 The initial attacks on Shaggy Ridge began on 27 December with a heavy artillery and air preparation of the Japanese positions around The Pimple, a steep rocky outcrop, which commanded the southern half of the position and had prevented the Australians advancing over the previous two months.These preparatory fires were followed by an assault up the steep slopes of The Pimple by the 2/16th Infantry Battalion, which employed ladders made out of bamboo to help scale the face of the slope.Held up overnight by a Japanese pillbox, the 2/16th resorted to explosives to destroy it.