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Viet Cong and PAVN logistics and equipment

The Main Force of the People's Liberation Armed Forces (better known as the Viet Cong or VC in the West) and the NVA (North Vietnamese Army/People's Army-Vietnam) used well-organized logistics methods to supply and equip their fighting forces. This logistics organization contributed to the defeat of their American and South Vietnamese (GVN/ARVN) opponents during the Second Indochina War (better known as the Vietnam War). For related articles on Strategy/Organization and Tactics see:

The VC in this article identifies the PLAF "Main Force" Chu Luc or full-time soldiers of the National Liberation Front, (NLF) an umbrella of groups set up by the rulers of North Vietnam to conduct the insurgency in the south. The term NVA identifies regular troops of the North Vietnamese Army as they were commonly known by their Western opponents. Collectively, both forces were part of PAVN, People's Army of Vietnam, which made up all armed forces of North Vietnam. Certain terms such as "NLF" and "VC" or "NVA" and PAVN" are used interchangeably, and they, along with others used herein such as "Chicom", "Liberation Army", "regime", etc. have no pejorative or partisan intent or meaning. They are incorporated here due to their widespread popular usage by both South Vietnamese and American military personnel and civilians, and common usage in standard histories of the Vietnam War.

VC/NVA equipment and weapons

Overall, the supplies and equipment of communist units were adequate, and their infantry small-arms were more than a match for those of their opponents. Contrary to some popular impressions of simple peasant farmers armed with pitchfork and machetes, the VC/NVA main units (as well as the local forces in the latter years) were well equipped with excellent modern arms either from Soviet bloc or Chinese sources. In the early years of the insurgency in the South a larger variety of weapons were used, ranging from old WWI bolt-action rifles to Nazi-era weapons, with procurement via a wide range of methods. Such variation and diversity continued throughout the conflict. By 1970 however, the communist inventory was increasingly standardized, even at the village guerrilla level. The following outline shows major weapons categories:

Small arms- rifles - The standard infantry weapon of the VC/NVA was the Soviet 7.62 mm AK47 assault rifle, or its Chicom copy, the Type 56 assault rifle. The Soviet SKS carbine/semi-automatic rifle or its Chicom version (Type 56 Carbine) was also widely used. Compared to the early American M-16 the rugged AK-47 in particular was more reliable and easier to maintain. The American M-16 also saw service, obtained through capture or black market purchase.

Machine guns, mortars and interchangeable ammo. Also of key importance to communist units was the interchangeability of the 7.62 mm ammunition between the AK-47 and other types of weapons. The 7.62 mm round not only worked well in the SKS carbine but also could be used in the Soviet RPD (weapon) light machine gun, another standard infantry weapon of the VC/NVA, capable of 650 rounds per minute. Heavier machine guns were sometimes used but often in set piece assaults, or in fixed mode- such as anti-aircraft weapons, due to their weight. Communist units also employed mortars frequently, with the Soviet 82 mm and its Chinese variants being the most common. French 60 mm mortars also saw some use.

Rockets and RPGs. The VC/NVA also made extensive use of the excellent Soviet designed anti-tank grenade launcher, the RPG. Originally designed to fight against armor, it was adapted for anti-personnel use to good effect. They also made use of the Soviet/Chinese 122 mm rocket which was used effectively against populated areas and large installations such as airfields. While inaccurate compared to more sophisticated weapons, the 122 mm rocket made an effective terror weapon when deployed against civilian targets. Other rocket types included tube-launched Chicom 107 mm and Soviet 140 mm variants.

Anti-aircraft missiles and batteries. The VC/NVA relied heavily on heavy machine guns and standard Soviet designed anti-aircraft batteries for air defense functions. In the latter year of the conflict, field units of the VC/NVA deployed hand-held Soviet designed anti-aircraft missile that presented a significant challenge to US air dominance, particularly helicopters. For strategic aerial defense, the North deployed one of the densest and most sophisticated air-defense systems in the world based on Soviet SAM missiles and radar batteries.

