Engineered Solutions – Masterpiece with SPMT for bridge installation
November 30, 2023 | Isabella Mittermair
Plenty of cameras and smartphones were drawn along Wiesbadener Straße in Niedernhausen/Hesse on July 1st: After all, it's not every day that a 73 metre long and 12 metre high steel arch bridge rolls right past the houses or hovers slowly over garden fences.
Raised by 4.5 metres
"We raised the bridge outside the town, using a stack lifting system, by 4.5 metres at the pre-assembly site and positioned the two SPMT's, each with 16 axles and superstructures, underneath. Due to the width of 12.5 metres, it was required to transport the bridge high enough to be able to drive over the garden fences with the lower edge," explains Felbermayr division manager Kees Kompier from Engineered Solutions. As a result, only a few branches and bushes had to be trimmed beforehand along the 500- metre-long transport route.
The eye-catching spectacle on the road with its nine per cent gradient lasted less than three hours. "That was a brutal slope for such a heavy transport," says Kompier. "But the SPMT's have a good braking and retention system, so the downhill journey went smoothly."
Stacked before insertion
The bridge was picked up by the climbing jacks in front of the first abutment and stacked to 1.5 metres - exactly in line with the slope for the insertion. "We then had a week to prepare for the insertion," says Kompier. Around 100 tonnes of steel-reinforced concrete slabs were positioned on the bridge during this time so that the centre of gravity could be shifted to the rear half.
Deutsche Bahn must be given three years' notice to close a section for construction work - down to the day, even for a regional line like this one. This is why all the preparatory work was coordinated for day X. The rail line was closed from Friday, July 7th, 11:00 pm to Monday, July 10, 5:00 am. "We then worked in two shifts day and night," recalls Kompier.
Bridge inserted over ten tracks
The Felbermayr team delivered the masterpiece with the insertion over the ten tracks south-east of Niedernhausen train station. The bridge was then raised again and picked up by two SPMT's with six axles each, on the heavier half. Positioned behind this, 2x10-axle SPMT's weighed down with steel plates served as additional drive and brake vehicles – to ensure maximum safety when inserting to the lower bridgehead opposite. Now weighing a total of 630 tonnes, the configuration was pushed over a hydraulic jack with slide bearings - 37 metres up to a shifting carrier with a 500-tonne step press in the middle of the tracks. "We had to set up this customised carrier with extra repositioning three weeks earlier due to the steep incline," explains Kompier. The arrival of the bridge, which appeared to float on the two sliding bearings of the centre support with millimetre precision, was a first-class spectacle.
Placed on abutments
The further insertion was just as precise. "The bridge was then taken over by climbing jacks, after which we dismantled the carriers and other auxiliary equipment, stacked the bridge 3.5 metres on the insertion side and placed it on the abutments. We were already enjoying a good meal together on Sunday evening by 7:00 pm," says Kompier, looking back. "So, we managed to get everything over the line quickly."
The twelve-member Felbermayr team succeeded in perfectly implementing a technically challenging project with the bridge insertion. There was only an extremely short preparation time of three months to do this. "We were given a lot of praise from the authorities, the developer, the owners and our partners. Everyone was really enthusiastic," enthuses Kompier.
