[191] 3/1 ComdD, Aug 52, pp. 3–4.
In the 24-hour period beginning at 1800 on 12 August, Marine artillery directly supporting the 1st Marines fired 10,652 rounds. Most of the ammunition was expended in support of the Bunker Hill defense; some was used in behalf of the Marines outposting Stromboli during the Communists’ early morning diversion that day. On the 9th, the direct support battalion, 3/11 (Lieutenant Colonel Charles O. Rogers), had fired about one-fourth of the 12–13 August total. Many of the shells that first day of the Bunker battle were preparatory to counterattacks for regaining Siberia.
When the retaking of Hill 58A was discarded in favor of the surprise attack on 122, the amount of artillery support was reduced, during the 1st Marines infantry preparations on the 10th and 11th, in keeping with the fire support plan. Upon seizure of Bunker, Lieutenant Colonel Rogers’ business immediately picked up and quickly reached a crescendo the following day, when the 10,652 shells fired became a Marine one-day battalion record for western Korea until the last stages of fighting in 1953. Other Marine artillery battalions fired reinforcing missions during the critical period as did the 4.5-inch Rocket Battery which fired a large number of on-call ripples. The regimental commander later recalled that “during some of the crises every gun that could bear on Bunker in the 11th Marines and reinforcing units was shooting there.”[192]
[192] BGen Frederick P. Henderson ltr to Hd, HistBr, G-3 Div, HQMC and MS comments, dtd 20 Jun 67, hereafter Henderson ltr III.
After a sharp drop on the 14th, the artillery support gradually decreased in proportion to the amount and strength of the enemy’s action against Hill 122. By 20 August, 3/11 was firing only 244 rounds a day. Only on the 26th, during a serious Chinese attempt to retake Bunker, did the number of artillery rounds match the intensity of the fire support rendered during the earlier part of the month.
It was not only the quantity of 11th Marines support that the infantry called for during the battle of Bunker Hill; quality was equally important. A majority of the more than 28,000 rounds that 3/11 fired during the eight days of Bunker Hill fell around the besieged outposts. Many rounds were fired in defense of MLR positions. In both of these types of protective fires, extreme accuracy and precision were required due to the proximity of enemy and friendly lines in order to prevent any “short” rounds from falling among Marine positions. Lieutenant Colonel Armitage recalled that during the height of the battle on the night of 12 August, “we did have a bad scare ... when Captain Connolly reported that friendly mortar fire was falling short.”[193] The battalion immediately ceased fire with its 60mms, 81mms, and 4.2s and each piece was checked; the culprit was quickly located and within 5–10 minutes 3/1 resumed fire.
[193] Armitage ltr and comments, p. 12.
During the August battle, artillery in general support of the entire division and I Corps artillery reinforcing the fires of Colonel Henderson’s regiment, stepped up their efforts to destroy the distant and more difficult targets, including mortars and artillery. These continued to be the main cause of Marine casualties. Some of the labors of the 11th Marines gun crews did silence enemy heavy weapons, but personnel losses from enemy shellings still mounted, especially in the infantry units. To assist in the location and destruction of the enemy artillery, aerial observers spent considerable time in spotting and fixing Chinese weapons positions.
Besides these counterbattery efforts, the 11th Marines employed other artillery means to provide the additional support the 1st Marine Division requested during Bunker Hill. Two of these were the counter-counterbattery and the countermortar programs, the former being a passive defense-deception program to minimize Chinese counterbattery fires against 11th Marines weapons. Nearly every day C Battery, 17th Field Artillery Battalion, fired special request missions.[194] Another type of fire, flak suppression, aided the cause of close air support pilots delivering ordnance against those Chinese positions taking Bunker Hill and Stromboli under fire. At night, illumination shells helped outpost and frontline Marines in locating groups of enemy massing for assault on Hill 122.
[194] Many of these targets were CCF choke points, dumps, and weapons emplacements. Targets were identified and confirmed by a highly developed system that employed air spotting, aerial photographic interpretation, artillery evaluation, and POW interrogation.