In February 1999 the Hagen-based heavy lift and project forwarder Rolf Riedl GmbH has been ordered to work out a feasibility study for transportation and an assembly concept for a 306 tons gas turbine supplied from production works in Berlin onto the foundations of a power station in Mainz-Wiesbaden.

Handling of the 306 tons turbine in the inland harbour of Mainz by an 800 tons lattice tower mobile crane.

After presentation of the transport and assembly concepts at the customer's Berlin works, the project team of the Riedl Group received the order - and a great commendation after the execution. For the pre-carriage from the works to the Berlin Western Harbour a combination of two 12 axle Scheuerle transport units had been deployed. In the Westhafen harbour the project team arranged handling of the turbine measuring 10,930 x 5,180 x 4,860 mm by a heavy lift crane of the BEHALA into a river craft.
In the inland port of Mainz the Riedl team deployed a lattice tower mobile crane (type Liebherr LDG 1800) handling the turbine from the river craft onto a 16 axle heavy duty trailer combination. The crane had been equipped by a main jib of 35 m length, an extension derrick of 31.50 m length, 250 tons shifting ballast and 160 tons revolving stage ballast.
The technical challenge of this operation emerged from the fact that the load pressure in duction into the quay might not have been possible if the water depth level would be below 2.50 m. If this would occur a crawler crane of very heavy type comparable to the largest one available in Germany, the Liebherr LRD 1800, would have to be put in operation. This would have created costs far ahead of an economic scale within the entire transport chain costs.
Therefore all water gauges at the Mainz harbour during the last ten years at the time of operation have been recorded in advance which average led the operators and shippers to an agreement allowing the operation of the cost-saving 800 tons mobile crane.

Under the arch-shaped underpass with 6.90 m in the centre line the transport unit had a clearance of only 80 cm at maximum.

Final transport leg of 2 km from the harbour to the power station had been fixed after several alternative route investigations in co-operation with authorities and energy suppliers. The agreed route led through a bottle neck at an arch-shaped underpass, the highest point of which of 6.90 m only surpassed the height of the transport unit (6 m) in the centre line by about 90 cm. This small difference had still to be deducted by the height of strong steel plates which had to cover tram rails for load distribution.

Approaching final job site a second tractor unit had to be deployed pushing the transport unit over a gradient road way.

Final part of the entire operation had been the mounting and assembling works executed by the Riedl Group unit Riedl & Stöcker GmbH, also based in Hagen. By means of a rigging device (type 48A) of 800 tons lifting capacity the turbine had been lifted off the trailer combination, lowered down onto a sliding track and shifted close to final position. After another remodelling of the sliding tracks of the rigging device the turbine had to be lifted up onto the 3 m high supporting legs of a compressor and finally assembled ready for operation.

By means of an 800 tons lifting device of Riedl & Stöcker the turbine was lifted up to its final position at the power plant on the 3 m high supporting legs on top of a compressor.