Siege of Dien Bien Phu
1953 - 1954

French Arrival: 20 Nov. 1953

by David Parham

At 10:35 on November 20, 1953, the first airborne elements of the French force began to descend on the valley of Dien Bien Phu. Their mission was to open the old airfield and secure the area around it.

At right, a French company on patrol. Note the variety of weapons as well as races in the unit.

Due to the shortage of C-47 and C-119 "Flying Boxcar" aircraft, only two airborne battalions could be dropped in the initial phase. They were the best in Indochina. The 6th Colonial Parachute Battalion (6th BPC), a commando outfit, was led by the legendary Major Bigeard. The 2nd Battalion of the 1st Regiment of Parachute Light Infantry (II/1 RCP) jumped under the command of Major Brechignac.

Together with airborne artillery and engineers, they helped form Airborne Battle Group No. 1 (GAP 1). The 1st Colonial Parachute Battalion (1st BPC), another elite unit, completed GAP 1 later in the day. The paratroopers quickly dispersed the small Viet-Minh units that had been using the valley as a rest and training area. On November 21, the Command Headquarters for the entire Dien Bien Phu operation under Brigadier General Gilles parachuted into the secured drop-zone.

Also added was GAP 2 led by Lieutenant Colonel Langlais and consisting of the 1st Foreign Legion Paratroop Battalion (1st BEP), 8th BPC, and the 5th Vietnamese Paratroop Battalion (5th BPVN). Support troops and an air liaison team rounded out the 4,560 man force which was soon joined by 700 members of the 1st T'ai Partisan Mobile Group (GMPT 1), a local guerrilla unit.

French Command

To allow him to resume his post as commander of all airborne forces in Indochina, Gen. Gilles was relieved as commander of Dien Bien Phu in early December. His successor was Colonel Christian Marie Ferdinand de la Croix de Castries, a cavalryman who personified the mobile spirit expected of the new airhead. As envisioned by Gen. Navarre, Dien Bien Phu was not to be a static hedgehog, but rather a jumping-off point for offensive operations against the Viet-Minh. Dien Bien Phu would also establish a land link with French forces in northern Laos and would provide support for Lai Chau, another airhead, until its eventual evacuation.

That the new base might attract enemy attention was considered no problem and Gen. Navarre seemed to seek such a confrontation. If necessary, Dien Bien Phu could act as an independent fortress with more troops and continuous air support.

The wisdom of this plan was questioned, however, by Major General Rene Cogny, Commanding General of the Ground Forces in North Viet Nam, and the man responsible for operations at Dien Bien Phu. He felt Dien Bien Phu should simply be a "mooring point" or resupply area for tribal guerrilla units that were to disrupt the Viet-Minh's rear areas. Aware of the limited troops and airplanes available and the high priority of other operations, Gen. Cogny warned that a sizeable immobile force could be imprisoned in such a remote area and stand little chance for escape or support.

These misgivings were apparently not heeded by Gen. Navarre even when he received the unexpected information that at least four of the enemy's divisions, including the 351st Heavy Division, were advancing on the lightly defended position at Dien Bien Phu. The 5,000-man garrison was then ordered to engage in two competing miasions. First, "at least one half of its strength" was to mount offensive operations designed to inflict heavy losses on the enemy and to delay his laying a siege ring around the valley. They were also to maintain a link-up with French-Laotian forces to the west.

Second, the defenses around the airfield were to be strengthened so as to allow its "free use." This meant security within a radius of five miles around the airfield and defense of a roughly circular area with a perimeter of thirty-one miles. Experience had shown that a 700- man battalion could hold at most a line of 1,500 yards. The valley of Dien Bien Phu demanded thirty-six battalions for its defense, but only six were already in position.

Thus, the garrison at Dien Bien Phu was expected to operate both offensively and defensively from a position they could not easily leave nor adequately defend. By early December, Gen. Navarre had foreswom the option of evacuating the troops at Dien Bien Phu and looked instead for them to entice the Viet-Minh into a massive set-piece battle. It was a gamble, but Navarre was sure he would be the winner.

