Although the objectives of Operation RIPPER had been reached, General Ridgway planned to continue the UN offensive for the purpose of keeping the enemy off balance during his offensive preparations. The Eighth Army had been attacking with few and brief pauses for regrouping even since 21 February, and the commanding general wished to maintain its momentum. An advance of the 1st Marine Division to a new Line CAIRO was ordered by IX Corps on 26 March. This was simply a northeast extension of the old line to the boundary between IX and X Corps (Map 9). There was no need for the 5th Marines to advance, and the 1st Marines and KMC Regiment moved up to the new line on schedule without opposition. Eighth Army units had made average gains of about 35 miles during the last three weeks while driving nearly to the 38th Parallel. On 29 March, General Ridgway published a plan for Operation RUGGED. It was to be a continuation of the offensive, with Line KANSAS (Map 8) as the new objective. While other 1st Marine units were being relieved by X Corps elements, the 7th Marines was to be moved up from reserve near Hongchon and attached to the 1st Cavalry Division for the attack beyond Chunchon, evacuated by the retreating enemy.[144] [144] EUSAK _Cmd Rpt_, Mar 51, 18–19. On 1 April the Marines were informed of sweeping changes in IX Corps plans. Instead of being relieved, the 1st Marine Division was to continue forward with two infantry regiments plus the KMCs. Its new mission called for a relief of the 1st Cavalry Division (with the 7th Marines attached) north of Chunchon. This modification gave General Smith the responsibility for nearly 20 miles of front.[145] [145] Smith, _Chronicle_, 1 Apr 51. “I visited this front frequently,” commented Major General A. L. Bowser, the G-3 of that period, “and it was difficult at times to even locate an infantry battalion.... Visitors from the States or FMFPac were shocked at the wide frontages.”[146] [146] BrigGen A. L. Bowser, ltr of 14 Feb 58. _38th Parallel Recrossed by Marines_ Further IX Corps instructions on 2 April directed that the 1st Marines go into Division reserve near Hongchon while the 5th Marines and 1st KMC Regiment attacked. The deep, swift Soyang-gang, fordable in only a few places, lay squarely in the path of the 5th Marines. Speculations as to the method of crossing became rife just as air mattresses were issued. And though the officers denied any such intent, the troops were convinced that inflated mattresses would be used.