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Bar arch bridge for the western regional bypass in Frankfurt lifted into place with great precision.

Darmstadt, 03.06.2024. In a spectacular operation, the 1300-tonne tied-arch bridge with a span of 113 metres was installed in its final position over the railway tracks of the Frankfurt-Mannheim line at the Waldstadion in Frankfurt am Main on Friday. This makes the future route of the Regional Tangent West (RTW) clearly visible for the first time: its light rail vehicles are scheduled to run over the bridge from 2028.

The Donges SteelTec assembly team began preparations for the final assembly of the bridge on Wednesday. In order to hoist the steel colossus into position, it was first stored on two huge mobile platforms (SPMT) in the days leading up to its installation. The self-propelled modular transporters with their 288 individually steerable wheels were set in motion late on Corpus Christi evening and manoeuvred the bridge as close as possible to the tracks. A lattice boom crawler crane then took over on the opposite side of the tracks and gently lifted the steel giant over the tracks.

A total of 500 tonnes of counterweights were needed so that the crane monster could hold half the bridge load of 680 tonnes. These were brought in by 20 articulated lorries, while 70 lorry transports were needed to erect the crane. For hours on Friday morning, the bridge was suspended from the crane on one side while it was attached to the eastern abutment. At midday, the crane then lowered the striking tied-arch bridge onto the western abutment, accompanied by applause from the numerous spectators. The work seemed slow, but the time pressure was great. Deutsche Bahn had only closed the railway line between Niederrad and the airport for 24 hours.

The Donges team on site was visibly satisfied and proud of the smooth installation process. ‘On a lift like this, it’s important that everyone knows what their job is and that everyone communicates well with each other. We are an experienced and well-rehearsed team and recognise our responsibility for the safety of those involved and the structure. A big thank you to everyone who made this great engineering achievement possible,’ says the responsible Donges project manager, Aaron von der Heyden.

On Thursday, 2 May 2024, the official start of construction of the Mainflingen Main Bridge took place. Over the next 7 years, the replacement construction of the 450 metre long bridge will be realised by the consortium Adam Hörnig Baugesellschaft mbH & Co. KG and Donges SteelTec GmbH. The current bridge is a three-span tension chord construction with a span of 62.5 – 135 – 62.5 metres. It is followed by a 190 metre long foreshore bridge in prestressed concrete construction.

The federal government is investing around 192 million euros in this construction project. It is due to be opened to traffic in 2031

A 3D model of the Mainflingen Main Bridge, which was created on the basis of BIM planning, gave the guests on this day an impression of this challenging bridge construction project.

A new tied-arch bridge will be built near Bad Camberg in 2025

Congratulations to our bridge construction team on the new contract! Together with the construction company Albert Weil AG, we have been commissioned by DB Netz AG to build the new Erbach railway overpass near Bad Camberg.

Approx. 720 tonnes of steel are required for the 2-track tied arch superstructure with reinforced concrete abutments. The entire steel structure will be manufactured at our plant in Darmstadt and then transported to the construction site in central Hesse using heavy goods vehicles. There, the components will be welded together at the pre-assembly site to form the approx. 60 metre long bar arch and then the supporting structure will be driven into its final position in October 2025 using SPMTs (Self-Propelled Modular Transporters). A particular challenge for our assembly crew will be to install the bridge precisely during a shutdown period.


Special geometry of the bridge requires a high degree of precision from our welders

After 10 weeks of production, the foot and cycle path bridge over the B426 in Mühltal, Hesse, was lifted into place in the night of 16 to 17 February 2024. The bridge has created a publicly accessible footpath and cycle path between Rheinstraße and the Ruckelshausen business park, which also provides access to the Riese & Müller company car park.

The biggest challenge when lifting the centre section of the bridge was to simultaneously insert the 4.5 m wide and 23 m long steel structure into six differently orientated supports with the help of two cranes during the lowering process. The two stairway sections were placed to the north and south of the bridge during the night and will be welded in place over the next few days. A total of 114 tonnes of steel were used for the bridge, including the superstructure, stairs, supports, railings and steps.