Grenades, booby traps and mines. The VC/NVA used a wide variety of grenades from explosives inserted into discarded American C-ration cans to modern Chicom types. Booby traps were the province of guerrilla level forces more so than the VC/NVA regulars. The infamous punji sticks soaked in excrement and urine received much press, but they were of negligible effect compared to the massive quantity of anti-personnel and anti-vehicle mines deployed by main communist units. These quantities increased vastly as the North stepped up infiltration into the South. Mines and booby traps applied significant psychological pressure on US/ARVN forces and slowed and disrupted both military operations and civilian life.

Tanks and artillery. Fighting a mobile guerrilla war much of the time, the VC/NVA could not deploy large quantities of heavy artillery or tanks. Exceptions were the set piece siege battles such as at Khe Sanh or heavy artillery duels against US batteries across the DMZ. It was only after the shift to conventional warfare in the 1972 Easter Offensive, and the final conventional campaign in 1975 (when US airpower had vacated the field) that tanks and heavy batteries were openly used in significant numbers. When using heavy artillery, the VC/NVA relied on high quality Soviet-supplied heavy 120 mm and 130 mm guns that outranged American and ARVN opposition.

VC/NVA Logistics

Austerity of Communist force requirements

VC/NVA logistics were marked by austerity, but sufficient supplies, equipment and material were on hand to furnish final victory. Consumption levels were much less that those of their American/ARVN opponents. It is estimated that a VC/NVA division in the south typically required only 3 tons of supplies per day. Total requirements to run North Vietnam's overall war machine were comparatively small, an estimated 6,000 tons annually in 1967, well below port and rail capacity. US Intelligence estimates of all Communist non-food requirements in the South averaged about 15 tons per day (or 1.5 to 3 ounces per man) in low intensity periods.

In 1968 with the Tet Offensive and other major operations, these numbers surged but still weighed in at a modest daily 120 tons. By contrast a single US heavy combat division required about 5 times this amount. The problem was not the total incoming quantity but moving material up the Ho Chi Minh Trail and other transmission paths, to the point of battle operations. Soviet bloc and Chinese shipments easily met ordinary communist force requirements. Internal supply from within South Vietnam was also crucial particularly food supplies. Overall, communist logistical operations were successful.

Support by the Soviet bloc and China

Communist bloc support was vital for prosecution of the war in the South. North Vietnam had relatively little industrial base. The gap was filled primarily by China and Russia. The Soviet Union was the largest supplier of war aid, furnishing most fuel, munitions, and heavy equipment, including advanced air defense systems. China made significant contributions in medicines, hospital care, training facilities, foodstuffs, and infantry weapons.

Since China bordered Vietnam, it was an immensely important conduit of material on land, although the Soviets also delivered some of its aid by sea. Soviet aid outstripped that of China, averaging over half a billion dollars per year in the later stages of the war, with some $700 million in 1967 alone. China provided an estimated 150 million to 200 million annually, along with such in-kind aid as the deployment of thousands of troops in road and railway construction in the border provinces. China also provided radar stations and airfields where North Vietnamese aircraft could marshall for attack, or flee to when in trouble against American air forces. These airbases were off-limits to American retaliation.

The railway network in the Chinese provinces bordering North Vietnam was of vital importance in importing war material. American Rules of Engagement forbid strikes against this network for fear of provoking Chinese intervention. Thousands of Chinese troops (the PLA's 1st and 2nd Divisions) made important contributions to Hanoi's war effort- building or repairing hundreds of miles of track and numerous other facilities such as bridges, tunnels, stations and marshalling yards. Chinese troops also built bunkers and other fortifications, and manned dozens of anti-aircraft batteries. In all, some 320,000 Chinese soldiers served in Vietnam during the war.

