Wind turbines… majestic giants of the sky, rooted to the ground or standing proudly out to sea. At the heart of many turbines is a ZF gearbox, which is converting kinetic energy in the wind via the endlessly spinning blades into electrical energy via the generator. The bigger the giant, the bigger the heart and all hearts need to be looked after - no matter their sizes. When it’s time for a check-up or even a bit of surgery, you need the right team.
The ZF team of up-tower technicians are the heart surgeons of the wind industry. Often, their operating theatre is 80 or more metres above the ground or the waves, temperatures vary widely and there is nearly always swaying of the workplace.
Marla has worked as a ZF Wind Power up-tower service technician in the US market for almost 4 years. She is challenged by heat, cold, rain, wind and more at these giddy heights. This makes her the perfect person to immerse us in the varied and exciting world of life up-tower.
During their missions, our sky warriors have amazing views from the top of the turbine. But how do they get there?
Technicians travel to the top with a ladder. “It is a physically demanding job,“ says Marla. “It’s not only the ladder, but you’ll have to carry the tooling with you as well. Of course there’s also the safety harness you’re wearing and the rescue gear. You can never leave without. Let’s say we always carry some 20 kilos extra with us.”
ZF Wind Power has developed its own precision tools to guarantee safe, high quality up-tower repairs. The company has designed specialist tooling for each gearbox model. When used in conjunction with carefully prepared and clearly defined working procedures, these tools guarantee the safety of the team and result in successful up-tower interventions. Large or heavy components are lifted to the nacelle by way of a crane. As the use of the crane is limited by a maximum wind speed of 8 m/sec - a speed often below the average wind speed at most sites (8-12 m/sec – depending on the site and the time of the year) it can happen that the team has to wait on site for a couple of days for safe operating wind conditions.
Mostly, the ZF field service team operates in the nacelle at height, but part of the job is done a lot closer to the ground in the workshop. “Many components are preassembled at one of our service facilities. In the USA, our Vernon Hills service center has a stock of gearboxes and components. Keeping a pool of gearbox components means component assemblies can be preassembled in the workshop, limiting the amount of work to be done on site. Working this way, components can be replaced within a few days if needed,” explains Marla. Thanks to ZF Wind Power’s unique Spare Parts Optimization Service, the team is also aware ahead of time when components will need to be replaced. This enables preparation that ensures access to the right component at the right time and thus minimizes any downtime.