What is ballast?

Originally, ballast was any heavy material, such as sand, gravel, stone, etc., carried by a vessel to ensure stability and avoid capsizing. When a vessel discharges its cargo, it needs to take on ballast to stabilize her when sailing. In the past, one of the hazards of improperly stored ballast was the threat of it shifting in heavy weather, causing many a vessel to founder. Ballast tanks are compartments within a boat or ship that holds water and can be filled or emptied in order to adjust the amount of ballast force. The basic concept of the ballast tank can be seen in many forms of aquatic life, such as the blowfish, and has been used many times by humans to serve a variety of purposes. In 1849, Abraham Lincoln, then an Illinois attorney, patented a ballast-tank system to enable cargo vessels to pass over shoals in North American rivers.