army advance, had its hands full on the Roer front. Here there was no immediate assembly problem, although the army would have to plug the gaps left as divisions pulled out for the Ardennes. Ultimately, however, the Fifteenth might be reinforced from the OKW reserve and join the attack. If the Fifteenth Army is excluded the German attack front extended for 143 kilometers (89 miles). The main armored concentration, however, would take place on a frontage of 97 kilometers (6 miles) .
The timetable for final assembly in attack positions required three days, or better, three nights, since nearly all movement would be confined to hours of darkness. To prevent premature disclosure by some unit wandering into the assembly area, all formations except those already deployed on the original Seventh Army front or immediately behind it were banned from crossing the Army Group B base line, twelve miles behind the front, until the final assembly was ordered by Hitler. Once across the base line every movement had to follow rigid timing. For further control the infantry and armored divisions were each assigned two sectors for assembly. Infantry Area I was marked by a restraining line six miles from the front; Area II extended forward to points about two and a half to three miles from the front. Armor Area I actually was east of the base line which served as the forward restraining line; Area II was defined by a line six to ten miles from the front. The armored divisions, of course, would be strung out over greater distances than given here but their assault echelons would be fitted inside the two armored areas.