Part 1. February 1951: Back to the Han
Part 2. March- April 1951: On to the Parallel
Part 3. April-May 1951: the Communist Spring Offensive
Part 4. June-July 1951: North to Kaesong
Part 1. February, 1951: Back to the Han
By late January the immediate crisis was over, but as the armies started north again it was still a new war. Not only had the arrival of the Chinese made it difficult to see the conflict as a mere police action against a minor league aggressor; it had also forced the United Nations and the United States back to the original aim of repelling aggression, and in doing so had changed the nature of the fighting. Avoidance of defeat at the Pusan perimeter had been followed by a resort to an amphibious strategy and to larger goals, and by four months of rapid movement up and down the peninsula. But this was history. By January the objectives had been revised, no plans for great amphibious operations existed, X Corps had been integrated into Eighth Army, a more or less continuous front now stretched from sea to sea. Although the focus of action had always been on land, the campaign in Korea in the first half of 1951 was more than ever a ground war.
Depending upon one’s preconceptions, one could look at the Korean War as a land campaign with amphibious aspects or as an amphibious war with resemblances to a continental struggle. Whatever the precise nature of this hybrid conflict, which indeed varied with the passing of time, it posed difficult problems of marrying the divergent histories of the Pacific and European theaters of operations, and of coordinating forces which postwar military doctrine had attempted to separate. These difficulties had been briefly apparent during the defense of the perimeter in the previous August; inevitably, with the coming of a stabilized front, the question of how to integrate a naval force into a land campaign again arose. This question had implications for almost all the subdivisions of Naval Forces Far East.
The fate of the Marine Division, designed, trained, and so far largely employed as a force to bridge the gap between control of the sea and large-scale operations ashore, was paradoxical. The postwar years had seen the Marines repeatedly accused of trying to develop a "second army," and much effort had been expended within the Defense Department to reduce the corps to guard functions and to prevent its again developing a force of the size and sort so useful in the war against Japan. Now, however, in the existing stringency of Army units, the Marines were integrated into Eighth Army along with the rest of X Corps; after a period devoted to guerrilla-chasing in the neighborhood of Andong they would find themselves committed by higher authority to sustained land combat. Although there was no question of their competence to perform such duty, this continued employment on inland work made it difficult to maintain their special skills, divorced as they now were by distance from the Amphibious Force and naval gunfire support, and by doctrine from their Aircraft Wing.
In July CincFE had promised General Craig that the integrity of the Marine air-ground team would be preserved. But circumstances alter cases, and this situation did not outlast the Hungnam evacuation. With a single front in existence, and with ground commanders eager to share the benefits of Marine close air support, MAW 1 was absorbed by the Fifth Air Force and employed in accordance with Air Force doctrine. The wing’s commanding general found himself bypassed in the operational chain of command, and efforts by the division to have their own planes assigned to their support were turned down. The long history of cooperative training and the great fund of recent experience acquired at Inchon and at the reservoir were to a considerable degree sacrificed, and so far as air support in the line was concerned the Marines now had to take pot luck with everyone else.
The Amphibious Force, perhaps the most important single weapons system of the war so far, and the one whose capabilities had governed both advance and retreat, was still on hand, but commitment of the landing force to the ground front had greatly limited its future possibilities. As the new year opened, the principal activity of Admiral Doyle’s units was in preparation for a possible large-scale emergency evacuation of the Korean peninsula. Surveys of Korean and Japanese beaches, begun in anticipation of a forced and hasty departure, were continuing at a rapid rate, and by June would have provided essential information on some 40 miles of strategically located shore line. The single untoward incident to mar this operation occurred on 19 January, halfway between Kunsan and Mokpo and far south of the battle-line, when some apparent civilians, previously engaged in conversation with Bass’ survey party, produced concealed weapons, killed two, and wounded three.
This hydrographic work, however, required the participation of but a fraction of the force. The greater part of Task Force 90 was consequently divided into three roughly equal groups, and an employment schedule worked out which assigned one to amphibious training of Army troops in Japan, and one to upkeep and maintenance at Yokosuka, while the third remained on call for services to the forces in the peninsula. On 15 January the job of transporting refugees and prisoners to Koje Do and Cheju Do was assigned CTF 90, and five days later an AKA lifted the first load of refugees from Pusan. This was the last task imposed upon Admiral Doyle. At Pusan, on the 24th, he was relieved by Rear Admiral Ingolf N. Kiland, in a ceremony which numbered CincPacFleet, ComNavFE, and Commander Seventh Fleet among those present.
Along the coastline matters were less changed, and in both Yellow Sea and Sea of Japan the Blockading and Escort Force continued to perform its duties. If fire support of amphibious operations was no longer required of the gunnery ships, the blockade remained important, and there were coastal targets to bombard. In the east, where the enemy had been checked at Mukho, the front was still susceptible of support by naval gunfire. But the fighting was less intense than in the previous summer, and as both sides increasingly concentrated their weight of effort in the central mountains, the pace of action on the coastal road diminished.
For the minesweepers, however, nothing had altered. Their work continued as before, and their tasks remained arduous, uncomfortable, and dangerous. The short winter daylight hampered operations; the winter weather, with high winds and freezing spray, made small ship work particularly uncomfortable. There was always the chance of new minefields or of the replenishment of those previously swept; the continued possibility of influence mines increased the load; intelligence reports indicated that the enemy was preparing a new mining campaign. Minesweeping capabilities, nevertheless, had been increased, and something better than the shoestring force of the previous autumn was now on hand. The four DMS, oversized for their task, had proven only marginally useful, and two were shortly to be returned to the United States, but 13 AMS and 2 AMs were now available, and 2 more of the latter were en route. Although the LST conversion to headquarters ship and helicopter base was still in the works, the force was profiting from the support of the LSD Comstock. In the naval establishment at large the efforts in updating and improving mine warfare, begun following the unpleasant experiences at Wonsan, were being pressed. Technological development was being expedited, and the coordinated tactical employment of patrol plane and helicopter search and of underwater demolition teams was moving forward. With the reestablishment early in the year of the Mine Force Pacific Fleet, and the appointment of Admiral Higgins as type commander, the sweepers at last acquired a home of their own and an administrator who cared.
In January, in addition to routine checks of vital areas like the Chinhae entrance channel, the main effort of the minesweeping forces was devoted to the clearance between 36° and 38°40', of an inshore lane, for the east coast fire support ships. This work, which permitted more effective support of the ROK I Corps on the coastal road, was completed by early February, but again at a cost. On 2 February the AMS Partridge hit a mine about a mile off Sokcho, just north of the parallel, and sank in ten minutes with a loss of ten killed or missing and six severely wounded.
With the completion of this sweep, fire support activities were stepped up. Along the eastern coast four of the eight destroyers of Task Group 95.2 were continuously on station, with one pair patrolling the 100-fathom curve north to the limit of the blockade, while the second provided fire support to the Korean troops. At Mukho, and at Yongchu Gap to the southward, ROKN forces had established minor operating bases, from which their small craft sortied to collect intelligence from behind enemy lines, and to tighten the blockade through control of North Korean junk traffic and of South Korean fishing.
Although the hydrography of Korea’s western shore greatly limited the possibilities of naval gunfire, Task Group 95.1 was also active. In the west the prevalence of islands permitted the establishment of useful advanced bases, and the advance of 1950 had brought possession of holdings off Inchon and Haeju, of the Sir James Hall Group near the 38th parallel, of Cho Do and Sok To off the Taedong estuary, and of islands in the Yalu Gulf. Most of these islands were informally controlled by guerrilla groups, and employed as bases for intelligence activities and for raids behind enemy lines. But responsibility for three of them–Ochong Do off Kunsan, Tokchok To in the Inchon approaches, and Taechong Do off the Ongjin peninsula–had been assigned to Admiral Andrewes’ West Coast Group, and these islands had been given ROKN garrisons in January. Inshore patrol of the shallow coastal waters was provided by four groups of Korean ships, supported as necessary by Andrewes' surface units, which otherwise continued to maintain their designated blocking points, patrol northward into the Yalu Gulf, and bombard targets of opportunity.
For the carriers of Naval Forces Far East the deployment of January was little changed. With stabilization of the front and the passing of the emergency a reduction of Seventh Fleet strength from four carriers to three seemed feasible, and arrangements for regular maintenance desirable. Leyte, present in the Far East on loan from the Atlantic Fleet, was consequently headed homeward late in January, and a rotational schedule established which would send a third of the force at a time to Yokosuka for a ten-day stay. Taken together with the similar deployment of the ships of Task Force 90, this made for a considerable eastward shift in the logistic center of gravity, and for a corresponding reorientation of Service Force effort from Sasebo to Yokosuka.
The departure of Leyte left the Pacific Fleet with four fast carriers, Valley Forge, Philippine Sea, and Princeton in Korean waters, and Boxer under overhaul at San Francisco. But the reactivation of mothballed ships was proceeding apace, and more were coming. Bon Homme Richard and Essex were on the way, with arrivals in Far Eastern waters scheduled for May and August; shortly Antietam would be removed from the Reserve Fleet for arrival in October. By autumn the Pacific Fleet would contain seven operational fast carriers, compared with the three of the preceding June, and units on duty in the forward area could be rapidly and heavily reinforced.
Although Badoeng Strait and Sicily had left the Yellow Sea following the evacuation of Inchon, and had subsequently off-loaded their squadrons and sailed for the United States, west coast carrier operations did not lapse. The work of Triumph and Theseus had shown the need for carrier aircraft to enforce the blockade, to provide air strikes, aerial photography, and close support, and to spot gunfire for west coast surface units. On 7 January, as the escort carriers departed, Theseus again assumed the load, and following representations by Admiral Andrewes a continuity of effort was assured. The CVL Bataan, which had operated with the escort carriers during the critical period of the Inchon evacuation, was assigned by Admiral Struble to Task Group 95.1, and began to alternate ten-day periods of duty with Theseus as the principal unit of Task Element 95.11.
Something new had by now been added in the field of embarked aviation with the activation of an antisubmarine warfare task group, established by ComNavFE in view of the possibility that the intervention of new armies might be followed by an intervention of new weapons. An antisubmarine squadron was embarked in Bairoko, the escort carrier which in December had brought Air Force and Marine jet fighters to the Far East, and two destroyer divisions were added to make up Task Group 96.7, operating out of Yokosuka under the control of ComNavFE. Since enemy submarines did not in fact appear, this Hunter-Killer Group confined itself to training duties with the destroyers that were rotated through it from the other forces in Far Eastern waters.
Yet while the deployment of carrier strength remained the same, the problem of optimum employment was again much to the fore. Having been used first in long-range interdiction and emergency close support, and then in two landings and an evacuation, Task Force 77 now found itself faced with the long haul. In January its work had been principally in support of the battleline and in attacks on southward moving Chinese forces, a function of great importance in view of the withdrawal of shore-based squadrons to Japan. But as the ground situation stabilized, and the move back north began, the question of the relative usefulness of close support and interdiction arose once more.
