BW3-1 Overfly

Donges SteelTec builds mega bridge at the Nuremberg-East motorway junction

 The 600-metre-long motorway bridge spans the Nuremberg-East junction in an arc. The so-called overfly is designed to allow motorists to practically fly over the A6/A9 junction. The bridge is intended to prevent traffic gridlock at this junction.

The 9,000-tonne steel structure is being pushed over the motorway. Our foreman Manfred Lind and his team pre-assembled the bridge piece by piece next to the motorway and then, with the help of the yellow front end, pushed it centimetre by centimetre over the motorway – while traffic continued to flow underneath the bridge. The final delicate moment for Lind and his team was lowering the bridge one metre to its final position. In the end, every millimetre counts. The gap between the bridge and the bearing on which it rests must be wafer-thin. ‘The steel bridge has to rest on a bearing because it moves. When it gets warm, it gets longer, and when it gets cold, it gets shorter,’ explains Manfred Lind. It took more than two years for the steel structure to reach this point.

As soon as the bridge is resting on the bearings, the concrete workers on the bridge will start concreting the roadway. The opening of the 65 million euro overfly is planned for early 2026.

Bayerischer Rundfunk has made an impressive film about this, which can be viewed here.

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Pfaffendorf Bridge

Steel girders weighing tonnes for the new Pfaffendorf Bridge in Koblenz lifted into place by floating crane

The new Pfaffendorf Bridge connects the city centre of Koblenz with the right bank of the Rhine. In mid-June, the first steel girders weighing several tonnes for the new Rhine bridge in the river section were lifted into place using a floating crane. The seven steel parts weighing up to 480 tonnes for the first of five construction phases were lifted into place by crane from a pontoon in the Rhine. Due to the low water level, the Rhine first had to be dredged deeper at the lifting point so that the pontoons could be moved safely for the 600 tonne crawler crane.

The steel girders were manufactured as individual parts weighing up to 90 tonnes at our plant in Darmstadt, then transported by heavy goods vehicle to Mannheim, where they were pre-assembled into large components and transported by ship down the Rhine from Mannheim’s Rheinau harbour to the construction site in Koblenz.

‘The good preparation of our bridge construction experts and the precision work of our technical office, production and assembly team made it possible to lift in this challenging bridge structure with millimetre precision,’ says Stephan Langer, Head of Bridge Construction at Donges SteelTec.

Once the first bridge components have been lifted into place on the castle side, further steel components will follow in autumn and winter 2025, including on the Pfaffendorf side. The concreting of the second river pier was already completed here last week. The bridge is scheduled for completion in 2029.

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A6 Grumbachtal Bridge

Grumbach Valley Bridge gap closure successfully completed

The steel assembly of the Grumbach Valley Bridge near Sankt Ingbert was successfully completed with the lifting of the last two sections of substructure 1.

The two box girder strands of the substructure comprise a total steel tonnage of approx. 2,400 tonnes. The last two sections were lifted into place from a crane position behind the abutment on the Saarbrücken side of the bridge structure. Using a 750 tonne crane, the two sections were lifted off the heavy-duty transporters, turned and then lifted into their final position. This created the conditions for concreting the carriageway slab. Donges SteelTec has thus once again demonstrated its capabilities in the construction of large bridges.

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A6 Grumbachtalbrücke

Assembly start of the 2nd construction phase of the Grumbach Valley Bridge near St. Ingbert

In April 2023, construction work on the 1st construction phase of the Grumbach Valley Bridge was completed and traffic was diverted to the newly constructed structure. Following the demolition of the existing structure and the construction of the first substructures, our assembly team has now set up the construction site for the assembly of the steel structure of the 2nd construction phase (substructure 1) for the Mannheim direction of travel.

In the first assembly phase, two auxiliary supports were erected over the past few weeks to store the 262-tonne steel structures. The first large components were then transported overnight from our plant in Darmstadt to the construction site in Saarland using heavy goods vehicles. There they were first turned on the ground and then lifted into their final position using two 650 tonne mobile cranes. Once the steel parts had been successfully lifted into place, the component joints were welded and then coated with corrosion protection.

A total of 22 sections and 6 cross beams for the entire substructure are assembled in this way.

