loodlijn
Loodlijn is a Dutch term that can refer to two related measuring tools, both depending on a weight and the force of gravity to establish a reference line. The most common meaning is plumb line, a line with a weight (often called a plumb bob) at its end. When suspended from a fixed point, the weight pulls the line taut and the line aligns with the vertical. This vertical reference is used to check whether surfaces or structures are truly vertical, to transfer elevations from a known point to another, and to align elements such as walls, columns, or door frames. While modern construction frequently relies on spirit levels and laser devices, the plumb line remains a simple, reliable tool in settings without power or where a direct vertical reference is needed.
The second sense, more historical and nautical, refers to a depth-sounding line. This is a line marked
Etymology derives from lood (lead) and lijn (line). In practice, loodlijn commonly denotes the plumb line, while