The past years have shown that preventive flood protection in the city of Cologne has gained greater importance, due to the vicinity of the Rhine.
The basis of performance was the design of closing structures on eight existing tunnel portals of Cologne’s city railway.
The closing structures differ from each other due to the relevant site conditions. The structures were designed both as flap gates and as mitre gates.
The flap gates are gates positioned horizontally on the top edge of the tunnel and may be swivelled and lifted into their end positions by means of electrical lifting cylinders.
The mitre gate structure consists of two gate leaves permanently located on the side walls of the tunnel; for the closing procedure, they are lifted, closed and lowered by means of electrical cylinders. The gate stop is located, and the force transfer takes place in the existing tunnel structure.

Special services:
- Cooperation in project control
- Surveying
- Management information
- Construction material inspection
- Expert opinion on noise emissions
- Engineering design evaluation
- Risk assessment (acc. to machinery directive)
- Expert opinion on through-connection
- Preparation of technical documentation
- Recalculation of tunnel structures
- Routing plans
- Urban design plans