The imposing Hamburg headquarters building of Hapag-Lloyd, overlooking a stretch of water on the city’s Ballindamm, is more than just another corporate building for the city.

As the global base of a major container line, it is the visible tip of a vast iceberg of maritime businesses in Hamburg, mainly the funds – known as KGs from kommanditgesellschaft, the German name for the funds’ legal structure – that own a high proportion of the world’s shipping fleet.