Son of Francis O'Brien and of Eily Anne O'Brien (nee Yearbury), of Auckland City, New Zealand

At dawn on the 26 March the two infantry brigades lay well concealed on their start lines with both flanks secured. The attack was planned to take place at 4 pm by which time the armoured division would be in readiness. The 8th Armoured Brigade with each of its three tank regiments leading one of the infantry battalions, would cross the Roman Wall as the barrage came down on its opening lines, and would then move behind the barrage with heavy tanks in the lead, followed by light tanks, after which would come infantry carriers. The infantry would follow on behind the armour as it crossed their start lines and make for the first objective which lay 2000 yards ahead along a line running at right angles to the El Hamma road. The final objective was 3000 yards beyond the first, along the line of the Wadi Hernel and beyond the summit of the pass. The El Hamma road was the right boundary of 24 Battalion's advance, and its point of contact with 23 Battalion's left. On 6 Brigade's western flank, 25 Battalion was to give supporting fire to the advancing troops, and also assist the Divisional Cavalry in mopping up the Djebel Tebaga foothills. The 1st Armoured Division would move up the rear of the assaulting lines, pass through the New Zealand Corps on its final objective at dawn and wait there till the moon rose soon after 11pm before going on to capture El Hamma.

A dust-storm was blowing on the morning of 26 March, but it abated to some extent after midday and the air cleared. This was fortunate as a concentrated air attack was to be made on enemy lines half an hour before zero by fighter pilots and tank-busters. Tanks of 8 Armoured Brigade lay concealed in wadis and behind spurs on the high ground to the right and left. Under a continual rain of fine blown sand the men of the 24 Battalion had to lie in close, as their trenches were on an open flat. Gradually the day wore on, and early in the afternoon the period of suspension merged into one of sustained action. AWMM