The Ho Chi Minh and Sihanouk Trails

(see Wiki article Ho Chi Minh Trail for more details)

Construction of what was to become the famous Ho Chi Minh Trail extended over decades, with elements put in place during the anti-French struggle of the Viet Minh. Known to the North Vietnamese as the Truong Son Strategic Supply Route, the Central Committee of the Lao Dong Party ordered construction of routes for infiltration as early as 1959, under the 559 Transport Group. The Trail was a complex web of roads, tracks, bypasses, waterways, depots, and marshaling areas, some in total. It snaked through parts of North Vietnam, Laos and Cambodia. US policymakers made ground attack against Trail networks in these countries off limits, (until limited operations were permitted late in the War) and communist forces took full advantage of this to move massive quantities of men and material into South Vietnam to attack US and ARVN troops. As the war progressed, communist forces expanded and improved the Trail, moving material by truck, installing missile batteries for air defense and laying fuel pipelines. Air interdiction of the Trail hurt communist efforts but failed to stop the logistical buildup on a sustained basis.

Trail installations and movement

Installations on the trail. The Trail had over 20 major way-stations operated by dedicated logistics units or Binh Trams, responsible for air and land defence, and delivery of supplies and replacements to fighting points in the South. Commo-Liaison units also operated along other trail segments and were tasked with providing food, shelter, medical support and guides to infiltrating troops between Trail segments. The Binh Trams were responsible for numerous functions in the sector of the Trail it controlled- including subordinate camps and way-stations, the care and feeding of troops, road repair, anti-aircraft defenses, vehicle repair and maintenance, and medical care. Each binh tram had its own force of porters, guides, engineers, specialists, transportation units and infantry. Some binh trams had extensive anti-aircraft defenses. The Mu Gia binh tram area for example, was estimated to have no fewer than 302 anti-aircraft positions as early as 1966, a deadly flak trap for US aircraft. By 1973, gun batteries had been supplemented with Soviet-supplied SAMs on various parts of the Trail.

Trail movement. Most material movement in bulk was not by gangs of sweating coolies, but modern Soviet-supplied trucks. These vehicles rolled on a "relay" basis, moving mostly at night to avoid American air power, and the trail was plentifully supplied by jungle-like camouflage at all times. Way stations were generally within one day's travel from each other. Trucks arriving at a station were unloaded, and the cargo shifted to new trucks, which carried out the next segment of the journey. Having plenty of both time and manpower, this "relay" method economized on wear and tear upon the valuable trucks, and maximized hiding opportunities from prowling US aircraft. The method also spread out available cargoes over time and space, enabling the entire network to better bear losses from such deadly enemies as the American C-130 Gunship, and such technologies as movement sensors.

Sihanouk Trail in Cambodia

The Sihanouk Trail was the American name for the network of roads, waterways and paths cutting through Cambodia that supplied communist forces. This network was considered an integral part of the overall supply system incorporating Laos and North Vietnam and centered around the Cambodian port of Kompong Somor Sihanoukville. The unit tasked by Hanoi with organizing movement was the 470th Transport Group, which established a similar network on binh trams' and way-stations.

"".. military supplies were sailed directly from North Vietnam on communist-flagged (especially of the Eastern bloc) ships to the Cambodian port of Sihanoukville, where that nation's neutrality guaranteed their delivery. The supplies were unloaded and then transferred to trucks which transported them to the frontier zones that served as PAVN/NLF Base Areas.[8] These Base Areas also served as sanctuaries for PAVN/NLF troops, who simply crossed the border from South Vietnam, rested, reinforced, and refitted for their next campaign in safety." See Wiki article Sihanouk Trail for more detail.

