1st Division's advance continued to be slow. The German defenders were in a favorable heightened position, from which they could overlook the approach routes of the Allied forces. The German tactic was to fight mainly in the thick woods, where American artillery and aerial support was ineffective and a state of bloody trench warfare emerged. The Americans had to take hill after hill in heavy fighting, while casualties were mounting. Numerous German counterattacks slowed the advance down even more, often taking back ground which had just been captured in a bloody fight. In an act of desperation, Collins moved in virtually all of his available artillery to blast a way for the 1st Division on 21 November. With the Allied advance already flagging in the first phase of the offensive, CCA of the 3rd Armored Division was assigned to the northern part of the 1st Division's left flank. The armored attack was able to capture the castle at Frenzerburg (near Inden). This fight lasted until 28 November. Meanwhile, GFM Rundstedt decided to inject some reinforcements into the battle, but only if two divisions were simultaneously pulled out from the front for the Ardennes Offensive preparations. Therefore, the 3rd Parachute Division was transferred to the front, while the bled out 12th and 47th VGD were withdrawn. The logistical difficulties and the inexperience of the new opponent aided 1st Division and it was finally able to push out of the forest, taking Langerwehe, Jüngersdorf and Merode by 28 November. Nevertheless, the dire situation did not change, and a violent counterattack by 3rd Parachute Division at Merode led to the destruction of two companies. At the beginning of December, 1st Division was worn out and had already suffered about 6,000 casualties.