Transformatorenhaus, Technology museum in Lohr am Main, Germany

The Transformatorenhaus, known as the Isolatorenmuseum, is a technology museum in Lohr am Main housed in a disused tower substation on Haaggasse. Its two floors, each measuring 2.5 by 2.5 metres, hold more than 600 insulators from over 40 countries, collected by electrician Lothar Vormwald and his wife Daniele. The exhibits range from finger-thimble-sized telecommunications insulators to a three-part 380-kV chain over 3 metres long and weighing 150 kg.

The building was constructed in 1920 as a transformer station and converted to a museum in 2004 to document the evolution of electrical infrastructure. This repurposing preserved the original structure and made its technical history publicly accessible.

The collection displays porcelain and glass insulators from many countries, showing how power transmission evolved throughout the 20th century. Visitors see handcrafted pieces alongside modern industrial products and understand the practical demands of this hidden infrastructure.

The museum has limited opening times and typically requires advance notice for visits. It helps to check opening days ahead and contact directly if interested in visiting.

The smallest pieces are insulators from telecommunications lines, no bigger than a thimble; the largest is a three-part chain from a 380-kV line, over 3 m long and weighing 150 kg. Most of the insulators date from 1919, the same year as the building, and many still show their maker's mark and year.