For both these types of operation Task Force 77 had certain advantages not shared by other U.N. forces. Historically, naval aviation had been more sympathetic to close support than had the Air Force; the tradition was reflected in pilot training and doctrine, in tendencies in aircraft design which permitted heavier loads and more time on station, and in techniques of accurate dive bombing derived from a generation of training for attack on maneuvering ships. Although the communications problem, central to the close support difficulties of the early months, still remained, the Army’s situation was so far improved that the normal air request net worked adequately in periods of relative inactivity, if not in time of crisis. Coordination of the carrier effort with that of Fifth Air Force had also shown some progress: daily by noon the air plan for the morrow was passed to JOC, while problems arising from crowded radio channels and last minute changes were reduced by the dispatch of a communications relay plane ahead of each strike, to shop for a controller and then brief the strike leader on a clear channel. All things considered, air support was going reasonably well.
Yet in interdiction, which in the context of the moment meant primarily the destruction of rail and highway bridges, the carrier air groups also had solid advantages. Even when based in Korea and modified by tip tanks, the F-80 Shooting Star, for the moment the standard Air Force fighter-bomber, lacked sufficient range and lift to accomplish much north of the Pyongyang-Hungnam radius, while from Japanese bases its load rarely exceeded two rockets and a tank of napalm. The F-51 Mustang had excellent lift and endurance, but was considered too vulnerable to the increasing threat of jet fighters for employment far to the north. The B-26 and B-29 had the lift and range, but were unsuited to attacks on small targets and were vulnerable, respectively, to antiaircraft and fighter opposition. Such opposition, of course, presented problems to the carrier planes as well, but approach routes and attack tactics were more flexible than those of horizontal bombers, the movable base and the built-in range of its aircraft permitted escorted strikes to the uttermost ends of Korea, and the load and accuracy of the AD made it uniquely effective against bridge targets.
As to the choice of employment one could find all opinions in all services. Although as a result of the earlier campaigns there had developed a strong Army school, particularly within X Corps, which favored the Navy-Marine system of close support, Admiral Struble’s Christmas Day offer had elicited a request from EUSAK for interdiction of the northeastern transportation network. Doubtless a doubled carrier force, with half assigned each function, would have suited the Army best, but the postwar military establishment had not been designed with an eye to this. In its absence, and as operations went on, there ensued a period of debate and discussion which lasted through February.
In December, following the Chinese intervention, FEAF had prepared a new interdiction plan; in January, reports of rail activity in the northeast had led General Stratemeyer to inquire about the capabilities of the fast carrier task force in this regard. If the effort in close support were not to be diminished these capabilities were limited: only in the presence of Valley Forge, whose lack of jet squadrons was made up by a surplus of F4Us, could a two-carrier force take on the added load; with Valley Forge present, or with all three carriers in the line, two strikes a day could be sent northward on interdiction missions without prejudice to the support of the battleline. In response to FEAF’s inquiry such an effort was begun, although both ComNavFE and Commander Seventh Fleet reaffirmed their view that given only suitable control facilities, close support was the most effective contribution the carriers could make, and urged that it remain the primary function. But in reply FEAF again put forward the need for interdiction to forestall a renewed Chinese offensive.
On 18 January the issue was discussed in a meeting at Taegu between Admiral Struble, the other major commanders in Korea, and the Army and Air Force Chiefs of Staff, out once again from Washington. Whatever the views of the other services, the Navy remained on the side of close support. After conferring with his carrier commanders, following his return to the fleet, Admiral Struble observed that an assignment to armed reconnaissance would be executed to the best of his capability, but reiterated his opinion that support of the line was more effective, and was punishing the enemy more severely, than was generally realized.
By this time the Chinese had broken contact and, following the reconnaissance to Suwon, General Ridgway had ordered a two-divisional advance toward the Han River. To assist this operation, known as "Thunderbolt," Yellow Sea forces were strengthened by the dispatch of Saint Paul, escorted by two destroyers, to provide 8-inch gunfire at Inchon. On both coasts, as the armies moved forward, the carrier air groups continued to contribute to the support of troops in the line.
With planning for the future still in flux, with the Marines chasing guerrillas in the southern mountains, and with Task Force 90 dispersed, there was no possibility of a flanking amphibious operation. Yet intelligence indicated an extreme Chinese concern with the landing in the rear, and if no such stroke was possible one could always pretend. As Eighth Army advanced and as ROK forces on the eastern shore were also moving forward, Admiral Smith conceived the notion of assisting their progress by an amphibious feint in the Kansong-Kosong area, some 50 miles beyond the front lines, where a slightly expanded coastal plain and a road through the mountains to the central front provided a logical objective for an assault from the sea. For this enterprise, Operation Ascendant, CTF 95 borrowed two AKAs, two LSTs, and a couple of rocket ships from the Amphibious Force, secured a promise of assistance from the fast carriers, and set sail on 29 January in his flagship, the destroyer tender Dixie, with his gunnery ships in company.
At 0700 on the 30th the bombardment group, Missouri, Manchester, and their screening destroyers, opened a vigorous fire on the Kansong area, and throughout the day the minesweepers, landing craft, and rocket ships went through their paces. After retiring seaward during the night, the force reappeared next morning off Kosong to repeat the bombardment effort. If the effectiveness of these maneuvers on enemy troop dispositions was largely unassessable, the operation was at least unique in the presence of a destroyer tender as flagship and participant in beach bombardment. Since such an event may never recur, let the record show that at 1400 on the 31st Dixie commenced firing on the beaches at Kosong, and expended 204 rounds.
At Inchon, where Saint Paul had arrived on 25 January, a second deceptive operation was scheduled to follow. There Admiral Hillenkoetter had been greeted by some short salvos from Wolmi Do, but with the assistance of an air strike from Theseus, and gunfire from Ceylon and some destroyers, the Wolmi batteries were neutralized and the Kimpo-Kumpo area subsequently kept under intermittent bombardment. On 6 February Admiral Andrewes sailed from Sasebo in Belfast to administer the pretended landing, and two days later, after some shooting in support of ROK troops at Kangnung, Missouri was started west.
Captain Kelly reached Inchon on the 8th, with two AKAs and an LSD, to simulate pre-landing operations; on the next day Missouri arrived and began to bombard enemy positions; a demonstration involving two transport divisions was planned for the afternoon tide of the 10th. But the affair was cancelled as a result of successes ashore: enemy resistance in the west, which had stiffened at the start of the month, gave way suddenly on the 9th, and the Chinese retired from the area; on the afternoon of the 10th Inchon was occupied by a party of ROK Marines from Tokchok To, and by nightfall American troops had reached the banks of the Han.
The reoccupation of Inchon was more than welcome. For the past month, as in the previous summer, Pusan had been a madhouse, as the difficulties of supplying the armies through a single port were compounded by the need to plan a complete and to accomplish a partial evacuation of Korea. Unfortunately, however, the advantages of a second port could not at once be realized. Not only would operations necessarily remain limited until the security of Inchon could be assured, but the demolitions of the previous month had to be cleared, a situation which raised some questions as to the wisdom, for the side which enjoyed command of the sea, of the policy of "blow and go" which had governed the evacuations. To accomplish the necessary restoration of facilities, and to get the port in working order, Admiral Thackrey had sailed from Yokosuka on 10 February with an amphibious task group carrying the Army’s 2nd Engineer Special Brigade. He arrived on the 15th just as a new emergency was developing.
Map 22. Back to the Parallel, 16 January–20 April 1951.
The advance to the Han and the recovery of Inchon had been followed by hard fighting in the center. There the move north from Wonju had begun on 5 February, and there, while giving way in the west, the enemy had reinforced his defenses. On the 11th the Chinese pushed a heavy attack down the valley north of Wonju, punched a hole in the ROK lines, and brought about a local collapse in which for four days large gaps existed in the front. One river valley to the eastward, similar difficulties arose from a thrust aimed south at Chechon, while between Wonju and Seoul an enemy column struck southwestward toward Suwon. Such was the pressure in the center that on the 14th the Marine Division was relieved of its anti-guerrilla efforts in the south and ordered up to Wonju, while in the west the threat to Suwon brought an alert from Eighth Army for a possible evacuation of Inchon.
As a result of this alert, received just as the effort to open the port was beginning, Admiral Thackrey decided to avoid drying out LSTs on the mudfiats, and to limit his rate of unloading so that no more would be put ashore than could be packed up inside of 12 hours. With time the situation improved, but for the rest of February a truck shortage limited EUSAK’s acceptance of cargo to a mere 500 tons a day, while a 48-hour withdrawal notice remained in effect for a full month. Considerable congestion resulted, as the ships of Task Group 90.1 being used to work the port and those held against the possibility of evacuation were joined by new arrivals with supplies for Eighth Army, and by early March, Thackrey was crying "Hold, enough!"
Prompt reinforcement of the menaced sectors checked the mid-February threat, and by the 18th the Communists had given up and were retiring. General Ridgway now resumed his advance with Operation Killer, a move forward by IX and X Corps in the center which would bring them abreast of the line in the west, and would clear the Wonju-Kangnung road. On 21 February the Marine Division led out from Wonju, and for the remainder of the month Eighth Army moved forward against varying resistance and through abominable terrain, its movement hindered by the beginning thaw and by heavy rains which turned all roads into mudholes. By the end of the month, however, the Marines were approaching Hoengsong and the objectives of "Killer" were in hand, while on the Sea of Japan the maritime flank had been pushed forward in a great bound.
There Admiral Smith had had his eyes on the strategic islands north of the parallel, and in his concept of operations for February had noted that their occupation would be "of inestimable value," both for control of enemy junk traffic and minelaying and to provide potentially valuable staging areas. In order to undo, at least to some extent, the effects of the abandonment of northeastern Korean footholds, he proposed a heavy bombardment of Wonsan, to take place with or immediately after that at Inchon, and to be accompanied if possible by seizure of the islands of Yo Do and Ung Do which guard the harbor entrance. The idea seemed good and the execution proved better, when enemy reaction to the bombardment stimulated the seizure of an island even further in.
At sea February was a rough month, and on 13 days the blockading ships found their operations seriously hindered by foul weather. On the 12th, nevertheless, the minesweepers went in to check the Wonsan channel, and four days later two destroyers entered to bombard the port. On the 18th, in a return engagement, the destroyer Ozbourn was hit by artillery fire, apparently originating from the island of Sin Do, two miles off the tip of Kalma Pando. The result of this impudence was an air strike from Task Force 77 that very day, a bombardment by Belfast on the 19th, and the appearance on the morning of the 24th of two destroyers, a frigate, and an ROK LST with an assault party of 110 Korean Marines. Lacking a shore fire control party, the arrangements to support the Sin Do landing were somewhat complex: the Koreans had been given a portable radio, but the only interpreter was on the cruiser Manchester offshore, and messages to the supporting destroyers had to be relayed; Manchester’s helicopter, which provided aerial observation, was in communication with the destroyers but not the landing party. But all went well: two hours of bombardment were followed by an unopposed landing, and the island was soon declared secure. United Nations forces were back at, if not in, Wonsan.
The Wonson siege begins: Paracutin rearming Manchester; in the background LSTs and minesweepers anchored in the lee of snow-covered Yo Do. March 1951. (Photo #80-G-427259).
With these February operations the tempo of naval gunfire began a rapid rise. Where ammunition expenditures in December at Hungnam had set a new record, those of January had plummeted. But with clearance of the coastal fire support lane and with seizure of the Wonsan islands there came a radical increase, and by March the expenditure of 5-inch ammunition had become phenomenal. That this fluctuating consumption imposed heavy problems upon the logistic agencies may be seen from the statistics in Table 15.
