Energiefabrik Knappenrode in <a href="//commons.wikimedia.org/wiki/Hoyerswerda" title="Hoyerswerda">Hoyerswerda</a>-Knappenrode: Planetary gearing of about 2 m in diameter
Frank Vincentz
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>