The enemy had much to gain by taking Khe Sanh. If they could seize any portion of Quang Tri Province, the Communists would have a much stronger bargaining position at any future conference table. In addition, the spectre of Dien Bien Phu which was constantly raised in the American press undoubtedly led the enemy to believe that the coming battle could not only prove successful but decisive. If the garrison fell, the defeat might well turn out to be the =coup de grace= to American participation in the war. At first, the Marines anticipated a major pitched battle, similar to the one in 1967, but the enemy continued to bide his time and the battle at Khe Sanh settled into one of supporting arms.(79) At Khe Sanh, the periodic showers of enemy artillery shells were, quite naturally, a major source of concern to General Tompkins and Colonel Lownds and they placed a high priority on the construction of stout fortifications. Understandably, not every newcomer to Khe Sanh immediately moved into a thick bunker or a six-foot trench with overhead cover. The colonel had spent most of his tour with a one-battalion regiment and had prepared positions for that battalion; then, almost overnight, his command swelled to five battalions. The new units simply had to build their own bunkers as quickly as they could.(80) [Illustration: Marines at the combat base run for cover when warning of enemy rocket or artillery attack is sounded. (USMC Photo A190245)] [Illustration: Machine gunners lie on top of trench cover while they search for enemy movement. (USMC Photo A190929)] The regimental commander placed a minimum requirement on his subordinates of providing overhead cover for the troops that would stop, at least, an 82mm mortar round. The FSCC determined that one strip of runway matting and two or three layers of sandbags would fill the requirement. The average bunker usually started as an 8x8 foot dugout with one 6x6 inch timber inserted in each corner and the center for support. The overhead consisted of planks, a strip of runway matting, sandbags, loose dirt, and more sandbags. Some enterprising Marines piled on more loose dirt, then took discarded 105mm casings and drove them into the top of the bunker like nails. These casings often caused pre-detonation of the heavier-caliber rounds. The combat engineers attached to the 26th Marines could build one of these bunkers in three or four days; the average infantrymen took longer. Overhead cover for the trenchlines consisted of a strip of matting placed across the top of the trench at intervals and reinforced with sandbags. The defenders could stand up in the trench during periods of inactivity and duck under the matting when enemy rounds started to fall.(81)