In this same sector Marines in late September attacked the northern slope of Hill 122, where the enemy still maintained a foothold. The proximity of Marine defenses at Bunker Hill to enemy positions, separated in some places by as little as 30 yards, was the cause of frequent contact and clashes. Marines raided the enemy side of Bunker, using demolitions and portable flamethrowers to destroy trenches and bunkers, and their occupants. Tanks and artillery assisted in these brief offensive actions, usually undertaken at night. Flares were used frequently to aid in identifying and striking targets and in assessing the results.
It became routine during the last days of September for the Chinese to probe the Marine defenses at the Hills 124–122 axis. There did not appear to be a serious or determined assault to take either outpost, however. The Marines considered the infantry probes as just another form of harassment, although perhaps more personal and direct than the Chinese shelling, which inflicted daily losses. On the division right, Colonel Moore’s 7th Marines, which had moved into this sector on 7 September, found enemy activities about the same. Artillery rounds caused the greatest number of casualties, although these attacks were not particularly spirited. Many enemy contacts occurred during the Marine combat patrols that largely characterized frontline operations at the end of September.
Chinese Intensify Their Outpost Attacks[225]
[225] Unless otherwise noted, the material in this section is derived from: FMFPac, 1stMarDiv Sum, Jul-Oct 52; 1stMarDiv ComdD, Oct 52; 1stMarDiv G-3 Jnls, 1–7 Oct 52; 1stMarDiv PIRS 706–713, dtd 1–8 Oct 52; 1stMar, 5thMar, 7thMar, 11thMar, 3/1, 1/7, 2/7, 3/7 ComdDs, Oct 52; KMC Regt UnitRpts 214–220, dtd 2–8 Oct. 52.
With the beginning of October, the 1st Marine Division became aware of certain changes that were occurring to its front. In the center sector, for the first time in two weeks there was no significant enemy ground activity, yet across the entire Marine front there was a build-up of enemy shelling. Part of the increased bombardment was directed at Hill 86 in the KMC sector, one of the positions recently cited as integral to the defense line in this area. Beginning at 2000 on 1 October, the Chinese broadcast a warning that they would knock down the outpost bunkers there unless the Korean Marines surrendered. When the KMCs manning the position did not, of course, surrender in reaction to this blatant propaganda tactic, the Chinese began showering Hill 86 with artillery rounds. During the next 20 hours, 145 rounds fell on and around the outpost. This incident marked the first time that the Chinese mainline forces had carried out an announced threat.
This type of operational tactic—first to warn, then to carry out the threat—was not, however, the reason for the increased Chinese shelling. Rather, as it turned out, the enemy was about to embark on a series of limited objective attacks against the division flanks, starting first with major outposts guarding the most critical terrain on the MLR. The artillery and mortar fire of the 1st had been but an initial step. At 1830 on 2 October, Communist direct fire weapons opened up from an area 2,800 yards northwest of OP 36, lashing all the KMC outposts within range. A tank platoon, dispatched to counter the fire, returned at 1915 without having located the hostile emplacements. Shortly after the tanks returned, an extremely heavy artillery barrage again fell upon all of the KMC regimental outposts. Ten minutes later, seemingly on the signal of one red and one green flare, the enemy guns lifted their preparatory fires to permit an infantry attack. The ground action simultaneously struck OPs 37, 36, and 86, the forward positions closest to the Sachon River.
At OP 37, the defending Korean Marine platoon fought valiantly for more than an hour against the assault of two enemy platoons, each of which required a company-size reinforcement before the Korean Marines were finally ousted. Although temporarily dislodged, they reorganized at the base of the position for a counterattack. Two counterattacks were made the next day, the second one carrying the Koreans to the top of the hill. Fierce enemy mortar and artillery shelling forced them to seek the shelter of the reverse slope before again renewing their assault. On 4–5 October, the outpost changed hands four times. At 1340 on the latter date, a heavy enemy artillery and ground attack compelled the KMCs to abandon their ravaged outpost; this withdrawal ended friendly control of OP 37 for the rest of the month.
Nearby OP 36 was also lost. In the course of the night the Korean Marines on OP 36 turned back two Communist assaults, but fell under the weight of the third. By sunup on 3 October, the exhausted Korean Marines were forced to give ground; the Chinese immediately occupied OP 36 and held it.
One more KMC outpost was to fall during the first week. OP 86 guarded the southwestern two-thirds of the regimental sector and frequently was the target of artillery shelling and ground attacks. This position was also the most distant from the main line and the closest to the Sachon River.
The heaviest Communist attack on 2 October was against the KMC platoons defending Hill 86. Nearly a battalion of Chinese took part in this action, finally overpowering the outpost just before midnight. The defenders withdrew south to the bottom of the hill, where they were comparatively safe from enemy fire. Resting, receiving reinforcements, and regrouping during the early morning hours of the 3d, the Korean Marine force observed friendly artillery and air pound the outpost preparatory to their counterattack. It was made at 1015 and succeeded, after two hours fighting, in routing the Chinese from the outpost.