French Preparation

The next several weeks saw the attempted enactment of Gen. Navarre's orders and expectations. The paratroopers and engineers repaired the airfield and cleared away vegetation from possible fields of fire. Bunkers and trenches were begun, though with no especial hurry as the soldiers were as yet unaware of the approaching Viet-Minh columns. Forewarned by Saigon, Col. de Casties ordered all positions to be fortified to resist artillery shells of 105-mm caliber. More engineers were required, and by late December, the entire 31st Engineer Battalion was airlifted into the valley. Their commander calculated that to adequately fortify Dien Bien Phu for its proposed garrison of ten infantry and two artillery battalions, he needed 36,000 tons of materials.

From the villages and surrounding areas only 2,200 tons of construction wood could be found. The remaining 33,800 tons of construction materials would have to be airlifted, requiring 12,000 flights of C-47 aircraft, the standard transport of the French Air Force in Indochina. Relying on the daily deployment of eighty aircraft to Dien Bien Phu (the maximum number of transport aircraft available) and assuming nothing else but engineering materials were carried, five months would be required to turn Dien Bien Phu into a defensible fortress.

However, Gen. Cogny in Hanoi and Col. de Castries on the scene decided that permanent fortifications would not be necessary due to the offensive operations then in progress. The requirement of ten infantry battalions was also scaled down because of manpower needs in other areas of Indochina. The allocation of air transport of engineering materials was officially cut to 4,000 tons, mostly perforated steel plate (PSP) for the airfield and barbed wire.

The engineers started work to protect the headquarters command post, the signal center, and the underground hospital. Materials were not available for any other positions, so they were made of earth, sandbags, and wood scraps. Connecting trenches, basic to any large defensive position, were begun between some positions, but could not be completed because of the shortage of men and materials.

Some peripheral positions were protected by conventional minefields, including electrically detonated "bouncing mines," and "nagel" (jellied napalm stored in ten-gallon drums dug into the steeper hillsides that could be command detonated). The engineers also built roads and bridges to connect the various positions and dirt revetments to shelter the six light observation aircraft and a flight of F8F "Bearcat" fighter-bombers which were to operate from the airfield.

The individual strongpoints were organized into three subsectors although each position developed a personality of its own due to the multiplicity of races and units that made up the French Union forces at Dien Bien Phu. Each major position was designated by a distinctive codename. To the north, T'ai tribesmen and mortar crews at Anne-Marie guarded the Pavie Track, a narrow jungle trail, while the heights of Gabrielle were ably prepared by soldiers of the 7th Algerian Rifle Regiment.

The central subsector straddled the Nam Yum River and included the command headquarters, the main depots and artillery batteries, and the hospital. On the west, Foreign Legionnaires defended the Pavie Track and the airfield from Huguette. They were flanked to the south by other Legionnaire and T'ai units at Claudine and the tiny post of Francoise. Although these positions sat behind a barbed wire minefield, they lacked connecting trenches and were exposed to enemy observation and fire from nearby hills. To the east lay Eliane, a small hill garrisoned at various times by French and Vietnamese paratroopers, T'ai auxiliaries, and Moroccans.

Strongpoint Dominique was an important artillery observation post because it towered above the valley floor and other hills. However, no barbed wire entanglements or minefields guarded its eastern approaches which were covered with low underbrush. It was expected (hoped?) that the Algerians and mortar crews of Dominique would be protected by neighboring strongpoints. The final central position was Beatrice, really a satellite post charged with denying Provincial Road 41 to the Viet-Minh.

At right, American-built M24 light tank fords a stream during operations in 1953. The components for ten such tanks were flown into Dien Bien Phu and reassembled there to form the backbone of the counterattack force.

Isabelle was the third subsector and almost a fortress in itself with its own artillery and tanks. But its main positions were constructed in the middle of a swamp and the "fortress" was only 2,000 feet long at its widest point. The Foreign Legion and Algerian battalions, plus the T'ai auxiliary companies of the stronghold Wieme, were never to be subjected to the repeated mass attacks that assaulted the main garrison, but they were pulverized by ceaseless enemy artillery fire which they had to suffer alone when even tanks and artillery could not keep open the road to the north.

