Uncle Ho’s Hideout #12 – NVA Air Defenses

mpaign Series Vietnam | Uncle Hos Hideout

In Uncle Ho’s Hideout series, David Galster shares some of his tips and techniques in scenario research and design for CS: Vietnam.

Dear Compatriots,

You are probably aware that the North Vietnamese employed large numbers of anti-aircraft guns on the trail. They also deployed SAM missiles at entry points, like Mu Gia pass. Hopefully, this article will provide more insight into the NVA’s vast air defenses, and their effectiveness.

Air Defense Organizations

One historical Vietnamese reference claims that 2455 aircraft were shot down along the Ho Chi Minh trail. Extensive anti-aircraft (AA) units were deployed. Doan 559 had six known air defense regiments: 224, 280, 282, 284, 591, and 593.

In June 1966, the 367th Air Division was created. The forerunner was the 367th Advanced Artillery Regiment. At certain times, this division also protected the trail. Most of the weapons were employed at storage sites and base area complexes.

At the bombing halt in November 1968, there were about 200 guns of all calibers in Laos. When the USAF shifted its emphasis from North Vietnam to Laos, the North Vietnamese presumably redeployed large numbers of guns to that area. At any rate, the gun count in Laos rose rapidly, reaching about 500 by the first of 1969, and peaking at almost 600 in May 1969.

The basic artillery unit in the NVA was the battalion. Each battalion is equipped with 12 guns. Various battalions may be grouped as a composite regiment to fit the terrain or specific needs of its assigned mission. Regimental organizations of three artillery battalions were typical. The regiment may have a mixture of artillery pieces, but each battalion was equipped with only one type and caliber of guns.

AA Gun Specifications

Several anti-aircraft gun types, of Soviet design, were used. The DShK 12.7-mm machine gun was a very common. It was portable, and had an effective altitude range of 5000 ft (1500 m.) Another weapon was the ZPU series 14.5-mm machine guns. These towed units could be grouped in single, double, or quad mounts. (ZPU-1, ZPU-2, or ZPU-4) The ZU-23-2 was a 23-mm towed machine gun, with dual mounts.

The most widely used larger gun was the Type 55 37-mm machine cannon. It predominated in the air defense regiments. Its effective altitude range was up to 10000 ft (3000 m)

Both forward air controllers and strike aircraft were vulnerable to these weapons, the latter particularly during recovery from ordnance delivery dives.

The gun crews were tireless and proficient in protecting their positions by frequent movement, digging, and camouflage, so that positions were rarely seen unless the weapons fired.

Guns of 23 and 37 mm were captured in the A Shau Valley during the summer of 1968. Since that time, aircrews continued to report firings from such weapons near the Laotian and Cambodian borders. These guns had sustained rates of fire of 200 rounds and 80 rounds per minute, respectively, and effective slant ranges to 8200 ft. (2500 m)

Larger guns such as the S-60 57-mm and KS-19 100-mm machine cannons also saw trail service. A few of the largest guns, the 85-and 100-mm, were deployed in Laos during the period. The Chinese used these guns to protect roads they were building in northwestern Laos, but of more significance to US aircrews, the North Vietnamese positioned 85 and l00-mm guns along their side of the Laotian Border, close enough that cross-border firings threatened USAF aircraft over Laos. Occasionally, such guns were moved across the border. The 85-mm gun had a maximum effective slant range of 27500 ft. (8400 m) the 100-mm, 39,000 ft. (11900 m). Both had rates of fire of 15 rounds per minute. They had been controlled by radar in North Vietnam but, no positive evidence of radar control in Laos is known.

Characteristics of AA Weapons used in Vietnam

While the numbers of larger caliber guns increased, mobile defense for truck convoys was added by introduction of Soviet armored vehicles carrying two automatic weapons, and by mounting AA machine guns on trucks.

There were always four to five times as many prepared positions as there were guns, with the weapons being shifted rapidly from one site to another. Gun sites were usually lightly revetted; however, later in Laos, more heavily constructed revetments were like prepared positions, so that the defense structure along principal roads took on permanence. Sites were camouflaged adroitly, using vines and trees trained to trellises and netting made from or covered with local vegetation. Frequently sites were so well hidden that, even when found, photo intelligence could not determine the exact caliber and number of guns.

As gun crews gained experience, they displayed more subtle tactics. Not all the guns in an area would fire at every pass made by aircraft, so that pinpointing the sites for subsequent attack was further complicated. Decoys were built, sometimes made into flak traps by addition of real guns near enough to fire on strikes that took the bait. While the 23-mm and heavier guns were located on the routes, and near the point targets to be protected, machine guns were located randomly, particularly on ridgelines some distance from the roads.

Gunners frequently allowed one or two passes to be made without opposition, hoping to lull the aircrews into complacency, while studying flight patterns and altitudes, then opening up in barrage fire. The gun crews knew how to use bases of clouds to estimate heights, and how to evaluate terrain  to determine the most likely approach routes.

DShK 12.7 mm AA Gun

DShK 12.7 mm AA Gun

37-mm AA Gun

37-mm AA Gun

SAM Sites

The SA-2 Guideline (S-75 Dvina in Russian designation,) was the epic surface-to-air-missile (SAM) system with a rich history. It is also one of oldest SAM, still used in some countries, since 1957. Middle range SA-2 missile systems entered in service in USSR in 1957 as a replacement for antiaircraft guns. In May 1960, Gary Powers’ U-2 spy aircraft was shot down near Sverdlovsk. Two years later, during the Cuban Missile Crisis, another U-2 was shot down. This demonstrated SA-2 effectiveness, but the Vietnam War is where the SA-2 got its legendary status.

By the end of 1966, 1017 firings had destroyed 39 US aircraft. Missiles from any one of the 152 SAM capable sites served to force US aircraft down into the conventional fire envelope, but also caused aircrews to jettison ordnance, and decreased their bombing accuracy due to evasion.

The SA-2 missile system’s destructive parameters ranged from about 11-31 km, and to 83000 ft (25000 m) AGL. These were deployed in battalions.

Typically SA-2 battalions consisted of three batteries: Radio Technical Battery (RTB), Combat Security Section (OBO) and Start Battery (SB).

The RTB consist of a Fan Song radar, command van, apparatus van, and diesel generators. This battery provides all technical control for the radars.

The OBO consists of early warning radars, which secure the site with targets, conduct reconnaissance, and recognize threats at long distances from the site.

The SB consists of six launchers and six transporter-loaders, towed by semi-trucks.

SA-2 Battalion dispositions

The first indication of their Vietnam deployment was sporadic interception of radar signals associated with SAMs, emanating from the panhandle of North Vietnam. In December 1969, two SAMs were fired at a formation of three B-52s near Ban LaBoy. And in January 1970, photo reconnaissance and electronic intelligence located three active sites in the southern tip of the panhandle, providing coverage into Laos about 9 km at Ban Karai and 18 km at Mu Gia Pass. Later in the month, a site appeared just north of Ban Karai, giving 28 km coverage into Laos.

Two more unusual weapons of marginal utility were employed by the NVA air defense in southern Laos. Starting in 1969, unguided rockets were fired at USAF gunships. The frequency of firings increased dramatically in early 1970, and the rockets were more often associated with AA fire. The rockets, probably 122 and 140 mm, did not have proximity fuses, and missed by long distances. No US aircraft were lost.

SA-2 SAM Launcher


The NVA had a massive air defense system, which created a major challenge for US aircraft attempting to interdict the Ho Chi Minh trail.


