Mammoet has played a key role in the construction of Energie Baden-Wuerttemberg AG’s (EnBW) new hydrogen-ready fuel switch power plant in Altbach/Deizisau, Germany.
Built next to the existing coal-fired power station, which must remain operational as part of Germany’s strategic power reserve, the new combined cycle gas turbine (CCGT) facility will be capable of operating on natural gas, hydrogen, or a blend of both fuels.
The close proximity of the two plants meant space was extremely limited during construction. To overcome this challenge, Mammoet implemented a just-in-time delivery approach to ensure components arrived exactly when needed and avoided site congestion.
A temporary jetty was also built to allow continuous operation of the main crawler crane, supporting the offloading and installation of key components.
Precision delivery and limited storage
The first challenge was how to deliver and store the heavy components. The on-site storage space was not sufficient, so Mammoet proposed storing the largest items at its yard in Schiedam, the Netherlands.
From there, the components were transported to Germany by sea, stored, and then shipped to Altbach on river-going vessels just in time for installation.
The project required a new jetty to avoid disrupting the existing one used for coal deliveries.
“This existing jetty serves as the primary delivery point for all coal transported by boat and rail. Using it would have significantly interfered with the activities at the site. We conducted a study for EnBW to explore alternative solutions. Based on this, we proposed constructing a temporary jetty directly in front of the construction location. This would position the main crane in an optimal location to facilitate both the transshipment and installation of the components,” said Andreas Franzke, Senior Sales Manager Segment Lead Power & Nuclear at Mammoet.
Handling complex and fragile components
The project included the handling and installation of several large components, including HRSG modules, a gas turbine, a generator, a transformer, and stack modules.
The 15 HRSG modules, each weighing between 80 and 250 tonnes, required special care because of their 30-metre length and flexibility.
“It is a flexible module that does not tolerate deformation and therefore had to be kept perfectly straight at all times,” said Leonid Sinelnikov, Project Manager at Mammoet. “We meticulously examined every stage of their handling to ensure they remained undamaged. This included ground preparation at Schiedam and the use of specialized lifting beams and rigging tools for their transportation and offloading.”
Two crawler cranes—a 1,350-tonne main crane and a 600-tonne tailing crane—were used to lift the modules from horizontal to vertical positions. Because the cranes’ extended booms reached into controlled airspace, clearance from Stuttgart Airport was required for the lifts.
The installation of the 400MW gas turbine brought another challenge. Its base plate needed to be perfectly level due to the design of its supports.
“This is not standard practice for a cargo exceeding 350t,” said Leonid. “Heavy steel rigging typically allows for some tolerances. Massive slings and grommets are never exactly the same length, which would not meet the precise tolerances required by the client.”
To achieve this precision, strand jacks were integrated into the crane rigging, allowing the team to fine-tune the level during the lift.
Teamwork and detailed planning
The stack modules, which combine to form a large chimney, were also complex to deliver. Each section, weighing up to 95 tonnes and standing 18 metres high, was prefabricated off-site and transported using Mammoet Self-Propelled Modular Transporters (SPMTs).
Although the journey along public roads was only 75 metres, the route planning, 3D scanning, and preparation took weeks to complete to ensure safe delivery with minimal disruption.
With many heavy and fragile components arriving at an active construction site, precise coordination between multiple contractors was essential.
From sales and planning through to engineering and on-site operations, Mammoet teams worked together to deliver a seamless, end-to-end solution.
Mammoet said its expertise in engineering, project management, and logistics planning ensured the project progressed safely and efficiently despite the constraints of the site.