Wear and tear and a risk of flooding are the main reasons that Slussen in Stockholm has to be rebuilt. Skanska is one of the construction companies that will carry out the project during the period 2016-2022. The City of Stockholm has given us the contract to undertake four of a total of approximately 25 sub-projects. Two of the projects are the largest regarding the complete reconstruction of Slussen.
1. A lock system with quays
We are rebuilding the current lock system. The work comprises demolition as well as reconstruction and a new build around the water area in Slussen/Söderström. Two new drainage channels for Lake Mälaren will be built, a new lock between Lake Mälaren and the Saltsjön, quays, bridge supports and a water culvert.
The project is a performance contract.
2. Engineering structures
Firstly, we will conduct shaft, demolition and ballast work to allow for foundation-laying, piling and concrete work. Thereafter we will construct the new structures at Slussplan and Strömkajen. The project is a performance contract.
3. Main bridge over Söderström
We are building a steel bridge, which is 140 meters long and 45 meters wide. There are high demands on materials and workmanship. The project is a design-construct contract.
4. Drainage openings
Part of the work includes building a new slipway and two new drainage channels. Currently the water is drained through the Karl-Johan lock and the old Nils Ericson lock. The Karl Johan lock, built in 1935, will be demolished as part of the reconstruction. The Nils Ericson lock, from 1850, will become a fish ladder. The openings will be installed in 2019 and 2022. The project is a design-construct contract.
Cooperation as a method of working
Three of the projects are carried out with increased cooperation with the client due to uncertainty and major technical challenges. We are working with budgets, planning, project engineering, safety and so on, together with the client.
Factors of uncertainty that affect the execution:
- Authorization issues regarding detailed development plans and environmental judgements
- Uncertain starting times
- Uncertainties regarding the conditions of the foundation and obstacles in the ground
- The presence of archaeological remains
- Uncertain drainage conditions
- Uncertainties in how traffic will be temporarily directed through the Slussen area during the construction period
Major work on a small surface area
Major and complicated work will be carried out on a small surface area, while at the same time daily life, traffic and public transport around Slussen must function as normal. Several operators have to share the same space, which requires consideration and dialog. The available surface area is very small for storage and logistics. All this places great demand on careful planning.
There are many challenges with the new Slussen. It is a long way down to firm rock and there are many valuable, culturally historical buildings to take into consideration. It must be possible to drain water from Lake Mälaren to the Saltsjön, the drainage capacity needs to be the same during the entire construction period. Time is also a factor.
Safety for the public
Many people circulate around Slussen both day and night. Accordingly, there is a high demand for surveillance and exterior protection such as fences and barriers. For us at Skanska, safety is greatly prioritized for both third parties and our employees.