Franz Grollmann (1911–1999) was a German organ builder born in Hamburg. He began his career in organ building in his hometown, where he completed his master craftsman examination on January 10, 1940. After returning from being held as a prisoner of war in Siberia, Grollmann worked for Paul Rother and later became an intonateur at the workshop of Rudolf von Beckerath in Hamburg from around 1951 to 1958. In 1958, he established his own organ-building workshop in Hamburg, which he operated until 1977. His workshop specialized in building organs with mechanical or electric action.

In 1960, Heinz Hoffmann joined Grollmann's workshop, eventually taking over the business in 1977 and renaming it "Heinz Hoffmann Orgelbau." Hoffmann had also trained at Beckerath and continued the tradition of organ building, producing around 40 new organs and undertaking numerous restorations and modifications until 1990. The business was further passed on in 2001 to organ builder Martin Harms, who relocated the workshop to Stelle in the Harburg district.

https://de.wikipedia.org/wiki/Franz_Grollmann