An airfoil comprising: a leading edge and a trailing edge ; a suction surface and a pressure surface , the suction surface and the pressure surface both extending axially between the leading edge and the trailing edge , as well as radially from a root section to a tip section of the airfoil ; a cooling passageway located between the suction surface and the pressure surface ; a plurality of axially elongated oblong pedestals arranged in a first radial column , wherein each of the plurality of oblong pedestals includes a curved axially upstream end and a blunt axially downstream end ; a plurality of downstream pedestals arranged into a second radial column ; and a plurality of upstream cylindrical pedestals arranged in a third radial column , a fourth radial column and a fifth radial column , wherein: the curved axially upstream end and the angular axially downstream end are connected by two substantially parallel sides , or each of the plurality of oblong pedestals tapers from the curved axially upstream end and the angular axially downstream end ; characterised in that the plurality of oblong pedestals connect the suction surface to the pressure surface at the trailing edge of the airfoil , and the downstream end terminates at the trailing edge of the airfoil ; and both the plurality of oblong pedestals and the plurality of downstream pedestals are more densely packed than the plurality of cylindrical pedestals are packed in the third column , the fourth column and the fifth column . a leading edge and a trailing edge ; a suction surface and a pressure surface , the suction surface and the pressure surface both extending axially between the leading edge and the trailing edge , as well as radially from a root section to a tip section of the airfoil ; a cooling passageway located between the suction surface and the pressure surface ; a plurality of axially elongated oblong pedestals arranged in a first radial column , wherein each of the plurality of oblong pedestals includes a curved axially upstream end and a blunt axially downstream end ; a plurality of downstream pedestals arranged into a second radial column ; and a plurality of upstream cylindrical pedestals arranged in a third radial column , a fourth radial column and a fifth radial column , wherein: the curved axially upstream end and the angular axially downstream end are connected by two substantially parallel sides , or each of the plurality of oblong pedestals tapers from the curved axially upstream end and the angular axially downstream end ; characterised in that the plurality of oblong pedestals connect the suction surface to the pressure surface at the trailing edge of the airfoil , and the downstream end terminates at the trailing edge of the airfoil ; and both the plurality of oblong pedestals and the plurality of downstream pedestals are more densely packed than the plurality of cylindrical pedestals are packed in the third column , the fourth column and the fifth column . the curved axially upstream end and the angular axially downstream end are connected by two substantially parallel sides , or each of the plurality of oblong pedestals tapers from the curved axially upstream end and the angular axially downstream end ; characterised in that the plurality of oblong pedestals connect the suction surface to the pressure surface at the trailing edge of the airfoil , and the downstream end terminates at the trailing edge of the airfoil ; and both the plurality of oblong pedestals and the plurality of downstream pedestals are more densely packed than the plurality of cylindrical pedestals are packed in the third column , the fourth column and the fifth column . <EOS>