Hybrid masts in the Black Forest

Poles for Baden-Wuerttemberg/Germany and Switzerland

The German-Swiss holding Energiedienst AG supplies large portions of Baden-Württemberg and Switzerland with power. One part of the Group, German network operator ED Netze, has been a customer of Tecpoles for more than ten years and orders several hundred hybrid masts each year. In early 2018, numerous wooden masts that had fallen or broken off due to the stormy depression in the Black Forest needed to be replaced unexpectedly as well.

Power failure from the Burglind stormy depression

Dirk Umland, power line team leader at ED Netze, sent pictures from one location “where the Burglind storm knocked down ten wooden masts along a one-kilometre stretch. Only the wood substitute mast that was replaced two years ago remained standing.” The wooden masts fell victim to the well-known domino effect: When one mast fell over, it took down the next. It was only the much sturdier hybrid mast from Tecpoles that put an end to it. All in all, Burglind caused more than 60 medium voltage failures in the southern part of the Black Forest; within two weeks, 15 wood substitute masts were installed to replace broken wooden masts in the area south-east of the Feldberg mountain. While the communities affected were back on the network within a few hours, expert Umland is sure of one thing: “If only wood substitute masts had been installed, we would not have had any power failure at all.”

Large order

“We provide Energiedienst with between 600 and 800 masts each year”, Herbert Gabriel estimates, a sales employee in the back office and on the sales force of the Energy Division of Tecpoles. In this way, the wooden masts – which are either rotten or no longer able to withstand extreme storm events after some 40 years – are being successively replaced.

Hybrid – practical and sturdy

As a long-time customer, Energiedienst was one of the first to learn about the new wood substitute masts, which the Neumarkt company launched on the market in 2008 in two versions: solid-wall steel poles on the one hand and hybrid masts on the other. The lower section is made of galvanized steel and the three-metre long upper section of glass fibre reinforced plastic (FRP).

A few hybrid masts were tested in a pilot project – and were convincing. One thing that impressed the Black Forest company was that the three-metre-long FRP upper sections were drilled directly on site and tailored perfectly to the cross arms being used; another was the fact that the FRP mast sections are so lightweight. “If necessary, they can be carried by hand with only a few men”, Gabriel explains. From that time on, only the hybrid masts have been used by the energy provider in Baden-Württemberg as wood substitute masts for medium-voltage lines.

Hybrid or steel – depending on the cross arm

Energy providers like Energiedienst which also use arch supports or triangular cross arms along with level cross arms have had very positive experiences with the hybrid masts, since the FRP upper section can be drilled directly on site to match the cross beam before being mounted onto the steel lower section, after which the cross arm is attached on top. Bird protection covers are not necessary for the non-conductive plastic version.

Other energy providers are changing over to the level cross arm and exclusively use the somewhat more economical steel solid-wall masts from Tecpoles. In these cases, the steel masts are pre-drilled in the factory so that only the cross arm still needs to be attached on site. Advantage: The customer can order the masts and cross arms from Tecpoles as a complete package.