In a week’s time, without interference from PVA or Korean People's Army (KPA) forces, the Regimental Combat Team 31 (RCT 31), US 3rd Infantry Division and a US 1st Marine Division shore party group totaling some 3,800 troops loaded themselves, 1,100 vehicles, 10,000 tons of other cargo, and 7,000 refugees aboard transport ships and LSTs provided by Admiral James H. Doyle’s Task Force 90.

[5] On the 11th, as the ROK from Songjin as well as the Marine and Army troops from the Chosin Reservoir came into Hungnam, the perimeter around the port consisted of a series of battalion and regimental strongpoints astride the likely avenues of PVA/KPA approach some 12–15 miles (19–24 km) outside the city.

The US 3rd Infantry Division still held the large sector assigned to it when Almond first shaped the perimeter, from positions below Yonpo Airfield southwest of Hungnam to defenses astride the Chosin Reservoir road at Oro-ri (40°02′17″N 127°25′26″E / 40.038°N 127.424°E / 40.038; 127.424) northwest of the port.

Battalions of the US 7th Infantry Division stood in breadth and depth along the Pujon Reservoir (40°36′40″N 127°32′28″E / 40.611°N 127.541°E / 40.611; 127.541) road north of Hungnam, and three regiments of ROK I Corps guarded approaches near and at the coast northeast of the port.

But Almond expected his beachhead defenses would be tested by PVA/KPA units approaching Hungnam along the coast from the northeast, from the Wonsan area to the south, and especially from the direction of the Chosin Reservoir.

The likelihood that PVA/KPA forces pushing to the coast to reoccupy Wonsan would block the routes south of Hungnam had prompted Almond to discard any thought of an overland withdrawal to southern Korea (nor had MacArthur ordered such a move).

The larger exodus was to be by sea, with the Hungnam defenses contracting as Corps' forces were loaded, but airlift was to be employed for as long as Yonpo Airfield remained within the shrinking perimeter.

To supervise the actual loading of troops and materiel at water's edge, he organized a control group under Colonel Edward H. Forney, a Marine officer serving as Almond's deputy chief of staff.

On the Navy's end of the out-loading procedure, Doyle, through a control unit aboard his flagship USS Mount McKinley, was to coordinate all shipments, assign anchorages, and issue docking and sailing instructions.

Almond also dispatched a control group under Lieutenant colonel Arthur M. Murray from Corps' headquarters to Pusan to receive troops, supplies, and equipment arriving by sea and air and to move them as rapidly as possible to assembly areas.

The 1st Marine Air Wing, based at Yonpo and aboard escort carriers, was to devote its full effort to supporting the corps operation.

Reinforced by ships supplied by Admiral Arthur Dewey Struble, the Seventh Fleet commander, Doyle eventually was able to employ seven carriers in throwing a canopy of aircraft over the Corps area and to deploy one battleship, two cruisers, seven destroyers, and three rocket ships in a maneuver area reaching 10 miles (16 km) north and south of Hungnam to answer Almond’s requests for gunfire support.

[5]: 166–8 To begin an orderly contraction of defenses as X Corps’ strength ashore diminished, the units on the perimeter were to withdraw deliberately as the 1st Marine Division embarked toward the first of three phase lines that Almond drew around Hungnam.

In the southwest this first line rested generally along the Yowi-ch’on River, just below Yonpo Airfield and elsewhere traced an arc about 3 miles (4.8 km) from the heart of Hungnam.

[5]: 168–9 Almond published his formal evacuation order on 11 December, the date on which MacArthur visited Korea and flew into Yonpo Airfield for a conference with him.

Although Almond had planned to evacuate government officials, their families and as many others as shipping space allowed, he had not anticipated that thousands of civilians would try to reach Hungnam.

To prevent overcrowding and infiltration, military police, intelligence agents, and perimeter troops attempted to block civilian entry, particularly over the Hamhung-Hungnam road, which carried the larger number of refugees.

Those civilians already in Hungnam and those who managed to reach the city were screened, then moved to the southeastern suburb of Sohojin, where Corps' civil affairs personnel distributed food and organized them for evacuation as shipping space became available.

Although original plans called for the ROK to go to Pusan, MacArthur, apparently as a result of his 11 December visit to Korea, had directed that the Corps' units then on the Hungnam perimeter be sea lifted to Samch’ok.

The bulk of the PVA in the Chosin Reservoir area apparently were taking time to recuperate from losses suffered in the cold weather and recent battles.

On the 23rd, when Soule pulled his regiments to the last Corps' phase line in preparation for the final withdrawal from Hungnam, only a small amount of mortar and artillery fire struck the perimeter troops.

[5]: 172–3 By morning of the 24th the perimeter was silent and remained so as the last of the 3rd Division's service units loaded and as Soule started his rearguard action to take out his regiments and artillery.

In the final steps, Doyle's warships laid down a wide barrage about 1.5 miles (2.4 km) inland as the last platoons of the covering force loaded and as the 10th Engineer Combat Battalion and Navy demolition teams blew up the port before leaving the beaches aboard LVTs and LCMs shortly after 14:30.

About 200 tons of ammunition, a similar amount of frozen dynamite, 500 thousand-pound aerial bombs and about 200 drums of oil and gasoline had not been taken out, but all of this [had] "added to the loudness of the final blowup of the port of Hungnam.

While the move could be considered a withdrawal from a hostile shore, neither PVA nor KPA forces had made any serious attempts to disrupt the operation or even to test the shrinking perimeter that protected the loading.