"considerable exercise of firmness" was needed to get them to obey orders. Thiepval Ridge After Flers-Courcelette (15 Sep) Haig, perhaps believing a decisive breakthrough to be imminent, initially envisaged Gough attacking Thiepval, together with further attacks by Fourth Army and by the French further south – an attack by ten divisions. Gough's plan was for 18th Division to capture Thiepval and Schwaben Redoubt, 11th Division to capture Mouquet Farm and Zollern and Stuff Redoubts (roughly north of Mouquet Farm) while on the right 1st and 2nd Canadian divisions were to attack from Courcelette to Regina Trench which lay just beyond the ridge line. Gough allocated all seven of his tanks (five of which broke down before reaching the lines) to the Canadians. The preliminary bombardment began on 23 September. This was the heaviest barrage yet fired by Reserve Army, assisted by an indirect machine gun barrage into the German rear areas. Gough had 570 field guns and 270 howitzers to attack along a front (roughly twice the concentration of 1 July, but only half that of the Battle of Bazentin Ridge on 14 July and much the same as that of the Battle of Flers–Courcelette on15 September. Allenby's Third Army was to co-operate with an attack on Gough's left flank (Haig diary 24 September 30 September). In the event poor weather delayed the attacks until the early afternoon of 25 September. As Gough planned to use a few tanks to assist his attack, Haig ordered him to delay until the following morning when they could be concealed in the morning mist but in the event further delays, for which the reason is unclear, meant that Gough attacked at 12:35 pm on 26 September, exactly a day after Rawlinson and Foch. Four divisions of Canadian and II Corps attacked between Courcelette and Schwaben. The Battle of Thiepval Ridge was Gough's most ambitious operation to date. The attack of 26 September showed the improvement in British tactics. Mouquet Farm at last fell in the afternoon. On the western sector, lodgements were gained in Zollern, Stuff and Schwaben redoubts and British forces pushed to the edge of St Pierre Divion. Thiepval was surrounded and captured by Maxse's highly trained 18th Division by 08.30 on 27 September. By 30 September, after fierce hand-to-hand fighting in which the British suffered 12,500 casualties, had been gained, an advance of between . Regina Trench and parts of