 To supplement the preliminary offshore bombardment and aerial assaults, some of the landing craft were equipped with artillery and anti-tank guns to provide close supporting fire.The Allies had decided not to immediately attack any of the heavily protected French ports and two artificial ports, called Mulberry harbours, were designed by COSSAC planners.Each assembly consisted of a floating outer breakwater, inner concrete caissons (called Phoenix breakwaters) and several floating piers.