“Summary of The History of Songs and the Exhibition of the Truong Son

Traditional Convention – Ho Chi Minh City,” Committee of Transportation Training

“Air Tactics Against NVN Air Ground Defenses 1 December 1966-1 November 1968,” Major John C. Pratt

“USAF Tactics Against Air & Ground Defenses In SEA (U) November 1968 – May 1970,” Lt. Col. Monte D. Wright

mpaign Series Vietnam | Uncle Hos Hideout

Uncle Ho’s Hideout #11 – Truong Son Ground Combat

mpaign Series Vietnam | Uncle Hos Hideout

In Uncle Ho’s Hideout series, David Galster shares some of his tips and techniques in scenario research and design for CS: Vietnam.

Dear Compatriots,

There were many US attempts to use ground forces for reconnaissance to disrupt the trail. This issue discusses these efforts and their effectiveness.

Leaping Lena

In the early period of Yankee Team, General Westmoreland realized difficulties in aerial reconnaissance as monsoon weather promised to  obscure visibility, and altitude restrictions reduced photo resolution. Ground surveillance was the only way, he believed, to detect Communist positions, supply areas, and infiltration movements with precision.

With the Laotian neutrality treaty in effect, MACV had to rely on local Laotians or Vietnamese for scouting, and supply them with logistic support. “Leaping Lena” became the program. The Phase I scenario would parachute radio-equipped teams into landing areas by unmarked VNAF-piloted aircraft. The teams were expected to remain in enemy territory up to thirty days, observing in daytime, moving at night, and reporting observations by radio. They could request aerial resupply if necessary, and depart on foot or by helicopter. After studying their intelligence, MACV would launch Phase II cross-border operations to disrupt NVA lines of communication.

The first team was airdropped 24 June 1964, and three more the next day, finally the fifth on 2 July. One team got lost and never communicated, the second was captured when it landed in an enemy-held village, and three remained in radio contact until July 9 when all communications ceased. Only six of the forty paratroopers succeeded in returning on foot to South Vietnam, bringing back low-level intelligence of little value. The first mission was a total failure.

Evidently, the teams got no assistance from the local populace, who feared reprisals. But MACV staff thought the teams did not make bold penetrations due to lack of leadership and discipline. The airdrops by unmarked aircraft, flown by VNAF pilots were considered unsatisfactory.

Washington officials thought these initial problems could be overcome, and approved a second operation beginning 1 August. US jumpmasters would accompany each VNAF aircraft. But, personnel problems continued and the operation was cancelled.

Shining Brass

Months went by with discussions and disagreements over how to conduct ground surveillance. Political ramifications of violating Laotian neutrality was the main issue.

A new program, “Shining Brass,” was conceived in March 1965. It called for US and South Vietnamese Special Forces, with USAF support, to make trail incursions. The aim would be to collect hard intelligence on infiltration, designate targets for air strikes, and harass the enemy. Westmoreland considered the capability of the tribal roadwatch teams in Laos, already engaged in intelligence collecting and targeting, too limited. He observed that the teams were assigned to just a few key areas, furnished very little data on fixed enemy targets, and did not reconnoiter Lao territory contiguous to South Vietnam.

When Steel Tiger operations continued into October 1965, MACV’s long-planned Shining Brass concept was approved. Shining Brass teams accompanied by US advisers would enter Laos by land from Dak To and Dak Prou. Initial team penetrations into Laos would not exceed 20 km. Helicopters were to be used solely for ferrying in additional needed personnel, and for resupply and evacuation. Only USAF BANGO F-4 Phantoms on strip alert should be called for airstrikes. The JCS requested  a forty-eight hour advance notice of launch, plus progress, and final reports.

Three training missions came first. Each team, composed of three to six US Army and eleven South Vietnamese Special Forces were airlifted into designated locations by two VNAF CH-34 helicopters from Kham Duc, just inside South Vietnam. Reconnoitering their areas, the teams found ample evidence of Viet Cong presence: food, supply caches, bivouac areas, buildings, personnel, and trails. When one team called for a strike, USAF aircraft quickly hit targets selected by the team and marked by an airborne USAF FAC. The results were deemed “excellent” with buildings and storage caches destroyed. The coordination between ground and airborne FACs and between an airborne FAC and the strike aircraft also proved highly satisfactory.

The first “live” operation of Shining Brass was 18 October. Eleven South Vietnamese and several US Army advisers to a landing zone 4 km from the designated target area. An Air Force FAC forward air controller and two USAF strike aircraft orbited nearby. Scouting on foot, the team found an extensive encampment and supply storage base. During a brief skirmish with Communist troops, the South Vietnamese scout leader was killed. Nonetheless, the Shining Brass unit stayed in the target area three more days. During this time, the team made several requests for air strikes, but weather canceled all air operations in the vicinity until November.

The NVA appeared to have firm control of the area, and support of local Montagnards. So, MACV ordered a large-scale Steel Tiger attack on team-designated target areas. Thirty-eight USAF F-4Cs and F-105s from Thailand attacked with a FAC supporting. Half of the bombs of sixteen aircraft were fuzed for delayed explosions upwards to thirty-six hours. Strike pilots observed numerous fireballs and explosions, and the FAC pilot reported many of the enemy were killed.

Trees and jungle foliage, however, obscured most of the results. Bomb damage assessment eventually confirmed some destruction in about ten percent of the target area including six underground bunkers. Photos revealed eight nearby bunkers remained undamaged. Ambassador Sullivan, who had not been enthusiastic about Shining Brass, now informed Washington that initial operations were “a good beginning.”  As tactics were perfected, he said the incursions promised to make the Laotian panhandle “rather uncomfortable for the Viets.” A second mission was similarly successful. MACV’s Shining Brass teams launched many more ground reconnaissance probes into the Ho Chi Minh Trail.

Eventually, Laotian Military Regions III and IV developed “roadwatch” teams in areas near the Bolevens Plateau, and the Saravan area. These coordinated well with SPOOKY gunship truck-busting operations. Ultimately, they observed enemy depots and parking areas, and gained intelligence through tapping NVA telephone lines. The teams ambushed and destroyed enemy trucks, ammunition, and gasoline drums. They also planted anti-tank mines along the trail, and photographed destroyed trucks.


Saravan was a major city and crossroads within the trail network. Until 1970 however, the NVA was bypassed it, and did not challenge the Royal Laotian Battalion (BV 41,) and its three attached armored-car platoons garrisoned there. But in late 1970, two NVA battalions attacked, and captured the city. It became a Truong Son headquarters for Base Area 612.

In fall 1971, Laos retook it during Operation “Sayasila.” Later that year, at the beginning of the dry season, the NVA recaptured it. The 10th Rifle Battalion, of the 39th Regiment, 968th Division occupied it.

Again in the fall of 1972, Laotian Military Region IV retook Saravan in Operation Black Lion using GMs 41 and 42. It began with the NVA 968th Division dry season campaign, which involved a two-pronged thrust. The 39th Regiment  struck south from its position at Khong Sedone on the Se Done (Xekong) River, while the 9th Regiment advanced west along Route 23.

The NVA objective was to menace Pakse. However, with CIA advice and assistance, the Royal Laotian Army launched a highly effective spoiling operation, Black Lion IV, in October 1972. Two irregular “Groups Mobile” (GM’s 41 and 42) were inserted by helicopter into the Saravan area over a three-day period.

The operation caught the NVA by surprise. Only the 10th NVA Rifle Battalion defended Saravan. GM 42 air-landed west of the Saravan airstrip, unfortunately near the NVA 39th Regiment training area. After considerable difficulty, half of the GM landed, and secured the airstrip. By the time the strip was secure, several helicopters were hit, and were unable to continue. Fortunately, Air America continued the lift until the entire GM 42 was in the landing zone. With the loss of the helicopters, the airlift of GM 41 was delayed a couple of days.

Despite setbacks, Black Lion IV effectively aborted the NVA 968th Division dry season plans. The 9th and 39th Regiments were forced to wheel around from their forward positions, and move 75 km back to recapture Saravan.

