A 440-m bridge had to be built across a valley to connect a new section of highway, requiring 14 steel girders to be set onto concrete piers. Each piece of the bridge measured 96 m long by 7 m high; with the required load-securing devices each section weighed 295 tonnes.
"We needed only 31 trucks to transport the crane from a wind turbine erection site to Luxembourg. The crane was set up and ready to work in one-and-a-half days," said Peter Frechen, transportation logistics and heavy crane dispatcher at Steil.
To lift the loads, Steil's team erected the Superlift 3800 crawler in a SSL1 configuration with a 72 m main boom, 250 tonnes of counterweight on the superstructure, 50 tonnes of central ballast, and 200 tonnes of counterweight on the superlift tray. To provide stability during the lift, Steil's rigging team configured the vario hookblock with dual hooks and a spreader.
Using two hoisting wire ropes and ten-part reeving, at 18-tonnes per reeving, Steil required 360 tonnes of lifting force.
To place the girders in their supporting pylons, they were first lifted to a height of 22 m, swivelled to the side, before the crane crawled forward 50 m in the direction of the bridge piers. The ground was reinforced with steel plates to provide adequate stability. Once the crane had positioned itself the load was swivelled back and set down on the corresponding bridge pier at a working radius of 23.5 m.