Of the Sihanouk Trail and Cambodia, one American military history says:

"The continuity in the infiltration corridor through Cambodia and Laos mitigated against the forces being stopped. Unlike Greece, fifteen years earlier, which had been able to seal its borders with the help of neighbors, South Vietnam could not count on such aid. Cambodia's port of Sihanoukville made possible the flooding of the South Vietnam battlefield with a family of Sino-Soviet equipment that was completely compatible with that used by VC/NVA forces in the rest of Vietnam. The overthrow of Sihanouk and the closing of the Sihanoukville port in early 1970 were too little too late. Laos was still a wide-open corridor, and U.S. forces were withdrawing. It was never a question of victory for the North, it was only a matter of time."

Effectiveness of the Trail despite interdiction efforts

By 1969 the Trail was a sophisticated logistical web with paved roads, truck parks, maintenance and supply depots, and well organized and defended terminuses and bases, moving thousands of men per month into the battle zone. A fuel pipeline was even in place by 1969, and this was to multiply, together with other installations such as missile batteries, as the conflict extended. The need for massive amounts of construction hand-labor actually decreased on the Trail as heavy quipment like bulldozers and rush crushers were deployed, and both miles of road built and truck traffic expanded. By war's end almost a million soldiers had made the trip down the Trail, and tens of thousands of tons were being transported annually.

Massive American efforts in the air failed to stop the men and material pushed forward by Hanoi. Bomb tonnages dropped on the Trail in Laos offer some indication of the scale of the American campaign: 1969- 433,000 tons, 1970- 394,000 tons (74,147 sorties), 1971- 402,000 tons (69,000 sorties). However with only 15 non-food tons a day needed for low-intensity operations in the South, PAVN could keep its war-fighters in business indefinitely by moving about 6,000 tons annually. Amounts ten times or more this size however, were entering the top of the logistical pipeline before trickling down into South Vietnam, Laos and adjoining border regions.

A post-war analysis by the BDM Corporation, a think-tank contractor in Vietnam, summarized the efficiency and effectiveness of VC/NVA logistics as follows:

Subsequently the Communist Vietnamese leadership outlasted America's eight-year combat effort in Southeast Asia, and finally reunited Vietnam by force of arms. A major factor contributing to their success was the remarkable logistical support they created in an integrated network of bases, sanctuaries and lines of communication. Indeed the sanctuaries gave them the trump card that enabled them to fight a protracted war and outlast the United States commitment to the Republic of Vietnam.

Logistical organization and facilities

Supply from inside South Vietnam

While outside material was vital to the war effort, much of the resources needed were obtained inside South Vietnam. Tonnages needed for communist forces were modest for the low-intensity protracted war style. One CIA study in 1966 found that the bulk of supplies needed were generated within South Vietnam. Food was always had locally, taxed away from peasants, purchased or even grown by Liberation Army units. Captured stocks were also exploited. American logistical largesse also provided a bonanza as fraud and corruption siphoned off resources. Both weapons and food for example were readily available on the black markets of South Vietnam.

This capability of generating resources internally contributed to the mixed results obtained by massive US interdiction efforts- such as the bombing campaign in Laos. Big search and destroy operations seized hundreds of tons of rice and other material in remoter base areas, but these could be regenerated and restocked again when roving US troops invariably moved on to their next sweep. The Ho Chi Minh Trail consumed massive amounts of attention, but the internal pipelines were also crucial, and these were not closed off because the US and particularly the GVN failed to control the major population concentrations effectively.

North-South organization

NVA headquarters in Hanoi was responsible for the coordinating the North to South logistical effort. To this end, it deployed 3 special formations.

The 603rd Transport Battalion handled sea infiltration and supply movement.
The 500th Transport Group handled movement of troops and supplies in the North in preparation for the journey south
The 559th Transport Group was the biggest of the three, numbering an estimated 50,000 troops with 100,000 civilian porters in support. It handled all storage, movement, anti-aircraft defense and fortification on the Ho Chi Minh Trail which snaked through parts of Laos and Cambodia.
The 470th Transport group was established to move material from Cambodia

Logistical organization inside South Vietnam

Within SVN, the NLF military HQ, COVSN, had responsibility for overall logistical coordination. This changed as the war went on, and the NVA took over more responsibility in-country after the 1968 Tet offensive. This takeover involved setting up new headquarters and replacing fallen VC with NVA regulars. Within the southern logistical organization, 3 agencies were responsible. Sub-sections of these operated at different levels, from Interzone to village.

