With its height of 100 m and imposing dome 33.5 m in diameter, the “Our Lady of the Assumption and Saint Adalbert” in Esztergom is one of the biggest churches in the world. The present church in classicist style, which stands on a hill in the former Hungarian capital directly overlooking the Danube, was built starting in 1820 and was meanwhile in urgent need of refurbishment. Since access to, and the use of, this listed building were not allowed to be impaired while the dome was undergoing essential restoration work, it was imperative to find a solution that dispensed with ground supported scaffolding. The contract was awarded to Belvárosi Építő Kft., who fully exploited the possibilities offered by Layher’s Integrated System. For the first time ever, the Layher Allround Bridging System was combined with the Allround FW System, in order to bridge the dome’s diameter at a height of 34 m and provide a solid foundation for the scaffolding itself, which weighs a massive 80 t.
A team of civil and structural engineers and other construction pros got together with the scaffolding specialists, their customer and Layher Hungary to develop an integrated system solution. To rule out problems when the scaffolding was erected, plan the assembly work as diligently as possible and coordinate the logistics, Layher’s application engineers provided upfront support in the form of detailed digital 3D drawings in LayPLAN CAD as well as digital advance planning using Layher SIM® (Scaffolding Information Modeling).
“We weren’t the only ones that described it as one of the most complex scaffolding structure assignments ever”, says Patrik Tóth, Technical Team Lead at Layher Hungary. “We had to bridge the full 26 m of the dome diameter at a height of 34 m in a way that was self-supporting before we subjected to the 80 t load of the dome scaffolding. That was, and still is, pretty spectacular”, he adds.
Sensitivity and the courage to innovate were called for
“The assignment promised to be very exciting and challenging, not least due to the location. Esztergom Basilica is one of the biggest churches in Central Europe and it’s surrounded by other historic monuments. Apart from good ideas, a highly sensitive approach was also called for when the scaffolding was erected”, explains László Ruzsics, General Manager at Belvárosi Építő Kft. “A lightweight access bridge was constructed on the church floor from Layher Allround FW Systems and lifted by winches to a height of 34m. After this auxillary load bearing element had been anchored to the window ledges, the main load bearing Layher Allround Bridging System was added onto the FW System. Finally, Layher Allround FW elements were used again to connect the main bridging systems at a 90 degree angle and achieve the final load bearing skeleton as well as the required load bearing capacity”, Ruzsics continues. What made this such an unusual project was that the Allround Bridging System had never previously been used together with the Allround FW System. Layher was able to realise the entire scaffolding solution with standard system components and avoid the need for an expensive and complicated, customised steel beam structure.
Allround System’s possibilities fully exploited
Two elements made from Allround Bridging Systems and supported on the window ledges serve as a special bracing structure for the work scaffolding underneath the dome. Bridging structures built with the Allround FW System were assembled to these elements at a 90° angle. The overall structure is capable of supporting the 80 t weight of the work scaffolding without any problem. A platform was then mounted on top of this supporting structure to allow the restoration work to be carried out safely. The fact that the elements are structurally and dimensionally integrated in Allround Scaffolding meant the way was clear to continue working with Allround standard components. This flexible and lightweight modular scaffolding system enabled the work scaffolding to be adapted quickly and easily to the dome’s geometry. Approximately 30 m high, it has two working levels that are no trouble to extend if the restorers so wish.
“They can assemble and dismantle it very fast because the Lightweight components weigh so little, and there’s no unnecessary load on the structure if no work is taking place”, says Gusztáv Pruzsinszki, Scaffolding Engineer at Layher Hungary.
Scaffolding also had to be erected around this element in order to renew the gold plating on the cross because it could not be removed. Since the structure had to cope with high wind loads and other weather conditions 100 m above the ground, sturdy scaffolding using Allround material was once again a must.
An experienced team
In addition to Layher’s Integrated System, the scaffolding team’s assembly expertise was a key factor in the project’s smooth execution. With many years of experience behind them, the erectors were able to complete the work at a height of 34 m not only safely but above all fast. The detailed preparations with the LayPLAN CAD software enabled the toughest challenges to be detected upfront during the planning phase, so that solutions could be found to maximise efficiency and safety.
Before the structure was actually installed in the church, the scaffolding pros conducted an outdoor trial, to ensure that the work could also take place safely and without any problems 36 m up. Extensive loading tests were carried out to verify the calculations. All measurements confirmed that the envisaged structure would function as planned.
Since 2006, the specialists at Belvárosi Építő Kft. have acquired a reputation for outstanding technical work when it comes to restoring Hungary’s historic monuments. This rapidly growing company currently employs 90 people of its own plus several subcontractors at its site in Szentendre, around 20 km north of Budapest.
