ALE’s bespoke onshore wind tower heightening pushes engineering boundaries
Renewables – onshore wind
- Bespoke solution
- Time savings
- Reduced costs
ALE has achieved another world first and provided a bespoke engineering solution to heighten the prototype of one the world’s highest wind towers, the Nabralift self-erecting tower, with limited use of cranes for significant time and cost savings in Navarra, Spain.
ALE was tasked with transporting and heightening the self-erecting wind tower, weighing 450t, so Nabrawind Technologies could develop future onshore wind farms without the need to perform solely crane operations and the associated costs and time involved in additional equipment, civil and logistical works. They also wanted a solution that was as time-effective as possible, so operations could continue even at high wind speeds.
Measuring 160m high, this tower is the third tallest in the world. ALE utilised 12 axle lines of SPMT to transport the tower to the assembly area. The crane installed the first 62m and once enough height clearance was reached steel lattice sections were introduced underneath. This was repeated for each of the seven sections, until reaching 160m.
The bottom shape of this first structure was modified into a three-pointed star from where three low-height gantries, one at each corner, were used to jack-up the whole structure.
This self-erecting tower system breaks all logistical barriers to install towers at any hub height.
This methodology made it feasible to continue raising the tower sections even if weather conditions became hostile (prototype developed with winds up to 16m/s) as the lateral guidelines along the gantry frames constrains the lateral movements and keeps the tower vertical.
“It is fantastic to have been given the opportunity to work on this unique project and showcase our capabilities within the onshore wind market. Recognising our track record in Spain, the client was confident we could supply the complex solution necessary,” explained Project Engineer David Arias Blanco.
“By providing this customised solution, our client can now have the means of developing onshore wind farms in the most cost and time effective method ever thought possible. This is game-changing technology, specifically for those located on difficult-to-reach islands or mountainous sites. From our findings, we are already developing engineering processes to fulfil the requirements of future large-scale installations with an aim to develop two towers a week.”
ALE has worked alongside the client to develop the methodology used for this prototype for the future production of these wind towers from 2019.