The Finance and Economic grouping was the chief fund raiser, banker and purchasing agent.
The Rear Services grouping provided logistical support for military operations, such as digging bunkers or hauling supplies.
The Forward Supply Council marshaled the money and resources raised by the Finance section, and the services of the rear Group. It controlled civilian labor recruitment, and military recruitment including drafting men into the VC, among other things. Party membership was strongest in the Forward Supply Council.

Overlap and duplication

There was a significant overlap of logistical functions in the communist organization, as the NVA and the VC/NLF civilian agencies worked an area. However overall control was always in the hands of party cadres at all levels, from province down to village. Duplication also produced a wider range of alternative sources for supplies, and made the whole structure more resilient. An American or ARVN sweep for example that wiped out several supply caches did not shut down the whole district. Supply routes using multiple sources, (waterways, black-market transactions, cross-border sanctuaries, etc.) could be reopened, and laborers from other regions could be shifted into reconstruction work once the Americans or ARVN left (as they usually did).

Civilian porters

Civilians labor was crucial to VC/NVA success, and was deployed in building fortifications, transporting supplies and equipment, prepositioning material in readiness for an operation, and general construction such as road repair. Labor was recruited primarily by impressment/draft, or as a way to pay off VC taxes, although volunteers motivated by ideology also took part. Twelve to sixteen hours of work per day were expected of laborers. Civilians undertook various pledges as directed by the regime (the "three readies", the "three responsibilities" among others,) as part of a high mobilization of the population for total war in the North and areas controlled by the VC/NVA in the South.

Load bearing by porters was greatly enhanced by the use of ingenious "steel horses" - bicycles specially modified by widening the handlebars, strengthening the suspensions and adding cargo pallets. Guided by two men, the specially modified bikes could move 300-400 pounds, several times that of a single porter. Older men made up many of the long-term laborers as those younger were drawn off into combat and female labor was used extensively in a wide range of logistics tasks.

Port and water transport facilities

Communist forces also made extensive use of Vietnam's large network of rivers and waterways, drawing heavily on the Cambodian port of Sihanoukville, which was also off-limits to American attack. Some 80% of the non-food supplies used by the VC/NVA in the southern half of South Vietnam moved through Sihanoukville.

Some port areas of North Vietnam were also vital to the logistical effort, as were ships by socialist nations that fed the continual stream of war material. Attacks on these were also forbidden by American policymakers. Until late in the War, American pilots, hindered by their government's Rules of Engagement, could only watch helplessly as munitions, heavy weapons and advanced components like SAM missile batteries were unloaded at such harbors as Haiphong. By 1966, some 130 SAM batteries were in North Vietnam by US estimates, manned primarily by Russian crews.

Weapons resupply and communications

VC/NVA weapons had to be moved from shipment points in the North, Cambodia or down the Ho CHi Minh Trail. Small, jungle workshops made simpler types of ordnance such as reloading rifle cartridges or grenades. A large amount of small supply depots, widely dispersed to guard against attack, furnished units on the move. Impressed labor groups of civilians also hauled ammo and supplies for the Front. ARVN and US sources were also significant localized conduits of arms. VC fighters in some areas ironically treasured the American M-16 rifle despite its sometimes quirky performance, for the wide availability of both the weapon and its ammunition on the black market or through purchase from corrupt ARVN soldiers, or through the careless handling and loss of magazines by US troops.

