The wintrack - slender Transmission Towers for the Randstad380 Trail
The new pylons that will be used for the Randstad380 project use a very different visual language than the old steel lattice constructions. Thanks to their contemporary and restrained shape and colour they are less disruptive and blend well in the Dutch landscape. Furthermore they create a smaller magnetic field.
The familiar steel truss pylons have been used for decades. Designed to last a hundred years, they are strong, reliable and transparent due to their subtle structure. However, they do have a number of disadvantages. Apart from maintenance issues, it is mainly the width of the magnetic field that poses a problem. Because of the width of the steel truss the conductors are hanging far away from each other, leading to building restrictions of approximately 300 m along the power line. And that is a problem in the densely populated Randstad.
For the new part of the trail that completes the 380 kV circuit in the Randstad, Zwarts & Jansma has designed Wintrack, new pylons that solve these problems. Now, the clustered circuits are attached to two slender cones. Because the conductors are placed close to each other, they considerably reduce each others magnetic fields. This means that the building restrictions due to the magnetic field can be reduced to 100m. The impact of the magnetic can be even further reduced by hanging the conductors higher, increasing the height of the pylons or by placing them in close succession.
The new pylons are also advantageous regarding maintenance. Because of the simple and smooth structure they are less damageable. Even though not much maintenance work is expected, various possibilites of maintenance work have been anticipated. The highstep system will be used to climp the pylons. Contrary to the traditional climbing irons one uses one rail that can only be climbed with special material. That way the pylon gets not only more beautiful, but attracts less misuse.
Photographs: TenneT/Chris Pennarts, Tom Bakker