The enemy was kept at a discreet distance throughout the night by continuous artillery fires supplemented by ripples from Captain Eugene A. Bushe’s Battery C, 1st 4.5´´ Rocket Battalion. An acute shortage of trucks made it necessary for most of the troops to hike. Then came the task of organizing the new Division defenses on a line running northeast and southwest through the northern outskirts of Chunchon (Map 10). Planning continued meanwhile for further withdrawals to positions astride the Hongchon-Chunchon MSR.[187] [187] CO IX Corps _IXACT 1370_; 1stMar _HD_, Apr 51; 5thMar _HD_, Apr 51; 7thMar _HD_, Apr 51. A “ripple” normally consists of 144 rounds fired simultaneously by six launchers. It was apparent by this time that the enemy had been badly mauled on the IX Corps front. The Communists were now making a supreme effort to smash through in the I Corps area and capture Seoul. It was believed that they had set themselves the goal of taking the city by May Day, the world-wide Communist holiday. In this aspiration they were destined to be disappointed. They tried to work around the Eighth Army’s left flank by crossing the river Han to the Kimpo Peninsula, but air strikes and the threat of naval gunfire frustrated them. Another flanking attempt 35 miles to the southeast met repulse, and before the end of the month it was evident that the Chinese Reds would not celebrate May Day in Seoul. Generally speaking, the Eighth Army had kept its major units intact and inflicted frightful losses on the enemy while trading shell-pocked ground for Chinese lives. The night of 27–28 April saw little activity on the IX Corps front, adding to the evidence that the enemy had shot his bolt. The next day the 1st Marine Division, along with other Eighth Army forces, continued the withdrawal to the general defensive line designated NO NAME Line (Map 10). Further withdrawals were not contemplated, asserted the IX Corps commander, who sent this message to General Thomas: It is the intention of CG Eighth Army to hold firmly on general defense line as outlined in my Operation Plan 17 and my message 9639, and from this line to inflict maximum personnel casualties by an active defense utilizing artillery and sharp armored counterattacks. Withdrawal south of this line will be initiated only on personal direction of Corps commander.[188] [188] CG IX Corps msg to CG 1stMarDiv with plans for withdrawal, 28 Apr 51.