Until the first of March, the camp had received intensive fires from heavy artillery pieces located in reinforced, dug in positions well inside Cambodia. At times as much as one round every 45 seconds had been rained on the Allied camp for protracted periods. However, the enemy guns were so located that their muzzle glow could be observed from the friendly post thus allowing the Allies to predict the incoming artillery in sufficient time to preclude heavy casualties. In an effort to penetrate the barriers protecting these enemy artillery pieces, the tanks were employed in an indirect fire role, using concrete piercing fuzes. The collocated artillery battery's fire direction center and spotter aircraft assisted with fire adjustment. This met with only limited success since the 90mm ammunition was unable to penetrate the Red defensive positions.
