Topping-out at maincubes’ Berlin data centre campus marks major milestone for JSM’s first project in Germany
History is made
JSM Group has celebrated the topping-out of the 110 kV substation at maincubes’ BER02 data centre campus in Nauen, near Berlin. The ceremony on 13 October marked the completion of the building’s structure just six months after construction began, and followed a month after the pipe-laying ceremony on the project’s high-voltage cable route.
As general contractor, JSM is delivering both the substation and the six-kilometre cable route that will connect the campus to the Wustermark substation. It is JSM’s first project in Germany.
Marking the milestone
The Richtfest is a centuries-old German construction tradition that marks the moment a building’s structure is complete, and above all thanks the people who built it. The ceremony opened with a welcome from Thomas Wacker, Chief Development Officer of maincubes, followed by an address from Dr. Michael Wiebersinsky, Mayor of Nauen, and a speech from Peter Östlund, Managing Director of JSM Services. Foreman Orhan Sahin of construction partner Lupp then delivered the traditional topping-out speech beneath the wreath.
“Today there is no longer a wooden roof truss here, but concrete and steel,” said Peter Östlund. “Yet the essence of a topping-out ceremony remains the same: it is a celebration of gratitude towards the people who built it.”
Six months of progress
Works began in February on waterlogged ground, and investigations revealed topsoil up to three metres deep rather than the one metre expected. The team replaced around 4,200 cubic metres of soil before progressing through a summer of site temperatures up to 41°C, carrying out concrete pours in the early hours to stay on programme.
Since then, the team has:
- Embedded around 250 tonnes of structural steel in the concrete
- Installed around 3,500 square metres of precast walls and ceilings
- Lifted an eleven-metre-span filigree ceiling into place in a single day
Powering mainHub Berlin
The 200 MVA substation is the first building block of maincubes’ new data centre campus and will house four transformers, each weighing just under 70 tonnes. Building services installation begins at the end of October, followed by the transformers.
On the cable route, the team has laid more than 27 kilometres of protective conduit, excavated around 14,000 cubic metres of trench and milled more than 3,000 tonnes of asphalt, with ten horizontal boreholes planned to cross the L161 and B5 roads.
Thomas Wacker, Chief Development Officer of maincubes, said:
“The topping-out of the substation marks an important milestone in the development of mainHub Berlin and brings us one step closer to delivering the infrastructure needed to support the campus. A reliable power supply is fundamental to the long-term success of any data center, and we are pleased to see this critical element taking shape on schedule. The progress achieved in just six months is a testament to the commitment and expertise of everyone involved. We look forward to the next phase as we continue to bring our vision for mainHub Berlin to life.”
24,000 hours without a lost-time accident
Around 24,000 hours have been worked across the substation and cable route without a single lost-time accident. In line with JSM’s safety culture, the celebration itself was alcohol-free.
“It’s about the sense of responsibility we feel to ensure that everyone who works here gets home safely in the evening,” said Peter Östlund.
Built together
JSM thanks all partners involved, including Lupp, TTSP, BS Schwarzbart and Raible + Partner, along with the suppliers, logistics teams and drivers supporting the works.
“This is our first project in Germany,” said Peter Östlund, “but certainly not our last.”