Table 15.—AMMUNITION EXPENDED IN BOMBARDMENT
For the Seventh Fleet carriers February was a period of transition. Close support of the battleline continued, as did intermittent strikes against transportation targets, but the generalized nature of FEAF’s basic request for interdiction led to duplication of effort with Bomber Command. Yet the problem remained and, following repeated reports of heavy movement on the Hoeryong-Wonsan line, FEAF directed Fifth Air Force to attack a group of bridges in the northeast. But to ask this was to ask too much. On 15 February General Stratemeyer advised Admiral Joy that the withdrawal from forward air bases had made operations in northeastern Korea difficult for Fifth Air Force, occupied as it was by commitments to the support of Eighth Army, to bomber escort, and to interdiction in the northwest. Stating that "naval air could greatly assist interdiction" by covering the northeastern route, he requested a ten-day effort against important bridges and proposed, if this were agreeable, to reschedule the work of Bomber Command, both to prevent duplication in the northeast and to improve coverage in the northwest. The proposition was accepted by ComNavFE, and Commander Seventh Fleet was instructed to apply his principal effort for the next ten days to the Hoeryong-Wonsan railroad.
As this work began the Chinese again disappeared from the front, and Eighth Army resumed the advance. The generalized chaos and the very large number of dead that U.N. troops discovered on their way north from Wonju went far to bear out Admiral Struble’s feeling that close support had hurt the enemy more than was generally appreciated. On the other hand the altered ground situation emphasized the desirability of cutting the flow of supply and reinforcement, so as to prevent Communist recuperation. On 20 February Admiral Joy moved to coordinate the efforts against the east coast transportation line by providing the carriers and gunnery ships with a list of rail and highway bridges accessible to naval gunfire, 13 in the Wonsan area, 23 in the north on the shores of Kyongsong Man, and 25 in the region south of Songjin which had been the target of earlier attacks by raiders from Juneau, Bass, and Perch. As the dispatch went forth it was already being implemented, for Missouri, now returned from her west coast bombardment duties, was dispensing 16-inch shells against the multiple bridges which span the double river at Tanchon. On the 22nd and the 23rd this enterprise was continued, and the expenditure, with helicopter spot, of an average of 166 rounds a day effectively subdivided these overwater structures.
The assignment of the fast carriers to rail interdiction had originally been scheduled to run through 25 February; on that date ComNavFE ordered it continued; by month’s end it had become the primary task. To Admiral Ofstie it so commended itself, in view of the preoccupation of Fifth Air Force in the northwest and of the greater effectiveness of Bomber Command in attacks on marshalling yards and supply areas; on 28 February he proposed that his force apply its main effort to interdiction, set up a schedule for future operations, and made recommendations for more effective coordination with the work of the bombardment ships.
Essentially this shift from close support to interdiction was the result of differential capabilities, deriving in large measure from the existing air base situation. For the United Nations, at this time, Korea formed a large beachhead, in which inward or outward deployment followed the fortunes of war. The retirement of the armies from North Korea and the redeployment of the greater part of land-based air strength to Japan had returned the peninsula to the stage which, in a normal amphibious operation, precedes the introduction of garrison air. In these circumstances Fifth Air Force found itself obliged to abandon the interdiction function, and on 26 February, as Task Force 77 began its extended stint in the northeast, the responsibility for northwestern Korea reverted to the B-29s of Bomber Command.
Difficult though the situation still remained, it was about to improve. The Army had started north the latter part of January; as March opened, the objectives of "Killer" were in hand and the U.N. line, both stable and relatively straight, extended eastward from the lower Han through Hoengsong, and thence northeasterly to Chumunjin. In these circumstances it was possible to return evacuated air units to Korea: in early February the Marines had moved three fighter squadrons in from Japan, and by month’s end Fifth Air Force squadrons and supporting units were preparing to return. At Wonsan in the east, and from Inchon to the Yalu in the west, U.N. forces held islands off the enemy shore. Along both coasts, from the battleline to the northern limits of the blockade, the surface units of Task Force 95 patrolled and bombarded. The effort of the fast carriers had shifted northward, and was focused on the rail lines leading down from Manchuria. Eighth Army was preparing a new offensive.
Part 2. March–April 1951: On to the Parallel
On 2 March the Marine Division, spearheading the drive up the center, captured Hoengsong. With the aims of "Killer" accomplished, EUSAK now planned a further advance, Operation Ripper, which by pushing onward through Hongchon to Chunchon would outflank Seoul, and gain a line in the neighborhood of the 38th parallel. This new move would take General Ridgway’s armies through the region of the enemy’s January offensive, and as it had for the Communists, so now for the United Nations the topography of the area would pull the armies to the right and away from the axis of the peninsula. As Eighth Army moved onward through the central hill country the valley roads would lead not toward Pyongyang but north through the mountains to Kansong, Kojo, and Wonsan on the eastern coast. In this situation, and as the battleline had now acquired a national compartmentation with U.N. and Chinese forces in the west and center, and with the eastern flank remaining an all-Korean affair, it was hoped to split the Chinese off from their indigenous subordinates. Finally, as in the operations of February, General Ridgway intended to inflict maximum attrition on the enemy, and by keeping the pressure on to inhibit his preparation of a new offensive.
To assist the planned advance EUSAK had again asked for an amphibious demonstration in the Yellow Sea. Feeling that the speed of earlier efforts had not given the sluggish enemy sufficient time to react, Admiral Andrewes now planned for deliberate fraud. Beginning on 27 February the air activities of Bataan were increased and localized; for two days the DMS Carmick, the frigate Alacrity, and two Korean YMS swept northward along the coast and into the mush ice of the Taedong estuary; there followed a cruiser and destroyer bombardment. On 3 March the amphibious element of three APAs and two AKAs appeared, escorted by two destroyers, to steam northward along the shore. Half way to Cho Do the transports reversed course and retired to Inchon, whence they made an ostentatious departure on the 5th to continue the effort at mystification.
After a heavy artillery preparation, Operation Ripper was launched on 7 March, and began a steady progress up the center of the peninsula. Seoul this time was captured not on the beaches of Inchon but on the Pukhan: as the 25th Division forced the Han near its junction with that river and moved on to the north the capital was outflanked, and on the 15th was reoccupied without a fight. But two conquests and two liberations had taken a frightful toll, and hardly a tenth of the city’s original population still skulked amid the ruins On the east coast, as "Ripper" began, the destroyers continued to provide fire support; at Inchon the heavy cruiser Saint Paul remained on station, her 8-inch guns closely tied in with I Corps artillery. But with the flanks holding and the center advancing, and with Task Force 95 concentrating on the disruption of enemy transport and supply, gunfire support was for the moment of secondary importance and the trend of naval activity continued northerly. Task Force 77 was working over east coast transportation targets; east coast bombardment efforts were centered at Wonsan and Songjin; in the northwest Belfast, Kenya, and associated light units shot up enemy positions at the mouth of the Taedong estuary.
Since 16 February Wonsan had been under siege, and of the 31 days of March found itself subjected to gunfire on 31. As April opened, all important harbor islands had been occupied by the U.N., the record for continuous naval bombardment, established at Vicksburg almost a century before, had been surpassed, and a long and uninterruptedly difficult future lay ahead of the town. Enemy response to these operations involved a build-up of artillery and garrison forces, and a persistent if small-scale effort to remine the harbor: of the 28 mines swept in March–some of them new and shiny–20 were swept at Wonsan. Despite frequent and increasing artillery opposition, the sweepers worked persistently to enlarge the bombardment lanes, while the gunnery ships, beneficiaries of the effort, supported them by counterbattery fire and bombardment. On 1 March Korean agents reported that the enemy was unloading Soviet mines at the Kalma railroad siding, and on the 7th a bombardment of this target by the light cruiser Manchester brought a gratifying high order detonation of a boxcar full.
The precaution of arranging for east coast intelligence sources proved rewarding in other ways. On 15 March, in response to reports from ashore of enemy troop concentrations, a special event was laid on. Rapid fire bombardment of reported assembly areas in the neighborhood of Wonsan by Manchester and the destroyer Lind brought reports of 6,000 and 2,000 casualties respectively, and follow-up information from agents ashore indicated that the civilian population had fled the city and that morale among the military was not good. Pressure from the sea nevertheless continued undiminished: an enemy effort to land by sampan on ROKN-occupied Tae Do, off the end of Kalma Pando, was repelled; on the 24th a fire control party was put ashore on Tae Do by the destroyer English, with beneficial results in the spotting of bombardment.
At Songjin, 120 miles to the northeast and halfway to the Siberian border, a similar if less intensive siege had meanwhile been commenced. Mine reconnaissance of Songjin, carried out in the first days of March, was followed by daily bombardment of the port and of rail bridges neighboring the town, and in the first week of April a major minesweeping effort was undertaken to provide increased maneuvering room for the firing ships.
In addition to the work at the bombline, and at Wonsan and Songjin, intermittent bombardment of bridge targets was conducted in Kyongsong Man to the northward. On three days in mid-March, from the 14th to the 16th, Missouri was in action against east coast transportation targets in the Chongjin area, after which she moved southward to fire on the coastal rail line in the neighborhood of 400 and to shoot up Wonsan.
By this time the efforts against enemy transportation targets were beginning to develop into a concentrated and coordinated campaign. The Communists, of course, had long since lost the use of the sea; seaborne import of useful objects from Vladivostok or from China ports had been eliminated, along with coastal traffic, in the first days of war. Enemy logistics therefore depended on the two principal land transport nets, the western rail and road complex, in which the lines from the lower Yalu and from Manpojin joined in the area north of Pyongyang, and the eastern route, in which the tracks south from Hoeryong and southeast from Hyesanjin met at Kilchu and continued down the coast to join the transpeninsular line below Hungnam. In the west the mission of interdiction had been assumed by Bomber Command; the eastern rail and road lines, more distant from U.N. bases, became the responsibility of the Navy.
These tasks would of course have been far simpler had only the position at Wonsan been maintained. Given the topography of east central Korea, and the resulting configuration of the rail and road net, such a foothold would have blocked enemy supply of the eastern front, while Marine fighter-bombers based on Kalma Pando would have had the entire transpeninsular line and a major portion of the western transportation system within the 100-mile circle. As it was, however, the evacuation of X Corps, the result of fears for Eighth Army rather than of doubts as to the feasibility of holding a perimeter, led to the imposition for the remainder of the war of a heavy and continuing burden upon the carrier and gunnery forces.
In the circumstances, however, it was fortunate these forces existed. With them, in the continued absence of air and submarine opposition, targets 400 miles from the nearest U.N. airstrip could be kept under dive bomber attack, and coastal targets 300 road miles behind the lines subjected to naval gunfire. The importance of such action had been emphasized in early 1951 by intelligence of a strenuous impending enemy logistic effort on the east coast route, by the knowledge that some reorganized North Korean divisions were scheduled for rail movement south from Hoeryong, and by expectations of an important secondary traffic from Manpojin through Kanggye by rail, across to the Chosin Reservoir by truck, and thence down to Hamhung. It was in the context of this intelligence that ComNavFE had accepted FEAF’s request to put the fast carriers on interdiction, and had moved to shift the efforts of Task Force 95 from control of the sea approaches to the interruption of land transport by providing the list of rail and highway bridges.
