Not military, but almost 20 years in a heavy rescue and engineering unit of the German civil defense. The unit was non-combatant (though I got trained in explosives and demolitions), but in many aspects equipped like a military engineering platoon in the British Territorial Army. Rank structure was based on the military one, but with different names due to the non-combatant status.
Smallest unit was a “Gruppe” (section), 12 guys riding on one truck (divided into two teams (“Trupps”) of four plus team leader (“Truppführer”) each, a section leader (“Gruppenführer”) and a driver. Two (respectively 3 for a reinforced platoon) rescue sections plus one heavy equipment support section ( 1 Section leader, 1 driver, 5 men in a support equipment truck) plus one platoon command team (1 platoon leader “Zugführer”, 1 driver, 1 platoon command team leader ,“Zugtruppführer”, equivalent of a platoon sergeant and one dispatch rider) formed one platoon (“Zug”).
Service was/is voluntary. During cold war our training was aimed at rescueing people from collapsed buildings after bomb raids, NBC protection/ decontamination, reconstruction of damaged and destroyed essential infrastructure, like roads, bridges, drinking water supply, sewage disposal (to prevent diseases), repair of essential gas and electricity connections.
My highest rank was acting section leader.
Jan