite leading and trailing edges (28, 29) and radially between an outboard tip and an inboard end that attaches to a root configured for attaching the rotor blade to the rotor disc wherein the airfoil comprises a twisting configuration in which the airfoil is constructed having a twist about a longitudinal axis as the airfoil extends radially between the inboard end and the outboard tip; and a midspan shroud comprising a pressure wing extending from the pressure face of the airfoil and a suction wing extending from the suction face of the airfoil; wherein the pressure wing and the suction wing of the midspan shroud are configured so to cooperatively form an interface between installed neighboring ones of the rotor blades within the row of samely configured rotor blades; wherein the interface comprises: a pressure wing contact face disposed on the pressure wing that opposes across a gap a suction wing contact face disposed on the suction wing, wherein an untwisting of the airfoil causes relative movement between the pressure wing contact face and the suction wing contact face; and a predetermined offset between the pressure wing contact face and the suction wing contact face, characterised in that the predetermined offset of the interface comprises a radial offset, the radial offset comprises the pressure wing contact face being offset from the suction wing contact face in an outer radial direction, the predetermined offset being configured for desirably aligning the pressure wing contact face against the suction wing contact face when an expected operating condition closes of the gap such that contact therebetween results, wherein the expected operating condition comprises one causing the twisting configuration of the airfoil to untwist sufficiently to close the gap; and wherein the expected operating condition comprises a predetermined rotational speed of the rotor blade within the turbine. an airfoil defined between a concave pressure face and a laterally opposed convex suction face, wherein the pressure face and the suction face extend axially between opposite leading and trailing edges (28, 29) and radially between an outboard tip and an inboard end that attaches to a root configured for attaching the rotor blade to the rotor disc wherein the airfoil comprises a twisting configuration in which the airfoil is constructed having a twist about a longitudinal axis as the airfoil extends radially between the inboard end and the outboard tip; and a midspan shroud comprising a pressure wing extending from the pressure face of the airfoil and a suction wing extending from the suction face of the airfoil; wherein the pressure wing and the suction wing of the midspan shroud are configured so to cooperatively form an interface between installed neighboring ones of the rotor blades within the row of samely configured rotor blades; wherein the interface comprises: a pressure wing contact face disposed on the pressure wing that opposes across a gap a suction wing contact face disposed on the suction wing, wherein an untwisting of the airfoil causes relative movement between the pressure wing contact face and the suction wing contact face; and a predetermined offset between the pressure wing contact face and the suction wing contact face, characterised in that the predetermined offset of the interface comprises a radial offset, the radial offset comprises the pressure wing contact face being offset from the suction wing contact face in an outer radial direction, the predetermined offset being configured for desirably aligning the pressure wing contact face against the suction wing contact face when an expected operating condition closes of the gap such that contact therebetween results, wherein the expected operating condition comprises one causing the twisting configuration of the airfoil to untwist sufficiently to close the gap; and wherein the expected operating condition comprises a predetermined rotational speed of the rotor blade within the turbine. a pressure wing contact face disposed on the pressure wing that opposes across a gap a suction wing contact face disposed on the suction wing, wherein an untwisting of the airfoil causes relative movement between the pressure wing contact face and the suction wing contact face; and a predetermined offset between the pressure wing contact face and the suction wing contact face, characterised in that the predetermined offset of the interface comprises a radial offset, the radial offset comprises the pressure wing contact face being offset from the suction wing contact face in an outer radial direction, the predetermined offset being configured for desirably aligning the pressure wing contact face against the suction wing contact face when an expected operating condition closes of the gap such that contact therebetween results, wherein the expected operating condition comprises one causing the twisting configuration of the airfoil to untwist sufficiently to close the gap; and wherein the expected operating condition comprises a predetermined rotational speed of the rotor blade within the turbine.