Such target information was most helpful, but for a number of reasons effective interdiction of Communist supply lines remained extremely difficult. This was so in the first instance because of the enemy’s logistic austerity. As compared with a figure of 50 pounds per day for the individual in the U.S. Eighth Army, and of 64 pounds per man-day with the Fifth Air Force in Korea’s heavy logistic requirements figured in, the best available estimates indicated that the Communists subsisted on a supply basis of ten pounds per man per day. Measured against this requirement, which worked out at about 50 tons per day per division, the North Korean transportation net was more than adequate, although its peacetime capacity had been gravely diminished by damage to rails and rolling stock and by limitation to night movement. In early March the capacity of the west coast rail line was estimated at between 500 and 1,000 tons per day, and that of the east coast railroad at about 500, while highways in the west and east were capable of transporting 1,000 and 500 tons per day respectively. In these circumstances it appeared that the enemy could support half a million troops, with something over a third dependent on the east coast rail and road nets.
Interdiction of these routes depended, at least in the first instance, upon bridge demolition, and modern reinforced concrete bridges, hard to hit and hard to destroy, requiring the hitting power of battleship or heavy cruiser main battery fire, or of the AD attack plane. Experience gained as the campaign progressed showed force requirements of about 60 rounds of 16-inch gunfire or of 12 to 16 AD sorties per bridge destroyed, so that for battleship and carrier alike, two a day was the average capability. Knocking down the bridges was therefore well within the realm of possibility, but while the rail net could be thus fragmented the effect on highway travel was less decisive: a truck can be detoured more easily than a train, and the supply of trucks from north of the border was a continuing one.
In his dispatch of 28 February Admiral Ofstie had proposed to rotate the efforts of his force between the area north of Hamhung, the complex south and west of Hamhung-Wonsan, and the route between Hamhung and the Chosin Reservoir, and had observed that better coordination with the gunnery ships would be helpful to the enterprise. The proposed procedure for Task Force 77 was approved by Admiral Struble; with reference to the comments on naval gunfire, however, Commander Seventh Fleet somewhat sourly observed that coordination between Task Force 77 and Task Force 95 was in the hands of ComNavFE. Passing upward through the chain of command, CTF 77’s plan received the blessing of NavFE headquarters; arrangements for exchange of information between Bomber Command and the carriers were worked out; and the force set to work in the area east of a line drawn south along 127°E, and thence through Yangdok to Kumwha. Ultimately the coordination with Task Force 95 would also come.
Map 23. Interdiction, 1951.
Within the carrier task force the campaign was carefully planned. Since the 395 major bridges in eastern North Korea afforded a surplus of targets, a research effort was undertaken which cut the list to 48 "key bridges," structures in difficult terrain which were hard to bypass, and which once destroyed would have to be rebuilt. Attack on these key bridges was to be supplemented by track breaking, by destruction of minor bridges in areas where no key structure existed, and by surface gunfire at specific points along the coast, of which Kyongson Man, Songjin, and Iwon were of primary importance. The backbone of the striking force was provided by the ADs, lifting three 2,000-pound GP bombs apiece, and accompanied by F4Us for fighter cover and flak suppression, each with a 1000-pound bomb for added striking power. The entire campaign was backed up by a comprehensive and continuing program of aerial photography. Maximum economy of effort was derived from careful briefing, and no pilot was sent off without one or more photographs of his target.
Through March and into April the carrier planes ranged over northeastern Korea, covering the four degrees of latitude from the 38th parallel north to beyond Chongjin. As the three complexes named by CTF 77 were attacked in regular succession, the box score grew and the impact upon the enemy became severe. The effectiveness both of the bridge strikes and of Communist efforts to undo the damage may be seen in the history of the most famous of east coast structures, the bridge below Kilchu, where the railroad crosses what came to be known as Carlson’s Canyon.
Of the valley named in his honor, Lieutenant Commander Harold G. Carlson, commanding officer of VA 195 in Princeton, was the Vespucci rather than the Columbus, exploiter rather than discoverer, for the bridge that crossed it was first sighted by a shipmate, Lieutenant Commander Clement M. Craig, while flying homeward on the morning of 2 March from a strike on Kilchu. Eight miles southwest of that town the rail line, tunnelling through the hills, emerges briefly to span a gully and then disappears again underground. Twin tunnels had been dug in preparation for double tracking, and two sets of piers erected, but only a single track had been thrown across the chasm on a six-span bridge, 650 feet long and 60 feet high. The tunnels made it difficult to bypass; its height made it difficult to repair. That afternoon a strike was flown off which damaged the southern approach.
Next day Commander Carlson led a second flight of ADs against the bridge. As a result of this event one span was dropped, a second damaged, two more shifted out of line, and the site rechristened by Admiral Ofstie in honor of the strike leader. Four days later, on 7 March, a follow-up attack dropped the northernmost of the previously shifted spans.
The attacks on the railroad bridges quickly resulted in pile-tips of supplies at breaks in the line, in concentrations of vehicles to truck material past the choke points, and in energetic efforts at repair. By 8 March the Corsairs were loading with 100 and 250-pound bombs for employment against these accumulations of supplies and vehicles, while the ADs and the heavy ordnance were reserved for the interdiction targets proper. At Carlson’s Canyon the vigor of the enemy effort was revealed on the14th by photo plane inspection which showed rough but effective repairs in the form of wooden cribbing, built up to replace the missing spans. Strike 4 followed the next day, knocked down all new construction, dropped another span at the southern end, and damaged the northern approach; but within two days large piles of wooden ties had been assembled in the gully preparatory to re-reconstruction. The extraordinary persistence of this engineering effort, paralleled at all important broken bridges, testified to the importance of the east coast rail net, demonstrated the availablity of repair crews and materials, and imposed upon the task force the requirement of rephotographing all key targets at four-day intervals.
Following the strike of 15 March Admiral Ofstie recommended to ComNavFE that Bomber Command be asked to inhibit repair activity by seeding the gully with long-delay bombs. In spite of JOC concurrence FEAF’s first reaction was adverse, but a study of photographs provided by the task force showed the site to be a prime objective for this combination of naval and Air Force capabilities; on the 24th a B-29 was sent out with a bomb load fused for long and varying delays, and three days later the effort was repeated.
Despite this useful contribution, the enemy continued to press the work with great determination. On 20 March photographs again revealed large piles of construction material. By the 30th, cribbing of the four central spans and the northern approach had been completed, transverse members had been installed, and only the rails were lacking. On 2 April, therefore, Admiral Ofstie sent off Strikes 5 and 6 which destroyed the whole works, knocking down all rebuilt cribs and spans and leaving only the concrete piers.
AD in a glide-bombing run. A broken rail bridge, a newly-constructed bypass, and breaks in the new line. In the background the shore of the Sea of Japan. October 1951. (Photo #80-G-435044).
If it did not discourage the enemy, this destruction at least forced him to change his plans. Reconstruction of the bridge was abandoned and the labor force put to work on the building of a four-mile serpentine which would bypass bridge and tunnels alike. This bypass required eight new bridges of its own, but all were short and low; although a number were knocked out in April, the new simplicity of repair made the site no longer an attractive one, and the attention of the force was shifted southward to the area of Songjin. There, after first breaking some low bridges north of the city, CTF 77 turned to the area south of the town, where the bridge-tunnel-bridge sequence was three times repeated close to the water’s edge, and where gunfire from the besieging destroyer could delay the rebuilding of structures taken out by air attack. Already once destroyed and once repaired, these bridges began to receive the concentrated treatment on April Fool’s Day, and here through June the same sequence of destruction, cribbing, destruction, and bypassing would take place.
On 4 April, after 38 days of concentrated effort in interdiction, Admiral Ofstie turned over tactical command of the force, and Princeton sailed for Yokosuka for an overdue period of rehabilitation and maintenance. In this period 54 rail and 37 highway bridges had been rendered inoperable, 44 more had been damaged in varying degree, and the railroad tracks had been broken in more than 200 places. For much of the Korean War, pliots’ claims are difficult to assess, and statistics of attacks against such evanescent targets as personnel, rolling stock, and guns must be taken as approximations only. But of these bridges it is possible to speak with some confidence, for in Task Force 77 "inoperable" meant that photographs showed one or more spans destroyed.
Table 16.—Task Force 77 Rail Interdiction, February–April 1951
||Rail bridges inoperable
4 April 1951
|Hoeryong south to Chongjin
|Chongjin south to Pukchong
|Inland from Tanchon, Songjin, and Kilchu
|Pukchong south to Wonsan and inland to the Chosin and Fusen
|Wonsan west to Yangdok
|Wonsan south to Chorwon and Kumwha
Enemy response to this extremely destructive campaign was not limited to the effort in reconstruction. Antiaircraft defenses of key points were rapidly increased, and there developed an extraordinary increase in truck traffic which brought April air sightings of vehicles to more than four times the January total. Since trucks and antiaircraft, unlike bridges, were available on requisition from the north in practically unlimited quantity, it was soon apparent that interdiction could hardly be absolute, and that to maintain its effectiveness would require continuous effort. Nevertheless the work of the fast carriers had been fruitful: the east coast rail system, which had carried two-thirds of North Korean traffic in February, in March moved less than half the total and in April less than a third, and east coast enemy road transport was likewise proportionately reduced.
Table 17.—GHQ United Nations Command Analysis of Enemy Transport, January–April 1951
|Daily average sightings
| Railroad cars
Estimated percent of total enemy rail or road traffic, transpeninsular route excluded:
| East coast rail
| East coast road
| West coast rail
| West coast road
Despite the virtues of modernity, as exemplified in bombing and bombardment, it remains true that the surest way of getting explosives where you want them is the old-fashioned one of putting them there by hand. With this sometimes forgotten truth in mind, ComNavFE in mid-March had conceived the idea of assisting the interdiction of the east coast rail line by a commando raid. A special task organization, Task Force 74, was set up under Admiral Hillenkoetter; 250 men of the Royal Marine Commando were embarked in the LSD Fort Marion and a UDT detachment in the APD Begor. Following rehearsals at Kure these ships set sail for Sorye Dong, eight miles south of Songjin, with a somewhat elaborate supporting force composed of Saint Paul, two destroyers, and six minesweepers.
The operation took place on 7 April. Owing in part to the directive, and in part to limited communications facilities in the participating ships, command arrangements were rather unorthodox. The landing itself was the responsibility of Captain Philip W. Mothersill, commanding officer of Fort Marion and Commander Amphibious Group, and Admiral Hillenkoetter controlled only the supporting ships. Instead of awaiting an expression of readiness on the part of the landing force commander, transfer of control ashore was to take place automatically the moment the troops hit the beach, although, oddly enough, fire support and air control personnel were to remain subordinate to the Amphibious Group. Shore fire control personnel from a Marine Anglico had been offered but declined; the SFCP, composed of ship’s company from Saint Paul, was inexperienced in troop fire support and lacked direct communications with the landing force.
The raid at Sorye Dong: LVTAs leaving the well of Fort Marion with the Royal Marine raiding party. 7 April 1951. (Photo #80-G-428316).
To the distress of the landing force commander, who felt that it would reveal intentions and gain him a warm welcome ashore, a conspicuous minesweeping effort had been arranged. The landing itself, scheduled to take place in the pre-dawn darkness, was to be preceded by UDT beach reconnaissance, but pea soup fog frustrated the latter and delayed the former until 0800. Beach intelligence, based on few photographs and faulty interpretation, had promised a sandy shore with suitable exit for tracked vehicles; in fact no exit existed and the beach was fouled by boulders which, but for the fortunate absence of swell, would have ripped the tracks off the LVTs.
