The Battle of Nam River was an engagement between the United Nations Command (UN) and North Korean forces early in the Korean War from August 31 to September 19, 1950, in the vicinity of the Nam River and the Naktong River in South Korea. It was a part of the Battle of Pusan Perimeter, and was one of several large engagements fought simultaneously. The battle ended in a victory for the United Nations after United States Army (US) troops repelled a Korean People's Army (KPA) attack across the river.
Positioned in defense of Masan during the Battle of Masan, the US 35th Infantry Regiment, 25th Infantry Division took up positions along the Nam River, one of the many tributaries of the Naktong River on the southern flank of the Pusan Perimeter. The KPA 7th Division crossed the river on August 31, and though the 35th Infantry stemmed the KPA advance, thousands of KPA troops exploited a hole in the line and surrounded the regiment. What followed was an intense battle in which the US and KPA units were heavily engaged all along and behind the Kum River line. Eventually, the KPA force was routed by the US troops.
During the battle, the US Army's 35th Infantry division was instrumental in forcing back the KPA division and preventing it from advancing to capture Pusan. The 35th Infantry's performance in the battle earned the regiment a Presidential Unit Citation.
Background
Pusan Perimeter
From the outbreak of the Korean War and the invasion of South Korea by the North, the KPA had enjoyed superiority in both manpower and equipment over both the Republic of Korea Army (ROKA) and the UN forces dispatched to South Korea to prevent it from collapsing. The KPA tactics were to aggressively pursue ROKA/UN forces on all avenues of approach south and to engage them aggressively, attacking from the front and initiating a double envelopment of both flanks of the unit, which allowed the KPA to surround and cut off the opposing force, which would then be forced to retreat in disarray, often leaving behind much of its equipment. From their initial June 25 offensive to fights in July and early August, the KPA used these tactics to effectively defeat any ROKA/UN force and push it south. However, when the ROKA/UN forces, under the Eighth United States Army, established the Pusan Perimeter in August, the ROKA/UN troops held a continuous line along the peninsula which KPA troops could not flank, and their advantages in numbers decreased daily as the superior UN logistical system brought in more troops and supplies to the UN forces.
When the KPA approached the Pusan Perimeter on August 5, they attempted the same frontal assault technique on the four main avenues of approach into the perimeter. Throughout August, the KPA 6th Division, and later the KPA 7th Division, engaged the US 25th Infantry Division at the Battle of Masan, initially repelling a UN counteroffensive before countering with battles at Komam-ni and Battle Mountain. These attacks stalled as UN forces, well equipped and with plenty of reserves, repeatedly repelled KPA attacks. North of Masan, the KPA 4th Division and the US 24th Infantry Division sparred in the Naktong Bulge area. In the First Battle of Naktong Bulge, the KPA division was unable to hold its bridgehead across the river as large numbers of US reserve forces were brought in to repel it, and on August 19, the KPA 4th Division was forced back across the river with 50 percent casualties. In the Taegu region, five KPA divisions were repulsed by three UN divisions in several attempts to attack the city during the Battle of Taegu. Particularly heavy fighting took place at the Battle of the Bowling Alley where the KPA 13th Division was almost completely destroyed in the attack. On the east coast, three more KPA divisions were repulsed by the ROKA at P'ohang-dong during the Battle of P'ohang-dong. All along the front, the KPA troops were reeling from these defeats, the first time in the war their tactics were not working.
September push
In planning its new offensive, the KPA command decided any attempt to flank the ROKA/UN force was impossible thanks to the support of the UN naval forces. Instead, they opted to use a frontal attack to breach the perimeter and collapse it; this was considered to be the only hope of achieving success in the battle. Informed by intelligence from the Soviet Union, the North Koreans were aware of the UN forces building up along the Pusan Perimeter and that they must conduct an offensive soon or they could not win the battle. A secondary objective was to surround Taegu and destroy the UN units in that city. As part of this mission, the KPA would first cut the supply lines to Taegu.
On August 20, the KPA commands distributed operations orders to their subordinate units. The plan called for a simultaneous five-prong attack against the ROKA/UN lines. These attacks would overwhelm the ROKA/UN defenders and allow the KPA to break through the lines in at least one place to force the ROKA/UN forces back. Five battle groupings were ordered. In the southern part of its sector, where the US 25th Infantry Division held the UN line, KPA I Corps planned a strong attack, coordinating it with an attack against the US 2nd Infantry Division to the north. The KPA 6th and 7th Divisions received their attack orders on August 20. The plan called for KPA I Corps to assault all along the line at 22:00 on August 31. The 6th Division, farthest south on the right flank, was to attack through Haman, Masan, and Chinhae and then capture Kumhae, on the west side of the Naktong River delta 15 miles (24 km) from Pusan, by September 3. The division zone of attack was to be south of the highway from Chinju to Komam-ni to Masan. The 7th Division, next in line north of the 6th Division, was to attack north of the Masan highway, wheel left to the Naktong, and wait for the 6th Division on its right and the KPA 9th Division on its left to join it. Part of the 7th Division was concentrated in the Uiryong area west of the Nam River. This plan pitted the 6th Division against the US 24th Infantry Regiment and the 7th Division against the US 35th Infantry Regiment. As a part of this plan, the KPA 6th Division had been engaging the 24th Infantry at Battle Mountain for several weeks prior, with no gains for either side.
