“Despite its dimensions, the Mega Windmill Trailer XL drives incredibly smoothly”

May 2022

This interview with Ter Linden Transport previously appeared on Transport en Logistiek.
By: Mirjam Oskam

Ter Linden Transport from Doetinchem has been transporting wind turbines for decades to both new and existing wind farms where the turbines are being replaced. The Gelderland company recently put the first Mega Windmill Trailer XL into use. This unique trailer, developed by Nooteboom, is suitable for the transport of tower parts with a diameter of over 6 meters.


Windturbines. Not only are there more and more, but they are also getting bigger and bigger. In the eighties and nineties, the white colossus still had an axle height of 25 to 30 meters, and the latest generation of wind turbines is a factor of 7 higher. As a result, the base masts are becoming wider, a trend that has major consequences for transport. Ter Linden Transport, specialized in transporting wind turbines, came up with the solution together with Nooteboom: the Mega Windmill Trailer XL. The 4-axle jeep dolly and 7-axle self-steering dolly of the trailer both have an adjustable lift adapter that can be moved in all directions by using a remote control, which makes connecting and disconnecting a tower section very easy.

“In recent years, we have continuously adapted our equipment to the ever-growing masts”, says Nico Koster, managing director of Ter Linden Transport. “Fortunately, we are always informed in advance by wind turbine manufacturers. When the diameter of the tower sections was going to be 4 meters twenty years ago, we sat down with Nooteboom.”

As a result of this conversation, the trailer builder developed the first Mega Windmill Trailer for Ter Linden Transport in 2003, of which 120 are now on the road. “We looked for a solution in which the combination, even with a tower section with a diameter of 4 meters, would fit under a viaduct.” Koster explains that the solution was found in clamping the mast between a jeep and self-steering dolly. The hydraulically adjustable lift adapters allow the trailer to lower up to 5 centimeters above ground level. The solution became the standard in wind turbine transport and other manufacturers also developed a similar alternative.


XL Version Mega Windmill Trailer

Now Ter Linden Transport has a first again. “As soon as we saw that the masts would become even wider, we entered into a dialogue with Nooteboom again”, explains Koster. The result is an XL version of the Mega Windmill Trailer, with which tower parts with a diameter of up to 6,300 millimeters can be transported.

The biggest change from its predecessor is the width of the 7-axle air-suspended self-steering dolly. A width of 2,840 millimeters is necessary to be able to safely move the wider tower parts, sometimes weighing almost 100 tons, over the road, even at high speeds of up to 80 km/h.


Superior Maneuverability 

Koster explains that the maneuverability and ease of operation of the trailer are maximum. “Despite its size, it rides very smoothly due to the large number of steering points.” The track covered is not determined by the steering behavior of the vehicle, but by the size of the tower. The lift adapter at the front is connected to the control system of the trailing dolly via a turntable. The load can rotate at an angle of approximately 80° with respect to the jeep dolly and self-steering dolly, making it possible to make very sharp, almost right-angled and narrow turns without leaving the road.

“Four of the five tower sections of the latest generation of wind turbines are so large that transport cannot simply take place by road.”


The number of steering points also means that maintenance costs are lower than comparable transport solutions. Koster speaks from experience. “Since the commissioning of the first Mega Windmill Trailer in 2003, we have been tracking the maintenance costs per trailer per year and see a clear difference with other trailers. Both the braking system and the tires wear twice as slowly. And there are quite a few tires on it,” he says with a laugh. The jeep dolly is also equipped with electronic air suspension with starting aid for more grip when starting from a standstill.

The unique design and construction of the adjustable lift adapters ensure a very low dead weight of about 7 tons. “That is the advantage of the Mega Windmill Trailer, but also a disadvantage,” explains Koster. “Where other systems are more multifunctional, this one can only be used for wind turbine components. On the other hand, the lower weight and shorter combination length also have advantages in obtaining exemptions.”

Last mile

The new MWT-XL is suitable for wind turbines with different diameters, but the largest tower parts are only transported on the trailer during the last kilometers. “Four of the five tower sections of the latest generation of wind turbines are so large that transport cannot simply take place by road. These parts are brought as close as possible to the final destination via sea and inland vessels, from where we take care of the last mile transport.”

Koster explains that the specialized work requires the necessary preparations. “With a length of 50 meters, a width of more than 6 meters and a total weight of more than 120 tons, it is often quite a puzzle to find a place from where the tower parts can and may be transported to their final destination. It starts with a route study, we make simulations and often road adjustments have to be made as well; that makes it quite complicated. It helps enormously that the load can be lifted up to 1.5 meters above ground level using the lift adapters, so that we can easily turn over a crash barrier, ditch or roundabout.”

Scale up to two or three XL trailers

Ter Linden Transport once started as a towing and salvage service, but has now become a well-known name in exceptional transport. The company has specialized in the transport of wind turbine parts since the early 1990s and, if desired, also provides the correct permits, transport assistance and possibly necessary police escort. Koster expects to scale up to two or three extra large Mega Windmill Trailers in the future. “Not only the number of wind farms is growing, but therewith also the dimensions of wind turbines. ‘Tall trees simply catch a lot of wind’ and we adapt our fleet to that.”

Source: Transport & Logistiek