A new Marine artillery tactic about this time was the counter-counterbattery program instituted by the 11th Marines. The regiment had developed this technique to counter superior enemy artillery strength. This situation, as well as the fact that I Corps artillery available to the division was considered inadequate for counterbattery support, led the Marine division to adopt the new program in May 1952. One provision required a battery in each battalion to select counter-counterbattery positions and occupy them for 24 consecutive hours each week. Another proviso of the program was the selection by each battalion of 10 roving gun positions that were to be occupied by a single weapon rotated to each place at least once weekly. By these tactics, the artillery regiment hoped not only to mislead the Chinese in their estimate of the strength and location of Marine artillery but also to dilute enemy counterbattery intelligence by causing him to fire into areas just vacated by friendly guns. “The effectiveness of the program was demonstrated on numerous occasions when the enemy fired counterbattery into unoccupied positions.”[117] An added advantage was that of providing deeper supporting fires on target areas.[118]
[117] PacFlt EvalRpt No. 5, p. 8-51.
[118] LtCol Bruce F. Hillam comments on draft MS, dtd 31 Aug 66.
Still another concept regarding the employment of artillery developed during the early days of the JAMESTOWN defense. The 11th Marines had advised the infantry regiments that it could effectively fire on enemy troops attacking friendly positions if the Marines had overhead cover. The idea was to use variable time (VT) fuzes[119] with the standard high explosive (HE) shells. Artillery battalions supporting the frontline regiments registered on positions occupied frequently by patrols going forward from JAMESTOWN.
[119] A type of proximity fuze, the V.T. depends upon an external source, such as an electronic signal, rather than the force of ground impact, to detonate the shell at a predetermined height over the target.
According to the recollections of veteran artillery and infantrymen in the division, the first occasion that pre-planned artillery fire was placed on friendly positions occurred in May 1952.[120] The episode involved a 2/7 platoon patrol that late on 18 May was ordered to return to the MLR from an outpost on the former OPLR. Operating forward of the center regimental sector,[121] the platoon commander, Second Lieutenant Theodore H. Watson, directed that two of the three Marine squads return to the MLR. The remaining unit, surrounded by about 50 Chinese, engaged them in a brisk fire fight.
[120] 1stMarDiv ComdD, May 52, p. 4.
[121] The 7th Marines advanced to the line to relieve the 5th Marines in the center sector on 11 May.
When the artillery fired to seal off the enemy and box-in the defensive position failed to discourage the hostile force, Lieutenant Watson ordered his men into the shelter of two nearby bunkers. He then requested the artillery to place VT directly over his positions.[122] The volleys of overhead fire and effective Marine small arms fire then forced the enemy to call off his assault. Although the exact number of Chinese casualties could not be determined, the new fire technique fully accomplished its purpose—repelling the enemy force.
[122] The artillery regiment had earlier developed the “box-me-in” fires for outpost defense. If under heavy attack the outpost could call for these pre-planned close-in fires that completely surrounded the position. In event of radio or wire communication failures, the outpost could call for “box-me-in” or “Fire VT on my position” by signal flare or other pyrotechnic device. Henderson ltr II.