Germany-headquartered Kahl Group utilised two Goldhofer modules and a high girder bridge to transport the world's most powerful transformer, a Siemens 1100 kV UHVDC, which had a deadweight of 535 tons (485 tonnes).

The transformer was moved from Siemens' manufacturing plant in Nuremburg, Germany, to the port of Nuremburg. André Krause, project manager with the Kahl Group, said a THP/ST 10 P (1+1) module was positioned at the front of the trailer combination, and at the back a PST/SL-E 10 P (1+1) was deployed.  The G2 I K 600 high girder bridge, developed by Goldhofer and Greiner, was coupled in the middle, which ensured that both the load-bearing requirements and the height restrictions were met along the route.

With a length of 63 m, a width of 7.45 m and a height of 6.1 m, the laden rig had an overall weight of 875 tons (793.8 tonnes).

"With Goldhofer's heavy-duty and self-propelled modules coupled in parallel we were able to minimise the overall length of the combination so as to guarantee the manoeuverability needed for the critical passages, like the underpass under the Minerva Bridge," said Krause.

In preparation for the move, Krause utilised Goldhofer's dedicated easyTRACK and easyLOAD software to simulate the journey as realistically as possible, to ensure optimum positioning of the combination with regard to weight distribution and the load's centre of gravity.

However, an unforeseen obstacle was discovered just outside the exit of the Siemens plant, which almost put paid to the whole operation. An incorrectly parked truck left too little space for the combination to pass. A tow truck was used to move a vehicle parked on the other side of the road out of the way. Although narrower than originally calculated, there was enough space for the rig to pass.

After an operation lasting just under 20 hours, the rig reached the port of Nuremberg. The transformer was loaded onto a barge for delivery to Antwerp, before beginning its 3,300 km journey to China by sea.

"This mega transport operation was a successful premiere for us; we have another three of these giant cargos coming up for the power generation industry," said Krause.