Shells were tested successfully at the Wahn artillery range near Cologne on January 9, 1915, and an order was placed for 15 cm howitzer shells, designated ‘T-shells’ after Tappen. A shortage of shells limited the first use against the Russians at Bolimów on January 31, 1915; the liquid failed to vaporize in the cold weather, and again the experiment went unnoticed by the Allies.