Various Rejected Plans to “Isolate the Battlefield”

As early as March 1965, the US Military had many discussions on how to best block the Ho Chi Minh trail. The Army’s solution was to “isolate the battlefield” by inserting a corps of three to five U.S. divisions across South Vietnam and the Laotian panhandle to the Mekong River. John McNaughton, Assistant Secretary of Defense, predicted the rejection of such advice by higher authorities unless convinced that victory could not be won any other way.

Vietnamese General Cao Van Vien was promoted to Chief of the Joint General Staff (JGS) in October 1965. With this appointment, Vien was considered by American observers to be one of the most powerful people in the government. Vien was a  strategic thinker and reformer as JGS Chief.

In 1965, he proposed invading Laos and establishing a defensive line across the southern portion of that country in order to cut off the Viet Cong’s flow of supplies coming down the Ho Chi Minh trail. Vien met with President Johnson in February 1966 to discuss the plan, but Johnson refused to authorize US military support for the campaign and it never went forward.

General Westmoreland considered Khe Sanh important, but reasons changed through the course of the war. Intelligence was the primary reason for holding Khe Sanh in 1964. In fact, recon forces there were first to confirm that Main Force NVA units were operating inside South Vietnam.

By 1966, Westmoreland thought of Khe Sanh as part of a larger strategy. “I still hoped some day to get approval for a major drive into Laos to cut the Ho Chi Minh Trail,” he said, “in which case I would need Khe Sanh as the base for the operation.”

In a meeting with Lt. Gen. Lewis Walt, commander of III Marine Amphibious Force (MAF), Westmoreland said that he placed great strategic importance on Khe Sanh. He believed it was absolutely essential to hold the base, which explains why he ordered Marines there. In September 1966, MACV began detailed planning for an invasion into Laos, and in October an airfield was built.

In April 1967, two strategic options were pitched to President Johnson: one by Westmoreland, to enter Laos; and one by adviser Walt Rostow, to invade North Vietnam just above the DMZ. Although both were rejected, Westmoreland never gave up hope, and from August to October he upgraded the airfield at Khe Sanh so that it could serve as the advance base for a Laotian invasion. As soon as the airfield reopened, he began to stockpile supplies for the invasion. But, the US had no political will to “isolate the battlefield,” and block the Ho Chi Minh trail with a fortified line in Laos.

Lam Son 719

In early 1971, MACV had intelligence of an NVA logistical build-up in near Tchepone, and wanted to disrupt a potential offensive. There was reluctance to let the South Vietnamese (ARVN) go it alone against the NVA. But, US and South Vietnamese high commands also hoped a victory in Laos would bolster ARVN’s morale and confidence, showing that could defend their nation given continuing withdrawal of US troops.

MACV Commander General Creighton Abrams felt pressured by Nixon through an NSA aide, Colonel Alexander Haig. Haig later wrote the military “lacked enthusiasm,” and that “prodded remorselessly by Nixon and Kissinger,” the Pentagon finally began the planning. Other potential benefits were discussed. Admiral John S. McCain (CINCPAC) advised Admiral Thomas Moorer, JCS Chairman, that an offensive against the Ho Chi Minh Trail might compel Souvanna Phouma, “to abandon the guise of neutrality and enter the war openly.”

On the South Vietnamese side, operation command, control, and coordination would prove to problematic. President Nguyen Van Thieu assigned General Hoang Xuan Lam to lead the operation. But, in the highly politicized South Vietnamese command structure, Lt. General Le Nguyen Khang, Marine Corps commander and protege of Vice President Nguyen Cao Ky, outranked General Lam, Similarly, Lt. General Du Quoc Dong, Airborne Commander, outranked Lam also. After the operation began, both men remained in Saigon, and delegated their authority to junior officers rather than take orders from Lam.

MACV began planning for an attack against NVA Base Areas 604 and 611 in early January 1971. The task was assigned to Lt. General James W. Sutherland, XXIV Corps commander.  He was given only nine days to submit a plan for approval.

Individual units did not learn about their planned participation until mid-January. The ARVN Airborne Division received no detailed plans until 2 February, less than a week before the campaign planned to begin on 8 February.  This was of crucial importance, since many of the units, particularly the Airborne and the Marines, had worked as separate battalions, and were not experienced in maneuvering in adjoining areas. Lack of adequate time for planning and preparation, as well as absence of any questions about operational reality and ARVN capability would prove disastrous.

Situation Map of Lam Son, 1971

MACV kicked off their part of the operation, called “Dewey Canyon II”  on 30 January. The armor and engineer elements of 1st Brigade, 5th Infantry Division headed west on Route 9 while the infantry were heli-lifted into Khe Sanh. By 5 February, Route 9 was secured to the Laotian border. Simultaneously, the 101st Airborne Division began a feint into the A Shau Valley in order to draw NVA attention away from Khe Sanh.

At the combat base, poor weather, obstacles, land mines, and unexploded ordnance delayed airstrip rehabilitation a week behind schedule. The first aircraft arrived on 15 February.

After a massive preliminary artillery bombardment and B-52 Stratofortress missions, the ARVN attack began on 8 February, when a 4000-man ARVN armor/infantry task force consisting of the 3rd Armored Brigade and the 1st and 8th Airborne Battalions, advanced west unopposed along Route 9.

This operation was named “Lam Son 719.” This was for the village of Lam Son, birthplace of legendary Vietnamese patriot Le Loi, who defeated an invading Chinese army in 1427. The numerical designation came from the year, 1971, and the main axis of the attack, Route 9.

To cover the northern flank, ARVN Airborne and Ranger elements were deployed to the north of the main advance. The South Vietnamese 39th Ranger Battalion was heli-lifted into a Landing Zone (LZ) “Ranger North,” while the 21st Ranger Battalion moved into Ranger South. These outposts acted as “tripwires” for any communist advances.

Meanwhile, the 2nd Airborne Battalion occupied Fire Support Base (FSB) 30, while the 3rd Airborne Brigade Headquarters and the 3rd Airborne Battalion went into FSB 31 Troops of the 1st Infantry Division simultaneously combat assaulted into LZs Blue, Don, White, and Brown and FSBs Hotel, Delta, and Delta 1, covering the southern flank of the main advance.

The ARVN central column advanced down the valley of the Se Pone River, a relatively flat area of brush, interspersed with patches of jungle, and dominated by heights to its north, and the river and more mountains to the south. Almost immediately, supporting helicopters took fire from the heights, where NVA gunners fired down on the aircraft from pre-registered machine gun and mortar positions.

Worse still, Route 9 was in poor condition. Only tracked vehicles and jeeps could traverse it. This put the burden of reinforcement and resupply onto the helicopters. And, this logistical support role was made increasingly more dangerous by low cloud cover and incessant anti-aircraft fire.

The armored task force secured Route 9 all the way to Ban Dong (known to the Americans as A Luoi), 20 kilometers inside Laos, and approximately halfway to Tchepone. By 11 February, A Luoi had become the central fire base and command center. The plan then called for a quick ground thrust to secure the main objective, but South Vietnamese forces stalled at A Loui. They waited on orders to proceed from General Lam. Two days later, Generals Abrams and Sutherland flew to Lam’s forward command post at Dong Ha in order to speed up the timetable.

The NVA countered by isolating the northern firebases from air resupply by anti-aircraft guns. (AA) The outposts were then pounded by round-the-clock mortar, artillery, and rocket fire. Although ARVN firebases had artillery, their 105 Howitzers were quickly outraged by  Soviet-supplied 122mm and 130mm pieces. They simply stood off at distance, and pounded the positions at will. The defensive edge that might be provided by tactical B-52 bomber strikes was nullified by close-in tactics of the communist forces. Massed ground attacks, supported by artillery and armor would then finish the job.

