Its left forward company, which held the railway bridge northwest of Dernancourt, had a Lewis machine gun post thrust out on the far side of the bridge. The 52nd Battalion's fourth company was located in a valley north of Buire-sur-l'Ancre near battalion headquarters, but the 4th Pioneer Battalion had dug a series of support posts along the lower slope, about behind the railway line. These posts ran through an abandoned casualty clearing station (CCS), but did not reach as far as the cemetery west of the Dernancourt–Laviéville road. Being on an exposed slope, these posts were unoccupied during the day, but the fourth company had orders to occupy them in case of attack. If this occurred, the commanding officer of the 52nd Battalion, Lieutenant Colonel John Whitham, had been given a company of the 51st Battalion, which was to automatically replace the fourth company of the 52nd Battalion in the valley north of Buire-sur-l'Ancre as soon as it moved forward. In the 13th Brigade area was another unoccupied trench, located at the top of the slope, about to the right rear of the 47th Battalion's support line, which had been dug prior to First Dernancourt. Two pairs of Vickers guns of the 13th Machine Gun Company were deployed on the slope above the railway embankment, with a third pair in the area of the left forward company, and several others further west. Whitham had also been given the rest of the 51st Battalion to use as reinforcements if necessary. In the meantime, the balance of the 51st Battalion was deployed along a line running south of and parallel to the Albert–Amiens road, north and northwest of Buire-sur-l'Ancre. The remaining battalions of the 13th Brigade, the 49th and 50th Battalions, were held as the divisional reserve in a line well to the rear, west of the village of Bresle. The 13th Brigade had substantial British artillery support available, comprising the 95th Royal Field Artillery (RFA) Brigade, belonging to the 21st Division, as well as the 65th and 150th RFA Brigades, which were Army-level assets. These artillery units were deployed on the eastern outskirts of Bresle. The German attack against the 4th Division, known as "Unternehmen Sonnenschein" (Operation Sunshine), was to be delivered by the XXIII Reserve Corps using three divisions.