Unable to push north into the Netherlands, the Allies in western Europe were forced to consider other options to get into Germany. In the summer of 1944, the Allies suffered from a large supply crisis, due to the long supply route. But by the fall of 1944, this had largely been resolved by the Red Ball Express. As part of the Siegfriend Line Campaign, the Allies tried to push into Germany towards the Rhine. As a first step, Aachen was captured during a heavy battle. The Germans now had the advantage of their old fortification system, the Siegfried line. During the Battle of Hürtgen Forest, the Allies fought a long battle of attrition with the Germans, which ended initially in a stalemate, with the Allies unable to take the complete forest. The battle of the Hürtgen Forest was later absorbed by a larger offensive, Operation Queen. During this offensive, the Allies intended to push towards the Ruhr, as a staging point for a subsequent thrust over the river to the Rhine into Germany. However, against underestimated and stiffened German resistance, the Allies were only able to make slow progress. By mid-December the Allies were finally at the Rur, but by then the Germans had prepared their own offensive through the Ardennes, which was launched in the midst of an unsuccessful Allied attack against the Rur dams.