ADIt

An adit is a horizontal or nearly horizontal passage leading into a mine from the surface, primarily used for access, drainage, or ventilation. Unlike vertical shafts, adits enter the terrain at ground level or gently incline and run into the ore body or workings. They are designed to provide a gravity-driven path for water to drain from the mine and to supply air for working galleries, often also allowing ore or waste to be transported to the surface.

Construction and use vary by mine, but adits are typically driven through rock by drilling and blasting or mechanical methods and then supported with timber, steel, or concrete linings where needed. Drainage adits collect groundwater and channel it to discharge points, while intake or ventilation adits provide a fresh-air supply to prevent gas buildup and improve working conditions. In many mines, a single adit serves multiple functions, and additional shafts or winzes may connect deeper levels to the adit system.

Relation to shafts: adits are horizontally oriented and commonly require less pumping than vertical shafts to remove water, though they may still need pumping at times. In contrast, shafts provide vertical access to deeper levels. The term adit is used worldwide, with historical significance in mining districts such as those in Europe, the Americas, and parts of Asia.

Today, many adits survive as historical features, while some remain in active use for drainage, water management, or tourism, illustrating the evolution of mining technology and safety practices.