In these circumstances it was well that opposition was negligible. Operations proceeded deliberately, the demolitions were satisfactorily accomplished, and by 1600 the landing force had reembarked. But the whole comedy was labor lost: the point of attack was just south of some of Task Force 77’s favorite bridges, the rails were red with rust, and local inhabitants reported that for 40 days and 40 nights no train had passed through Sorye Dong.
By this time the ships, the commanders, and the crews who had carried the burden during the early months of the war were being rotated homeward. Hoskins, Hartman, Higgins, and Doyle had already moved on to new commands, and as spring came more and more new faces blossomed in Korea. Naval reservists, who had earlier come forward in drafts and as individuals, now began to arrive in organized units: the first weekend-warrior aviation unit, a PBM patrol squadron, had reached Japan in mid-December; in late March the first reserve air group arrived when Boxer, her long-delayed overhaul at last completed, returned to relieve Valley Forge. Also embarked in Boxer was Rear Admiral William G. Tomlinson, Commander Carrier Division 3, whose impending arrival at last permitted Admiral Ewen to go home. But Philippine Sea, his long-time flagship, remained, and her flag quarters were taken over on 25 March by Vice Admiral Harold M. Martin, who three days later relieved Admiral Struble as Commander Seventh Fleet.
This shift in the principal naval operating command was followed, in early April, by changes in subordinate echelons and by a major structural revision of Naval Forces Far East. Admiral Andrewes, who following promotion to vice admiral earlier in the year had for six weeks commanded Task Force 95, was relieved by Rear Admiral Alan K. Scott-Moncrieff, RN, and command of the Blockading and Escort Force reverted to Admiral Smith. Service Force units, previously organized in separate Seventh Fleet and NavFE groups, were consolidated into Task Force 92; with the departure of Captain Austin, who had run the logistics for Inchon, Wonsan, and Hungnam, command of this force devolved upon Captain Wright, formerly ComServDiv 31. And with these changes Admiral Martin got something that Struble had repeatedly sought without success, when on 3 April Task Force 92, Task Force 95, and all U.S. Navy destroyers in the Far East were assigned to his operational control.
With this consolidation only the patrol planes, the submarines, the Hunter-Killer Group, and the Amphibious Force remained directly under ComNavFE, and these would be assigned to Seventh Fleet as need arose. One result was a considerable simplification of command relations and of the associated communications problem as between Eighth Army, Fifth Air Force, and theater naval forces; another was an improved coordination of carrier and gunnery units in the east coast interdiction campaign. Admiral Ofstie had earlier commented on the economy of effort to be derived from such coordination, then requiring action at the NavFE level, and while exchange of information had been improved the results were not yet wholly satisfactory. Following the reorganization of 3 April, however, Commander Seventh Fleet assumed responsibility for the interdiction campaign. All heavy ships were absorbed into Task Force 77, while Task Force 95, composed of two U.S. destroyer divisions, the ROK Navy, and units of other U.N. member nations, became in fact as in name the Blockading and Escort Force. Shortly Admiral Martin would delegate responsibility for east coast interdiction, gun-fire as well as air, to CTF 77, and by instructing him to make recommendations for supplementary commando raids ensure that there would be no more Sorye Dongs.
Through March, while the aviators were breaking down the bridges, Operation Ripper had continued, with U.N. forces pressing onward through the razor-edged mountains and precipitous valleys of central Korea. Although winter had ended, the spring thaws and heavy rains continued to make movement difficult, while to the delays imposed by nature were added the delaying operations of small enemy groups. Only in mid-month was variety provided by a singular operation in which the remnants of the North Korean 10th Division, which the Marines had earlier been chasing through the upper Naktong Basin, moved northward, fought their way through the ROK lines from the rear, and disappeared into the distance.
The escape of these people was regrettable, but was compensated for by more important developments. The advance of IX and X Corps in the center had freed the flanks for rapid movement, and in the west, following the reoccupation of Seoul, the I Corps moved raipdly to the Imjin River. There by month’s end the line had been pushed forward to the 38th parallel, while on the east coast ROK forces had again crossed into North Korea.
In the west, too, the logistic situation was easing. At Inchon, by midMarch, the MSTS representative had opened his office ashore, and on the 17th EUSAK lifted its 48-hour evacuation notice. On the 25th, with the Army engineers ashore and with unloading proceeding at a rate of over 3,000 tons a day, Admiral Thackrey closed down his operations and departed. Although the delay had been considerable, it was less than that in exploitation of the neighboring strategic prize, for Kimpo did not become fully operational until May.
With the armies of the U.N. astride the 38th parallel, the question of how far to press the advance again presented itself, this time to be answered on tactical grounds. For some time intelligence had indicated that the Chinese intended to hold at the dividing line, while preparing for a major offensive in May. Since there was plenty of evidence, not least the Communist diligence in bridge repair, to show that these preparations were being earnestly pressed, this intelligence was taken seriously. To hinder the enemy build-up and to maintain pressure on the Communist armies, EUSAK had planned a further move. The Imjin River would remain the western anchor, but the remainder of the front would be advanced across the parallel, to shorten the line and to provide a labor-saving ten-mile water frontage at the Hwachon Reservoir. This movement, Operation Rugged, began on 5 April.
In the air, too, the enemy was growing stronger. In late March Communist air strength was estimated to have reached a total of some 750 aircraft of all types, and B-29 attacks on northern targets were meeting heavy MIG opposition. Ominously, on 29 March, a twin-jet bomber was sighted over central North Korea; equally ominously, efforts were underway to rehabilitate the North Korean airfields.
This threat found the forces of the United Nations in an extremely vulnerable position. Nine months of exemption from the dangers of air attack had taught bad habits. On shore, camouflage discipline was nonexistent, housing and equipment were disposed in orderly rows about the Korean landscape, stockpiles were open and conspicuous, aircraft were parked in close formation on unrevetted airfields. Along both coasts blockading ships operated without air cover, which in any event could hardly have been provided, and skills in air defense had rusted. For the naval forces the danger was emphasized on 15 April, when the ROK frigate Apnok, straggling in somewhat undisciplined fashion from a force returning from the Yalu Gulf, was attacked by three enemy propeller-driven aircraft. Apnok fought back well, and shot down one of her attackers, but her topsides were chewed up by strafing and near misses, and there were numerous casualties among the crew.
FEAF, in the meantime, had been watching the Communist airfield reconstruction, and on 13 April began a neutralization campaign which, for the balance of the month, would see a dozen B-29s sent off daily to crater the runways and seed them with delayed-action bombs. As a further precautionary measure, an agreement had been concluded between FEAF and NavFE which provided that in the event of an emergency the air defense commander would have control of all shore-based naval and Marine fighter planes. For the Air Force, still desirous of gaining operational control of naval air, this seemed little enough, and the exemption of embarked aviation as "an integral part of the fleet" from this prior commitment was disappointing. But reasons for retaining this freedom of action shortly became apparent.
The commitment of the Marine Division to the mountain front had limited the offensive capabilities of the Amphibious Force to the conduct of feints and demonstrations. This, however, was a game at which two could play, and resurgent Communist activities in the Formosa area now had impact on Korean naval operations. Since the summer of 1950 the Formosa Strait patrol had been continued by long-range search planes and by a small destroyer force. But with the new year intelligence of troop and junk concentrations in mainland ports suggested the possibility of an invasion attempt when the April good weather came. In mid-February Struble had again visited Formosa, and an improved and expanded Formosa defense plan had been prepared. Late in the month ComNavFE took cognizance of the situation, and inaugurated a series of experiments to determine the optimum choice of weapons against a junk fleet.
In warfare between forces of radically different technological capabilities the advantages are not all on one side. In Korea the virtues of primitivism in conflict with technology had been clearly demonstrated in the difficulties that had beset Eighth Army, mechanized, heavily equipped, and road-bound, when locked in combat with the lightly armed, ridge-running levies of North Korea and Communist China. The difficulties of successfully interdicting the supply lines of an army whose logistic requirements per man were about a sixth of those of U.S. forces had reinforced the lesson, which promised also to apply to action between naval air and gunnery forces and fleets of wooden junks.
Such fleets present numerous small targets, hard to hit, impossible to sink, and whose destruction may prove excessively costly in ammunition expenditure. On 24 February, therefore, with the Formosan question in mind, ComNavFE directed Admiral Thackrey to provide some samples at Yokosuka for practice purposes. Eight 60-foot Korean junks were salvaged at Inchon and brought across in the LSD Tortuga; a sunken Chinese 100-foot 600-tonner presented more difficulties, but in time was floated, beached at Wolmi Do, and embarked in the LSD Colonial for delivery to Japan. In March and April extensive tests were conducted under the direction of Rear Admiral Edgar A. Cruise, commander of the Hunter-Killer Task Group. But his report on ordnance selection was not completed until May, by which time the Communist build-up in Formosa Strait had already had strategic effect.
The intelligence from the south and the coming of the invasion season made a show of force appear in order. On 8 April, therefore, with Admiral Martin in Philippine Sea and Admiral Tomlinson as OTC in Boxer, Task Force 77 left Korean waters and steamed southward through the East China Sea. On the 13th Admiral Martin flew in to visit the Generalissimo at Taipei, and an air parade was flown over Formosa to strengthen Nationalist morale; two days earlier a similar demonstration had been made along the three-mile limit off the Chinese mainland pour encourager les autres; on both days high-altitude photography of selected coastal staging areas was carried out. On the 14th the force again headed northward and on the 16th resumed its efforts in interdiction of the northeastern transportation net. But while the demonstration may have had value in Formosa, it had proven costly in Korea: although Bataan and Theseus had been shifted from the Yellow Sea to the east coast, their weight of effort had proven insufficient, and the eight-day hiatus in fast carrier operations had left the interdiction program almost out of hand.
Important though they were, these workaday problems were for the moment overshadowed by events on a higher level, for following a series of public and private disagreements concerning Far Eastern strategic aims President Truman on 11 April relieved CincFE of his commands. Where the military had already had to adjust to an Amphibious Force without a Marine Division, to a Marine Division without its Aircraft Wing, and to a United Nations force shorn of its amphibious capability and limited in strategic aim, the world now faced the problem of adjusting to a Far East Command without General MacArthur. "New war" had required a new commander.
The manifold responsibilities of Supreme Commander for the Allied Powers, Commander in Chief United Nations Command, Commander in Chief Far East Command, and Commanding General, U.S. Army, Far East, now devolved upon General Ridgway, who was in turn relieved at Eighth Army by Lieutenant General James A. Van Fleet, USA. Having been concerned with the implementation of the Truman Doctrine in Greece, a country also in large part surrounded by sea and troubled by visitors from beyond the northern mountains, General Van Fleet found himself in a not unfamiliar strategic situation. Under its new commander Eighth Army continued its northward advance, while preparing, in anticipation of a CCF offensive, for a fighting retirement which would inflict maximum punishment on the enemy. By the third week of April the Hwachon Reservoir had been reached, and from the Imjin to the Sea of Japan the line ran some ten miles north of the parallel.
