The III. SS-Baubrigade was a forced labour unit manned by camp inmates that was formed in September 1942 at the Buchenwald camp.

Commanders

SS-Obersturmführer Karl Völkner (15 Sep 1942 – ? June 1944)
SS-Oberscharführer Freys (? June 1944 – 20 July 1944)
SS-Obersturmführer Fritz Behrens (21 July 1944 – ? Apr 1945)
SS-Untersturmführer Merkle (? Apr 1945 – ? May 1945)

Sources used

Karola Fings - Krieg, Gesellschaft und KZ: Himmlers SS-Baubrigaden
Andrew Mollo - Uniforms of the SS: Collected Edition

Reference material on this unit

Karola Fings - Krieg, Gesellschaft und KZ: Himmlers SS-Baubrigaden