Battle
North Korean crossing
The KPA 7th Division troops committed all of their effort into attacking the US 35th Infantry line. At 23:30 on August 31, a KPA SU-76 self-propelled high-velocity gun from across the Nam fired shells into the position of G Company, 35th Infantry, overlooking the river (35°20′42″N 128°23′49″E / 35.345°N 128.397°E). Within a few minutes, KPA artillery was attacking all front-line rifle companies of the regiment from the Namji-ri bridge west. Under cover of this fire a reinforced regiment of the KPA 7th Division crossed the Nam River and attacked F and G Companies, 35th Infantry. Other KPA soldiers crossed the Nam on an underwater bridge in front of the paddy ground north of Komam-ni and near the boundary between the 2nd Battalion, led by Lieutenant colonel John L. Wilkins Jr., holding the river front and Lieutenant colonel Bernard G. Teeter's 1st Battalion holding the hill line that stretched from the Nam River to Sibidang-san and the Chinju-Masan highway. The 35th Infantry, facing shortages of materiel and reinforcements, was under-equipped but nonetheless prepared for an attack.
At the river ferry crossing site in the low ground between these two battalions (35°18′54″N 128°23′53″E / 35.315°N 128.398°E), the regimental commander placed 300 ROK National Police, expecting them to hold there long enough to serve as a warning for the rest of the forces. Guns from the flanking hills there could cover the low ground with fire. Back at Komam-ni he held the 3rd Battalion ready for use in counterattack to stop a KPA penetration should it occur. Unexpectedly, the National Police companies near the ferry scattered at the first KPA fire. At 00:30, KPA troops streamed through this hole in the line, some turning left to take G Company in its flank and rear, and others turned right to attack C Company, which was on a spur of ground west of the Komam-ni road. Elements of C and D Companies formed a defense line along the dike at the north edge of Komam-ni where US tanks joined them at dawn. The KPA, however, did not drive for the Komam-ni road fork 4 miles (6.4 km) south of the river as the US commander, Lieutenant colonel Henry Fisher had expected; instead, they turned east into the hills behind 2nd Battalion.
The position of B Company, 35th Infantry, on the 1,100 feet (340 m) Sibidang-san, flanked the Masan road 2 miles (3.2 km) west of Komam-ni and gave the company a commanding view over the surrounding countryside. It was a key position in the 25th Division line, and 25th Division commander General William B. Kean was aware the KPA would consider it important ground to target for attack. The KPA preparatory barrage there lasted from 11:30 to midnight. Under this cover, two battalions of the KPA 13th Regiment, 6th Division, moved up within 150 yards (140 m) of the American foxholes. At the same time, KPA T-34 tanks, SU-76 self-propelled guns, and antitank guns moved toward Komam-ni on the road at the foot of Sibidang-san. A US M4A3 Sherman tank there destroyed a T-34 just after midnight, and a 3.5-inch Bazooka team destroyed a self-propelled gun and several 45 mm antitank guns.
On the crest of Sibidang-san, an antipersonnel minefield stopped the first KPA infantry assault. More attacks followed in quick succession, all of which were repulsed by the US troops' superior firepower. By 02:30 the B Company riflemen were so depleted of ammunition that they began stripping machine-gun bullets from the ammunition belts and using them in their rifles. The 1st Platoon of C Company, at the base of the mountain behind B Company, climbed Sibidang-san in 45 minutes with an ammunition resupply for the company. Just before dawn the KPA attack subsided. Daylight revealed a vast amount of abandoned KPA equipment scattered on the slope just below the crest, including 33 machine-guns. Among the KPA dead was the commanding officer of the 13th Regiment.
At daybreak on September 1, a relief force of C Company headquarters troops, led by US tanks, cleared the road to Sibidang-san and resupplied the 2nd Platoon, B Company, with ammunition just in time for it to repel another KPA assault. This failed assault resulted in the killing of 77 and capturing of 21 KPA. Although the 35th Infantry held all its original positions, except that of the forward platoon of G Company, 3,000 KPA soldiers were behind its lines. The farthest eastern penetration reached the high ground just south of Chirwon overlooking the north–south road there.
In the meantime, the KPA 6th Division had made breakthroughs in the US 24th Infantry sector to the south, overwhelming the regiment and forcing it back. The 2nd Battalion, 24th Infantry, on the ridges overlooking Haman, was pushed back as its soldiers retreated without orders. Survivors from the 24th Infantry's 1st and 2nd battalions later appeared in the 35th's lines, and the regimental commanders found that the entire regiment had crumbled under KPA attack. Kean ordered the 1st Battalion, 27th Infantry to move in and help restore the 24th's position.
North Korean infiltration
In a counterattack after daylight, K Company and tanks had partially regained control of the ridges overlooking Haman, but not completely. Large numbers of KPA were behind the battle positions of the 35th Infantry as far as the Chirwon-ni and Chung-ni areas, 6 miles (9.7 km) east of Komam-ni and the front positions. The KPA continued to cross the Nam River after daylight on September 1 in the general area of the gap between the 1st and 2nd Battalions. UN observation aircraft spotted an estimated four companies crossing there and directed fire of the 64th Field Artillery Battalion on the crossing force, which destroyed an estimated three-fourths of it. Fighter planes then strafed the survivors. Another large group of KPA were spotted in the open at the river later in the day and American aircraft directed artillery fire on the column, with an estimated 200 KPA casualties.
The KPA I Corps plan of attack below the Nam River was for its 6th Division to push east along the main Chinju-Komam-ni-Masan highway through the 1st Battalion, 35th Infantry, and at the same time for major elements of its 7th Division to swing southeast behind the 2nd Battalion, 35th Infantry, and cut the Chirwon road. This road crossed the Naktong River over the cantilever steel bridge at Namji-ri from the US 2nd Infantry Division zone and ran south through Chirwon to join the main Masan highway 8 miles (13 km) east of Komam-ni near the village of Chung-ni, 4 miles (6.4 km) northwest of Masan. These two avenues of approach, the Komam-ni-Masan highway and the Chirwon road converging at Chung-ni, formed the axes of their attack plan.