Kentledge

Kentledge refers to a system of weighted blocks used to provide ballast for ships. These blocks are typically made of iron or concrete and are placed in the lower parts of a ship's hull to increase its stability. Ships, especially those that carry cargo which may be unevenly distributed or removed during a voyage, require kentledge to maintain a safe and upright position in the water. Without adequate ballast, a vessel can become unstable, increasing the risk of capsizing.

The amount and placement of kentledge are crucial for a ship's seaworthiness. Naval architects calculate the precise weight and distribution needed based on the ship's design, its intended cargo, and expected operational conditions. Kentledge can be temporary or permanent. Temporary kentledge is often used during the construction or repair of a ship, or for vessels that do not regularly carry cargo that provides sufficient natural ballast. Permanent kentledge is incorporated into the ship's structure.

In modern shipping, while water ballast systems are widely used, kentledge can still be employed, particularly in specialized vessels or for specific operational needs. The use of kentledge is a historical practice that has evolved with shipbuilding technology. It remains an important concept in naval architecture and maritime safety, ensuring that vessels can operate safely in various sea conditions. The term itself likely derives from older nautical terminology.