Battle of Crater Hill The Battle of Crater Hill was the last part of the Shaggy Ridge campaign . It was the Japanese regimental headquarters , and it was here the defences were well positioned and entrenched . Last - ditch fight . Despite the Japanese loss of Kankiryo Saddle and Shaggy Ridge , the Japanese intended to put up a last - ditch fight for their regimental headquarters on the peak of Crater Hill . This was the main Japanese stronghold in the area and was atop a knoll north east of Kankiryo Saddle . Battle . On the 25th the Australian 2 / 10th and 2 / 12th probed the Japanese defences on all sides of Crater Hill seeking the most suitable approach for an attack . There were skirmishes in which both sides suffered casualties . A patrol led by Lieutenant Coles of the 2 / 2nd Pioneers , fired on small bands of retreating Japanese infantry and saw numerous positions and ammunition dumps which had been abandoned . Brigadier Frederick Oliver Chilton was informed that the main attack was held up on the southern slopes of Crater Hill , and at this point decided to try encircle and surround the Japanese . While the 2 / 10th and 2 / 12th held the enemy on the southern slopes and tried to push forward or flank the position , the 2 / 9th decided to assault the feature by sending two companies in a wide outflanking movement to the north across the tip of the Mindjim Valley and round the Japanese right flank . Marshall ' s assault . Captain A . Marshall ' s company led off around 10 : 30 , the morning of the 26th , passing from Shaggy Ridge through Kankiryo Saddle and then to the north , with Captain Taylor ' s company following to provide flank protection . By midday Marshall reported that he had advanced some and passed through several abandoned positions although he had seen no enemy . He pushed on at 5 : 00 pm in the afternoon he reached the summit of 4100 . The main Japanese position was now to the south between Marshall and the 2 / 10th and 2 / 12th Battalions . Leaving Taylor to occupy the summit of 4100 , Marshall moved south towards Crater Hill in an attempt to surprise the Japanese position from the rear . He met them about south - east from the summit just on dusk . The leading Australian infantry platoon attacked but withdrew because of heavy machine - gun fire . At 7 : 00 pm Marshall sent 6 platoon , commanded by Lieutenant White , round the right flank . Approach from this flank was hazardous and White was killed . Japanese surrounded . The Japanese on Crater Hill were now surrounded . Chilton at this point realised the positions were well prepared for defence , and a large number of machine guns were positioned . He decided to opt for a siege of the headquarters , using mortars , artillery , and dive bombing aircraft . Following further harassment from the Australian infantry , and dive bombing from Kittyhawk fighters and mortar attacks , the Japanese were gradually being weakened , and started to retreat from Crater Hill . A company led by Captain A . Marshall , the 2 / 9th , got to within of the summit , but could not get past the trees and the steep rockface . Another company , led by a Captain Taylor , made an alternate attack and killed 19 Japanese , while Marshall retreated to Kankiryo Saddle . Mallyon ' s command . Lieutenant A . R Mallyon took command . On the 1 February , his company , the 2 / 10th and Taylor ' s of the 2 / 9th finally closed in the summit and entered the entrenchments , found them to be abandoned , the Japanese had fled their headquarters position . Mallyon was then amazed to see two Salvation army officers approaching the position from the other direction , laden with comforts . They explained to him and his surprised troops they had approached the area because they had been told it was unoccupied the previous day . After the battle , the area was surveyed and found to contain 40 pillbox es and foxholes , in the immediate Crater Hill area , which the Australians had fought through , and 100 or so in the immediate vicinity . The Japanese had left a number of dead and some artillery pieces .