Abstract: A power cable including: a conductor, an insulation system including an inner semiconducting layer arranged around the conductor, an insulation layer arranged around the inner semiconducting layer, and an outer semiconducting layer arranged around the insulation layer, an elastic mechanical support layer arranged around the outer semiconducting layer, a metallic water blocking layer having a longitudinal weld seam, the metallic water blocking layer being arranged around the mechanical support layer, wherein the mechanical support layer is permanently thermally expanded radially as a result of a heat treatment process, thereby mechanically supporting the metallic water blocking layer.