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.


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 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.


Donges pushes bridge Overfly over Nuremberg East interchange

The bridge structure 3-1 Overfly transfers an exit of the motorway A6 Rifa Amberg over the motorway junction Nuremberg East and thus reconnects the motorway A6 to the motorway A9. The new construction will improve the performance of the Nuremberg East junction.

The bridge construction is a combination of continuous girder and cable-stayed bridge and can therefore be classified as an extradosed bridge. Donges SteelTec is constructing the complete bridge in the so-called cycle basement in 6 sections. After assembly, each section is hydraulically shifted longitudinally over the abutment and the concrete piers. The next section is then connected to the displaced end of the previous section until the opposite abutment is reached.

The steel composite structure, 588 m long in total, impressively spans the 115 m span with a total of 5 pairs of pylons. Up to 55 stranded cables form the cables of the stay cables. A total of approx. 8,600 tons of steel will be used for the 588 m long bridge.

The displacement of the bridge, including the already assembled pylons and cables, is carried out in 6 cycles with the maximum displacement distances of 115 m. A 50 m long cantilever bridges the free spans during shifting and compensates for the deflections of the bridge due to its own weight when it runs onto the next pier. Shifting takes two days per cycle. It takes place on special shifting rockers and is carried out with the help of greased shifting plates that allow the steel construction to slide forward successively. In this way, the shifting load that the hydraulic presses have to apply can be reduced to a maximum of 10 % of the bridge weight.

On 22.06.2023 the 3rd shifting cycle was successfully completed, the next components of the 4th cycle are currently being assembled. The steel construction work will continue until 2024.


Donges SteelTec builds bar arch bridge for the Regionaltangente West (RTW) in Frankfurt am Main

An impressive bar arch bridge is currently being built at the Frankfurt Stadion S-Bahn station and thus right in front of the Waldstadion Frankfurt. The bridge structure carries the new RTW line over the existing Deutsche Bahn AG track system.

The superstructure of the bar arch bridge with a span of approx. 113 m is being built in steel construction and is divided into two arch levels consisting of stiffening girders, arches and hangers, as well as an orthotropic carriageway and walkways with cable ducts on both sides.

Design, fabrication and corrosion protection of the steel components were carried out at the Donges SteelTec GmbH plant in Darmstadt.

Parallel to the fabrication, the individual foundations were produced on the construction site and the auxiliary scaffolding was prepared for the erection. The steel structures were delivered by heavy-duty transporters to the pre-assembly site, where a mobile crane placed the components directly into the assembly position. Due to the very tight space conditions on the construction site, the pre-assembly began in the eastern area of the assembly area. Here, the first third of the superstructure with axis 10 was assembled in a horizontal position and then moved along the assembly area in a westerly direction using an SPMT (Self-Propelled Modular Transporter) so that the other steel sections could then be added.  Welding and corrosion protection work is currently underway on the site until autumn 2023.

For the actual insertion over the DB tracks in May 2024, the superstructure will be stacked in the storage axles to shunting height, transferred to SPMT and aligned in the shunting position. During a 24-hour break in rail traffic, the superstructure will be pushed over the track field with maximum cantilever and taken over on the opposite side by a lattice boom crawler crane.

We are very pleased to be able to carry out this exciting project close to home.


One of the highest railway bridges in Europe gets a new steel superstructure

At 96 m, the Jauntal Bridge in Austria is one of the highest railway bridges in Europe. In the course of the construction of the new double-track Koralmbahn railway line, the existing single-track structure of the Jauntal Bridge will be upgraded to a modern, double-track steel truss composite structure. Donges SteelTec has been awarded the contract for the manufacture, delivery and assembly of the steel superstructure. The 3300 tonne steel structure will be manufactured at the Darmstadt plant. The 428 m long steel structure will first be assembled in three segments on a pre-assembly area below the existing bridge. The three structural elements are then moved transversely and longitudinally one after the other. In the process, the old and new supporting structures are connected to each other and the existing bridge is also pushed out.

The spectacular assembly work high above the river Drava begins in early January, when the first of the three segments of the new superstructure is first shifted transversely and then coupled to the existing structure. The first longitudinal shift will then follow in February. A technical and logistical challenge for our employees and, after the Danube bridge in Linz (bypass bridges), another milestone for our company in neighbouring Austria.


Bridge construction division is pleased with major contract for the replacement construction of the Pfaffendorfer Bridge in Koblenz

Donges SteelTec, as part of the ARGE Pfaffendorfer Brücke consortium, has been awarded the contract for the replacement construction of the Pfaffendorfer Bridge in Koblenz.

As an important link across the Rhine, the existing bridge must be completely replaced by a new one. For this purpose, the 311 m long steel composite bridge, which is broken up in the area of the pier coves, will first be built in the lateral position next to the existing bridge and, after the demolition of the existing bridge, will be moved transversely into the final position.

Donges SteelTec is taking over the technical responsibility for the entire structure by preparing the structural analysis of the river bridge, the assembly planning and the execution and workshop drawings within the consortium. Around 5,500 tonnes of steel structure will be manufactured and corrosion-protected in the halls of Donges SteelTec GmbH in Darmstadt. Afterwards, the steel elements, weighing up to 450 tonnes, will be successively transported by ship via a pre-assembly site on the Rhine to the construction site, where they will be assembled above the Rhine by means of floating cranes.

The work for the new Rhine bridge will be carried out between 2023 and 2027



Donges SteelTec moves 1400-ton steel bridge of the motorway A73 into final position

Even storm “Zeynep” and “Antonia” could not stop our technicians: At the end of February, the second superstructure of the motorway bridge in the direction of Bamberg was shifted at the A73 junction Breitengüßbach Süd. The steel structure, which weighs around 1,400 tonnes, is 150 metres long and approx. 18 metres wide, was pushed into its final position over the weekend across the B 4 trunk road, the railway tracks and a field path. Completion of the 3-span steel composite bridge is planned for autumn 2022.

First steel component of the 7-span Thulba viaduct shifted.

Darmstadt/Oberthulba, June 2021. Last weekend, the first longitudinal shifting of the steel superstructure for the new Thulba viaduct took place. The steel colossus was moved 66 m. However, the high summer temperatures on Friday not only caused problems for our assembly team, but also for the steel structure. This resulted in deformations of the steel component due to uneven heating. However, our experienced fitters quickly found a solution to this unforeseen challenge, so that the final position of the bridge section was reached on schedule on Saturday morning.

The replacement of the Thulba viaduct is a steel composite bridge with two superstructures, which crosses the A7 between Würzburg and Fulda in the Bad Kissingen/Oberthulba section. The bridge has a total length of 460 m each and runs up to 53 m above the valley. The steel structure tonnage totals 6,000 tonnes.