highline179 - Construction and start-up
The construction of the highline179 alone can be called spectacular, as quite some courage and a head for heights was required from the workers on site to manage this project. The plan was to complete construction with minimal environmental impact.
The finished construction was to be slim and narrow to optimally blend in with the surrounding natural setting. The constructors were also tasked with building the highline179 in such a way that one person alone would make it swing when setting foot on it, but also so that this swinging motion would not be lost with the maximum number of persons allowed on the bridge.
Exactly these properties are reflected in the term Tibet-style: unsupported, light and swinging.
On 7 May 2014, in cold temperatures and rain, it was then time: construction work was officially started with the groundbreaking ceremony. Trees had to be felled, the underlying humus removed and soon rock was struck.
The foundation was erected. Then anchoring of the bridge began. Four concrete anchoring blocks on each side, eight in total, were constructed.
The concrete work on the Fort Claudia side could be carried out as usual with a concrete truck and pump, but the opposite side could only be reached by helicopter. Empty piping led through the anchor blocks, through which the drill-anchors were then led.
These anchors were then joined with the underlying rock using cement suspension. And with that, anchoring was completed.
Then galvanised steel uprights were erected. The uprights were so huge that they did not fit into the existing zinc baths. They had to be cut in half and then galvanised. Only on site were they then reassembled: an incredible 950 screws were required for this.
So far, so good. The next challenge wasn't long in coming: it was time to connect the two abutments of Ehrenberg and Fort Claudia. In order to complete this, a cord was tied to a drone and flown from Fort Claudia in direction of Ehrenberg ruins. When they succeeded, hemp ropes of increasing thickness were pulled across the valley on this cord, until finally you could attach the supporting cables. The 60 mm supporting cables are so strong that one of them could tow a Boeing 747.
Then installation of the bridge could begin. The individual elements were inserted one by one from the Fort Claudia side in direction of Ehrenberg, until the two valley sides were finally connected. A very emotional moment for all those involved in the construction, as the dream had now become true and the nearly impossible become reality.
As a safety measure, the B179 national highway was encased in the section potentially at risk during the entire construction period, so that traffic could flow uninterrupted.