At the end of July, Felbermayr Switzerland, Mägenwil successfully completed their first partial order of a large transport project. A total of four transformers will be replaced in the Grimsel region in Switzerland – the order includes the transport of the new transformers as well as the removal of the old ones.

Siemens Trafowerk Linz ordered the large transport of four new transformers, each weighing 95 tonnes, and Kraftwerke Oberhasli ordered the removal of the four old transformers from Felbermayr. It took about two years from the planning stage to the successful completion of the sub-project, the company said in its statement.

Large transport route plan

The first partial large transport commenced at the end of July 2021 – two of the total of four transformers to be transported were picked up at the Felbermayr warehouse in Linz and consequently taken over the Brünig Pass to Meiringen, a town located in the Swiss canton of Bern.

“Once there, the heavy freight was transferred to a beak bridge by means of a rostrum trailer,” explains Ingo Müller, project manager on the part of Bau-Trans. The further transport was about 30 kilometres and an astonishing 1,200 metres in altitude via the Aareschlucht gorge to the Gerstenegg portal and then via a very narrow access tunnel to the planned destination, the powerhouse of the Grimsel power plant. The two transformers were unloaded there with powerhouse cranes. But this was not the end of the operation – the first of a total of four old transformers was taken over as a counter-transport and transported down into the valley to Innerkirchen to the headquarters of Kraftwerke Oberhasli. Once there, the old transformers are dismantled one by one and scrapped.

Special challenges

​​​​​​​“Particularly challenging with this order was managing the planned transport route,” Müller reports. Especially the transport with the 10-axle low loaders over the Brünig Pass posed a great difficulty due to the inclines, declines and tight curves – both the ascent and the descent, with a total weight of about 250 tonnes, was a demanding task for all involved.

In addition, there was a construction site on a bridge, which meant that only one half of the bridge could be used during the crossing due to the bad weather, and the spatial conditions were thus cramped. In order to ensure sufficient clearance with the cargo, the transformers were loaded off-centre in the through-loading girder bridge.

Finally, it should be mentioned that the usual lengthy approval processes until shortly before the undertaking or start of the transport are always particularly demanding for all those involved in the project. This was also the case with this order. But project manager Müller emphasises: “Thanks to the meticulous organisational and technical preparations in Mägenwil and Lauterach, especially in cooperation with the customer, authorities and subcontractors, all open points were clarified prior to transport commencing. Thus, nothing stood in the way of a successful project start.