99.5906 was one of seven 0-4-4-0T Mallets built by Maschinenfabrik Gesellschaft Karlsruhe for the German army in 1918. The design was based on a batch of Albtalbahn locos that were similar to, but not the same as, the Nordhausen Wernigerode Eisenbahn Mallets. The army sold the locos in 1920 with one going to the NWE as their No.41, renumbered by DR to 99.5906.
The loco was photographed on Gernrode shed after it had finished working service trains for the day on 10 October 2015.