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BW3-1 Overfly

Overfly structure at Nuremberg East motorway junction moved to final position

Big praise for our project management and assembly team! Last Thursday, the final shifting of the 588 m long ‘Overfly structure over the A9 motorway at the Nuremberg East junction into its final position was completed with great precision.

Now the shunting rockers can be dismantled and the stacking towers erected so that the 8600 tonne steel structure can be stacked to its final height. The yellow front fork has fulfilled its function for moving the steel superstructure including the 5 pairs of pylons standing on it using the incremental launching method and can now be dismantled.

The ‘Overfly’ construction project comprises the construction of a 6-span bridge that spans the Nuremberg East motorway junction and crosses the A6 (Heilbronn – Amberg), the A9 (Berlin – Munich), the Amberg Munich ramp (2x) and the distributor carriageway (Berlin – Amberg).

Donges SteelTec manufactured and assembled the 588 m long six-span steel composite bridge, which impressively spans the individual support spans of 115 m with a total of 5 pairs of pylons. Up to 55 stranded cables form the cables of the stay cables. 8600 tonnes of steel were required for the construction of the flyover.

The incremental launching method of the steel composite deck slab with pylon spans of 64.00 m + 4 x 115.00 m + 64.00 m = 588.00 m over flowing motorway traffic posed a particular challenge for this bridge structure.

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A3 Steigerwald Motorway

Successful pylon installation on the Steigerwald motorway

Another milestone was reached on the A3 Steigerwald motorway last Wednesday: the pylons of the BW314a structure were successfully moved into position by the Donges installation team. This bridge is the twenty-first of a total of 22 planned steel structures and the first cable-stayed bridge in the project.

The pylons are technically challenging as they are inclined in two directions when viewed from above. The cross-section tapers towards the top. The pylons were assembled using two mobile cranes. Thanks to a hinged construction, the mobile cranes were then able to erect the pylons safely and precisely. There was a critical tilting moment during which the pylon swung through on the crane hook. This method made it possible to bring the pylon into a vertical position in a controlled manner and at the same time anchor it to the intended attachment points.

The bridge was planned almost exclusively with the help of 3-dimensional models, which made the construction and assembly planning much more precise.

In terms of steel construction, the BW314a structure is probably the most beautiful and challenging bridge on the Steigerwald motorway. As a cable-stayed bridge, it will attract attention above all through its architectural aesthetics.

With the successful erection of the pylons, the major project is nearing completion, at least as far as the steel construction is concerned.

The A3 Steigerwald motorway is a major infrastructure project that is of great importance for both local and national traffic.The expansion and modernisation of the route is expected to significantly improve road safety and traffic flow.

The client and the companies involved can look back with pride on the work carried out so far, which has paved the way for a modern and efficient transport artery through the Steigerwald.

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BW3-1 Overfly

Penultimate shifting cycle of the Overfly bridge over the Nuremberg East motorway junction successfully completed

The penultimate shifting cycle of the Overfly bridge structure was successfully completed by the Donges SteelTec assembly team.

The so-called extradosed bridge was moved into its final position using the incremental launching method. The steel superstructure of the bridge is prefabricated in sections at one end of the bridge on the pre-assembly site. From there, it is then moved to the opposite end of the bridge.

The incremental launching method makes it possible to avoid interfering with traffic as far as possible, as the bridge is moved across the motorway junction above the clearance of the lanes.

The Overfly bridge, including the already installed pylons and cables, is shifted in 6 cycles with a maximum shifting distance of 115 metres. The 50-metre-long stem spade bridges the free spans during the shifting process and compensates for the deflection of the bridge due to its own weight when it hits the next pier. Shifting takes two days per cycle. It takes place on special shifting rockers and is carried out with the aid of special shifting plates that allow the steel structure to slide forwards successively. This allows the shunting load that the hydraulic presses have to apply to be reduced accordingly.

The composite steel construction, which is 588 metres long in total, spans the individual support spans of 115 metres impressively 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 tonnes of steel will be used for the 588 m long bridge.

The components of the 6th cycle will be assembled over the next few months. The final shifting will take place in autumn 2024.

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Engineering performance at its best!

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.

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Ground-breaking ceremony for the Mainflingen Bridge

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.

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EÜ Erbach – New project for our bridge construction team

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.

 

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