By 1977 there were, however, more than 500 ships with a deadweight capacity of more than 2.3 million tons that can be loaded and unloaded by roll-on/roll-off methods.
Ngonyaka ka1977, kwakukho iinqanawa ezingaphezu kwamakhulu amahlanu ezinobunzi obuminzi obungaphezulu kwe sibini sinesiqingathu zamawaka eetoni ezinokuthwalwa kwaye zithulwe ngokwenqanawa eziqhutywa ekuqaleni kohambo ngenqanawa kwaye zithulwe ekugqibileni kwalo.