A turbine shaft comprising: a tubular body having an outer surface and an inner surface opposite the outer surface, the inner surface defining a hollow chamber within the tubular body, wherein the tubular body includes a first longitudinal axis concentric to the tubular body; and one or more shielded elliptical orifices, at least one shielded elliptical orifice comprising: an elliptical orifice in the tubular body including a major axis extending from a first side to a second side of the elliptical orifice, wherein the major axis is oriented at an angle parallel with a torque field of the tubular body; a first shielding orifice in the tubular body having a first axis collinear to the major axis; and a second shielding orifice in the tubular body having a second axis collinear to the major axis, wherein the elliptical orifice is located in between the first and second shielding orifice.