In December 2019, Tallinna Vesi announced a tender for the emergency repair of the sewerage pipe of Kadaka Boulevard. In August of the same year, there was a large-scale accident in this section. Subsequent studies showed that the 900-meter pipe was in very poor technical condition. Repairs were only possible if no sewage flowed in the pipe. Therefore, a 1.2 km temporary pipe (d 600mm) had to be built, through which the sewage was diverted around the section to be repaired during the repair work.
- 5 pcs. Hidrostal F10K-H01 990m3/h
- 3 pcs. control panel with frequency converter
- 4 pcs. BUSCH RC 004 F vacuum pump
- 2 pcs. generator 320kW with a control module
- 1 pcs. fuel tank 2900l to the main generator
- 1 pcs. 2400l heated fuel tank for the back-up generator
- 3 pcs. 4,5m high D600 metal pipe bridge
- 1200 m D600 metal piping
To install the pump, one of the wells on the route was opened. After that, the pumping station suction pipe with level sensors was placed, from which the control panels control the start and productivity of the pump consisting of five Hidrostal F10K-H01 dry mode submersible pumps. In addition, the control panels also send out SMS alarms if something happens to the pumps or the water level in the piping falls below a certain minimum level.
The power supply of the pump was based on two 320kW diesel generators, which were equipped with a control module that automatically starts the backup generator in case of a technical failure or shutdown of the main generator.
Due to the work taking place during the winter months, the backup generator was additionally equipped with a battery charger, coolant, and engine oil heater, and the heating was also installed on the fuel line and fuel tank.
The pumping line intersected between the pumping station and the final well with 1 intersection and 2 streets, the closure of which was not authorized by the local government. Therefore, during the construction of the line, 3 pipeline bridges had to be built, which crossed the carriageway at a height of 4.5 m from the road surface, to ensure the necessary passage for rescue equipment and trucks as well. The first 2 pipe bridges were also equipped with vacuum valves to prevent the siphoning effect, as the ground drop from the pump to the end well was 18 m.
Project in numbers
- The time for providing the service, including installation and dismantling, was 70 calendar days
- 8 employees were involved
- 2 trucks with hydraulic cranes, a towed basket lift and 2 cranes for the installation of pipe bridges
- 3 weeks planning
- 2,5 weeks installation
- 14 semitrailers with materials and equipment