Battle of Slater's Knoll - Aftermath

Aftermath

The day after the final Japanese assault on the knoll, 292 dead Japanese were counted around 'B' Company's perimeter. In total, over the course of the battle, the Australians counted 620 Japanese killed, and estimated that another 1,000 had probably been wounded. Four wounded Japanese were also taken prisoner of war. Casualties for the Australians included 10 officers and 179 other ranks killed or wounded, while there had been a further 81 Australians evacuated due to non-combat related issues. Wartime Japanese casualty estimates vary from these figures, however, claiming to have killed 1,800 Australians, while placing their own losses at 280 killed and 320 wounded. These figures are problematic, however; based upon the same report, the Japanese believed that there were only 400 Australians in the region during the battle, and yet they claimed to have killed almost five times that number.

Operationally, the battle proved to the Australian high command how effective armour could be when used in close co-operation with infantry and in protecting the lines of communication. Ultimately the battle proved to be a decisive Australian victory; however, if the Japanese commander had been more flexible in his tactics, the result might have been different. The Australian right flank had been vulnerable, but Akinaga did not exploit this opportunity. The Australians also failed to seize opportunities as they arose, for after the battle they did not follow up their success immediately. After the failure of the final assault, the Japanese had possessed no forces in the immediate vicinity that would have been capable of resisting any follow up forces that the Australians might have been able to bring up and it is possible that an advance could have been carried all the way to the Hongorai River. As it was, however, the Australian line of supply was stretched and it was necessary for a pause before the advance could continue in earnest.

In the days immediately after the battle, the Australians continued to carry out patrolling operations around the knoll. On 7 April, a patrol from the 9th Battalion clashed with a Japanese force of about 30 men and in the ensuing engagement four Japanese were killed, while a patrol from the 61st Battalion on 8 April killed another five. On 13 April, however, it was announced that the 7th Brigade would be gradually withdrawn and relieved by the 15th. Shortly afterwards, the 58th/59th Battalion replaced the 25th in occupation of the knoll, while the 24th Battalion resumed the advance along the Buin Road on 17 April, subsequently taking part in the fighting along the Hongorai River. The 9th Battalion, however, was not withdrawn immediately, and remained in the northern area until it handed over to the 57th/60th Battalion in early May. The fighting on Bougainville continued throughout April as the Japanese resisted the Australian advance and went on until July when the fighting petered out due to heavy rain and flooding.

After the war, the battle honour of "Slater's Knoll" was awarded to the 25th Battalion and the 2/4th Armoured Regiment. Neither the 9th or 61st Battalions were similarly credited, although there seems to be no explanation as to why.