The Liebherr Derrick 200 DR 5/10 Litronic carried out a job at an extreme altitude on the roof of the newly built Courtyard Marriot Hotel in Montreal, Canada. The derrick crane operated in a very constricted space on the hotel roof to remove the Liebherr 355 HC-L 12/24 Litronic luffing jib crane safely and reliably. The 355 HC-L climbed with the IC tower system in the building to a final hook height of over 130 m. The crane demon?strated its capacity and high hook speed, particularly in 1-fall operation during the erection of the hotel?s 42 storeys.

After completing the hoisting work, the rigging team dismantled the 355 HC-L within four days from the roof of the Courtyard Marriot Hotel using the derrick crane. In contrast to conducting dismantling work from the ground, this job did not require any major roadblocks which would have adversely affected the other construction work. The heavy components of the luffing jib crane were lowered safely and at an adequate distance from the building since the 200 DR has a variable radius of up to 25 m.

After dismantling the luffing jib crane, the derrick crane was used for a further two months on the hotel roof to help with the roofing work. After this, the 200 DR 5/10 Litronic derrick crane was also dismantled. Its low package weights and compact dimensions meant that the crane components could be lowered to the ground using a load elevator.

Adaptable universal machine
The derrick crane can be used to dismantle tower cranes in the 300 mt and more load capacity category. Depending on the customer?s needs, the crane can be configured for load moments of 100 mt or 200 mt. The supports on the 200 DR 5/10 Litronic can be swivelled and adjusted to the static situation of the sub-structure on the surface to ensure excellent distribution of the support forces. Depending on the requirement, this special crane can be used with or without supports, its so-called stiff legs.

Safety controller
When using the crane on buildings which are several hundred metres high, safety is particularly important. The safety PLC controller of the Liebherr derrick 200 DR 5/10 monitors all the movements with the time-tested functions of Liebherr luffing jib cranes. Sensors monitor the hoist height, load moment, jib angle and slewing gear and keep them to safe levels. The remote control enables the crane driver to operate the machine from the best possible location. After the luffing jib crane had been completely dismantled and lowered, the derrick crane can be split into individual components which can be lowered using the elevator shaft. The components have maximum dimensions of 2.20 m x 1.10 m x 1.10 m and do not weigh more than 1,000 kg.

The rigging team dismantled the 355 HC-L within four days from the roof of the Courtyard Marriot Hotel using the derrick crane.