Hofmann uses Terex crane with boom booster for wind turbine erection

To reach the required hub height of 164m, the Hofmann team equipped the crane with a full Boom Booster configuration, including a Flex Frame and Split Tray.

The Boom Booster system is a welded steel structure that is mounted directly on the crane and consists of up to seven 12m-long sections. When equipped with this system, Superlift 3800 units can reach a maximum hook height of 174m and lift loads of up to 80t when using this configuration.

“We’d already used the Superlift 3800 to carry out several standard lifts for wind turbines with a hub height of up to 144m, but the project in Bickenbach was the first time we had to take a crack at a total wind turbine height of 227m,” said crane operator Christoph Bergmaier.

In order to erect the large wind turbine in the Hunsrück mountain range, the crane was equipped with a 165m main boom and a 12m LF jib.

The Superlift Split Tray is used when erecting the main boom. Once the main boom is set up, the counterweight that is no longer required can simply be uncoupled, after which  the crane can move with only the Superlift counterweight that is still needed.  After the crane is done with its work, the counterweight that was originally removed can be quickly put back in place in order to lower the main boom.

“This quick-coupling technology eliminated the work involved in rearranging counterweights for the Hofmann team, which reduced the setup time, eliminated the need for an assist crane, and made it possible to work with a smaller team,” Terex said.

The Flex Frame unit also proved to be helpful when setting up the crane, as the team used it to increase the Superlift radius to 21m so that it would be possible to erect the boom, with its total length of 177m, without the need for an assist crane.

Before this, however, the team had to overcome a different challenge, the relatively steep slope at the tough work site. “A boom with this kind of length needs to be kept at a perfectly horizontal position,” explains Bergmaier. Because of this, the technicians first had to set up a support platform of the same length in order to compensate for the slope.

Once all the preparation work was complete and the crane was set up, the team made the necessary arrangements so that the Superlift 3800 would have the required working configuration: The Superlift counterweight, which was only needed to erect the boom, was quickly removed without any need for the laborious rearrangement work that would have been required without the Split Tray option.

This left only 25t of “remaining counterweight,” which was still more than enough to enable the crane to handle all the upcoming lifts.

“On top of that, we used the Flex Frame to move the working counterweight up closer to the crane at a distance of 13m, which enabled us to comfortably maneuver with a minimal counterweight radius so that the tight space conditions at the work site wouldn’t get in the way,” said Bergmaier.