Dunno if this will help or confuse the issue further …..
Notes on German Ordnance 1841-1918 by Major James E Hicks, starting from page 44, and slightly edited for brevity -
GERMAN TRENCH AND FIELD ARTILLERY
General Characteristics of Minenwerfer
Balkan War, 1912.
2. It is said that the German officers who served with the Turkish Army against the Bulgarians in 1912-13 recognized the possibilities of such weapons at Adrianople and Chataldja, and it may have been on account of their reports that, before 1914, the Germans had already laid in a stock of them, and obtained considerable advantage by their use when trench fighting began.
Comparison with French Trench Mortar Material.
3. In general, the German Minenwerfer are lighter than French pieces of corresponding calibers, have shorter ranges, and are furnished with recoil and counter-recoil systems. The Fluegelminenwerfer has been said to be a copy of the English 9.2 inch trench mortar.
Hicks goes on to describe three trench mortars in the 'alter Art' (old Model) category -
> leichte Minenwerfer, alter Art (76 mm)
> mittlerer Minenwerfer, alter Art (170 mm)
> schwerer Minenwerfer, alter Art (24.5 cm)
Neuer Art (new model) trench mortars as well as the leicht Granatenwerfer (essentially a small spigot mortar) seem to have been introduced starting in 1916 or so.
This is a rather simplified account, as the topic is quite complicated. Jaeger's book mentions that the French high command had become aware of the existence of German minenwerfers as early as 1913, and that they were employed both in the attack upon Antwerp and in the defense of Hartmannweilerskopf. However, Germany had very few available at the outset of the war and those that they have were, at least initially, employed as specialist weapons by the Engineer branch of the army.
FWIW.
B