"Der Herr erschuf in seinem Zorn den Imbert mit dem Rütteldorn" - "the lord in his wrath created imbert with the..." "Rütteldorn" is difficult to translate. Imbert-Systems needed regular loosening of the pieces of wood. A metal rod was used for this, so called "Rüttelstange". That was a hard and dirty job. Therefore it was a very "popular job" with drivers and, better, stokers.