A detail from a pen-and-ink drawing shows the captain of a slave ship and the trade goods being brought ashore. The long crate probably carries muskets, and is marked 'Bristol'.

The Southwell made two slaving voyages, in 1746 and 1748, both organised by Michael Beecher & Co. The captain for both voyages was John Barickenridge. On the first voyage, he delivered 629 enslaved Africans to Jamaica, on the second 284 to Virginia. This suggests, given he had orders to buy 500, either a shortage of people to buy in Africa at that time or a high death rate on the transatlantic crossing.

Detail from The Southwell Frigate Tradeing on ye Coast of Africa, by Nicholas Pocock