VC/NVA formations suffered a shortage of modern radios. Although wire was sometimes run for field telephones in selected operations, they relied heavily on couriers for transmission of messages on the battlefield. A "drop box" system for couriers was also extensively used for intelligence communications. The whole network was segmented, so that one part did not know the other branches. A courier might leave a message at a specific drop location for another courier (a stranger to him or her). This segmentation helped protect against compromising the network when couriers were captured or killed. Segmentation enhanced security and was also sometimes used in moving troops - with guide units only knowing their section of the trail or transport network.

Food and medical care

Food. The bulk of VC/NVA foodstuffs was procured within South Vietnam via purchase, taxation on peasants in controlled areas, and personal farming by troops in remote areas. Households in areas under VC control were required to keep a certain minimum supply of rice on hand, and a large number of secret caches and supply dumps honeycombed the countryside. Food, along with almost any other item, was also obtained on Saigon's thriving black market. This included large quantities of American food aid to South Vietnam, a phenomenon sometimes observed by US troops that found enemy supply caches. Ironically, even the remnants of American airstrikes were pressed into food production. US patrols encountered numerous B-52 bomb craters used as fish and duckponds by Communist troops.

Medical care. Medical supplies used on the battlefield came from several sources, including Soviet bloc and Chinese shipments and "humanitarian" donations earmarked for civilian use from neutral countries, including Scandinavian nations. Medical care like other aspects of the logistical system was austere, and field hospitals, whether in caves, underground bunkers or jungle huts usually suffered shortages. A one day supply of medicines was usually kept on hand, with the rest hidden off-site until needed. About 7% of a typical VC/NVA division's manpower was made up of medical personnel.

Total mobilization in the North to fight US bombing

Dispersal and decentralization under heavy air attack. From 1965 to 1968, North Vietnam was bombed on a scale heavier than the that of the entire Pacific theater during World War II, and absorbed about 20% of US bombing efforts in Southeast Asia. Targeting however was tightly controlled and limited, and while most major industrial centers had been destroyed by 1967, imports from Soviet bloc countries and China furnished most war-making material. The country continued to function for war despite the aerial onslaught. Facilities and installations were widely dispersed and concealed. Some 2,000 imported generators provided essential power, and oil and gas were shuttled ashore on small craft from Soviet ships and stored in thousands of small drums throughout the countryside. A massive number of civilians were also evacuated to the countryside from the urban areas, along with factories and machine shops.

Personnel mobilization. American bombers caused substantial damage to Northern road and rail infrastructure, including bridges, culverts, depots, ports and docks. Nevertheless an enormous effort kept transportation networks open. Some 500,000 workers were mobilized to repair bomb damage as needed, with an additional 100,000 constantly at work. The largest repair organization was the “Youth Shock Brigades Against the Americans for National Salvation.” Numbering some 50,000 to 70,000 laborers, the brigades were made up of recruits between 15 and 30, with heavy female representation as young men were siphoned off for combat. Joined by assorted militia and self-defense forces, these quick-reaction units were often stationed along heavily bombed routes and deployed to repair bridges, roads, tracks, tunnels and other structures. Pre-positioning of these groups allowed them to spring rapidly into action after an attack had passed.

Road and bridge repair methods. There were several ways to keep traffic moving amid the destruction wrought by the bombers. Simple pontoon bridges were made of lashed together bundles of bamboo, topped by heavy wooden planking. Sturdier pontoon structures were made by tying wooden canal boats together - with camouflage measures to hide them during the day from aerial observation. Bridges were also built underwater to escape detection. Supplies, equipment and material was pre-stocked along roads, and near various choke points like ferry crossings so that repairs could be made quickly. Delayed action bombs caused special problems. Designated personnel were tasked with dismantling them, or watchmen kept them under observation- signaling all within blast distance to disperse when the bombs showed signs of detonating. Repairs were often done at night when the enemy aircraft would be less active.

