The British Empire had a way of killing two birds with one stone. Instead of building penitentiaries, they sent shiploads of convicted criminals to far-flung colonies, first America and then Australia, thus relieving Britain of their unwelcome presence and providing cheap labor for their colonies. They also reused large ships that were no longer capable of long voyages as prisons. These were called prison hulks, and convicts could be held on them for up to seven years awaiting transport. This became a particular problem between 1776, when transports to America stopped, and the first prison transport to Australia in 1787. Serious overcrowding continued long after as convicts were gradually sent elsewhere.
In 1801, London police magistrate Aaron Graham was charged with reporting on conditions in the prison hulks. He found that private contractors had been running them, with deplorable results. There were no standards for the treatment of prisoners, even for the amount of food they were given. The death rate was high, the hospitalization rate was higher, and the staff turned over often due to inadequate pay. Graham instituted reforms, including a government takeover of the ships' management, and posted daily food rations. The prisoners were to be given oatmeal and barley for breakfast and supper, and bread, meat, cheese, and beer for midday dinner. That sounds like a recipe for scurvy and other deficiencies, but it was a lot better than they had before the reform, and these were men who worked loading and unloading ships all day. Read about the conditions aboard prison hulks at the British National Archives. -via Strange Company