The conditions under which the action was fought were in some respects new. There was a well-defined trench line, running right across the Divisional front about 150 yards from the British front line, known as Pheasant Trench and New Trench; and, again, some 1200 yards in rear, Kangaroo and Beer Trenches also traversed the Divisional front. The defence, however, primarily consisted of concrete pill-boxes and fortified farms distributed throughout the area to be attacked, supported by troops concealed in shell-holes.[8] To meet these conditions every known "pill-box," farm, or fortified post had a specific body of troops detailed for its capture. The sole business of these troops was to follow the barrage until they reached their own particular objective, to overcome the enemy in the objective as quickly as possible, and then take their appointed place in the scheme of consolidation. In addition, the very fullest use was made of the enormous artillery and vast supply of ammunition at the disposal of the Divisional commander. The part played by the gunners in this attack was indeed considerable, the Divisional artillery, as usual, carrying out its allotted programme faultlessly. Briefly the artillery plan was as follows: The barrage was organised in depth in four zones. First came the main creeping barrage. This was fired by the 18-pounder batteries of the 255th, 256th, 58th and 59th Brigades, R.F.A., and advanced at the rate of 50 yards every two minutes for the first 200 yards, every three minutes up to the first objective, and finally 50 yards every four minutes up to the Blue line. In other words, the maximum average rate at which the infantry following the barrage could advance was 1500 yards per hour, the minimum 720 yards per hour--a cold-blooded operation which allows plenty of time for reflection. The 18-pounders of two further brigades of artillery fired a creeping barrage 100 yards beyond the main barrage. When the first objective had been captured, a pause in the advance of an hour was arranged, to allow time for cleaning up any pockets of the enemy still holding out, and for the troops for the final objective to move forward and deploy behind the barrage before it moved on. During this pause the No. 3 guns of each battery fired smoke shells, so that a screen of smoke was provided which concealed the infantry from the enemy's view.[9] Two hundred yards beyond the creeping barrage came the combing barrage. This was composed of all the 18-pounder batteries of the 65th Brigade Army field artillery, while a further 300 yards beyond all the howitzer batteries of the artillery at the disposal of the Division were employed. The combing barrage dwelt on all "pill-boxes," strong posts, &c., and also worked up and down the communication trenches. Beyond the combing barrage was a neutralising barrage of 6-inch howitzers and 60-pounder guns, which also dwelt on pill-boxes, &c.