On February 18, NVA forces attacked Ranger North with the 102nd Regiment, (308th Division) supported by PT-76 and T-54 tanks. Although ARVN units held though the night, their 39th Battalion was reduced from 500 to 323 men, and the commander ordered a retreat to the south. Only 109 survivors reached Ranger South.

Similarly, the NVA shifted attacks to Ranger South where ARVN troops held for two days before General Lam ordered them to fight their way to FSB 30.

On 23 February, the NVA attacked FSB Hotel 2, south of Route 9. It was evacuated the following day.

FSB 31 was next to come under heavy attack. NVA AA fire made resupply of the base impossible. Airborne Division commander General Dong ordered the 17th Armored Squadron to advance north from A Loui to reinforce the base. The force never arrived, due to conflicting orders from Generals Lam and Dong.

Lam Son LZ and operational situation

On 25 February the NVA deluged the base with artillery fire, and then launched a  armored/infantry assault. Smoke, dust and haze hindered observation by forward air control (FAC) aircraft, which was flying above 4000 feet to avoid AA fire. When a U.S. Air Force F-4 Phantom jet was shot down in the area, the FAC left the area of the battle to direct a rescue effort for the downed aircraft crew, sealing the fate of the base. NVA troops and tanks then overran the position, capturing the ARVN brigade commander in the process.

FSB 31 lasted only a week longer. In the five days between 25 February,and 1 March, three major engagements took place. With the help of air strikes, ARVN destroyed 17 PT-76 and six T-54 tanks at a loss of three of its five M41 tanks and 25 armored personnel carriers. (APC) On 3 March, the South Vietnamese column encountered a NVA battalion without supporting armor and, with the assistance of B-52 strikes, killed 400.

During each of the above mentioned attacks, Communist forces suffered horrendous casualties from aircraft and helicopter attacks, artillery bombardment, and small arms fire. However, they continued attacking with professional competence and determination. The North Vietnamese managed move 35000 troops into the battle area. This included three infantry divisions, (2nd, 304th, 308th), the 64th Regiment of the 320th Division, and two independent infantry regiments (27th and 28th), eight regiments of artillery, three engineer regiments, three tank battalions, six AA battalions, and eight sapper battalions.

To save face,  President Thieu and General Lam launched an airborne assault on Tchepone itself. Elements of the 1st Division were heli-lifted into firebases Lolo and Sophia and LZ Liz, all south of Route 9. Eleven helicopters were shot down, and another 44 damaged as they carried one battalion into FSB Lolo. Three days later, 276 UH-1 helicopters protected by Cobra gunships and fighter aircraft, lifted the 2nd and 3rd Battalions of the 2nd Regiment from Khe Sanh to Tchepone – the largest helicopter assault of the Vietnam War. Only one helicopter was downed by AA fire as the troops combat assaulted into LZ Hope, four kilometers northeast of Tchepone. For two days these battalions searched Tchepone and the immediate vicinity, but found little but the bodies of NVA soldiers killed by air strikes.

Their goal in Laos seemingly achieved, President Thieu and General Lam ordered a withdrawal of ARVN forces beginning 9 March. It continued through the rest of the month, destroying Base Area 604 and any supplies discovered in their path. The plan of operation Lam Son 719 was never to hold Tchepone, but to put troops there and destroy as much supplies and trail infrastructure as possible.


The US, South Vietnam, and Laos made many attempts to use ground forces for reconnaissance

to disrupt the Ho Chi Minh trail. The major Lam Son 719 operation came late in the war, and was not very successful. The trail was not blocked, and North Vietnamese supplies and troops continued to flow. The US did not have the political will to block the trail with troops and fortifications. The air war, aided by ground reconnaisance, was insufficient.


“Operation Lam Son 719,” Wikipedia

mpaign Series Vietnam | Uncle Hos Hideout

Uncle Ho’s Hideout #10 – US Interdiction Against Trail

mpaign Series Vietnam | Uncle Hos Hideout

In Uncle Ho’s Hideout series, David Galster shares some of his tips and techniques in scenario research and design for CS: Vietnam.

Dear Compatriots,

Did you know that there was yet another name for the Ho Chi Minh Trail? Indeed, the MACV nicknamed it “Sullivan’s Freeway.” This issue reveals why, and provides an overview of the vast trail interdiction efforts by the US.

Command Structure

Sorry for all the acronyms, comrades, but you can’t discuss the US Military without them. The highest command dealing with the Vietnam War was the Pacific Command, (PACOM). Its Commander in Chief, (CINCPAC), was Adm. Harry D. Felt, in Honolulu. Admiral Ulysses S. Grant Sharp, succeeded him in 1964. Admiral Sharp was deeply involved with many decisions involving the trail.

Three commands under Pacific Command were: US Navy Pacific Fleet, (PACFLT,) Pacific Air Forces, (PACAF,) and US Army, Pacific. (USARPAC)

PACFLT was headed by Admiral Thomas H. Moorer. A sub-component, 7th Fleet was commanded by Vice Adm. William A. Schoech. Carrier Task Force 77, (CTF 77,) provided many jet fighter-bombers.

PACAF was led by Gen. Hunter Harris. Subordinate commands were Thirteenth Air Force at Clark Air Force Base, Philippines, to 2d Air Division, (2nd ADVON,) an arrangement that remained in effect until April 1, 1966, when the 2d Air Division became Seventh Air Force, and was assigned directly to PACAF. Maj. Gen. Joseph H. Moore commanded 2d Air Division. Lt. Gen. William W. Momyer took over Seventh Air Force at its creation.

The key command under USARPAC was the US Military Assistance Command, Vietnam. (MACV)  Gen. William C. Westmoreland commanded MACV, and wanted maximum efforts to stop infiltration.

The main US Cabinet members involved in this saga were Secretary of Defense, Robert McNamara and Secretary of State, Dean Rusk. The Ambassador to Laos played a very big role, since the trail went mostly through Laos. In the early years, Leonard Unger was the Ambassador, but in November 1964, William H. Sullivan succeeded him. As we will see, Sullivan was a strong voice of restraint for all aerial operation aspects. His Air Attache, (AIRA,) was Col. Robert L. F. Tyrrell.

The Laotian Government was led by Prime Minister Souvanna Phouma. The Royal Laotian Air Force, (RLAF) was commanded by General Thao Ma. These leaders’ approval and participation was critical.

Early Aerial Reconnaissance

After the 1962 Geneva Neutrality treaty for Laos, reconnaissance flights were suspended. But, in 1963, Secretary McNamara  went to Saigon to review the overall situation and report back to President Johnson. One of his recommendations was to begin mapping the Laos-Cambodia-South

Vietnam borders to obtain data on infiltration routes. High-flying U-2 reconnaissance planes were assigned the aerial photography task.

In early 1964, Operation “Lucky Dragon” began with three U-2 planes from the 4080th Strategic Wing. They were based at the Bien Hoa airbase, and the film was processed at a lab at Tan Son Nhut airfield in South Vietnam.

The evidence for Communist infiltration into South Vietnam continued to accumulate with reports of newer weapons for the Viet Cong such as 75-mm recoilless rifles, heavy machine guns, 90-mm rocket launchers, and large caches of ammunition. There had also been some combat in Laos involving the Pathet Lao, which prompted efforts to provide the RLAF with T-28 aircraft. Another crisis was the junta led by Gen. Nguyen Khanh in South Vietnam.

After conferring with the Joint Chiefs of Staff, (JCS) including Air Force General Curtis LeMay, Secretary McNamara made further recommendations, one of which was to temporarily resume tactical aerial reconnaissance. This came only after obtaining Souvanna Phouma’s consent and acquiescence of Ambassador Unger, who agonized constantly over the international consequences of losing American airmen in Laos.

