A turbine shaft for use in a gas turbine engine, the 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, characterised by one or more shielded elliptical orifices, at least one shielded elliptical orifice comprising: an elliptical orifice in the tubular body extending from the outer surface to the inner surface, the elliptical orifice includes a major axis extending from a first side of the elliptical orifice to a second side of the elliptical orifice; a first shielding orifice in the tubular body extending from the outer surface to the inner surface, the first shielding orifice having a first axis collinear to the major axis, wherein the first shielding orifice is located at first distance away from the first side; and a second shielding orifice in the tubular body extending from the outer surface to the inner surface, the second shielding orifice having a second axis collinear to the major axis, wherein the second shielding orifice is located at second distance away from the second side, wherein the elliptical orifice is located in between the first shielding orifice and the second shielding orifice, wherein the major axis is oriented at an angle of about 45° away from a second longitudinal axis on the outer surface, the second longitudinal axis being parallel to the first longitudinal axis. 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, characterised by one or more shielded elliptical orifices, at least one shielded elliptical orifice comprising: an elliptical orifice in the tubular body extending from the outer surface to the inner surface, the elliptical orifice includes a major axis extending from a first side of the elliptical orifice to a second side of the elliptical orifice; a first shielding orifice in the tubular body extending from the outer surface to the inner surface, the first shielding orifice having a first axis collinear to the major axis, wherein the first shielding orifice is located at first distance away from the first side; and a second shielding orifice in the tubular body extending from the outer surface to the inner surface, the second shielding orifice having a second axis collinear to the major axis, wherein the second shielding orifice is located at second distance away from the second side, wherein the elliptical orifice is located in between the first shielding orifice and the second shielding orifice, wherein the major axis is oriented at an angle of about 45° away from a second longitudinal axis on the outer surface, the second longitudinal axis being parallel to the first longitudinal axis. an elliptical orifice in the tubular body extending from the outer surface to the inner surface, the elliptical orifice includes a major axis extending from a first side of the elliptical orifice to a second side of the elliptical orifice; a first shielding orifice in the tubular body extending from the outer surface to the inner surface, the first shielding orifice having a first axis collinear to the major axis, wherein the first shielding orifice is located at first distance away from the first side; and a second shielding orifice in the tubular body extending from the outer surface to the inner surface, the second shielding orifice having a second axis collinear to the major axis, wherein the second shielding orifice is located at second distance away from the second side, wherein the elliptical orifice is located in between the first shielding orifice and the second shielding orifice, wherein the major axis is oriented at an angle of about 45° away from a second longitudinal axis on the outer surface, the second longitudinal axis being parallel to the first longitudinal axis.