Concealment and evasion. Camouflage was used heavily. Roads were sometimes “roofed” with a network of branches, brush and other greenery, and vehicles on the roads sported foliage to aid in concealment. Night movement was almost constant, with drivers being guided on the roads by white poles painted by the Youth Shock Brigades, or personnel dressed in white. Truck headlights were sometimes mounted under the vehicle to help escape detection from the air. The North Vietnamese also took advantage of US Rules of Engagement. When a buffer zone policy was in effect near the Chinese border, US recon planes could see hundreds of loaded trucks massed in the buffer zone during the day, waiting to roll later at night. Truck driving was a dangerous task, and drivers were expected to not only dodge aircraft but help with vehicle and road repairs. Traffic was regulated by numerous civilian helpers, often young girls.

Effectiveness of mobilization. American bombing could be ineffective against both the landscape and determined repair attempts. A massive 1966 bombing mission by thirty B-52’s for example attempted to pulverize vital stretches of the strategic Mu Gia pass. Two days later however the traffic was moving again, despite huge landslides caused by the giant bombers, and the use of numerous delayed action munitions. On the vital China to Hanoi corridor, most major bridges, roads and rail lines were back in operation within 5 weeks after the American bombing halt in 1968. The large number of waterways in Vietnam were also put to good use in moving material. In terms of stopping Hanoi's ruthless drive for reunification, the overall US bombing campaign, with its varied stops and starts, was ultimately ineffective in the face of cascading imports from socialist allies, diplomatic, political and technical restraints on American action, and the stoic determination and endurance of the North Vietnamese.

The most dangerous period for the North appeared to be in 1972, when US aerial forces under President R. Nixon launched the brief but devastating Linebacker I and Linebacker II bombing raids. These attacks removed many of the restrictions upon previous American targeting, seeded Northern waters with mines that cut Soviet and Chinese imports to a trickle, exhausted national air-defenses and crippled whatever significant remaining industrial plant and transportation network was left in the North. However such severely damaging American efforts were not sustained. By the time of the Linebacker offensives (a few weeks each), most US forces (over 500,000 troops) were already out of the Vietnam theater. Over 150,000 Northern soldiers however remained in the South after the 1972 Offensive, expanding the conquered zone and biding their time, until the final Ho Chi Minh Campaign in 1975.

The infiltration south

Trail movement and hardships

NVA units deemed ready for infiltration were transported from the training centers by train or truck to the coast, at places like Dong Hoi, where they received additional rations. From there they marched south and southwest, towards the Demilitarized Zone (DMZ) or Laos, using a variety of routes. Movement was at night to avoid American air attacks. Within the DMZ, there was a rest pause of several days as infiltrators staged for the crossing. Moving in company or battalion sizes, units departed at two-day intervals, with most crossing into Laos along a system of thousands of tracks, roads and paths known as the Ho Chi Minh Trail.

NVA infiltration routes were keyed to the Military regions the infiltrators were assigned to. PAVN units headed for the Tri-Thien region closest to the northern border might infiltrate directly across the DMZ. Those headed further beyond might travel through Laos. The Sihanouk Trail in Cambodia was opened in 1966 to enable PAVN to infiltrate and resupply COVSN in the southernmost zone of South Vietnam.

The Ho Chi Minh Trail covered a wide diversity of rough terrain. Steep mountain slopes had steps gouged into them for climbing. Ravines were bridged with crude bamboo suspension bridges. Ferries shuttled troops across rivers and streams, and crossings were sometimes laid underwater to avoid aerial detection. Large gangs of civilian laborers were drafted to keep the network functioning.

A daily march cycle might begin at 4:00am with a pause around noon, and continuation until dusk- 6:00pm. Generally there was ten minutes of rest per hour, with one day of rest every five. Fifteen to twenty-five kilometeres were covered daily depending on the terrain. Movement was in column, with point and rear elements. Armed liaison agents, who knew only their section of the Trail, led each infiltrating group between way-stations. Way-stations were located deep in the forest, and contained caches of supplies for use by the infiltrators. They were guarded by detachments of the 559th Transport Group. Sometimes the troops camped on the Trail itself between stations.