At sea as on land, operations continued in routine fashion. On the east coast the sieges of Wonsan and Songjin went on, with daily bombardment and daily minesweeping. For the sweepers, life had been eased by the arrival of LST 799, whose conversion to minesweep tender and helicopter base had been completed; her presence also proved a boon to U.N. pilots, who could now ditch damaged planes in Wonsan harbor in confidence of expeditious rescue. In early April a new technique was developed by the Wonsan besiegers when an Air Force night intruder pilot employed his previous experience in the artillery to coach ships’ gunners on to targets they could not see. This happenstance was followed by a visit of the Task Force 95 gunnery officer to the pilot’s parent squadron, and by a developing coordination of gunfire illumination with air bombardment, strafing, and spotting, which was limited in its prospects only by the number of available intruder aircraft.
In the northeast, where the interdiction campaign was now the sole responsibility of Task Force 77, the fast carriers had resumed their effort, and while the rotating emphasis on different sections of the transportation net continued, the focus, with Carlson’s Canyon bypassed, was on the bridges south of Songjin. In the Yellow Sea the carrier element worked over western Hwanghae Province, the surface ships continued their missions of bombardment and patrol, and guerrilla raiding forces were put ashore. In all services all hands had been alerted to the impending attack, which indeed the enemy had advertised, in his press and on his radio, as one designed utterly to destroy the forces of the U.N. This time, at any rate, there would be no surprise.
Part 3. April–May 1951: The Communist Spring Offensive
The enemy offensive broke on the evening of 22 April with a thrust down the center by the Chinese 20th Army. South of Kumwha the ROK 6th Division collapsed under the weight of the attack, and as the enemy poured through the gap between the Marines and the 24th Infantry Division, General Van Fleet ordered a withdrawal. Four days went by before the assault was checked, and in this interval, with the enemy out in the open and moving, more than a thousand close support sorties by Fifth Air Force and carrier-based aircraft inflicted very heavy casualties.
Map 24. Communist Offensive and U.N. Advance, 21 April–30 June 1951.
The attack in the center and the U.N. retirement which followed had opened the valley of the Pukhan and the Chunchon-Seoul road. On the 26th, therefore, the Communists launched their main effort in an attempted double envelopment of Seoul, in which one prong was pushed down the Pukhan valley, while in the west an attempt was made to ferry troops across the Han onto the Kumpo peninsula. Both moves failed. The eastern threat to the capital was checked by the 24th and 25th Divisions, while on the Han a busy day of strafing by aircraft of the West Coast Carrier Element limited the arrivals to a number easily dealt with by the ROK Marine battalion defending the Kumpo peninsula. In the end the enemy advance in the west central sector reached a maximum of about 30 miles; east of the Hwachon Reservoir the Communists captured the town of Inje on the Hongchon-Kansong road; on the east coast they moved forward some five miles. But despite casualties estimated at ten times those of the U.N. no decisive advantage had been gained, and by the 29th the front was stabilized once more.
Once again the enemy offensive brought an immediate response from U.N. naval forces. On 23 April Task Force 77 began a ten-day sustained effort in support of the battleline. On the next day the first of a series of amphibious feints was carried out. On the 26th the threat to Seoul brought another evacuation alert at Inchon: cruiser Toledo was sent in to provide 8-inch gunfire support and once again Admiral Thackrey was ordered up to take charge. By the 1st of May, as redeployment shipping was beginning to arrive, some 200,000 refugees had clustered in the Inchon area.
The Chinese breakthrough in the center posed urgent requirements for air support, but the Korean airbase situation remained difficult. In April, in addition to the 5 Marine squadrons in Korea, only 3 of the 18 Air Force groups committed to the conflict could be based in the peninsula; in May runway difficulties at Taegu forced the closing of that field and the return of its F-80s to Japan. Over and above the airbase problem the operations of both carrier and land-based squadrons were complicated by the seasonal bad weather. Fog was reported at sea on 17 days in May, rain and low ceilings were prevalent, and visibility in the combat area was further restricted by smoke haze from brush fires set by the enemy for protection against air attack.
These circumstances called for the immediate shift of fast carrier operations from interdiction to close support, and for the greatest possible weight of effort. To avoid the loss of a day in four in refueling and rearming, Admiral Ofstie on 24 April began a schedule of daily replenishment. For ten days the force joined the logistic ships in late afternoon to load until midnight, and while this made for a long working day, it also made it possible to keep pace with the high rate of expenditure of aviation gasoline and ordnance.
To this shift in carrier employment and this intensification of operations there was also added an increase in strength. On 1 May, as Boxer returned from Yokosuka, the retirement of Philippine Sea was delayed, and for three days three carriers were kept on the line. On the same day, as the result of pressure in the west, Bataan’s replenishment period was cut short, her pilots were recalled from leave, and she was sailed from Sasebo for the Yellow Sea. There she joined HMS Glory, recently arrived as relief for Theseus, and there from 2 to 6 May the two ships worked together to strengthen the west coast effort.
Although close support was for the moment the primary task, the most striking carrier operation of the period was the attack on the Hwachon Dam, which by impounding the waters of the upper Pukhan both provided a barrier to movement and held back water usable for tactical purposes. In January, in the hope of impeding enemy progress, Eighth Army had asked FEAF to hole the dam, but an attack by a couple of B-29s with 6-ton guided bombs had failed of success. On 9 April, as Eighth Army was moving northward, the enemy had turned the trick, and by opening the gates had flooded the Pukhan and decommissioned some bridges. Two days later a small and hastily organized force of cavalrymen and rangers failed in an attempt to capture the dam; on 21 April the KMC Regiment had seized it, only to be ordered back as the Chinese broke through the line on the left. Now at April’s end, as the Chinese lunge expended itself, EUSAK again developed the desire to break the dam, wet down the Communists, and prevent them from using the water as a weapon.
On the afternoon of 30 April Admiral Ofstie received a photograph of the dam, with a notation requesting that two or more sluice gates be knocked out, and was informed that EUSAK was the requesting agency and wanted it done at once. At 1600 six ADs were flown off with two 2,000-pound GP bombs apiece, accompanied by five Corsairs for flak suppression, and a dive bombing attack was carried out which produced a hole in one gate. A request from EUSAK for another try and a night’s consideration led to a change in ordnance selection: on the next day eight ADs were launched with torpedoes set for surface run, and at 1100 the Skyraiders went in on this now unfamiliar mission. One torpedo was a dud and one erratic, but the remaining six ran true. One flood gate and the lower half of a second were removed, the dam’s western abutment was holed, and the enemy deprived of control of the waters.
By April’s end the offensive had been contained, and in the first two weeks of May, as Eighth Army probed northward and the enemy prepared for a second try, U.N. aircraft renewed their efforts in interdiction. This interlude brought a temporary expansion of the work of the fast carriers as the result of a request from the Joint Operations Center for help in the interdiction of the western rail lines. In response Rear Admiral George R. Henderson, who had just relieved Admiral Ofstie as CTF 77, advised the JOC that on 11 May he would strike railroad bridges in the triangle which connects Pyongyang, Sunchon, and the transpeninsular line to the east. On the morning of the 11th 32 ADs carrying two 2,000-pound bombs apiece, and accompanied by 32 F4Us for flak suppression and 16 F9Fs for top cover, attacked four of these bridges and dropped spans in three. This success elicited a further request from Fifth Air Force for the destruction of bridges in the rail quadrilateral which links Pyongyang with Sinanju, Kaechon, and Sunchon.
In reply to this message Admiral Henderson observed that while he would be glad to help out from time to time, existing obligations prevented his assuming any permanent responsibility. But the request for such a "substantial and continuing commitment" of the fast carrier effort brought ComNavFE to his feet, and on 16 May he informed Commander Seventh Fleet that such proposals should pass through appropriate service channels for action by higher authority. But by the time this dispatch was on its way the enemy was on the move again: on the 18th, EUSAK called for maximum effort in close air support, and when interdiction again came to the fore the situation had changed.
The failure of the Communists’ first attack, and their evident intention to try again, raised the question of the possible employment of new weapons and brought steps to guard against surprise. Where the first five months of war had produced 80 reports of possible submarine contacts, the second five months had brought a mere 16, a change which could be interpreted as either a threat or a promise. In the air, by contrast, there was no question as to the magnitude of the Communist build-up across the Yalu, nor as to the earnestness of the effort to rehabilitate North Korean airfields. Although no air commitment had accompanied the April offensive, the possibility remained, and on the 29th Commander Seventh Fleet again warned of the chance of surprise air or submarine attack.
For the carrier force, which could operate from beyond MIG range and fight off attacks from other aircraft types available to the enemy, the submarine presented the major hazard, but for the units of Task Force 95 the air question was the serious one. Admiral Smith had alerted his force in April; now on 10 May he advised his ships that the next ten days would be critical with regard to enemy commitment of air strength, credited the Communists with a capability of 300 offensive sorties a day, issued instructions as to procedures to be adopted under attacks of varying weight, and instructed replenishment vessels to avoid anchoring in forward locations.
In the event, although subsequent evidence indicated that the Chinese had hoped to provide their armies with air support, neither menace developed. FEAF’s attacks on North Korean airfields had kept the rehabilitation effort down, and on 9 May, following reports that 40 fighter planes had been sighted at Sinuiju, on the Korean side of the Yalu, Fifth Air Force sent up 250 Air Force and 56 Marine aircraft to deposit more than 40 tons of bombs on the airfield. In the air, despite promises to his troops, the launching of the second spring drive found the enemy no better off than had the first.
The weight of the April thrust toward Seoul had led General Van Fleet to bolster his forces in the western lowlands. Contrariwise, while this movement was in progress, the Chinese were shifting eastward to the central mountains, where on the night of 15 May they attacked in strength. On the Soyang River, southeast of the reservoir, the brunt of the attack was again borne by ROK divisions; again these dissolved, and in the exploitation phase the Communists advanced 25 miles down the valley and across into the upper waters of the Hongchon. To the eastward, in the Sorak Mountains, enemy units overran the ROK III Corps and filtered down to the southeast; on the coast the ROK I Corps withdrew south to Kangnung. In the west Chinese divisions crossed the Pukhan below Chunchon, and on the 17th opened a drive down the valley toward the Han.
As the ground forces struggled to check the attack the supporting arms again stepped up their action. Fifth Air Force increased its effort in close support; on the 17th, after being weathered out for two days, Task Force 77 began another stint of operating by day and replenishing by night; following an appeal from EUSAK for all possible support, Princeton delayed her departure for Yokosuka to permit another period of three-carrier operations. At Inchon, where the enemy was again within range of Toledo’s guns, the drive down the Pukhan brought another redeployment alert, and Admiral Thackrey, who had retained some Scajap LSTs for such a contingency, put in a request for further shipping against the chance that he would have to evacuate the city and the Kumpo peninsula.
This precaution proved unnecessary. In the center the 2nd Division, which had come a long way since the hard times on the Chongchon River, did what was necessary: although under pressure on three sides it maintained its integrity, held while so instructed, reopened its supply line, and retired on order, with minimum casualties to itself and maximum to the enemy. Three days of violent fighting in the Pukhan Valley saw the Chinese thrust turned back by the 25th Division. In the Sorak Mountains, some 20 miles below the parallel, the enemy was checked at Soksa by the 3rd Division, rushed eastward from Army reserve. By 21 May the Communists had been stopped all along the line. Despite a gain of 30 miles in the eastern mountains, and a considerable penetration in the Pukhan valley, nothing decisive had been accomplished, and the price had been higher than before. On the 23rd Admiral Thackrey began to release shipping from Inchon; on the 25th the evacuation alert was ended, all restrictions on stockpiling ashore were removed, and Toledo was at last relieved of her fire support duties.
