The particular challenge: the old units weighed 3.4 tonnes and the new ones 2.9 tonnes. A special helicopter was therefore brought in from Austria.

It spent the night at the Hangelar airfield and flew bright and early to the cathedral city. The helicopter was escorted on the ground by a tanker so it could refuel as required at the Media Park. The helicopter can lift a maximum weight of 4.2 tonnes. As the loads to be transported were only slightly lower in terms of weight, a minimum fuelling was required for the first step of dismantling the three old units.

The helicopter was then refuelled on the ground to lift the three new cooling units. The entire area around the Cologne Tower was closed to unauthorised persons during the operation, which lasted a good hour. It would have been too dangerous to leave the area open to spectators. After the operation, the helicopter flew directly back to its home base in Austria. “This was not a routine task, but everything went according to plan,” said Rheinenergie press spokesman, Christoph Preuß.

The company had appointed a specialist firm from Wuppertal for the difficult job. They were able to secure the 39 year old helicopter pilot, Andreas Goetzendorfer. He flew his Superpuma AS 332 helicopter, which can move particularly heavy loads, to the right place with centimetre precision. The flight manoeuvre started at 11.30am and was finished around 12.30pm. The old piston machines were replaced by slightly lighter screw machines.

The latter use less energy than their predecessors and can be operated more quietly. Besides numerous offices, the Cologne Tower also houses a hotel. The spokesman for Rheinenergie said the flight operation cost a total of Euro 60,000.

Original text: Jörg Manhold, Translation:kc