Piratsteg footbridge

The challenge

Demanding crane work on the A22

The complete overhaul of the Kaisermühlen tunnel is one of the largest tunnel support projects of the coming years. A total of 90 million euros are being invested in the renovation and technical upgrading of the tunnel system. In addition to installing a state-of-the-art ventilation system and modernising the lighting and safety equipment, the Piratsteg is also being renovated with the help of Prangl.

Our solution

Coordination of a 200-tonne telescopic crane and a 120-tonne telescopic crane

The Piratsteg footbridge spans the A22 and connects the Kaisermühlen embankment with the Alte Donau footpath. To handle the renovation, the Piratsteg footbridge, which is 51 metres in length and weighs 90 tonnes, had to be raised around 2.5 metres and supported. This required one 200-tonne and one 120-tonne telescopic crane. The narrow setup area required the use of the 200-tonne crane on one side, as only it was able to ensure the necessary lifting capacity with the outriggers only halfway extended. The two crane operators had to lift up the bridge in total synchronisation – and at a distance of approx. 40 metres from each other.

Overnight tandem lifting with time pressure

The lift made great demands on the Prangl team. In additional to plenty of experience, this primarily also required the ability to coordinate perfectly over the radio. The task was even more challenging thanks to the tight timeframe for completion. For safety reasons, the whole of the A22 motorway had to be blocked off for this tandem lift. However this could only be done from 2 - 5 am. Thanks to the excellent training of the crane drivers, good teamwork of those on site, and precise advance planning, the project was handled in the specified time and to the utmost satisfaction of all involved.