Operation “Yankee Team” began in May 1964. Admiral Felt ordered low altitude surveillance of specified infiltration routes leading from North Vietnam through Laos into South Vietnam, and against the Ban Thay complex east of Muong Phine. General Moore of 2d Division managed the operation. Four “Able Mable”  RF-101 aircraft from the 15th Tactical Reconnaissance Squadron immediately began flights from Tan Son Nhut Airfield. These would be later supplemented by Navy RF-8A aircraft, flown from the USS Kitty Hawk.

The RF-101C “Voodoo” had began service in 1957 as a reconnaissance jet. The twin turbojet engines provided power for a maximum speed of Mach 1.72. (1825 km/hr) It was used at low and medium altitudes. Six cameras took the place of radar and cannons in the reshaped nose, but it retained bombing ability.

The cameras had longer focal lengths for good photography at 15000 ft, (4570 m) but, cloud cover often forced them to use other cameras at lower altitudes. In some areas of Laos, Communist anti-aircraft guns were effective to 5000 ft. (1520 m)

On 6 June 6 1964, Communist anti-aircraft fire downed a Navy RF-8A near Xiengkhouang, Laos. The pilot, Lt. Charles F. Klusmann, was captured. President Johnson, with Prime Minister Souvanna’s approval, quickly ordered fighter escorts, and authorized return fire. Eight F-100 Super Sabres of the 510th Tactical Fighter Squadron (TFS) were deployed as escorts. They dropped two 750-lb bombs, and fired fifty-seven 2.75-inch rockets on NVA forces near Xiengkhaoung.

As more sorties were completed, considerable photography was turned over to the RLAF to assist its T-28 close air support and interdiction operations, but the photos often had insufficient detail and target resolution. This was partly due to Secretary McNamara’s injunction requiring Yankee Team aircraft to fly at medium altitude (10000 ft = 3048 m) to avoid losses. Proposals to fly reconnaissance well below this limit to obtain more detail of targets and target areas were usually turned down. State, Defense, and White House approval of each Yankee Team mission remained in effect, with exceptions considered case-by-case.

Reconnaissance missions generated another crisis in late November 1964 when NVA ground fire downed an F-100, and then an RF-101C. Gen. Hunter Harris, PACAF Commander, demanded retaliatory strikes with napalm and CBU-2A munitions near Mu Gia Pass. That location was intended for Hanoi to “get the message.” But Admiral Sharp, apparently sensing the unlikelihood administration approval, withheld the request. With the shootdown of the RF-101C, however, he personally recommended to the JCS a retaliatory strike. The joint chiefs also backed retaliation, but Washington, as usual, turned aside the requests for punitive strikes as they had “escalatory overtones.” Ambassador Unger halted all Yankee Team and Lucky Dragon U-2 missions over Laos until the JCS completed a review.

With the aerial photography obtained, intelligence personnel were able to identify numerous infiltration routes. NVA manpower and supply infiltration estimates, however, were based on captured Viet Cong interrogation. General LeMay was very positive about the contribution of air power. He was convinced that RLAF operations by US-trained Lao pilots had “paid off,” and Yankee Team raised Laotian morale, and furnished valuable data on Communist infiltration.

USAF RF-101C 'Voodoo'

Operation Barrel Roll

During the 1964 wet season, more evidence of NVA trail activity and hostile actions against reconnaissance missions occurred. General Westmoreland wanted to launch ground surveillance of the Ho Chi Minh Trail, as monsoon weather reduced Yankee Team effectiveness. And, in late November 1964, Ambassador Taylor warned that South Vietnam’s continuing political and military problems required more action. Asserting that the United States was playing a “losing game” in South Vietnam, he outlined several military options. He suggested slowly adding heavier bombings, and greater participation in Laos operations.

Taylor’s Phase I proposed one month of heavier airstrikes in the Laotian panhandle, and covert Plan 34A bombings of North Vietnam itself. If the North Vietnamese failed to heed the warning, then Phase II would begin US and Vietnamese Air Force (VNAF) strikes on North Vietnam just above the DMZ, and increase the tempo for six months to get all significant targets. President Johnson approved Phase I for missions along segments of Routes 8, 12, and 121 in the Laotian panhandle, with barracks and strongpoints as secondary targets.

Phase I and II became known as Operation “Barrel Roll.” Admiral Sharp alerted Generals Westmoreland, Moore, and Admiral Moorer prior to its start. The first mission was flown in December 1964 by four F-105 Thunderchiefs laden with 750-lb  bombs, CBU-2A bomblets, and AGM-12 Bullpup missiles. Accompanying the strike aircraft were four F-100s for combat air patrol, One  RF-101C  for post strike reconnaissance, two Korat-based F-105s for escort, and two refueling KC-135 tankers. The pilots flew along Route 8 and near the Nape bridge, spotting a vehicle on an apparent nearby sunken bridge serving as a bypass. One F-105 aimed six 750-lb bombs on the bridge, but they missed. The other three fighters struck secondary targets, with results obscured by cloud cover. The mission encountered no NVA ground fire.

Seventh Fleet went into action three days later. F-8 pilots searched for targets in the central Laotian panhandle. Finding none, they hit a bridge two miles east of the junction of Routes 8 and 12. They dropped thirty-two 250-lb bombs, which cut the road west of the bridge, and destroyed eight buildings, although the bridge sustained no major damage. Again, there was no anti-aircraft fire.

A USN F-8 Crusader on a carrier.

New Laos Ambassador Sullivan faulted the first two Barrel Roll missions for insufficient Vientiane coordination. An eight-hour delay in informing Col. Tyrrell failed to alert Air America search and rescue helicopters. (SAR) It did not help avoid interference with RLAF operations. Secondly, bomb damage assessment of PACFLT-destroyed buildings suggested they may have been civilian dwellings. Sullivan insisted on US/RLAF agreement on what constituted authorized targets. Admiral Sharp, concurring, directed that future targets of opportunity show “unmistakable” military activity, or a connection with attacks on clearly identified military convoys and personnel. He tasked General Westmoreland to coordinate authority for future Barrel Roll missions, and follow proven Yankee Team procedures.

If that wasn’t bad enough, on a night mission, PACFLT’s A-1H Skyraiders strayed off course from Route 23, and accidentally hit Ban Tang Vai village in Savannakhet Province. They destroyed five houses, damaged seven granaries, and reportedly wounded five civilians and five Lao soldiers. General Thao Ma was highly upset, and Ambassador Sullivan, with sharp words about “undisciplined pilots,” temporarily halted night missions.

In the last three months of 1964, the RLAF flew 724 sorties. And, from May through December, Yankee Team flew 880 missions. Despite this, there was no public or other reaction from Hanoi, and officials concluded the strikes failed to send a signal of American strength. Nonetheless, they believed it had a positive effect as it improved Lao and Thai morale, provided training and terrain familiarity for pilots, caused some defections of Pathet Lao, forced NVA dispersal or abandonment of fixed facilities, and disrupted the PL/NVA counterattacks at Muong Soui and elsewhere.

Operation Steel Tiger

In February 1965, Viet Cong attacked an American barracks and airfield near Pleiku, killing eight soldiers, wounding 104, and destroying several aircraft. This incident led to a decision by President Johnson to make retaliatory airstrikes on North Vietnam, and the “Rolling Thunder” program began. General Westmoreland wanted to consolidate the operations of Yankee Team, Barrel Roll, and Rolling Thunder under a single air program. But, Souvanna Phouma objected because they did not want RLAF involvement with bombing North Vietnam.

The Ho Chi Minh trail problem still persisted, however. The Army solution, (“isolate the battlefield”)  was to put a US Army Corps west of the DMZ across the Laotian panhandle, to block the trail. But, the political will for this simply did not exist. Air Force and Navy commanders wanted more air power.

