Abstract: An air cooled steam condenser for condensing exhaust steam from a steam turbine including a steam delivery manifold, first and second bundles of aligned elongated tubes extending downwardly at an angle to the axis of the steam delivery manifold, each bundle containing a plurality of elongated tubes having exterior aluminum fins, an exterior coating of aluminum and an interior cladding of stainless steel having a thickness between about 45 and 125 microns, wherein a height measured between the rounded ends of the tubes is greater than 220 mm or between 220 and 280 mm and the length of the tubes is greater than 11 m, preferably between 12 and 14 m or greater.