Roller dam

A rolling weir is a movable weir. The technique of rolling weir was developed by the German engineer Max Carstanjen (1856-1934) for the fortification of Schweinfurt. It was patented and built by Maschinenfabrik Augsburg -Nürnberg and 1902 first put into service on the so-called bottom outlet. It is also referred to as a drum weir.

The weir consists, depending on the width of the water body, of two or more military posts, in whose flanks the cylindrical hollow rollers are mounted height adjustable and rotatable by means of a chain drive. The tours are usually conducted inclined to reduce the operating forces. Outside the guide rollers are usually eccentric, so that can be controlled by raising or lowering while turning the jam of the upper water and the water flow above and below the weir.

Unlike the needle weirs rarely used rolling weirs are significantly easier to use and much more powerful. You can keep a higher water pressure and so a higher back - thus, a greater depth of water - produce, what, where appropriate, also allows greater distances between the barrages. When removing the waterways since the 1920s, the barrages were therefore mainly equipped with rolling weirs. Rolling shutters but today increasingly displaced on waterways the most commonly used, are inflatable dams.

Through the world's largest rolling weir has the system Lock and Dam No. 15 in the American rock Iceland.