Impingement cooling of turbine blades or vanes

A turbine assembly comprising:

• a basically hollow aerofoil having at least a cavity with at least an impingement tube, which is insertable inside the cavity of the hollow aerofoil and is used for impingement cooling of at least an inner surface of the cavity, and with at least a platform, which is arranged at a radial end of the hollow aerofoil, and with at least a cooling chamber used for cooling of at least the platform and which is arranged relative to the hollow aerofoil on an opposed side of the platform and wherein the cooling chamber is limited at a first radial end from the platform and at an opposed radial second end from at least a cover plate, and
• wherein the impingement tube is being formed from a leading piece and a trailing piece both being inserted in said at least one cavity, wherein the leading piece is located towards a leading edge of the hollow aerofoil and the trailing piece is located viewed in direction from the leading edge to the trailing edge downstream of the leading piece and wherein the leading piece of the impingement tube extends in span wise direction at least completely through the cooling chamber from the platform to the cover plate and wherein the trailing piece of the impingement tube terminates in span wise direction at the platform.