Ambassador Sullivan suggested conducting systematic “chokepoint” strikes at key locations on vital  infiltration routes without diverting aircraft to other NVA supply areas as in the past. But, General Harold K. Johnson, Army Chief of Staff submitted to the president a twenty-one-point program for blunting Communist challenges in Laos and South Vietnam. Included in this program was stepping up Rolling Thunder strikes in North Vietnam, confining Barrel Roll operations to northern Laos, and a new air program to attack communist infiltration via the Ho Chi Minh Trail.

The new program, “Steel Tiger,” was authorized by President Johnson in March 1965.  Sullivan requested a rapid air response system to reduce procedural delays for strike clearances. He wanted on-call USAF aircraft at Udorn to hit preselected targets, and those spotted by roving roadwatch teams, some of which would receive radios. Further, he wanted photos processed at Udorn, where they could be collated with other intelligence data. Moore shortly stationed a small number of F-4 and F-105 on-call aircraft at several Thai air bases.

Rules of engagement for Steel Tiger included  enemy targets of opportunity, military vehicular and troop movements and anti-aircraft (AA) guns spotted within 200 m of designated roads. Camp fires and civilian habitations would not be attacked. Fixed installations were to be struck only in connection with attacks on clearly identified military convoys and military personnel, or when pre-briefed as primary and secondary interdiction target. Unexpended ordnance should be dumped in free strike zones. But, the directive eased previous rules permitting more pre-mission visual reconnaissance aircraft equipped with side-looking airborne radar and infrared, and to support more weather, pathfinder, flare, and search and rescue operations.

On April 3, PACAF led off with a two night operations, each mission consisting of a navigation and flare-carrying C-130 BLINDBAT accompanied by two strike B-57s. Scanning several routes under the glare of 126 flares, the pilots reported no significant sighting of enemy traffic. The next day PACAF sent seven B-57s and three escorted RF-101Cs in a daytime attack on Mu Gia Pass. The tactical jet bombers cratered a road and reseeded other routes with bombs. On April 5, four strike and four support F-100 Super Sabres (the latter for MiG combat air patrol) plus two RF-101Cs flew daytime reconnaissance over three routes and hit the Ban Phanop supply depot. The planes dropped seven 750-lb general purpose bombs, and expended four rockets on a building in the depot area. PACAF dispatched its F-105 Thunderchiefs on their first Steel Tiger mission on April 11 against two routes and a military site at Ban Langkhang.  By April 29, the two services had flown 791 Steel Tiger sorties of all types.

A USAF B-57 releasing its payload.

B-57 Bomber

Westmoreland asked for and Sullivan approved stationing of USAF aircraft on strip alert to strike fleeting targets, particularly trucks. In the Barrel Roll and Steel Tiger programs, the ambassador agreed to operations against “targets of opportunity,” provided rules of engagement were met. As a result, four USAF F-4Cs (codenamed BANGO,) were put on fifteen-minute strip alert at Ubon. Shortly after four F-105s (codenamed WHIPLASH,) were similarly placed at Takhli and Korat. On May 9 RLAF T-28s reportedly destroyed two tanks and five trucks, and hoping for a bigger kill, pilots requested  USAF assistance. An hour later, BANGO Phantoms arrived and, with T-28s marking targets, destroyed two more tanks, and damaged two. Pilots reported heavy ground fire with one hit on an T-28 which returned safely to its base. The chief air attache considered the USAF response, coordination, and mission results excellent.

More friendly fire incidents occurred, and Ambassador Sullivan halted all Steel Tiger reconnaissance missions from May 22 until June 7 to work out more stringent operational rules. Strikes on fixed installations, were prohibited unless associated with attacks on troops or similar military targets. All American aircraft overflying Laos had to maintain a minimum altitude of 10000 ft (3050 m,) and avoid the Savannakhet, Pakse, Saravane, Vientiane, and Paksane. Within the Steel Tiger boundary, Yankee Team reconnaissance aircraft were ordered to observe a minimum of 5000 ft (1525 m,) with requests for lower altitudes reviewed by the ambassador and his staff on a case-by-case basis.

Another plan concentrated more tactical air strikes against enemy routes, trails, and redoubts in the southeasternmost section of Laos next to the South Vietnamese border. The plan was translated into a new concept christened “Tiger Hound” by General Westmoreland. The “Tiger” connoted aggressiveness, and “Hound” for “smelling out” the NVA. The concept would extend the “in-country” or South Vietnamese war into this small sector of Laos.

Tiger Hound missions began in December 1965 with USAF-piloted O-1E forward air controllers (call sign HOUND DOG) began flying visual reconnaissance missions, and guiding PACAF F-103, BANGO F-4Cs, and PACFLT and Marine strike aircraft to numerous targets. USAF AC-47 gunships, which besides their attack role, served as flareships and FACs for other aircraft. In addition sectors of Barrel Roll and Steel Tiger were designated as A through G, but in pilot’s parlance, Alpha, Bravo, Charlie, Dog, Echo, Foxtrot, and Golf.

The success of Barrel Roll and Steel Tiger were reflected in these 1965 overall statistics: Destroyed 108 trucks, 712 structures, and 201 bridges. These programs damaged 115 trucks, 471 structures, and 174 bridges.

Zones of Interdiction of the Trail.

Truck Busting on the Ho Chi Minh Trail

AC-47 interdiction sorties evolved into a system of truck-busting. Two SPOOKY gunships were scheduled to fly continuous coverage at night.  One aircraft took off at 1800, the other at 2400. The gunships flew a planned schedule allowing at least four contacts per night with each of the roadwatch teams patrolling around the Ho Chi Minh Trail network.

After flying to the designated area, a Lao observer on board the gunship radioed a roadwatch team. If a target was seen in the area, the gunship would drop flares along the road in an effort to find the target. Once a truck was spotted, the gunship went into its strike orbit, and fired away.

The NVA responded with more and better air defense. Communist forces were equipped with various AA weapons including 37-mm guns which outstripped the range of SPOOKY ‘s miniguns. The NVA had well-organized road security. They used platoons and trained dogs against Laotian watch teams. The road watch and action teams in Military Region IV were composed of 12 men each. Since they could not speak English, signals were used in their communications with the USAF.

AC-47 Gunship "SPOOKY"

AC-47 Gunship “SPOOKY”

Arc Light

The first request for use of B-52 strategic bombers for “saturation bombing” came from General Westmoreland in November 1965. Sullivan concurred, providing Washington authorities gave “iron clad” assurances of no publicity. The first mission was approved and took place in December. Twenty-four B-52s from the 3d Air Division on Guam carried the strike on suspected infiltration targets near the South Vietnamese border. Refueled by SAC KC-135 tankers, the aircraft dropped BLU-3B bomblets and 750-lb bombs. As there were no followup ground patrols of the bombed area, results were indeterminate.

The use of B-52 Stratofortresses would continue under code name “ARC LIGHT.” Eventually, the 486th Bomber Squadron would be deployed to the U-Tapao air base in Thailand. These would be used throughout the war, not only for the trail interdiction, but for bombing in North Vietnam as well.

Commando Hunt

The operations Rolling Thunder, Barrel Roll, Steel Tiger, and Tiger Hound continued into 1968. After the North Vietnam bombing halt in late 1968, the Steel Tiger and Tiger Hound programs were consolidated into one called “Commando Hunt.” The North Vietnam bombing halt allowed them to shift sorties planned for North Vietnam to southern Laos. This added 480 missions daily against the trail.

This program differed from Steel Tiger in that greater use was made of sensors in the “Igloo White” program. Thousands of  seismic and acoustic sensors had been dropped along the trail to detect traffic, and the signals collected and analyzed at Nakhon Phanom.

