 Earlier that morning , at 04 : 45 , B and D Companies 3 RAR had moved north across the valley , while Anti @-@ Tank Platoon crossed the Imjin , taking up positions further north in order to protect the right flank . The assaulting companies would then move west towards a series of objectives before assaulting Hill 317 . Initially 3 RAR was to attack from the east , while 1 RNF would attack from the southwest through Hill 217 , however with the Fusiliers facing stiff resistance on Hill 217 itself they were unable to get forward to assist . The previous attempts to capture Maryang San had failed due to the approach to steep eastern slopes of the feature being across a wide , open valley that was dominated by enfilade fire from mutually supporting Chinese positions . Consequently , the Australians planned to cross the valley under cover of darkness and position themselves on the Chinese flank in the foothills , before scaling the position at first light . A Company would create a diversion on the left flank , while B Company would clear the lower slopes before D Company passed through to assault the Chinese main defensive position , known as the ' Victor ' feature , in a one @-@ up , one @-@ in @-@ depth assault . However , following the casualties of previous nights on Hill 199 , 220 and 355 , and the effect of constant shelling , 3 RAR was now reduced to just 320 men . In contrast , the Australians faced two fresh Chinese battalions on Maryang San , in total about 1 @,@ 200 men . 
