Smolensk 1943
At the Battle of Smolensk (1943), after a day of probing, the goal of which was to determine whether German troops would choose to withdraw or not from the first set of trenches, the offensive started on 7 August 1943 at 06:30 am (with a preliminary bombardment starting at 04:40 am) with a breakthrough towards Roslavl. Three armies (apparently under the control of Soviet Western Front) were committed to this offensive: the 5th Army, the 10th Guards Army and the 33rd Army, now under General V.N. Gordov.
However, the attack quickly encountered heavy opposition and stalled. German troops attempted numerous counterattacks from their well-prepared defense positions, supported by tanks, assault guns, and the fire of heavy guns and mortars. As Konstantin Rokossovsky recalls, "we literally had to tear ourselves through German lines, one by one". On the first day, the Soviet troops advanced only 4 kilometers (2.5 mi), with all available troops (including artillery, communications men and engineers) committed to battle.
Read more about this topic: 33rd Army (Soviet Union)