Commando Hunt was divided into phases, with each phase covering a wet or dry season. Phases I, III, V, and VII were in the dry seasons up until 1972. The even numbered ones took place in wet seasons from May to October. Phase I struck choke points where multiple roads converged. Mu Gia and Ban Karai passes were included in this. Phase II focused on the trail itself to hit the NVA where it was found. Phase III increased air attacks in southeastern Laos and extended the sensor fields. Monitoring of Tchepone was included. Phase IV returned the emphasis on choke points, and subsequent phases repeated the pattern, with modifications as they were needed.

he most effective was Phase V in the dry season from October 1970 to April 1971. An average of twenty-seven Arc Light strikes and 125 tactical air strikes were conducted daily. In January 1971, 2186 tactical air sorties were flown against suspected truck parks and storage areas resulting in 3720 secondary explosions and fires. The AC-130 Gunship “Spectre” was the most effective at truck busting. An estimated 19000 trucks were destroyed or damaged in Phase V. Indeed during Phase V, the NVA was not able to maintain an activity level in South Vietnam as in previous years.


The US interdiction campaign began very slowly from 1964, but reached a high level in the last few years of the war, particularly in 1971. Despite all of these efforts however, the NVA managed to move enough supplies and troops through the trail to South Vietnam to sustain its initiatives.


“Interdiction in Southern Laos 1960- 1968,” Jacob Van Staaveren

“The Ho Chi Minh Trail and Operation Commando Hunt: The Failure Of An Aerial Interdiction Campaign,” Dong Nguyen Ha

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Uncle Ho’s Hideout #9 – Construction and Truck Relays

mpaign Series Vietnam | Uncle Hos Hideout

In Uncle Ho’s Hideout series, David Galster shares some of his tips and techniques in scenario research and design for CS: Vietnam.

Dear Compatriots,

The North Vietnamese used many forms of transportation on the Ho Chi Minh trail. Did you know that even elephant convoys were sometimes used? After all, Laos was known as the “land of  a million elephants.” But, this report also focuses on road construction, trucking, and more efficient methods.

Transportation Overview

Senior General Van Tien Dung (NVA) described the end state of the trail, after the final 1975 victory: “The strategic route east of the Truong Song [Chaine Annamitique] Range, which was completed in early 1975, was the result of the labor of more than 30,000 troops and shock youths. The length of this route, added to that of the other old and new strategic routes and routes used during various campaigns built during the last war, is more than 20,000 km. The 8-meter wide route of more than 1,000 kms . . . is our pride. With 5,000 km of pipeline laid through deep rivers and streams and on mountains more than 1,000 meters high, we were capable of providing enough fuel for various battlefronts. More than 10,000 transportation vehicles were put on the road. . .”

The most important role for the Ho Chi Minh Trail was as a route to transfer troops to the south. The North Vietnamese claim two million personnel did transit the trail during the war. In the early part of the conflict, personnel infiltration from north to south was mostly in the form of native southerners who had moved north after the First Indochina War. They were sent back south to begin the fight again in to “liberate” South Vietnam. Up to 1965, approximately 40,000 such personnel returned south to form the core of the Viet Cong.

Initially, supplies were carried by porters, modified bicycles, oxcarts, and pack animals. In the early years, about 5000 tons per year passed along the trail. After road construction, truck transport increased this rate to over 12000 tons annually.

Primitive Transport

Starting in 1959, the trail had few roads passable by truck. But, thousands of porters, bicycles, pack animals, and wagons began movement of supplies.  Porters were best for short hauls when weather or bomb damage temporarily halted truck travel. They carried mainly food, but also carried small arms ammunition, and even bladders of petrol. Transit stations were placed one day’s walk apart, responsible for providing food, shelter, health, and navigation to the next station. These were used by troops traveling on foot as well.

One man with a bicycle could carry about three times the load porters could. Thousands of bicycles were bought from China and modified to carry pack loads. Two bicycle battalions were active in 1965.

Wagons pulled by oxen or mules, and pack animals, mainly mules, were also used extensively. A wagon could carry loads 15 times that of porters. As mentioned earlier, elephants were also used as pack animals.

The trek down the trail was grueling for traveling soldiers and workers dealing with hot, humid forests, as well as leeches, and malaria. The author, Dong Nguyen Ha, of The Ho Chi Minh Trail And Operation Commando Hunt, wrote: “The long distance and heavy loads, the savage sweep operations and bombing attacks conducted by the enemy, and severe weather conditions all combined to extend the time required for the march to five or six months, adversely affecting the health of our troops. On days when rice supplies were exhausted our soldiers had to dig up jungle roots to eat in place of rice. Almost all cadre and soldiers caught malaria, some soldiers died on the march, and a number had to remain behind in our medical clinics along the commo-liaison route.”

 Casualties caused by American airstrikes were low, accounting for only 2% of total personnel losses. Total losses to disease are estimated at 10 to 20%. Sick soldiers were left to recuperate at various way-stations. Transit time could take months, and sometimes entire units were disrupted and disbanded.

A Viet Minh Porter Column on Foot

A Porter Column on Foot

A Viet Minh Porter Column using Bicycles.

A Porter Column using Bicycles

A Viet Minh Porter Column using Elephants

A Porter Column using Elephants

Road Construction

Doan 559 began building roads immediately in 1959, but it would be 1965 before trucks became the main transportation mode. Every year, more engineer battalions were formed. By In late 1967, about 25,000 NVA troops and 40,000 laborers (mostly Laotian) were engaged in repairing, widening, and extending the routes. Bulldozers and other heavy equipment were being used. In 1971, there were eight engineering regiments. Road construction progressed at 450 km annually in 1965, and peaked at 1000 km in 1970.

The roads were 5.5 m wide, and gravel  or log corduroy were applied to harden the surfaces. These were generally capable of all-weather use. By 1973, trucks could drive the entire length of the trail without emerging from the canopy except to ford streams or cross on crude bridges built beneath the water’s surface.

Much of the road repair was done with manual labor, especially to repair bomb craters. A crater could be filled in within a day, to get that section of road back into service. But, bulldozers and other heavy equipment were used extensively.

To conceal their truck and troop movements, the North Vietnamese camouflaged routes and trails. Trellises, made by binding tops of trees together, covered truck, supply, and other installations. Any damaged jungle cover for trails was replaced with new foliage. Foliage was also scattered along well-worn tracks and paths that might be detected from the air. The deceptive practices of the NVA were numerous. To cross rivers and streams they used floatable spans, (hidden by day,) or underwater bridges. Communication workers strung telephone wires on five-foot poles along trail segments, the poles’ short length did not make a shadow long enough to be seen by air. After airstrikes, trail workers often burned gasoline-soaked rags along the side of roads to make attacking pilots think they destroyed or damaged several trucks.

Road Repair Crew

Road Repair Crew

Truong Son Trucking

After 1965, the North Vietnamese got serious with trucking. Trucks could carry 20 times more than oxcarts, 100 times more than bicycles, and 300 times more than porters. An estimated 6000 trucks plied the trail at any given time. Traveling mostly at night to avoid American airstrikes, trucks parked in stations about 3 km off the trail during the day. Trucks were extensively camouflaged.

A truck and its drivers were assigned to a 30 km segment of the trail, going back and forth. Usually, trucks had two drivers to alleviate fatigue, and assure convoy security. Supplies were off loaded from one truck to another at the stations. This practice assured drivers were familiar with their part of the trail.

If aircraft approached, anti-air monitors and special signals alerted drivers. This immediately halted all vehicles. Or, the drivers detoured into any available alternate paths away from the main one. Drivers often waited up to an hour after the last aircraft departed before resuming their journey. New radio-equipped “Polish Star 66” trucks arrived in North Vietnam in late 1965, and were first spotted on the roads in southern Laos during March 1966. Radios in truck convoys provided air attack warnings, and gave drivers more time to seek cover.

The trucks were mainly from Russia and China. WWII vintage trucks were used initially. The GAZ-63 was very common and made in the Gorky plant in Russia. These had six-cylinder engines, and         4-speed gearboxes. They could carry 2000 kg. The ZIL-157, made in Moscow was similar. This truck was also copied in China as the CA-30. The ZIL-130 was introduced later. It had a V-8 engine, 5-speed transmission, and could carry 4.5 tons payload.