French Firepower

To provide the overwhelming firepower that was expected to smash any attack by the Viet-Minh, more artillery was airlifted into the valley. Six batteries of four American 105-mm howitzers each were installed, along with a battery of four 155-mm howitzers, the largest field pieces available in Indochina. Three heavy mortar companies equipped with French 120-mm (4.2-inch) mortars were to provide the plunging fire needed to destroy enemy entrenchments. Also dug in were four quadruple mounts of .50-caliber machine guns, the famed "quad-fifties" that had been so effective in hacking to pieces Communist infantry in Korea. All of the artillery came under the command of Colonel Piroth, the deputy commander of Dien Bien Phu. He felt so confident that his artillery could destroy any guns that the Viet-Minh might somehow drag near the valley that in January, 1954, when a visiting French cabinet minister offered him more field pieces, Col. Piroth rejected the offer, saying he had more artillery than he could handle.

The fighting mobility of the growing garrison was centered around a light squadron of M-24 "General Chaffee" tanks. Ten of the eighteen-ton vehicles were flown in dismantled and assembled by mechanics at Dien Bien Phu. By mid-January, 1954, they were all operational and organized into three platoons, two of which remained at the main fortress while the third was assigned to Isabelle. The "Bisons," as they were known to the troops, came to be one of the most effective weapons for the defense of the garrison.

As the fortification of Dien Bien Phu continued, the airborne battalions began the reconnaissances-in-force aimed at gathering intelligence and denying the enemy access to the4 fortress. As soon as they ventured forth from their fortifications, however, the paratroopers ran into Communist ambushes. In early December, the 1st BPC and elements of the II/1 RCP advanced along Road 41, three miles from the center of Dien Bien Phu.

Ambush

Suddenly, in a narrow valley overshadowed by 1,200-foot hills, the column was enveloped by mortar and grenade-launcher fire that destroyed the lead platoon. The rest of the force quickly formed a hedgehog and with the help of artillery fire laid down by the main garrison's howitzers beat back the screaming waves of Viet-Minh infantrymen emerging from the thick foliage. The task force returned to its garrison burdened with fourteen dead and the knowledge that Dien Bien Phu was within range of a major Viet-Minh combat unit.

Just as the reconnaissances-in-force were shown to be hazardous undertakings, so did it become apparent that another responsibility of the fortress could not be easily fulfilled. The air-land base at Lai Chau began evacuation in December in the face of growing Viet-Minh activity. French aircraft removed local leaders and some military units, leaving twenty T'ai Irregular Light Companies to march overland to friendly bases, including Dien Bien Phu, some sixty roadless jungle miles to the south. The T'ai companies were harassed by Viet-Minh regulars, and the entire GAP 2 under Lt. Col. Langlais was ordered to link-up with the embattled tribesmen at Muong Pon. GAP 2 was subjected to ambushes along its entire route, causing delay and casualties.

Despite being aided by artillery fire and B-26 bombers, the French rescue force arrived at Muong Pon to find the T'ai companies there had been wiped out. In its return to Dien Bien Phu, GAP 2 suffered more casualties from Communist attacks and snipers.

The losses from this and other long-range operations forced the restriction of the reconnaissance missions to the immediate areas of the Dien Bien Phu valley. Some of the initial airborne units, notably the 6th BPC and II/1 RCP, had also been returned to the airborne reserve at Hanoi and were replaced by formations of Foreign Legionnaires and non-European troops, none of which were as experienced in independent sorties. Another reason for shorter patrols was to combat the increasing numbers of Viet-Minh around the French garrison.

Artillery Attack

On January 31, for the first time, 75-mm pack howitzers and 105-mm howitzers manned by Communist gunners of the 45th Artillery Regiment bombarded the Dien Bien Phu airstrip and strongpoints Eliane and Dominique. Transport aircraft and fighter-bombers over Dien Bien Phu also came under unexpected fire from the antiaircraft artillery of the 367th Flak Regiment. By only being able to fortify the valley floor around the airstrip, the French had allowed the Viet-Minh to develop positions along the hills which gave the Communist gunners excellent observation for their artillery.

The concentration of artillery seemed to indicate that a major Viet-Minh attack was imminent, but none materialized in February, much to the consternation of Col. de Castries and Gen. Navarre. Both men feared that the Viet-Minh would not attack Dien Bien Phu head-on, thereby denying the French the massive confrontation they felt sure they could win. In retrospect, their desire for such a confrontation is hard to comprehend. By mid-February, ten percent of the French forces available in the valley had been lost to hostile fire. No major replacements were sent, and to conserve manpower Gen. Cogay had ordered that future attacks be limited to "light reconnaissances" using "restricted amounts of personnel."

