Road project affects district heating pipes in Jordbro
Powerful equipment is needed to get a 900 mm diameter metal pipe through rock. The longest stretch through rock is 64 metres.
Road no. 259 south of Stockholm has been marred by accidents for years. When the Swedish Transport Administration started road and safety improvements in the area, it affected several of Vattenfall's district heating pipes. New pipes are therefore being laid, requiring hammer drilling.
The project is called 'Tvärförbindelse Södertörn' (the Södertörn link) and includes a new road with separate roadways for each direction, separate paths for pedestrians and bikes and new bridges. The new roads will run close to Vattenfall's CHP station in Jordbro and affect many of the outbound district heating pipes from the plant.
"When the Swedish Transport Administration builds new major roads, they don't want pipes running under them for district heating, electricity, fibre cables etc. That's to avoid having to dig them up in the future if they need repair," explains Johan Enström at FVB, the Project Manager on this project.
Vattenfall have to lay new pipes in the area because of the Tvärförbindelsen Södertörn project, and the three places where they cross the major roads have to be safe and protected.
"Hammer drilling is needed to get under the roads. This drilling technique is perfect for large bore pipes, and we are using DN 600 with an outer mantle of 900 mm diameter. Another advantage of hammer drilling is that it also works in rock, which is the case with this project," adds Johan Enström.
Hammer drilling involves using a compressor to give the drill crown enough force to drive it through the ground or rock at the same time as laying a conduit pipe. The conduit pipe is laid so that the pipes inside it can be replaced without having to damage the road surface above. This project involves stretches of 42 metres and 64 metres respectively, which is relatively long due to the road having four lanes.
One of the drillings is now finished and the district heating pipes are in place. The next will be done later this year. We also have to cross another road, but hammer drilling will not be required as sections of the road can be closed off at night for the work to be done."
The project should be completed during the winter of 2025.
For more details, contact:
Johan Enström: 026-14 02 20