Soviet built GAZ-63 Trucks

GAZ-63 Trucks

ZIL-130 Trucks - Camouflaged

ZIL-130 Trucks – Camouflaged

Truck Convoy

Truck Convoy

Viet Minh Trucks Fording a Stream

Fording a stream


Surprisingly, the North Vietnamese also built pipelines to move petroleum products. Three lines ran into Laos from Vinh in the North Vietnamese panhandle near tanker docking facilities. These went through the Mu Gia pass to points along the northern parts of the trail, and serviced truck parks.  Another ran through the Ban Raving Pass to a distribution point near Tchepone. From here, other lines extended to the Lao Bao Pass, and the A Shau Valley. The Soviet-imported plastic pipes were connected with metal couplings. Russian-made pumps pushed motor oil, gasoline, diesel fuel, and kerosene. A variety of petroleum products could be sent along the same line. Water mixed with detergent separated the shipments, and prevented contamination. The 592nd Pipelaying Regiment was responsible for this construction.

Men from the 592nd Pipelaying Regiment at work

Men from the 592nd Pipelaying Regiment at work


The North Vietnamese expended an all-out effort to create and operate the Truong Son. They endured many hardships, were very resourceful, adaptive to the environment, and could counteract the enemy’s efforts.

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Uncle Ho’s Hideout #8 – Origins of Truong Son

mpaign Series Vietnam | Uncle Hos Hideout

In Uncle Ho’s Hideout series, David Galster shares some of his tips and techniques in scenario research and design for CS: Vietnam.

Dear Compatriots,

Can you guess what year the phrase “Ho Chi Minh Liaison Road” was coined? It was in 1947, during the First Indochina War. The trail had origins long before the Americans got involved, and became agonized by it.

Early Trail Background

During WWII and the First Indochina War, the Vietminh needed and developed a “backwoods” trail system and logistic network. Although primitive, it helped connect the northern and southern parts of Vietnam. Three-month journeys over the land routes were not uncommon. After the French defeat in 1954, and the division of Vietnam at the 17th parallel, the trail became the main route for North Vietnamese (DRV) agents, (including Le Duan,) and communist-indoctrinated South Vietnamese “returnees” en route to South Vietnam.

To infiltrate men and supplies to South Vietnam, the DRV relied on the eastern sector of Laos contiguous to southern North Vietnam and northern South Vietnam. That is where the latticework of roads, trails, tracks, and waterways along the western slope of the Annamite Mountain chain. There were numerous valleys between rugged mountain passes with elevations of 1400 to 1700 meters. Roads generally followed valleys, and were often parallel to rivers, which served as alternate routes.

Although the trail was mostly in Laos, the communists called it the “Truong Son Strategic Supply Route” (Douong Truong Son,) after the Vietnamese name for the Annamite Mountain Range. This and the name “Ho Chi Minh Trail” were kept secret for a long as possible.

The trail areas in Laos consisted of jungle-covered mountains, some rising to about 2745 m in the north and 1525 m in the south. Tropical rain forests of mixed evergreens and deciduous trees are abundant. Other trees were second growth bamboo, wild banana, and scrub, and much of the ground is covered with tall tough grass called “tranh.”

Most of the rain falls between May and October. Overland travel is difficult and treacherous during this time. The dry season is the time when trails are firmer, and large scale movement is militarily feasible.

Until 1964, vehicles were confined to relatively poor roads, such as Routes 12 and 8 through the Mu Gia and Nape Passes respectively. Routes 23 and 9 led to Tchepone, or southern Laos via Route 23.

Ho Chi Minh Trail | Map of Southern Laos

Doan 559

In May 1959, the Communist Party Central Committee’s 15th Congress agreed on a resolution to develop and expand the trail. President Ho Chi Minh officially assigned the task of “Special Military Missions” to open the Truong Son Road, providing supplies and support for the battlefield in South Vietnam. From this, an organization called Doan (Group) 559 was formed. The number comes from the month, May = 5, plus the year = 59 to get the identifying number.

Colonel Vo Bam began organizing Doan 559, with an initial staff of 500 cadres and soldiers. They decided to develop roads on the west side of the Annamite Range to have better protection from South Vietnamese attacks.  In early June 1959, Group 559 organized survey teams to open the route to the south starting from Khe Ho. (7 km north of DMZ) Construction began, and by December 1961, gravel roads 5.5 m wide reached Route 9 at Muong Phin, Savannakhet Province. That year, Group 559 transported 5177 tons of weapons and equipment, and hauled 91 tons of rice. 7664 officers and soldiers moved through routes to battlefields, and 616 people from south to north. This was all done with maximum secrecy.

The terrain also necessitated a vast amount of bridging to span the numerous rivers, streams, and valleys. Enough roads were built by 1965, that heavy equipment and supplies were moved mostly by truck. Eventually, the engineering effort would make many of the routes all-weather, thus diminishing the seasonal nature of infiltration.

Doan 559 developed into a significant organization, similar to a military corps. Ultimately, it had general staff, political, transportation, and construction bureaus. There were 25 Binh Tram regiments, involved with operating the truck network. Doan 559 had 23 other military regiments under its direct control, including six engineer, six air defense, and others including two truck regiments, and two fuel supply regiments. There were three automotive repair workshops, and four field hospitals. The Binh Tram regiments also were supported by an infantry regiment, air defense battalion, separate engineer battalion, reconnaissance company, and a battalion of couriers.

Doan 559 Organization Chart

Doan 559 Organization Chart

Map Border Regions Laos & Vietnam

Base Areas

The network (for both vehicle and foot traffic) consisted of trails connected by a series of small rest-points, larger storage sites, and a few major base areas permanently manned. The network needed not only soldiers to operate the routes, but also personnel to feed and support the workers. The area around Tchepone was such a hub, and was listed as base area complex 604, one of the major locations for movement, storage, and other support activities.

One complex, typical of several others, was discovered by an American air cavalry unit, and dubbed the ‘City’. It had 182 storage bunkers each of 36 cubic meter capacity, 18 mess halls, a training area, and a small animal farm. It covered approximately three square kilometers, and the storage depot was capable of rapid receipt and issue of large quantities of supplies. From captured documents it was apparent that the ‘City’ had been in operation for at least two and a half years. The haul of weapons it yielded was enough to equip an NVA regiment.

The following key base areas were established:

There were five large Base Areas (BAs) in the panhandle of Laos (see map).

BA 604 was the main logistical center during the Vietnam War. From there, the coordination and distribution of men and supplies into South Vietnam and BAs further south was accomplished.

BA 611 facilitated transport from BA 604 to BA 609 and the supply convoys moving in either direction. It also fed fuel and ammunition to BA 607 and on into South Vietnam’s A Shau Valley.

BA 612 was used for support of the B-3 Front in the Central Highlands of South Vietnam.

BA 614, between Savannakhet, Laos and Kham Duc, South Vietnam was used primarily for transporting men and materiel into MR 2 and to the B-3 Front.

BA 609 was important due to a fine road network that made it possible to transport supplies during the rainy season.

The base areas housed numerous supply bunkers, storage areas, barracks, hospitals, and command and control facilities. These were concealed from aerial observation by an intricate system of natural and man-made camouflage that was constantly expanded and replaced. By 1973, trucks could drive the entire length of the trail without emerging from the canopy except to ford streams or cross them on crude bridges built beneath the water’s surface.

Base Areas on Truong Son

Base Areas on Truong Son


The trail network had primitive origins, but through the determined efforts of Doan 559, it became an effective supply network from which the war in South Vietnam could be executed.

I imagine Ho Chi Minh had much input on the trail management, because it was so very important strategically.

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