Bravida has secured an approximately SEK157 million contract to install and commission technical systems in Svenska kraftnät’s Citylink electricity tunnel beneath Stockholm. Working for the Hochtief Implenia joint venture, the engineering contractor will provide electrical, heating and plumbing, ventilation and control installations along the Anneberg–Skanstull section of the 400 kV transmission programme.
Bravida signed the agreement with the Hochtief Implenia joint venture in September 2026 and disclosed the contract details on 22 October. The contract was included in the company’s third-quarter order intake, while site work started during October. The installation programme is expected to run until June 2028, according to the contractor.
Bravida describes the work area as a tunnel approximately 13 kilometres long, with its deepest point around 100 metres beneath the surface. Svenska kraftnät gives the route’s more precise length as 13.4 kilometres, between Anneberg and Skanstull, and reports a depth varying from approximately 50 to 100 metres. The two descriptions are consistent, using different levels of precision.
The transmission operator identifies the route as a connection between substations in Danderyd and southern Stockholm, passing underneath central urban districts. It is designed to carry 400 kV alternating current cables as part of the wider Citylink network. The purpose is to create another high-capacity path across the metropolitan area, allowing electricity to be supplied from more than one direction as the network develops.
The tunnel, which Svenska kraftnät describes as approximately five metres in diameter, was excavated using a tunnel boring machine. The transmission operator specifies six ventilation shafts along the route, while Bravida identifies restricted access and long transport distances between work areas as particular construction difficulties. Deliveries, equipment movement and the sequence of installation teams all have to be coordinated within that limited underground space.
Bravida says the project may employ up to 12 salaried technical and management staff and 40 installers at peak activity. It specifically identifies restricted access and long movements between work areas among the delivery constraints. Those conditions affect the sequencing of electrical, mechanical and control installations, especially where multiple disciplines need access to the same section of tunnel.
Bravida’s package is for ancillary electrical and mechanical installations and their commissioning. It is not an award to manufacture or lay the 400 kV transmission cables themselves. Ventilation, plumbing and other support systems must work alongside the cable route and the tunnel’s access arrangements, but the contractor has not published the detailed equipment list or the architecture of its control systems.
Where several disciplines work inside a narrow tunnel, installation sequencing has a direct effect on access and safety. Ductwork, cable supports, pipework and control equipment all occupy physical space, and provision must be made for subsequent inspection and maintenance. The project’s shafts and access routes form part of those constraints; Bravida has not provided component-level drawings from which particular layout decisions could be confirmed.
Commissioning will also require the contractor to test its installed systems and their interfaces rather than treating every subsystem as an isolated assembly. The release confirms responsibility for commissioning but gives no project-specific acceptance thresholds, ventilation duty points or energisation schedule. The award should therefore not be interpreted as evidence that the transmission route is ready for service.
The work is part of Svenska kraftnät’s Stockholm Ström programme, undertaken with regional network companies Vattenfall and Ellevio. That programme encompasses a substantial collection of new cables, overhead lines, tunnels and substations intended to reinforce electricity transmission into the Stockholm area. The Anneberg–Skanstull tunnel forms one stage of the larger Citylink connection.
Citylink’s stated network purpose is to connect northern and southern Stockholm in a way that strengthens the security of regional electricity supply. Higher transmission capacity and alternative power paths may support demand from homes, transport systems and industrial sites, although neither the Bravida release nor the project description assigns a specific increase in megawatts to this installation package.
Bravida reports that site work started in October and expects its package to be completed in June 2028. Its contract is coordinated with the main Hochtief Implenia joint venture, which is responsible for the wider tunnel works. That timetable concerns the installation assignment; Bravida has not disclosed the completion date or total cost of the wider Citylink programme.
The SEK157 million order was signed in September and recorded in Bravida’s third-quarter order intake before Bravida disclosed the order on 22 October. As installation advances, the project’s next verifiable milestones will concern completion and commissioning of the support systems. The contractual scope does not demonstrate that 400 kV cables are energised or that the full Stockholm reinforcement programme has been handed over.