Special praise is due to the welding specialists at Donges SteelTec. They met the special welding requirements of the geometrically demanding steel bridge with great precision.


Donges SteelTec is once again involved in training international welding specialists this year.

Darmstadt, 19.02.2024. Donges has been building steel bridges and innovative steel structures for 150 years. Each structure is unique and a small masterpiece. To ensure that the high quality requirements for steel structures can continue to be met in the future, well-trained specialists are needed. With this in mind, Donges SteelTec not only trains construction mechanics and system planners in its own company in Darmstadt, but is also involved in training courses at the Hessen Metal College in Oberursel.

Dipl.-Ing. Andreas Schade, head of quality management/assurance and welding engineer at Donges SteelTec, once again took on part of the theoretical training for the “International Welding Specialist” course at the Hessen Metal College. The practical knowledge of the course participants was deepened during an excursion to Darmstadt in the production halls of Donges SteelTec GmbH.

We congratulate the 18 participants on passing their exams and wish them every success in their future careers.

Sophisticated assembly concept – Donges SteelTec scores with many years of experience and expertise in bridge construction

The consortium consisting of Adam Hörnig GmbH and Donges SteelTec GmbH was commissioned by the federal motorway authority Autobahn GmbH with the replacement construction of the Main bridge near Mainflingen. Our company’s expertise and many years of experience in the field of bridge assembly was a particularly important aspect in the successful acquisition of the contract.

The old Main bridge at Mainflingen on the BAB 45 motorway is being replaced by an elegant bridge with a tensioned chord structure.

At the location of the bridge, the River Main forms the state border between Mainhausen in Hesse and Kleinostheim in Bavaria. A slender steel composite construction and the low overall height of the bridging structure ensure that the replacement structure blends harmoniously into the varied river landscape.

The two superstructures have a total length of 450 metres. The 260 m long river bridge is designed as a three-span continuous girder in pure steel construction for the main supporting girders in the longitudinal direction of the bridge and in composite steel construction for the cross girders and carriageway slab structure. The supporting structure consists of a steel trough with box-shaped longitudinal girders and is spanned by chords, which are also box-shaped. The tension chord construction allows a slender centre span of 135.00 m above the river Main with two equal side spans of 62.50 m each. The slenderness in the centre of the span is approx. L/45. The tension chords are supported by approx. 15.00 m high pylons.

The displacement of the pylon locations compared to the existing structure results in a symmetrical situation along the Main axis.

The installation specialists from Donges SteelTec face a particular challenge. Due to the one-piece cross-section of the existing bridge, it is not possible to demolish half of it. The first superstructure (RiFa Gießen) of the A45 over the Main must therefore be built in a lateral position and later shifted crosswise over a length of 450 metres. The assembly of the steel structure is just as challenging. This will be constructed at the final position above the foreland on both sides of the Main on skidways and shifted longitudinally over the Main. The approx. 500 tonne centre section is then floated in over the Main, lifted and welded.

The entire construction project will last until 2031 and is an important milestone in the redevelopment of the German bridge landscape.

Donges SteelTec trainees visit the PTS and RTW construction sites in Frankfurt

“We offer our apprentices an exciting, comprehensive and practical training as a solid basis for the start of their professional life” with this motto Donges SteelTec advertises apprenticeships to young people.

Now the practical relevance was established for the prospective technical system planners and construction mechanics. Together with their training supervisors, the 15 technical and industrial apprentices of Donges SteelTec first visited the new Passenger Transport System (PTS) station under construction at Frankfurt Airport and then the RTW construction site (Regional-Tangente-West) near Frankfurt Stadium. Donges SteelTec has been commissioned with the manufacture, delivery and assembly of the complex steel structures for both construction projects.

