Fog covered the area around High Wood until 22 July when vague reports of German digging in front of the Switch Line were confirmed. The crew of a 34 Squadron aircraft dived through the mist and saw a new German trench, several hundred yards in front of the Switch Trench, parallel to the British line from Bazentin-le-Peitit to High Wood. This new Intermediate Line was full of German troops and the III Corps headquarters immediately cancelled the 19th Division attack on the Switch Line, to make the new line the first objective. On the night of the 51st Division attacked High Wood with two battalions of the 154th Brigade at to capture the rest of the wood and of the Switch Line. The British bombardment had begun at on 22 July, under the direction of low-flying British artillery-observation aircraft. German sources reported that the shelling was of "painful accuracy" and prevented the troops in High Wood from being relieved, despite the number of casualties. One battalion lost direction in the wood and had many casualties to machine-gun fire. The second battalion attacked up a dip to the south-west of the wood but was also caught by machine-gun fire from the Intermediate Line; by both battalions were back on the start line having lost