The two South African brigades advanced with 40mm Bofors guns marking the lines of advance between the respective battalions and the first objectives on the Corps objective line called "Oxalic" were occupied by the Natal Mounted Rifles at 2350. The Cape Town Highlanders were the last battalion to reach their individual unit objectives on Oxalic – and were established on Miteiriya Ridge by 0800 the following morning. The fact that the 1st and 10th Armoured Divisions had not broken through into the open areas west of the line as originally planned, meant that Montgomery had to change his orders – moving to an attritional World War I type of battle, which Montgomery in a semblance of a novelty – dubbed "Crumbling Actions." By the evening of 26 October (as from the H-Hour on the 23rd), the South Africans had suffered 600 casualties, as compared to 2,000 in the 51st Division, 1,000 Australians and a similar number of New Zealanders.