The hardships of the Trail were many. Casualties caused by American airstrikes were low, accounting for only 2% of total losses. More dangerous enemies included malaria, foot infections and a variety of other maladies. Total losses to disease are estimated at around 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.

Recruits were generally given an optimistic picture of conditions in the south, with claims that victory was close at hand and that they would be welcomed as liberators by their oppressed Southern brethren. They were often quickly disabused of such notions as they encountered sullen peasants and withering US firepower.

Techniques to deceive or fight US airpower and Special Ops troops

By 1968, business was brisk on the Trail. Ten thousand trucks could move at a time, and improvements were made continuously by the 559th Transportation Group. US air interdiction against the Trail increased as PAVN stepped up its activities. One method used to fight the effects of bombing was to separate the movement of men from the movement of material. NVA soldiers were limited to old pathways, while trucks were increasingly routed along newer, improved stretches of road. Since most of the US effort focused on trucks, the bulk of the fighting men were able to travel without the full weight of US pressure, although they sometimes came under attack.

Great pains were taken to camouflage movement. Wherever possible PAVN units minimized disturbances to the jungle cover, and even transplanted foliage from elsewhere to cover and conceal signs of movement. PAVN sources claim that the 559th Transport group camouflaged some out of the of trail. Techniques used to fool US airpower included underwater bridging and placing gasoline-soaked rags along the trail to fool pilots into thinking they had hit or ignited something of value. About 100,000 people were kept working on the Trail as porters, drivers, mechanics and anti-aircraft troops. By 1970, the entire Trail bristled with anti-aircraft batteries.

PAVN troops also encountered US movement, auditory and chemical ("people sniffer") sensors on various parts of the Trail. Sound/seismic sensors were countered by destroying them, moving them to useless locations, removing their batteries, playing tape recordings of truck traffic, and running herds of cattle over them. Chemical sensors were neutralized by leaving buckets of urine hanging on trees over the transportation network. Esoteric American technology- such as the Calgon brand "mud maker" compounds deployed to slow movement on the Trail were met with typical People's Army practicality. Logs and bamboo were laid over the quickly dissolving mud and the Northern fighters moved on. Special trail-watching and reaction units were also used to counter infiltration by US-MACV Special Operations teams. Local tribesmen recruited by PAVN for example would beat on pots or gongs to warn of the presence or landing of US Special Ops teams and high rewards were offered for assisting with their capture.

Volume of infiltration

VC/NVA Troop strengths during the Vietnam War are the subject of numerous controversies and contradictory claims. Official post-war North Vietnamese sources claim over half a million troops in place by 1967. US MACV estimates posit a more modest total of around 280,000. Force strengths will always be imprecise given the large number of irregular or part-time guerrilla elements.

Infiltration numbers increased yearly. In 1968 alone, some 200,000 NVA troops made the journey south according to some American estimates. Official Communist sources also confirm the massive buildup, although figures differ between American and Northern sources. According to the official People's Army of Vietnam (PAVN) History:

“In 1964 our army began to send to the battlefield complete units at their full authorized strength of personnel and equipment... By the end of 1965 our main force army in South Vietnam totaled almost 92,000... Our main force troops grew from 195,000 soldiers in early 1965 to 350,000 soldiers in May 1965 and finally to 400,000 by the end of 1965.. During 1966 the strength of our full-time forces in South Vietnam would be increased to between 270,000 and 300,000 soldiers... By the end of 1966 the total strength of our armed forces was 690,000 soldiers.”

Throughout a large portion of the War, North Vietnam denied that any of its soldiers were even in the south, but it is clear that the Communist forces were able to place tens of thousands of troops in the southern war zone, including complete units of regular NVA, rather than simply individual fillers.