Human cargo has been a form of exploitation for centuries, from the Slave Trade and the transporting of convicts to penal colonies in North Carolina and later, Australia, to the more recent Syrian refugee crisis. The ship itself is an all-in-one precursor to the factory, the prison, and the mental asylum. "A floating piece of space", "the great instrument of economic development” and paradoxically “the greatest reserve of the imagination", to quote Foucault.
The 'Coffin' Ship in particular was part of a lucrative business, much in the same way as bodysnatching, both operating at their height in the nineteenth century, and literally in the same sense: using bodies as commerce. Used during the Irish potato blight and the Clearances, the 'coffin' ship transported people across the Atlantic (although initially to port cities such as Glasgow and Liverpool) and was so-called due to the many who perished on board from typhus and cholera, so much so, it was rumoured that sharks could smell death and would follow the ships, with the bodies being thrown overboard in transit. The authorities thought of the shipping as a cheaper way to alleviate the problem back home, however, it was only ever going to be for those who could afford to pay the fare, because, unfortunately, there's always money to be made in times like these. The very poor, on the other hand, were left behind.