The Allies finally had a bridgehead on the Rhine. Over the coming days the Germans tried desperately to destroy the bridge, but to no avail. Eisenhower told Bradley to push five divisions across the Rhine to secure the bridgehead, but he did not let the 12th Army Group take immediate advantage of the opportunity offered. Instead, on 13 March, Eisenhower ordered Bradley to limit the expansion of the Remagen bridgehead to a maximum width of twenty-five miles and a depth of ten miles, lest it detract from the main effort by the 21 Army Group.
Although the Ludendorff bridge collapsed on 17 March, the Allies had built several pontoon bridges across the Rhine by then and had a strong bridgehead on the east shore. Hodges waited only for the word from SHAEF to attack.
Although Eisenhower continued to keep Bradley's 12th Army Group on a tight leash, he did modify his overall strategy in light of the rapid success of LUMBERJACK. At a 17 March meeting with Devers, Patch, and Patton, the supreme commander ordered changes to 6th Army Group's just initiated attack to advance to the Rhine in the Saar region--Operation UNDERTONE. The plan originally directed the Seventh Army to attack in the Saar, while de Lattre's First French Army defended on Patch's flank. Although Devers had initiated UNDERTONE on 15 March, Eisenhower proposed that Patton's Third Army attack across the northern portion of Patch's sector. This would allow the Seventh Army to focus more effort on the portions of the Siegfried Line in its zone. The plan would also create a pincer maneuver, with Patton attacking south and Patch moving north. When asked by Eisenhower if he had any objections to Patton's taking over part of his army's objectives, the affable Patch responded that the object was to destroy German forces, adding 'We are all in the same army.'
Patch and Patton worked out the details for the modified UNDERTONE on the run. The Third Army, though somewhat stretched, rapidly pushed toward Oppenheim, Worms, Mannheim, and Kaiserslautern. Patch's Army had difficulties as its units bumped up against the Siegfried Line. Nevertheless, on 19 March its forces captured Saarbruecken.