86 metres in just under 2 hours
Wind blades are increasingly the length of football pitches. Their transportation calls for intelligent solutions, and the use of what are known as self steering dolly trailer combinations has become standard. And for good reason, as wind turbine manufacturer ENERCON’s recent haulage operation showed, when the company transported the new XXL wind blade prototype for its E-175 EP5 turbine from Wilhemshaven to Aurich. The operation involved the deployment of a cutting edge combination of dolly, lifting adapter and self steering dolly trailer from German specialist vehicle manufacturer DOLL®.
Wind turbine blades are growing ever larger. The demand is for a greater working surface and a higher energy yield. ENERCON GmbH, the German market leader for wind energy technology, has developed a new rotor blade prototype for this type of XXL wind turbine. The E-175 EP5 turbine has a rated output of more than 6 MW and a blade diameter of 175 metres. Each wind blade is 86 metres in length. The challenge here was to safely transport the large prototype by road from Wilhelmshaven to its destination in Aurich, the location of ENERCON's wind blade test rig. The first stage from the wind blade manufacturing facility in Portugal to Wilhelmshaven was completed by sea. This was followed by road transportation – 60 kilometres – some of which along narrow country roads. This posed an enormous logistical challenge given the huge product dimensions. ENERCON commissioned haulage company Transannaberg with this challenging task. The contractor relies on DOLL®'s wind blade transport equipment – comprising a hydraulic lifting adapter on a 2-axle dolly and a four-axle "DOLL vario®" self steering dolly trailer – for such tasks.
"Transporting ever larger wind blades is no longer feasible in Germany using conventional extendable semi-trailers," explains Lukas Freericks, Technical Engineering & Support at ENERCON Logistik. "Only a self-steering dolly trailer allows the largest components of the latest ENERCON wind turbines to be transported."
Meticulous planning paid off: the wind blade was brought safely to its destination. The wind blade transporter covered the 60-kilometre route in under two hours. Road transport went smoothly despite the enormous total trailer length of around 100 metres.
"It wasn't just the extreme dimensions of the rotor blade of our new E-175 EP5 wind turbine that posed a challenge for logistics," says Freericks. "As we were transporting a prototype component, the 'usual' bottlenecks of junctions and crossroads also came in for particular attention from the wind blade logistics experts." These factors also played a role in the decision to choose the DOLL® transportation solution, as the DOLL® system has a high ground clearance. Unlike a multiple extendable semi-trailer, the DOLL® wind blade transportation system does not have a low-hanging telescopic beam underneath the load. This meant there was no need to dismantle obstacles along the route such as crash barriers, fences and walls, which would have been a time-consuming and costly process. The load simply passed over them.
Even overhead motorway gantries did not hinder transportation thanks to the solution’s low overall height. The retractable lifting adapter provides a low hitching point for the base frame. This allowed the wind blade to be lowered as far as possible to also pass under bridges, for example. The driver can raise the hydraulic lifting adapter to the required height whenever the vehicle has to negotiate a traffic island. The wind blade of the E-175 EP5 turbine is the longest that ENERCON has ever developed and produced. The area covered by the rotor circle is 24,000 m² – almost 60 per cent more than the previously best-selling ENERCON turbine type E-138 EP3.
Another factor enabling fast wind blade transportation is the excellent manoeuvrability of the vehicle combination. The four-axle self steering dolly trailer is equipped with DOLL®'s own hydraulic steering system and has a turntable with a steering angle of up to 85 degrees to the left and right. The driver always remains in control, even during the tightest manoeuvres, and can even move sideways in extreme cases. At the same time, the self-steering dolly trailer has a low unladen weight, allowing operation with very large and heavy wind blades along routes with weight restrictions.
The DOLL® system also offers haulage companies a great deal of flexibility. It is approved for the transport of wind blades from all major manufacturers, such as Nordex, Siemens-Gamesa, GE, Vestas, ENERCON and Suzlon. It simply requires the mounting elements and adapters appropriate to the particular wind blade. To this end, DOLL® works closely with its long-standing partner HAWART, which also collaborates with ENERCON. "The close two-way partnership with HAWART made it possible to quickly design the transport racks for our prototype," emphasises ENERCON logistics expert Freericks. "This gave us the certainty that our newly developed wind blade could be transported perfectly."
About DOLL Fahrzeugbau
DOLL Fahrzeugbau GmbH, headquartered in Oppenau in the Black Forest, is one of Europe's leading manufacturers of transportation vehicles for the defence, heavy haulage, airport equipment and timber transport sectors. The headquarters are complemented by subsidiaries DOLL Airport Equipment in Oppenau, DOLL America in New Jersey, DOLL TimTech in Mildenau and DOLL France in Paris. DOLL® also offers training courses, technical support, repair and refurbishment work, on-site service and a 24-hour spare parts service. Used vehicles complete the range of services. Founded in 1878, the long-established company now employs around 420 people building around 1,000 vehicles a year.
About ENERCON
As a pioneer of wind energy technology and a committed supporter of the energy transition, ENERCON has specialised in developing, producing, selling and servicing onshore wind turbines. Pursuing its mission of ‘Energy for the world’, it has been championing sustainable energy generation from onshore wind since 1984. Thanks to its innovative wind turbine technology, high quality standards and a total installed capacity of more than 60 gigawatts, it is one of the world’s leading manufacturers. Headquartered in Aurich, Lower Saxony, the wind turbine manufacturer employs around 13,000 people at administrative, sales, production and service locations around the world.