[4] Ridgway warned I Corps' commander General Frank W. Milburn against permitting any situation to develop during the operation that would require additional forces to extricate those initially committed.

The 1st Battalion, 15th Infantry Regiment, and two companies of tanks from the 3rd Division which followed the same axis to Kumnyangjang-ni received small arms and heavy mortar fire after turning west for 1 mile (1.6 km) on Route 20 toward Suwon.

On Route 1 the tanks and infantry received fire from a strong PVA force deployed 0.5 miles (0.80 km) south of Suwon and from machine gunners atop buildings inside town.

He also had directed Coulter to move the 1st Cavalry Division’s 70th Tank Battalion from its deep reserve location near Sangju in the Naktong River valley to Chinch’on, 15 miles (24 km) behind the Corps front.

[5]: 239 After receiving Ridgway's instructions on the 20th, Coulter scheduled for the 22nd a one-day operation built around the 70th Tank Battalion in which his force was to push north of Route 20 between Kumnyangjang-ni and Ich’on.

General Hobart R. Gay organized a task force under the 8th Cavalry Regiment commanded by Col. Harold K. Johnson that added infantry, artillery, and engineers to the tank battalion.

On 23 January his intelligence officer reported the bulk of the PVA XIII Army Group to be below Seoul in the area bounded by Route 20 on the south and the Han River on the east and north.

He planned to postpone the operation if for any reason on the 25th Fifth Air Force commander General Earle E. Partridge could not assure two successive days of maximum close support.

Although this flight did not conclusively disprove the current intelligence estimate, Ridgway was more confident that his forces would reach the Han, and he also saw possibility of holding the ground covered.

That night, from a forward command post established at I Corps headquarters in Cheonan, he ordered Milburn and Coulter to prepare plans for holding their gains once their forces achieved the fifth phase line stretching eastward from Inchon.

The initial phase line in the IX Corps zone traced the high ground just above Route 20 which included the area previously reconnoitered by Task Force Johnson.

Sharp counterattacks hit the Turks on the secondary road east of Route 1 and the 8th Cavalry in the Yangji-ri area, but in both instances the PVA eventually broke contact.

This disclosure and the general pattern of light resistance indicated that the XIII Army Group had set out a counter-reconnaissance screen to shield defenses or assembly areas farther north.

This location would place them generally along the second phase line, which coincided with Suwon and a stretch of Route 20 in the west, then tipped northeast to touch the Han 10 miles (16 km) above Yoju.

Elsewhere in both Corps' zones the advance became a plodding affair as the troop columns searched east and west of their axes while driving north for short gains through tough spots of resistance.

The PVA fought back hardest at Kumnyangjang-ni, which the Turks finally cleared at 19:30, and in the heights above Yangji-ri, where the 8th Cavalry lost 28 killed and 141 wounded while managing little more than to hold its position.

The intelligence rationale now taking shape assumed the Chinese units originally moving south of the Han to have started a gradual reduction of forward forces after determining generally the extent of the Eighth Army withdrawal.

To meet the probability of stronger resistance nearer the Han and to prepare for holding all ground gained, Ridgway on the 27th authorized Milburn to add the 3rd Division to the I Corps advance.

Previously assembled in a rest area about 7 miles (11 km) above the front, the 112th had received sudden orders to move south and oppose the IX Corps advance.

He did not release these forces for commitment in the advance, but he did take steps to ease the progress of the attack by instructing Milburn to plan a strong armored thrust through the coastal lowland on the west flank.

In his mind, inflicting maximum losses on the Chinese and North Koreans, delaying them as long as possible if and when they attempted to advance, preserving the strength of his own forces, and maintaining his major units intact remained the only sound bases of planning, both for current operations and at longer range.

MacArthur agreed that occupying Seoul would yield little military gain, although he believed that seizing the city would produce decided diplomatic and psychological advantages.

Ridgway, on the other hand, was primarily interested in holding whatever line best suited his basic plan of punishing the enemy as severely as possible at the least cost to his own forces.

The requests called for round-the-clock interdiction with special attention to nighttime operations and with the intensity to prevent enemy forces from moving north or south of the Han.

[5]: 254 The newest prisoners and documents captured by I and IX Corps indicated that the PVA/KPA units still south of the Han would keep only light forces engaged and would deploy in depth for a leapfrog delaying action pending an enemy offensive around 8 February.

Between 5 and 8 February the smaller armored forces ranging ahead of the I Corps’ methodical infantry advance were frequently delayed but seldom hurt by numerous minefields located on the curves and shoulders of roads and on bypasses around destroyed bridges.

[5]: 255 The strongest enemy positions facing the I Corps on the 8th lay between Routes 1 and 55 across heights centered on Kwanak Mountain, due south of Seoul, where the KPA 47th Division had been identified.

Earlier, after learning of the 47th Division's entry on line, Ridgway asked Admiral C. Turner Joy to arrange an amphibious landing demonstration at Inchon to discourage further strengthening of the KPA screen and perhaps draw off some opposing forces.

By holding this position the PVA could prevent IX Corps observation of the Yangpyong area, already recognized as the possible starting point of an enemy attack down the Han valley.

This theory gained support on the 10th when in clearing afternoon weather air observers sighted large numbers of enemy troops moving east on Route 2 along the north bank of the Han immediately behind the bridgehead area.