Moreover, the supplies to Dien Bien Phu were curtailed because of increasing Viet-Minh activity in Laos. This meant that artillery ammunition had to be conserved to such an extent that offensive actions by the French Union forces had no guarantee of artillery support. Nor could the French artillery silence the Viet-Minh howitzers and flak that continued to destroy emplacements, airplanes, and men. From early February until mid-March, French assault groups were deployed to destroy the Communist artillery which had proven invulnerable to counterbattery fire and tactical aircraft. While some Viet-Minh batteries were eliminated, the growing volume of artillery fire on the airfield and surrounding strongpoints showed that the Viet-Minh guns were not being reduced in number or accuracy.

The reason for this remarkable build-up by the Viet-Minh was due to the inability of the French to interdict their overland travel via jungle trails. Since ground operations had proven so ineffectual and disastrous for the French, they turned to airpower to destroy the Communist forces and supply lines converging on Dien Bien Phu. The Air Force of the Northern Command could deploy a maximum of seventy-five operational aircraft, mostly fighters and fighter-bombers, while the French Navy flew fighters and dive-bombers from offshore aircraft carriers and six heavy "Privateer" (B-24) bombers.

To destroy the Viet-Minh communications lines leading from the Chinese border at Mu Nam Quan over Provincial Road 13-B to the Red River and then along Provincial Road 41 to Dien Bien Phu, the combined French air elements used strafing, napalm, delayed-action bombs, and American-made "Lazy Dog" anti-personnel bombs. Still, the Communist supply routes remained open, largely due to the discipline of the coolies and road engineers who maintained and camouflaged the roads and built new trails when necessary and because of the murderous fire of the flak positions along the roads. Often every aircraft returning from a combat sortie would show flak damage, and the transport planes flying into Dien Bien Phu were subjected to increased antiaircraft fire, causing losses in aircraft and crews. When the casualties became prohibitive, the French diverted bombers to flak-suppressing missions, but the Viet-Minh supply columns, with a few Soviet-made trucks and thousands of hand-pushed bicycles, pack animals, and human carriers, continued to deliver the food and ammunition their soldiers needed.

By mid-March at Dien Bien Phu, the Viet Nam People's Army numbered 49,500 combat troops, with 31,500 logistical and support personnel. Another 23,000 Communist support troops and coolies were active along the communication lines. On the French side, by March 13, there was a total of 13,200 men in the valley, of whom about 6,800 could be considered front-line troops.

Viet-Minh Superiority

The Viet-Minh thus enjoyed a superiority in manpower of five-to-one over the French. In all modern armies, a three-to-one superiority is usually considered sufficient to achieve a victory in an infantry assault. Moreover, the Viet-Minh units deployed at Dien Bien Phu were almost all made up of experienced veterans. They included three full infantry divisions, the 308th, 312th, and 316th, plus elements of the 304th Division and the entire 148th Independent Regiment. Most of the Viet-Minh gunners had been trained in Communist China and then organized in a single artillery unit, the 351st Heavy Division (Reinforced), to concentrate their skill and firepower.

Including the guns of the 351st Heavy Division and those of the other Communist units, French intelligence sources estimated that the Viet-Minh finally fielded at Dien Bien Phu at least forty-eight pack howitzers of 75-mm caliber, forty-eight field howitzers of 105-mm caliber, forty-eight heavy 120-mm mortars, probably forty 75-mm recoiless rifles, and thirty-six heavy flak guns. In all, the Viet-Minh could count on a minimum of 200 guns above the 57-mm caliber, while the French never had more than sixty such guns, leaving them with a four-to-one inferiority in artillery firepower.

The Viet-Minh also had sizeable concentrations of 37-mm antiaircraft artillery guns of Communist manufacture, numerous .50 caliber heavy machine guns, and, in early May, Soviet-built "Katyusha" multitube rocket launchers. All of this material was dismantled and carried over jungle trails and roadless mountains, often under French air attack. Once at Dien Bien Phu, the artillery was reassembled and then positioned in strongly-built camouflaged emplacements. In the case of the howitzers, they were often dug in on the slopes of the hills facing the French, contrary to standard practice which called for the guns to be on the reverse slopes. The forward positions gave the Communist gunners accurate coverage of the French fortifications and airfield. In the coming weeks, the French were to lose more men to artillery fire than were killed and wounded by infantry weapons.

More Dien Bien Phu

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© Copyright 1973 by Dana Lombardy
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