According to the Wikipedia page of the M-24 Chaffee, ten of these tanks were sent to the french forces in Dien Bien Phu, where they provide "fire support".
Considering the French were outgunned by the artillery the Viet Minh was able to provide through jungle, why the M-24 were not used along the French elite infantry (like airborne forces or Foreign legion) to mount raids against the artillery positions?
The French aviation might even had supported these attacks with previous bombings.
Question:
Why the M24 Chaffee was not used as a tank at Dien Bien phu?
Answer:
The M24 Chaffee was used as a tank at Dien Bien Phu. They were critical in giving fire support to the French infantry in repulsing the many Viet Minh attacks over two month battle.
The Battle of Dien Bien Phu
The French deployed a small number of M24 Chaffee light tanks during the battle that proved critical in repelling the enemy's many attacks. With the exception of using heavy artillery and rocket-propelled grenade launchers (RPGs), the Viet Minh could not effectively fight back against the French armour, ensuring their use throughout the battle/seige.
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Question:
Why the M-24 were not used along the French elite infantry (like airborne forces or Foreign legion) to mount raids against the artillery positions?The French aviation might even had supported these attacks with previous bombings.
The French infantry was heavily outnumbered in the Battle at Dien Bien Phu (more than 3-1) and could not have been expected to penetrate up to 7-17 miles behind Viet Min lines, against an entrenched enemy, while navigating a jungle and climbing mountains to engage the Viet Min field artillery.
Viet Min Artillery included:
The tanks did somewhat offset the numerical superiority during the two month battle, however the lite tanks were designed for mobility and could not penetrate the heavily wooded jungle which surrounded the French base, nor could they climb the mountains to support an assault against the Viet Mihn artillery placements with surrounded and looked down on the French base.
Background
The major flaw in the French battle plan was their over reliance on air to defend and resupply their base. The French mistakenly believed the Viet Mihn had no anti aircraft guns. When the Viet Mihn guns appeared it made adequate resupply of the base impossible. Despite the fact the French were loosing more troops than they could replace through air resupply the French continued to send in re-enforcements. Likewise the inefficiency of the air resupply strategy proved detrimental to maintaining French fire power, supply, and moral.
To your question, They french were able to fly in their 10 M24 Chaffee tanks. Each of which were broken down into 180 individual parts, flown into the base, and then re-assembled.
The Americans who replaced the French after their withdrawal faced their own Dien Bien Phu predicament at the siege of Khe Sanh, 21 Jan - 6 Apr 1968. A siege ultimately broken by the Americans after 4 months. Instrumental in the Americans ability to resupply it's two Marine Regiments surrounded by 3 divisions of North Vietnamese, was a more capable air force and the helicopter. Both allowed the United States forces to maintain themselves over the siege until a relief column could reach the base after 4 months.
I had a friend who toured Khe Sanh a few years ago, and at one point his guide reached down and picked up a handful of dirt, lit a match and set it on fire. The US had dropped so much munitions around Khe Sanh that even to this day the soil still burns.
Sources:
To the extent that any tactic remotely associated with the French at Dien bien phu could be said to be not entirely stupid or insane, the French employment of the the Chaffees would be a good candidate. Fire support is what tanks do. If you're creating a fortress with the intention of drawing your enemy into the open where you can destroy him with fire then having armoured, tracked machines which can carry cannon and machine guns and thus be relatively less vulnerable to suppressing fire and using them in local counter-attacks would be helpful. Having a full regiment of tanks would have been more helpful, assuming that we can magic away the logistics of bringing them in (you may recall the French needed to disassemble the Chaffees just to fly them in) and supplying and maintaining them.
A study of the ground, both via maps and contemporary photographs, will show that the Viet Minh positions were primarily in the surrounding hillsides, which were forested. The VM artillery was rather quite well concealed and protected. They studied techniques employed to great effect by the Japanese in the second world war.
An attack, uphill, in fairly well vegetated ground, by just 10 tanks, would have been unlikely to achieve much. Armour needs to co-operate with other arms, especially infantry. The French would have needed to attach at least one or two battalions of their already small reserve, which would have probably gotten pinned down by the VM artillery, surrounded, then destroyed by the VM, which had about twice as much infantry as the French. It would be quite probable that the Viet Minh would have used 'Death Volunteer' sappers in their close-in attacks on the tanks themselves.
The French air force was hard pressed enough to carry out its attempts to bombard Viet Minh positions and to re-supply the garrison. It would not have had any extra capacity to co-operate with such a proposed operation. I don't think that the 1954 U.S.A.F. had much capability that would be similar to that of the Second Indochina war's Arc-light so assuming an alternate universe in which the Yanks help openly like that is rapidly a topic for the SF stack exchange site.
The French did use armour in the First Indochina war, often as part of battle groups called Groupement Mobile. In the Second Indochina war, the Free world forces (Americans, ARVN, and Australians among others) and the North Vietnamese used tanks. There was a famous small tank battle in 1969 and the 1972 and 1975 offensives saw the NVA use armour extensively.
Martin Windrow's The last valley might be an informative read. Simon Dunstan's Vietnam tracks has a chapter on armour in the First Indochina war. It has a fair number of photographs which are interesting.
Answer here:
The competence of the Viet Minh staff work would have been sufficient to plan for predicted fire missions on the French outposts and forming up positions and for hitting any force as it made its way to a hill. There would have been some field telephones in the VM trenches and they could use flares and runners if need be. The co-ordination would not be very good - perhaps Great war Hill 70 level – but would you want to be there?
If the attack takes place during the day the observation of the forming up of the French attacking force could be made from the hills as well as from the VM trenches. Spotting of shot would be from there as well. Tanks are noisy and the assembly of them would be a signal that they were going into action and the direction of attack. This holds true for day and night.
If the attack would take place at night there could be no co-ordination with the French air force as they didn't fly at night. The spotting of the VM artillery would be more difficult but stuff like star shell and WP are useful for this sort of situation.
You will recall that it is several hundred metres between the French outposts and the hill sides and it is mostly cultivated ground, without tree cover. During the siege the VM were busy building saps and a rather significant force of VM infantry could be assembled to close action. I would not put it past the VM to infiltrate men behind the main body of the attacking force and their start line. Assuming that any significant French force got to a hill side, it would then need to climb the hill under fire and then try to storm and destroy the dug-in artillery positions. As mentioned, the VM learnt from the Japanese about how to dig in artillery so just finding the dang things, let alone destroying them would be difficult. Then the French would need to try to do that for all of the rest of them.
And you do understand that Chaffees were light tanks for recce don't you?
What actual study of the matter have you made and what are your findings?