Naval gunfire support: A shore party from Toledo at an observation post overlooking the Han. May 1951. (Photo #80-G-432346).
The Communist spring offensive had brought about a sudden spate of simulated pre-landing operations by units of Task Force 90 and Task Force 95. The first of these, carried out on short notice on 24 April, consisted of a two-hour bombardment of Kosong by St. Paul, Helena, Manchester, and four destroyers. Five days later, on the 29th and 30th, Helena, Manchester, four destroyers, two attack transports and an attack cargo ship made a demonstration in the Kojo area, in the hope of taking pressure off Eighth Army. On the evening of 4 May General Van Fleet asked for another such affair on the 6th and 7th at Kansong; ComNavFE passed the word to Seventh Fleet to do what it could on short notice, and on the 5th Kosong was added as a target at the request of CincFE. On the desired date Helena and four destroyers bombarded as requested; fortuitously, their arrival coincided with a heavy enemy attack, and the bombardment, according to KMAG’s flatteringly redundant description, saved the ROK forces from "complete annihilation." On the 13th Eighth Army called for another demonstration at Kosong on the 18th and 19th; this request was cancelled two days later, but a west coast event already underway continued to its conclusion.
Feeling, as had his predecessor, that previous demonstrations had been too short and too transparent to produce the maximum reaction, Admiral Scott-Moncrieff planned this with some finesse. Rumors of an impending landing were spread by agents of Leopard Force, a west coast guerrilla organization, and so successfully that aircraft from Glory, flying cover for the minesweepers, reported a large sign near the landing area which read "Welcome, U.N. Army." By 20 May the preliminaries had been completed and Toledo and Commonwealth ships were on hand to provide fire support. In the afternoon a dozen LCVPs, three loaded with Royal Marines and the others empty, were put up on the beach opposite Cho Do, and the Marines made a brief unopposed excursion inland prior to reembarking.
The popularity of these small demonstrations with Army commanders, and the frequency with which they were requested, led to some study of their actual effectiveness and of measures which might make for greater realism. That the enemy, after the events of the previous autumn, was fully aware of the amphibious capabilities of the United States Navy was unquestionable: information from various sources indicated that special pains were taken to keep track of the movements of the Marine Division. But with the Marines in the line, and given the slow reaction time of the Communist armies, there remained the question of whether much was actually accomplished. Admiral Andrewes had been skeptical; after the operation of 20 May Admiral Scott-Moncrieff remained dubious, feeling that enemy communications were so poor that two or three days might pass before headquarters got the word. EUSAK, on the other hand, estimated that the Inchon feint in February had fixed two Communist divisions, and that the March operation off the Taedong had moved one; following the Cho Do affair in May reports were received of troop movements across the Taedong River into previously undefended areas of Hwanghae Province. Although it seems unlikely that enemy response to any particular demonstration was very impressive, their repetition did serve to emphasize existing possibilities, and to reinforce a real concern about a possible major assault in the Wonsan area. With the passage of time it also brought an increasing concentration of defensive force along the coasts, opposite Cho Do in the west and between Kojo and Hungnam in the east.
This concentration was heaviest at Wonsan, where day after day the siege continued. Uninterrupted bombardment and frequent air attack had obliged the Communists to commit large numbers of personnel to defense and to repair work and had curtailed enemy transport, but although the railroad had been stopped road traffic was harder to inhibit, and some 500 trucks were thought to pass through nightly. Attempting to take the pressure off, the enemy moved in increasing amounts of artillery and the Wonsan garrison stepped up its shooting; in late April an unsuccessful attempt was made to recapture one of the ROK-held harbor islands. Whether this enemy reaction amounted to a good return on the effort invested was another matter. CTF 95 had earlier advocated emplacing artillery on the harbor islands, but no such step had been taken and the responsibility for dealing with the shore batteries remained entirely upon the ships; additionally, the original offensive purpose of the siege had been undercut by the decision not to attempt a return to Wonsan. The absence of any very clear objective and the size of the commitment proved disturbing to Commander Seventh Fleet, who felt the entire concept of the operation needed some rethinking. Pending such clarification the cruiser previously assigned the Wonsan task unit was withdrawn, and the garrison situation rationalized by the assignment of a Marine officer to Yo Do as commander of the island’s defenses.
As the enemy’s second offensive slowed, the harassment of his seaward flanks was stepped up, and the Cho Do raid was followed by activity in the east. At Wonsan, following vigorous efforts by enemy artillerists which had damaged a destroyer and bounced a shell off one of the turrets of the recently arrived New Jersey, the rocket ships were sent in for two night bombardments of known gun emplacements. Plunging fire of 7,700 rockets delivered by LSMR 409 and ISMR 412 on 23 and 25 May had impressive results: intelligence agents reported that the enemy was clearing the harbor area of personnel; for three weeks the batteries remained silent. In the north, too, the pressure was maintained: in an interval between bridge bombardments in Kyongsong Man the, destroyer Stickell destroyed a 70-foot motor junk, and followed up by putting a landing party ashore to blow three more with hand grenades.
Even before the second Chinese push was halted General Van Fleet was preparing his reply. On 18 May he ordered all forces from the Marine Division westward to prepare to attack to the north; next day, with the situation in the eastern mountains improving, he included X Corps in this planned general advance across the parallel. On the 22nd the battle of the Soyang River entered its offensive phase as the Marines and the 2nd Division attacked to the northeast against vigorous resistance. In the west, at the same time, I Corps moved steadily northward toward the so-called Iron Triangle, the important and heavily defended area bounded by the towns of Chorwon, Kumwha, and Pyonggang. Since seizure of the Iron Triangle would open the corridor to Wonsan, this movement held great possibilities.
The advance up the Soyang valley toward Inje threatened to cut off the Chinese in the Sorak Mountain salient, and opened the possibility of a thrust through the mountains to Kansong which would trap the enemy forces on the coastal strip. To provide logistic support for such a move some Scajap LSTs, released from Inchon, were assigned to meet the advance at Kansong and establish an advanced supply base. But the threat at Inje made the operation unnecessary, the enemy pulled back, and on 29 May, with minesweeping completed and gunfire about to begin, ROK forces regained control of the Kansong area. By the end of the month the armies of the U.N. were back at the Hwachon Reservoir, and in firm possession of the line from which they had been dislodged by the attacks of April.
The two Communist thrusts and the U.N. counteroffensive had brought the enemy out into the open, and had provided profitable targets for air attack. The response to this opportunity had been vigorous: Fifth Air Force had stepped up its sorties in support of Eighth Army; Task Force 77 had shifted to continuous operations and daily replenishment; in times of crisis all three fast carriers and both light carriers had been put on the line. The statistical results were impressive: the Air Force claimed 21,536 enemy personnel "destroyed" in April and May; Task Force 77 aircraft claimed 1,400 killed on 29 May; on 4 June, following attacks by carrier planes, the advancing ground forces counted more than 1,000 dead.
Whether all this effort, indubitably severe in its effects on the enemy, amounted to efficient close air support was another matter. In his report for this period Admiral Martin observed that while three fast carriers had been employed at Army request, the calls for close support had never exceeded the capacity of two, the controllers had once again been swamped, and much ordnance had been dumped. Nor were the Marines more satisfied. In the later phases of the battle of the Soyang River the division, advancing at a rate of three miles a day against continuing stiff resistance, wanted and needed support from the air, and on two days requested all available aircraft. But advance requests, submitted on the previous day conformably with Air Force practice, were only about half-fulfilled. And while the use of special emergency requests produced a sortie total approximating that originally called for, processing delays were such that time from request to receipt of aircraft averaged 95 minutes.
Such delays, varying unpredictably from one to two hours, have obvious effects on the momentum of attack and on the health of the attackers. To those accustomed to getting strikes in 10 to 20 minutes from aircraft orbiting on station, they were unacceptable, and led to loss of confidence in air support on the part of front line commanders. On 31 May the division commander made the inadequacies of the situation the subject of an official report to X Corps, and such was the feeling within the division as to bring an investigation by the Commanding General, Fleet Marine Force Pacific, once again in Korea on an inspection tour. After working through the numerous and sometimes contradictory allegations, and attempting to separate fact from fancy, General Shepherd concluded that the JOC processing time, the remoteness of airfields from the front lines, the struggle between Mosquito aircraft and ground parties for control of strikes, and the unwieldy nature of the Army-Air Force system, which forced communications to parallel the chain of command all the way to the top and back again, added up to excessive and unacceptable delay. In March he had raised the subject with Fifth Air Force, but to little purpose; now he went to the top, and on 24 May discussed the close support question with CincFE. With General Ridgway’s view that it was improper for Marine air to support the Marine Division exclusively, General Shepherd concurred; for this problem, inevitable when a division with a private air force specializing in troop support was operating in company with air-starved Army units, no other answer was possible. But the basic difficulty was less the identity of the aircraft than the nature of the system, with all its built-in delays.
In June, as the Marine Division continued on the offensive east of the Hwachon Reservoir, two changes were made. Permission was secured from Fifth Air Force to keep four Marine aircraft on alert at an advanced airstrip, and to notify them of requirements by messages paralleling those to JOC. But direct communication with the airfield remained prohibited, the policy of scrambling and reporting was not permitted, and takeoff still had to await word from JOC. At the same time, in view of the radical discounting of routine requests in May, the Marines adopted a policy of submitting special requests only. But this proved self-defeating, as the resultant saturation of JOC communications facilities tended to offset other efforts to diminish delay time. This indeed was decreased in June to an average of 81 minutes, but the percentage of requests fulfilled dropped from 95 to 74 in good weather, and to 65 for the month as a whole, and nobody was much the happier.
Part 4. June–July 1951: North to Kaesong
By the 1st of June the ground forces had regained the line of the Hwachon Reservoir. Only in the eastern mountains, where the desired front turned sharply northward, were the Marines still fighting hard for their objectives, and there the drive up the valley of the Soyang was completed in mid-month. Since instructions from the Joint Chiefs had by now limited the advance to the neighborhood of this line, although permitting local action to gain more commanding terrain, General Van Fleet prepared to fortify his positions while at the same time pushing forward I and IX Corps into the Iron Triangle.
This operation continued throughout the first half of June. By the 11th both Chorwon and Kumwha at the base of the triangle had been taken, and two days later Eighth Army briefly entered Pyonggang at the northern apex. Northeast of Kumwha IX Corps units moved up to Kumsong, where the enemy was attempting to establish defensive positions, and in mid-month attempted to outflank the town on the east, a move which in the absence of JCS limitations might have opened the Wonsan road and liquidated enemy forces to the eastward. Given these restraints, however, the effort was not pressed, and Kumsong remained in enemy hands. Except on the shores of the Sea of Japan, where ROK divisions moved onward to the outskirts of Kosong, this June advance to Pyonggang and Kumsong marked the farthest north for the remainder of the war.
