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Distance Heating Tunnel Copenhagen

In May 2005 the KFT-JV consisting of Hochtief Construction AG and MT Højgaard, each with a 50 %, were awarded the contract to build the Copenhagen distance heating tunnel. The scheme is located within the City of Copenhagen and serves to expand and renew the existing distance heating distributor network belonging to the public energy provider as well as connecting up a newly constructed power station in the suburb of Amager. After building the roughly 3.9 km long tunnel, distance heating utility lines were installed in it by a different contractor. Water as well as water vapour is to be transported at temperatures of up to 300° C. The tunnel is largely located in homogeneous limestone with interbedded flint of varying thickness below the groundwater level and was driven by a tunnelling machine with earth pressure balance (EPB-TBM). The tunnel lining took the form of 30 cm thick steel fibre reinforced concrete segments. A fast-acting two component mortar was applied in view of the uncoupled segmental lining as well as the geological marginal conditions. The tunnel excavation began at Amagervaerket (access shaft) towards Adelgade. Here the TBM was rotated by 60° and the second tunnel drive in the direction of Fredensgade (target shaft) started. Apart from building the tunnel with 4.2 m internal diameter, three up to 45 m deep shafts were produced, in which later on the technical centres for operating the facility are to be located. To execute the work on the shafts, groundwater maintenance and cleaning units with pumping, preparation and Infiltration rates of up to 200 m³/h were installed. The excavation work was carried out protected by a 1.2 m thick bare pile wall integrated in the limestone extending down to a depth of as much as 25 m. Below the bore piling excavation proceeded successively with shotcrete support. Start-up tunnels with a larger cross-section and lengths varying from 12 to 20 m were produced by the NATM for entering and exiting with the tunnelling machine and for subsequent pipeline construction. The biggest challenge for tunnelling technology was represented by the flint that occurred in thickly stratified layers with strengths of up to 500 MPa. The cooperative approach prevailing between those involved is worthy of mention. A partnering model was agreed on by all those taking part (client, contractor and consulting engineer), which contained bonus arrangements for adhering to the prescribed cost frame as well as for attaining scheduled milestones. In hindsight this model proved to be a success for all those involved. The tunnel became fully operational in August 2009 after the first part-section from the access to the target shaft was commissioned at the beginning of 2009.


  • Country: Denmark
  • Region: Copenhagen
  • Tunnel utilization: Utility
  • Type of utilization: Distance Heating Tunnel
  • Client: Københavns Energi
  • Consulting Engineer: COWI
  • Contractor: Københavns Fjernvarme Tunnel Joint Venture (KFT-JV)/MT Hrajgaard, Hochtief Construction AG
  • Main construction method: Trenchless
  • Type of excavation: Shield machine (SM)
  • No. of tubes: 1
  • Tunnel total length: 3,900 m
  • Cross-section: 4.20 m (internal diameter), 5.13 m (external diameter)
  • Contract Volume: approx. 60 mill. euros
  • Construction start/end: May 2005 till August 2009
  • Opening: August 2009