ARGE Rheindüker

A 110 kV grid reinforcement was installed in the Cologne districts of Niehl and Mülheim as part of the extension to the Niehl combined heat and power plant. The planned line will run on the left bank of the Rhine from the Niehl 3 combined-cycle plant, passing along the streets Am Molenkopf and Kuhweg and under the Mülheim bridge.

The aim is for the pipeline to then cross the Rhine in a tunnel parallel to the bridge at Rhine km 691 and be laid on land again from the Mülheim fairground through the districts of Mülheim and Kalk to connect to the Kalk substation.

The scope of services entailed the construction of the Rhine culvert 644 m in length using a DN 2800 micro-tunnel machine with flushing conveyor and compressed air cushion (mixed shield) by SONNTAG Baugesellschaft mbH & Co. KG. Work included construction, backfilling and partial deconstruction of the start and end pits with watertight shoring. Start pit down to about 11.5 m beneath ground level. End pit down to about 22.5 m beneath ground level.

SWR installed DN 200 PP-HM protective ducts for 2 x 110 kV systems, including an accompanying cable and shielding conductor, a district heating pipeline feed (SMR DN 700/1000 PE) and return line (SMR DN 700/900 PE), a DN 400 high-pressure gas line, DA 110 PVC-U protective ducts for other media lines, including pull-in of multiple pipes. A base was constructed of thermal conductive concrete and the entire cross section filled after district heating and gas pipeline were fed in.

Once the protective ducts and base concrete were installed, the 110 kV systems were delivered and fed in on site.