This derives from the difference in the specific cost (i.e. the cost per ton of cargo over a given route) of transporting cargo by the specialised ship as opposed to transporting it by a universal ship.
Le nto isuka kumahluko wentengo okanye (ixabiso letoni yomthwalo ngokwexesha elinikoweyo) ixabiso lokuhanjiswa kwemithwalo ngenqanawa lokuthutha ngokuchasene nenqanawa yokuthutha iimpahla jikelele.