VHF antenna scaffolded on former Postbank Tower
24 m modular scaffolding do not normally present any particular challenge for scaffolding companies. But if a 300-kg material hoist is then to be integrated inside the scaffold, that's a bit more special. And when the scaffold is then to be assembled at a height of 86 m on the roof of an Berlin high-rise building, Schaarschmidt Gerüste from Petershagen/Eggersdorf, east of Berlin, comes into play. Built as the "Postscheckamt Berlin West" between 1965 and 1971, the 23-story building was a Postbank location for a long time. The powerful FM antennas on the building’s roof were used by several Berlin radio stations for program broadcasting in the past decades. With the increasing spread of the digital radio standard DAB+, however, fewer and fewer stations will be using FM in the future - the public broadcaster in Germany, for example, estimates that it will run until 2030. For this reason, the antennas are being successively dismantled, as is the case with this project. At the same time, the building is undergoing a general renovation.
Schaarschmidt Gerüste got the contract for scaffolding the antenna. Site manager Dirk Masche and his team had the challenging task of having the required RINGSCAFF modular scaffolding material from the scaffolding manufacturer Scafom-rux transported to dizzy heights for the first time. A cargo lift was available inside the building for this purpose, but it could only accommodate components up to a maximum length of 2.50 m. The design of the 24 m high scaffold with a footprint of 7.50 x 7.50 m was therefore limited to 2.50 bays. In addition, a working scaffold plateau had to be built to reach the foundation level for the antenna scaffold from the unloading station of the inner building cargo lift.
The 300 kg cargo lift to be installed on the roof was carefully disassembled into its components at ground level, then bolted back together at the top. For the lattice girders and stair elements to be used, which were too long for the indoor lift, an continuous thread was installed at the edge of the building to pull the parts up almost 90 m on the outside. Each lifting operation took 20 minutes - safety was the top priority. This also applied to securing the scaffolding material on the wind-exposed roof. Intermediate storage of material had to be elaborately secured against lifting; on the scaffolding itself, all the standards were connected in a tension-proof manner. All in all, the transport of the material took almost as much time as the erection of the scaffolding itself - 1 week each.
The top 4 m of the RINGSCAFF scaffold was netted all around for the antenna dismantling. The antenna was then dismantled piece by piece in 4 m steps, with the dismantled parts being brought down to roof level using the scaffold lift. Once 4 m had been removed, the scaffold was dismantled and the new top of the scaffold above 4 m was netted again. The whole dismantling process took 2 weeks. The planning and structural analysis were carried out by site manager Dirk Masche of Schaarschmidt Gerüste GmbH and the Berlin-based civil engineering company Bügler - Jaeck - Heyse. Schaarschmidt praised the fact that the RINGSCAFF elements could be secured immediately after installation and that no structural gaps had been created. In this way, it was possible to create system-compliant work surfaces all around.
In general, site manager Dirk Masche was enthusiastic about the project: "You don't often get such an interesting and exciting assignment. The job has once again shown what is possible with modern scaffolding systems and a motivated team.
Therefore, the project is part of a series of other spectacular scaffoldings that have already been implemented by Schaarschmidt Gerüst since its foundation in 2013. For example, in the Adlershof Center for IT and Media or in the Sony Center Berlin. With a staff of 20 employees, a wide variety of tasks are solved in the German capital and its surrounding area, such as the assembly of scaffolding and weather protection roofs or the design of special scaffolding. Schaarschmidt Gerüste emerged from Montagebau Schaarschmidt, which was founded in 1992 and is still active, specializing in the rental and repair of scaffolding material.