 Major H. Wrigley 's 2 / 5th Infantry Battalion of Brigadier Stanley Savige 's 17th Infantry Brigade , reinforced by two companies of Lieutenant Colonel T. G. Walker 's 2 / 7th Infantry Battalion , now took over the advance . The battalion 's task was to clear " The Triangle " , a map feature created by the intersection of three tracks north of Post 16 . Wrigley 's force had a long and exhausting approach , and much of its movement forward to its jump off point had been under Italian shellfire intended for the 16th Infantry Brigade . Awaiting its turn to move , the force sought shelter in Wadi Scemmas and its tributaries . Wrigley called a final coordinating conference for 1030 , but at 1020 he was wounded by a bullet and his second in command , Major G. E. Sell took over . At the conference the forward observer from the 2 / 2nd Field Regiment reported that he had lost contact with the guns and could not call in artillery fire . A wounded British tank troop commander also reported that one of his tanks had been knocked out and the other three were out of fuel or ammunition . No tank support would be available until these had been replenished . Sell decided that the attack must be carried out without them . 
