Wind Turbines

Krøll Cranes have developed an innovative solution to cater for the higher erection levels and heavier nacelle weight requirements of the wind turbine erection industry. Krøll Cranes have adapted and developed their high free standing heavy luffing crane designs and recently supplied cranes installation projects in Europe and Asia.
Krøll has successfully entered a market previously dominated by heavy crawler and all-terrain mobile cranes and has proven that large capacity free standing tower cranes are an effective and in many cases the only solution for wind turbine erection.
In conditions of restricted and limited access, small hardstands, high erection height levels, and large nacelle weights Krøll cranes have provided effective alternate solutions in conditions where crawler and mobile crane could not be applied.

Range
Current Krøll Tower Crane models for the wind industry offer lift capacities from 95 tonnes through 150 tonnes and heights under hook from 157 to 195 metres.

Demonstrated advantages

In recent projects employing multiple Model K760L Krøll Cranes in Thailand 70 units of Vestas wind turbines were erected to 140 metres height in 20 weeks showcasing and proving the clear advantages of the Krøll tower crane solution. On this recent project an optimized cycle time of 4 days per installation was achieved. This included, tower crane erection, wind turbine installation and tower crane dismantling all in single shift operations.
Krøll’s free standing mast designs require no tie in to the turbine tower of the wind turbine and impose no loads on the tower. The resulting time saving and increased safety during installation, erection and dismantling is very significant. Designers of wind turbine towers are also not restricted by the need to accommodate the additional forces of an erection crane.
Operational functionality of the tower crane at full erection height can be maintained in wind conditions up to 20 m/s and up to 15 m/s under full load.

Transportation and erection
Transportation logistics for Krøll cranes are similarly minimized with the maximum load width being 3.5 metres and maximum weights subject to the preferred degree of dismantling can range from 24 tonnes to 46 tonnes.
Low initial erection heights prior to commencing self-telescoping allow for attendant service cranes for erection and dismantling to be sized in the range 200 tonnes capacity to 400 tonnes capacity depending on model of Krøll crane.
With a choice of foundation configurations between embedded bolts and reusable cross bases the application of Krøll tower cranes also adapts easily to small hardstands thus minimizing the construction and access footprint. This gives rise to very substantial savings in civil ground works costs and also in many instances assists in meeting local environmental regulations and restrictions.
Turbine service applications.
Given the ease of transportation, rapid erection times, minimized service crane requirements and full free standing capability the Krøll tower cranes are well suited for long term post erection wind turbine service works. Returning a Krøll tower crane to site for future blade or nacelle maintenance would be very cost effective and could be achieved with minimum disturbance.

K760L, Thailand