During all this time a party of about a hundred of the 6th Black Watch and 5th and 7th Gordon Highlanders were in the centre of the "Y" Ravine, where they had been surrounded by Germans who had emerged from dug-outs and tunnels and pinned them to their ground by machine-gun fire. As soon as Colonel Booth and Lieutenant Leslie arrived and a bombing action had begun, these men began bombing outwards from their position, and cleared the whole ravine up to the third German line. General Campbell then ordered the 4th Gordon Highlanders to advance to the Green line. This operation was carried out without opposition, the 6th Black Watch in the Third German line joining in the advance. On arrival in the Green line, the 4th Gordon Highlanders learnt that the 7th Gordon Highlanders had not only reached the Green line according to plan, but had continued their advance 250 yards beyond in the direction of the Yellow line. At this point they encountered and captured fifty Germans. In this advanced position they remained for some considerable time, but as no troops came to support them on either flank, they finally withdrew to the Green line. Every runner that had been sent back by these companies to report their position was either killed or wounded in attempting to pass through the German trench system. Even after the capture of the Green line on the whole Divisional front, isolated pockets of the enemy continued to offer resistance, particularly on the south-western edge of the village. Here a belt of marshy country, just east of the mine crater, had been found impossible to cross owing to the depth of the mud. The result was that the Germans in this area were not put out of action until troops from the reserve had moved round the northern edge of the marsh and attacked them in flank. At 10.30 A.M. two tanks were sent forward to clear up isolated pockets of the enemy still holding out in the village. This was the first occasion on which the Division had co-operated with tanks. The condition of the ground was, however, such that the tanks only just reached the German front line. By the time they had travelled this distance they had built up great mounds of mud under their bellies, which prevented their further advance. One of the tank officers, incidentally a Scot, refused, however, to be prevented from joining in the fight. He therefore made some captured Germans carry his Hotchkiss guns and their ammunition up to the Green line, where he joined in the consolidation.