Lock

A gated section of a waterway, such as a canal or river, designed to raise or lower vessels between stretches of water at different levels.

A lock is an essential feature of many inland waterways, enabling vessels to navigate areas where the water level changes due to natural gradients, tides, or man-made structures such as dams. Typically, a lock consists of a chamber with gates at either end and sluices or valves to control the flow of water. When a vessel enters the lock, the gates are closed, and water is either added to or drained from the chamber to match the level of the waterway the vessel is moving towards. Once the water levels are equalised, the opposite gates are opened, allowing the vessel to continue its journey.

Locks are particularly common in canal systems, where they overcome elevation changes that would otherwise make navigation impossible. They vary in size and complexity, from small manually operated locks on narrow canals to large, mechanised locks capable of accommodating ocean-going ships. The operation of a lock requires careful coordination to ensure the safety of vessels and the efficiency of water usage. Some locks are staffed by lock keepers, while others are self-operated by boaters.

The invention of locks revolutionised inland navigation, enabling the development of extensive canal networks that facilitated trade and transportation. Modern locks continue to play a vital role in connecting waterways, supporting both commercial shipping and recreational boating.