carriers. The Panzer Lehr Division's infantry and engineers were entirely mounted in Sd.Kfz. 251 troop carriers, while the 1st Battalion in both Panzergrenadier regiments in 2. Panzer Division and 21. Panzer Division were half-equipped with armoured halftracks (Sd.Kfz. 251 troop carriers for 2. Panzer, U304(f) light armoured personnel carriers for 21. Panzer). German Bundeswehr When the armed forces of West Germany was formed as the Bundeswehr in late 1955, it was decided to readopt the Panzergrenadier doctrine instead of adopting the American doctrine of mechanized infantry using armoured personnel carriers as simple "battlefield taxis" and not as assault vehicles. This led to the development of the Schützenpanzer, lang, Typ 12-3 infantry fighting vehicle, introduced in 1960, followed by the Schützenpanzer Marder 1 in 1971, followed by the cancelled Marder 2 in 1991, followed by the Schützenpanzer Puma in 2010. Bundeswehr doctrine In the German army, Panzergrenadiere act as mechanized infantry and escort for tanks and other armoured fighting vehicles. According to the German central army regulation HDv 100/100 (2000 edition), the Panzergrenadiertruppe and their co-operation with other armoured troops is characterized as following: According to the HDv 231/100, the fighting of a Panzergrenadier Battalion is characterized by the following aspects: "The fighting of the battalion is characterized by: the combination of fire and movement, attacking in conjunction with main battle tanks, swift changes between mounted and dismounted combat, close cooperation between mounted and dismounted forces, the particularly mobile combat, [...]" Bundeswehr Panzergrenadier units After the newest phase of the transformation process the German Army will be fielding the following active Panzergrenadier battalions: Panzergrenadierbataillon 33, Neustadt am Rübenberge Panzergrenadierlehrbataillon 92 (Demonstration battalion), Munster Panzergrenadierbataillon 112, Regen Panzergrenadierbataillon 122, Oberviechtach Panzergrenadierbataillon 212, Augustdorf Panzergrenadierbataillon 371, Marienberg Panzergrenadierbataillon 391, Bad Salzungen Panzergrenadierbataillon 401, Hagenow Panzergrenadierbataillon 411, Viereck Additionally, in 2008 two inactive Panzergrenadier Battalions were formed: Panzergrenadierbataillon 908, Viereck (with Panzergrenadierbataillon 411 as supplying and maintaining unit) Panzergrenadierbataillon 909, Marienberg (with Panzergrenadierbataillon 371 as supplying and maintaining unit) Training and development of the Panzergrenadiertruppe is usually performed by the Armoured Corps Training Centre (Ausbildungszentrum Panzertruppen) in Munster, its commander holding the title of General der Panzertruppen. Some essential training courses, especially for urban warfare and fighting in forested terrain, are held at the Ausbildungszentrum Infanterie ("Infantry Training Centre") at Hammelburg. Bundeswehr Panzergrenadier equipment The main weapon system of the German Panzergrenadiers is the Schützenpanzer Puma infantry fighting vehicles. It was introduced beginning in