Light Artillery Shell (1)

Have two identical shells, ca. 170mm long (including projectile head, itself about 40mm diameter, 108mm length) brass shell casing 94mm length, 44mm diamter at the firing pin lipped end, Inscribed: Sgt Major E. Rowlands [Edward Rowlands, my grandfather] 115 Trench Mortar Bater[y] [polished, unclear] TRECH [assumed to be surname of maker, German POW?]