On 23 May 1944, 2 Canadian Infantry Brigade supported by the North Irish Horse, Royal Armoured Corps, attacked the Adolph Hitler Line between Acquino (Map Reference 7421) and Pontecorvo (Map Reference 7217). Lieutenant Carr-Harris was detailed to command a mine sweeping party to move forward with the leading battalion, the Princess Patricia's Canadian Light Infantry. This was to ensure that the tanks in support of the regiment got through the enemy defences.
At 0740 hours the tanks ran into a minefield in the area Map Reference 74718, 6. This Engineer officer at once moved forward with his party and in spite of heavy enemy artillery, mortar and machine gun fire began to sweep a line through the minefield. He carried on this task until he was wounded in the arm. In spite of his wound he refused to leave the battlefield until he was certain that the tanks were able to advance.
Lieutenant Carr-Harris' personal bravery and determination were an inspiring example to his men to carry on with the difficult task.