Lohnde safety gate on the Mittelland Canal

Where the Mittelland Canal crosses deep river valleys on a dam, there are security gates at the beginning and end of the dam section. By closing the gates, the duct in this section can be drained for inspections. The gates are operated by the operations center in Minden, the gate is checked once a month with a test run.

The security gate on the Mittelland Canal between Altgarbsen and Havelse is 15 meters high and the gate alone weighs 65 tons. It prevents, e.g. in the event of a dam bursting, water from escaping from the entire canal.

A safety gate is a structure used to securely close a navigation channel in the area of a causeway or a canal bridge, i.e., sections where the water level is above the surrounding terrain.[1] By lowering a steel closure body adapted to the canal bed, the entire canal section is prevented from leaking in the event of damage (e.g., a dam break) and the flooding of the surrounding terrain is reduced. There are safety gates that close automatically as soon as the canal water level has dropped by a certain amount.Safety gates can also be used to drain canal sections, e.g., for inspections or to repair damage to the canal bed seal.