 Indeed , the evacuation of casualties and the resupply of ammunition at times proved problematic , and heavy shelling and sniper fire disrupted stretcher parties and porters on a number of occasions , resulting in the forward companies running short of ammunition . Meanwhile , the quality of support given to the British and Australian infantry by the artillery and tanks was of a high standard and proved a critical factor . Indeed , the tanks had often operated in terrain to which they were unsuited , while the New Zealand gunners had fired over 50 @,@ 000 rounds in direct support of 3 RAR , blistering the paint off the barrels of their guns . Air support , including that provided by the South African Mustangs , had been important throughout . 