The two Donges site managers proudly presented the current assembly status of the projects, pointed out the technically demanding assembly steps to the young colleagues and explained the special working situation on a construction site. With great interest and impressed by the huge steel constructions that characterise both the PTS station and the new bar arch bridge of the western regional tangent, the trainees absorbed the many practical information during their tour of the construction sites.

Donges SteelTec promotes young scientists

Darmstadt, 19.10.2023. It pays to promote young scientists: Darmstadt-based Donges SteelTec GmbH has now awarded a total of 6,000 euros in prize money to four students at Darmstadt Technical University. This is the 11th time that the Donges sponsorship award has recognised outstanding bachelor’s, master’s or doctoral theses in the field of steel construction at TUDa.

The award fulfils several objectives for Donges SteelTec. “On the one hand, this is how we document our solidarity with the Technical University of Darmstadt, which is based on many years of scientific and personal cooperation,” explains Donges SteelTec Managing Director Dr Wolf Cornelius. On the other hand, as one of the leading German steel construction companies, Donges SteelTec is committed to thinking beyond the day and acting sustainably. “And this also includes promoting young technical talent, which is essential for the success of our economy in global competition.”

The jury, including Professors Lange and Vormwald from the Institute for Steel Construction and Mechanics of Materials at TU Darmstadt, sifted through numerous dissertations, bachelor’s and master’s theses and finally selected four young academics, whose work is of outstanding importance in the field of steel construction. The works awarded in two senses deal with the ecological-economic evaluation of sandwich elements, “3-D printing with steel: additive manufacturing of steel columns, the material behaviour of butt welded joints and the load-bearing behaviour of fillet welded joints under longitudinal shear. All papers have experimental as well as theoretical or numerical parts, which mutually confirm the results found.They all lead to findings on the basis of which structural components in steel construction can be designed more economically; thus an essential evaluation criterion for the submission was fulfilled.The four young engineers Alina Behrendt, Niklas Brand, Joachim Schliemann and Anusikah Sivakadadcham were honoured at the ceremony on 19 October 2023 in the guest house of the TU Darmstadt.

In his presentation of the company, Stephan Langer, bridge construction manager at Donges SteelTec, made special mention of the company’s involvement in the construction of the new stadium for the “Lilien” and thus led over to the evening’s keynote speaker, Rüdiger Fritsch. In his rousing speech, the president of SV Darmstadt 1898 provided insights into the business enterprise “football”.

At the subsequent get-together, around 100 guests, including many students from the Department of Civil Engineering at the TUD as well as business partners and employees of Donges SteelTec GmbH, found time to exchange ideas and network.

The next Donges Award ceremony will take place in two years’ time.

A look behind the scenes of the project!

The new Passenger Transport System (PTS) station will connect Terminal 3 of Frankfurt Airport, which is currently under construction, with the existing passenger facilities, the regional and long-distance railway station in the north and the Sheraton Hotel.

Donges SteelTec has been commissioned with the manufacture, delivery and assembly of the complex steel structure of the PTS station. The fabrication and assembly of the conical round supports and the cast nodes represent a special challenge here. The assembly work of module 1 is almost completed. The entire construction project will be completed by the end of 2023. The following photos give an impression of the huge steel construction before the final coating.


Donges SteelTec manufactures and assembles the steel structures for nine railway bridges

In the course of the flood disaster in July 2021, large parts of the Deutsche Bahn rail network in the Ahr valley were destroyed. Now, bridges and railway embankments along the route are to be rebuilt in a highly water-resistant manner. The main focus is on the bridges. The former round arch bridges are to be given a slimmer construction during the reconstruction in order to offer the (flood) water as little surface of attack as possible.

Donges SteelTec has been commissioned to manufacture, deliver and assemble the steel structures (4300 t) for nine steel trough bridges. The contract also includes workshop and assembly planning as well as all corrosion protection services, bearings, transition structure and railings.

We are pleased to be able to contribute to the reconstruction of the Ahr valley and are convinced that the decision to build the new bridges sustainably in steel construction is an additional measure to increase resilience against possible future flood events.