The reason is that as the size of ship increases, so the specific transport cost per ton of cargo drops, the reasons for which are explained elsewhere.
Klnobangela kukuba njengokuba inqanawa ikhula ngokobungakanani, zikwanjalo iindleko zothutho ngokwetoni yomthwalo ukuya zisihla, izizathu zichazwa kwenye indawo.