As before, operations on the east coast were assisted from the sea. As the forward movement of the ROK I Corps took it into the difficult hill country at the mouth of the Nam River, gunfire support became extremely active. On 4 and 5 June the heavy cruiser Los Angeles, a recent arrival in the theater, provided support at the bombline; on the 6th, joined by New Jersey, she bombarded enemy positions in the vicinity of Kosong; on the 7th, as the result of an emergency call from the KMAG party ashore, received while she was replenishing, she had the interesting experience of loading 8-inch ammunition from an AKA over one side while unloading it out the guns over the other.
In the east as in the west, the long Korean coastline invited efforts to make trouble in the enemy rear. For some time the APD Begor had been putting agents ashore by night along the northeastern coast, and while security was imperfect–on one occasion the ship’s departure from Pusan was announced by the North Korean radio the same evening–all the landings were successful. These nocturnal enterprises ranged from Chongjin in the north to Kojo, south of Wonsan, where on the night of 2–3 June Begor and her UDT complement landed 235 ROK guerrillas on an islet less than half a mile from the northern arm of the harbor. But this cloak and dagger business was a two-way street: 30 miles back down the coast, at the same time that the guerrillas were going in at Kojo, an ROK intelligence team, surrounded and hard-pressed by the enemy, was departing Kosong under cover of gunfire from an ROK PC and the destroyer Rush.
As the end of the U.N. offensive approached and the intensity of ground action diminished, the attentions of the gunnery forces shifted northward and fire support again gave way to bombardment. The communications centers of Wonsan and Songjin remained daily on the receiving end of gunfire from everything from LSMRs up to the battleship New Jersey. Far in the north the blockade of Chongjin was maintained, and the road and rail bridges leading south from that city subjected to frequent bombardment. On 8 June the efforts of the light ships were supplemented as Task Force 77 sent in Helena, now on her second tour of Korean duty, for three days work on transportation targets in the Songjin, Iwon, and Kyongsong Man areas, and ten days later Toledo gave Songjin a repeat performance.
In the operations of Task Force 77, where Bon Homme Richard had relieved Philippine Sea on the 1st of the month, a similar shift was apparent. Although support continued to be provided for the Marines east of the reservoir and for Army forces in the Iron Triangle, interdiction again became the primary task. A sufficient effort was committed to the northeastern rail bridges to keep them broken down, and an ambitious new inter-service effort, Operation Strangle, was begun.
Admiral Ofstie’s spring campaign had pretty well stopped the eastern railroad. But despite the efforts of Navy, Air Force, and Marines alike, truck traffic had continued to increase, and the daily average of North Korean vehicle sightings had risen spectacularly from 236 in January to 1,760 in May. Analysis of these sightings indicated that the enemy possessed some 20,000 trucks, a tenth of which arrived nightly in the combat zone, and suggested the difficulty of interdicting this logistic effort; it also brought a request from General Van Fleet to Fifth Air Force and to Task Force 77 to make the attempt. The importance of the problem was emphasized in early June by a GHQ announcement of the record vehicle sightings of the preceding month and, despite some skepticism within the Air Force as to its feasibility, the program was accepted on an experimental basis.
In the planning for "Strangle" the main north-south road routes behind the enemy lines were identified and parcelled out among the services. Three routes south and southeast of Pyongyang were taken by the Air Force; the two central routes, from Yangdok down the upper Nam and from Majon-ni south along the upper Imjin, went to Task Force 77; the Marines were assigned the roads running down from Wonsan and Kojo. Where defiles or watercourses made bypassing difficult, "Strangle Areas" were set up for cratering and for seeding with delayed-action and antipersonnel bombs.
From the very start the task was difficult, owing to the greater ease of bypassing by truck than by train, and to the fact that while almost all enemy movement was now night movement, all services were very limited in night capability. All hands nevertheless did their best, although the force requirements to keep the "Strangle Areas" strangled turned out to be somewhere between twice and five times those necessary to maintain an equal number of rail cuts. Dawn and dusk sorties were flown by the carriers, in addition to their normal daytime load, and the Air Force kept its B-26 intruders busily on the job. Best of all, perhaps, was the ingenious system evolved by the Marines, which teamed their night fighters with flare-dropping Navy patrol planes, and although these operations were extremely hazardous, owing to the restricted maneuvering room inside Korean valleys and the effect of the flares on night vision, good work was done. But in mid-June, after 13 days of "Strangle," a preliminary Air Force assessment indicated that while movement past the cut-points had been almost entirely stopped, and the enemy inconvenienced by being forced onto secondary roads, total north-south vehicle sightings remained about the same and arrivals in the front line area showed little ascertainable change. The conclusions were hardly encouraging, but as no obvious alternative presented itself "Strangle" was continued on into the summer.
Naval operations during the period of the enemy spring offensive and the United Nations advance to the north had not been without cost. The increasing strength of enemy antiaircraft was being felt: combat losses from April through June totalled 3 F9Fs, 8 ADs, and 19 Corsairs, and on 18 May Task Force 77 had its worst day of the war thus far when 6 planes failed to return. Enemy coastal batteries were also increasing in number, and not only in Wonsan. On 7 May the frigate Hoquiam was hit off Songjin, and on 14 June the DMS Thompson met trouble in the same area: having closed to 40-millimeter range of the beach and slowed to search for targets, Thompson was surprised when the enemy suddenly wheeled four guns out from under cover, opened fire, and scored 13 hits before the ship got clear.
The continuous efforts of the sweepers had by now largely conquered the minefields, but the threat remained, and on 5 May the first loss since February took place when the ROK JML 306 was sunk off Sok To. More serious than the anchored fields was the problem of drifting mines: not only were the Russian moored mines fused to remain armed after breaking loose, but many had apparently been launched as drifters, to take advantage of prevailing southerly currents. Increasing reports of floating mines came in from the Sea of Japan and from the North Pacific; in June the destroyer Walke, steaming some 60 miles offshore as part of the carrier task force screen, ran upon a floater which exploded on the port side aft, inflicting serious damage and killing 25; by autumn more than 300 mines would have been recovered on Japanese shores.
For the U.N. divisions in Korea the bill had of course been higher, although ground force casualties in April and May were less than half those of November and December, less even than those of January and February. But for the armies of Communist China the spring offensive had proved disastrous. United Nations’ estimates of casualties inflicted on the enemy claimed 70,000 for the April push, 90,000 for the week ending 23 May, and 147,000 for the two-week period from 20 May to 3 June; GHQ intelligence summaries estimated a total for April and May of 283,000, with 72,000 more in June. Figures like these do not, perhaps, inspire complete confidence, but unquestionably Communist losses were extremely severe, and while the impact of this bloody attrition on the manpower of China was minimal, its impact on the available total of trained military personnel was not. There was also a perceptible effect on morale, and prisoners began to surrender in unprecedented numbers: 3,000 Chinese were taken between 16 and 22 May and another 10,000 in the following week.
As the defeated Communists retired northward, with Van Fleet’s armies hard on their heels, command changes continued throughout the forces of the U.N. Subsequent to the attack on the Hwachon Dam, Admiral Ofstie had been relieved of command of Task Force 77 by Admiral Henderson, and on 17 May had taken over as Chief of Staff to ComNavFE. In April Major General Gerald C. Thomas, USMC, had relieved General Smith in command of the Marine Division; late in May General Cushman, who had come out with the brigade, succeeded General Harris in command of the Aircraft Wing, to be himself relieved two months later. With the ending of the threat to Inchon Admiral Thackrey went home; in June, Task Force 95 got a new commander in the person of Rear Admiral George C. Dyer. In the other services the same was true: the Army command had changed in April; in June command of FEAF was assumed by Lieutenant General Otto P. Weyland, USAF, previously vice-commander for operations; at Fifth Air Force, General Partridge was replaced by Major General Frank P. Everest, USAF. Of major force commanders present in the Far East when the troubles began, only Admiral Joy remained, and he was shortly to receive some temporary additional duty which would occupy his whole attention.
At home, meanwhile, the United States had resumed its peculiar custom of conducting foreign policy by congressional hearing. In 1949 the unification investigation had demonstrated, through its exposition of military capability and strategic intent, that the only war contemplated by the United States was a big war in defense of Europe, and had opened the door to aggression by proxy in Asia. Now in the MacArthur hearings the details of strategic planning were again spread upon the public record, to reaffirm beyond a shadow of a doubt that the United States, unwilling to become fixed in a secondary theater, neither intended to expand the war in Asia nor to attempt the forcible unification of Korea. This separation of the political aim of Korean unification from the military objective of repelling aggression was reaffirmed by the President in May, and by the Secretary of State and the Secretary General of the United Nations in early June.
Since the United States did not propose to advance farther into North Korea, and since the Communists were in no condition to advance southward, an agreement to disagree seemed possible, which, while leaving the world and Korea divided much as before, would at least liquidate the fighting. On 23 June the Russian representative at the Security Council, whose fortuitous absence a year before had permitted U.N. action, made a radio address in which he indicated that the chief string-pullers would look favorably upon negotiations for an armistice.
Soundings in Moscow confirmed the official nature of these views, and the offer was taken up. General Ridgway was instructed to invite the Communists to meet with U.N. delegates on board the Danish hospital ship Jutlandia in Wonsan harbor for discussion of an armistice. With the selection of Admiral Joy as senior delegate for the United Nations, Admiral Ofstie took over in Tokyo as acting ComNavFE, and Naval Forces Far East were alerted to support the armistice discussions. On 30 June the invitation was broadcast to the enemy.
The reply came the next day: while agreeing to meet for talks, the Communists suggested that the location be changed to the city of Kaesong, 35 miles northwest of Seoul. This counterproposal doubtless reflected the symbolic difference between a meeting in one of Korea’s historic cities, within Communist lines yet south of the 38th parallel, and one at sea on board a United Nations ship. Since the progress of negotiations would impede military action in the immediate neighborhood, it may also have indicated a desire to block the main road to Pyongyang. Possibly the Communists merely wanted the last word. The suggestion was quickly accepted, presumably in anticipation of an expeditious settlement, but in time the U.N. Command would regret this easy complaisance. On 8 July, following further communications, there was a meeting of liaison officers, and on the 10th, ComNavFE and his delegation confronted the Communists at Kaesong.
To the peoples of the non-Communist world the commencement of armistice discussions was heartening. Although Syngman Rhee went at once on record against all compromise, and demanded a continuation of the war for unification, elsewhere the hope that rational solutions would be quickly found produced a lifting of the spirit. These hopes were doubtless highest among the Americans, with their inbred belief in the value of the spoken and written word and their congenital distrust of the gloomy lessons of history. But even in the United States there were perhaps some whose experience encompassed negotiations with the Communists, and who could see the omens in the meeting at Kaesong.
The presence at the conference table of Chinese generals and an American naval officer called to mind the earlier discussions between Shufeldt and Li Hung-chang concerning the future of Korea, a future which intervening decades had done little to clarify. The antiquity of American concern with the welfare of the Koreans was recalled in the persons of the American interpreters, Lieutenants Horace G. Underwood, USNR, and Richard Underwood, AUS, grandsons of that Underwood who 66 years before had founded the Presbyterian mission to Korea. If these echoes of the past did not sufficiently suggest the intractability of the Korean question, and a likelihood that no speedy settlement would be reached, a contemporary incident, passing almost unnoticed, could have served as evidence that wars do not end all at once. On 30 June, on a little island in the northern Marianas, 19 Japanese soldiers and sailors, who for six years had refused to believe that their war was over, finally surrendered to the USS Cocopa.