The Middle Passage was the most infamous route of the triangular trade. This voyage carried Africans across the Atlantic Ocean. Captains of slave ships were known as either "loose packers" or "tight packers," depending on how many slaves they crammed into the space they had. However, most ships were "tight packers" (especially those in the 18th century); life for the slaves on these ships was extremely uncomfortable. Slaves were taken from the holding forts, shackled together impairs with leg-irons and carried to the ships in the dugout canoes. Once they were aboard, they were branded with red-hot iron, like cattle, to show who owned them and their clothes removed.
Slaves were housed in the ships as if they were cargo. Men were kept in chains while women and children were allowed to go free, they laid on specially built shelves with about 0.5 meters of vertical space. As long as the slaves were in the hold, they had to remain lying on their backs.
There were times when the captain of some ships would allow the slaves to be brought up out their dungeon area. However, the men's legs were linked to a chain running down the center of the ship's deck to prevent them from jumping overboard. While on deck a good captain would have the slaves washed down with warm vinegar and scrubbed and some did not bother in rough weather (would not allow the slaves out at all).
These conditions allowed for sickness and disease flourish and the slaves. The heat in the hold could be over 30 degrees and the slave would have no toilet or washing facilities, causing many to die. They were forced in these conditions for 6 weeks to 3 months depending on the length of the voyage. Other causes of death...