Liftra focuses on rapid loading for offshore projects

Technology to reduce number of lifts will be crucial

Decreasing the number of individual lifting operations taking place in port or at sea will become a central focus for offshore wind developers and contractors in future, according to Per Fenger, chief executive of lifting and transportation specialist firm, Liftra.

For the new generation of larger, direct-drive turbines destined for offshore use, Liftra has developed a hoist, known as the blade dragon, which ensures more rapid blade installation. The blade dragon allows individual blades to be installed using just one crane – rather than two - and in wind speeds of up to 12m/s, Fenger told Windpower Offshore.

Two turbine manufacturers – Areva and Mitsubishi – have already bought the tool, with Areva having used it to install about 30 blades thus far. With a substantial number of Areva machines due to be installed in German waters next year, its blade dragon looks likely to be in frequent use.

Mitsubishi's version of the blade dragon will be built to its specifications, which have yet to be confirmed.

Liftra also has a strong relationship with two other manufacturers of direct-drive turbines: REpower and Alstom. It has worked with REpower on blade installation for both its 5MW and 6MW turbines, while early this year Liftra assisted Alstom with the installation of blades for the first prototype of the 6MW Haliade, currently under test at an onshore site near Saint-Nazaire.

During 2013 Lifra will once again work with Alstom, as the French manufacturer installs the Haliade offshore, at the Belwind 2 site.

From Liftra's perspective, once a manufacturer of direct-drive turbines has a substantial number of units to install it becomes logical to deploy a solution, such as the blade dragon, that allows blades to be installed using a single crane. At some point, the slow speed, cost and complexity of additional and unnecessary crane lifts cannot be ignored.

Liftra has already had success in introducing system and products for improving the efficiency of tower loading. Instead of loading one tower at a time onto a vessel for sea transportation, the industry needs to be moving toward tower stacking, argues Fenger. Liftra introduced its first stacking frame in 2006, which has since evolved. Several respected names use Liftra stacking frames, including Siemens, REpower and Acciona.

Fenger's hope is that Lifra's technical solutions to lifting challenges will become industry standards, allowing the wind sector to reduce the length of its operations and, thus, its costs.

Founded in 2003 and with headquarters in the Danish city of Aalborg and offices in Germany, Spain, USA and China, Liftra focuses solely on serving the wind energy sector.