The 1st Commonwealth Division, of which 3RAR was a part, was to advance across the Imjin River and take a line of heights from 19th Chinese Division. The Chinese line was not continuous, but rather consisted of company and battalion sized entrenchments on the key hills. Maryang San (Hill 317) is the steep hill in the left far distance. This photograph was taken from UN lines prior to the assault on the hill. In October 1951 the hill was captured by 3rd Battalion, Royal Australian Regiment during Operation Commando. Lt Colonel Frank Hassett, commanding 3RAR, used a tactic that had been successful for the Australians against the Japanese in similar terrain in New Guinea during WWII. Called running the ridges, it involved attacking along the crest of a ridge rather than up the sides. The operation began on 3 October with 28th Brigade attacking supported by 16th Field Regiment, Royal New Zealand Artillery and Centurion tanks of 8th Kings Own Irish Hussars. First B Company 3RAR took Hill 199 which Hassett intended to use as a base for the main attack along the Maryang San ridge two days later. Meanwhile C Company moved forward to support the attack of the Kings Own Scottish Borderers (KOSB) on the next hill to the south, Kowang San. The KOSB attack failed, so on the following day C Company was committed to attack the hill from the north-east. This time the hill fell. On 5 October the main assault on Maryang San commenced. In a successful attempt to deceive the Chinese that the main Australian attack was coming from south of Maryang San, A Company attacked west along a parallel ridge, capturing a Chinese position and drawing local Chinese reserves towards it.
The main attack along the northernmost ridge was a series of company assaults. First B Company took ‘feature whiskey’ and provided fire support when D Company assaulted through and took the next two Chinese positions. Lastly C Company, which had marched by a circuitous route from Kowang San, passed through B and D Companies along the ridge top and seized the crest of Maryang San. The battle was not yet won as ‘the Hinge’ and Hill 217 remained in Chinese hands. Believing 3RAR required support to take the whole hill, the divisional commander sent the Royal Northumberland Fusiliers (RNF) to aid 3RAR. This battalion attacked but failed to take Hill 217. On 7 Oct 3RAR, now in one body along the spine of Maryang San, attacked and took the Hinge. Chinese reinforcements from 3rd Battalion 571 Regiment arrived to counterattack. A bombardment from Chinese artillery, the worst the Australians had experienced in the war so far, preceded an assault by the fresh Chinese battalion but the assault failed. The Chinese conceded defeat and withdrew to the next line of hills two kilometers away, also evacuating Hill 217.
Australian casualties were 20 killed and 104 wounded. The two Chinese battalions that 3RAR opposed lost 340 killed and wounded. The taking of Maryang San has been seen as a classic battalion operation and is described in the official history as ‘the greatest single feat of the Australian Army during the Korean War.’