southern part of the battle (involving French forces) called Battle of Montdidier (). The infantry had outrun the supporting artillery, and the initial force of more than 500 tanks that played a large role in the Allied success was reduced to six battle-ready tanks within four days. On the Canadian front, congested roads and communication problems prevented the British 32nd Division from being pushed forward rapidly enough to maintain the momentum of the advance. The Chipilly Spur was still in German hands. The Germans on the ridge commanded a wide field of fire to the south of the Somme, and poured devastating machine gun and artillery fire that kept the Australian Corps pinned down across the river at Hamel. The job of taking Chipilly Ridge was ultimately assigned to three battalions of American doughboys from the 33rd U.S. Infantry Division. According to B.J. Omanson, During the 33rd U.S. Division's assault on Chipilly Ridge, Corporal Jake Allex, a Serbian immigrant from Kosovo, took command of his platoon after all the other officers had been killed. Corporal Allex led them in an attack against a German machine gun nest, during which he personally killed five enemy soldiers and captured fifteen prisoners. For his actions at Chipilly Ridge, Corporal Allex became the second American soldier to be awarded the Congressional Medal of Honor during the First World War. On 10 August, there were signs that the Germans were pulling out of the salient from Operation Michael. According to official reports, the Allies had captured nearly 50,000 prisoners and 500 guns by 27 August. Even with the lessened armour the British drove into German positions by 13 August. Field Marshal Haig refused the request of Marshal Foch to continue the offensive, preferring instead to launch a fresh offensive by Byng's Third Army between the Ancre and Scarpe. This offensive, the Second Battle of the Somme, took place 21 August – 3 September 1918. Aftermath The Battle of Amiens was a major turning point in the tempo of the war. The Germans had started the war with the Schlieffen Plan before the Race to the Sea slowed movement on the Western Front and the war devolved into trench warfare. The German spring offensive earlier in 1918 had once again given Germany the offensive edge on the Western Front. Armoured support helped the Allies tear a hole through trench lines, weakening once impregnable trench positions: the