At dawn, the mist had not yet lifted, and the engineers of the 32nd Division had already begun their busy day. Chen Qianming, commander of the engineer company, stood alone beside the newly built shelter department, inspecting the war-torn war zone. The Vietnamese army's 160 mortar shells, a new type of weapon, had already been shown in the previous day's attack – they could burrow into the ground two meters before exploding, and the destructive power was enough to terrify anyone.
Such shells are a great challenge for traditional defensive measures. The existing trenches and shelters were extremely vulnerable to such an attack, and many of them had been severely damaged or even collapsed after repeated shelling. Chen Qianming knew that if a solution could not be found quickly, the lives of the soldiers would be at great risk. Before his eyes was a new attempt - a kind of defense project called "steel plate roof".
1. Defense handover and reconstruction
The task of the 32nd Division to succeed the 14th Division of the 40th Army was particularly important both strategically and tactically. In the context of the complex battlefield, the early battle of the 40th Division was mainly offensive, but the continuous heavy rain and the continuous collapse of the original fortifications made their defensive deployment extremely fragile. Under these circumstances, the task of the 32 Division to take over the positions became more urgent and difficult.
During the takeover, the 32nd Division was confronted with a series of collapsed trenches and cat's ear holes, which were once shelters for soldiers and were now dangerous ruins. The damage to the position was severe, which not only affected the immediate defense capability, but also posed a threat to the morale and safety of the soldiers. Under these circumstances, the 32nd Division had to immediately begin large-scale reconstruction and reinforcement work to repair and improve the solidity and functionality of the defenses.
During the reconstruction work, the 32nd Division first conducted a thorough assessment of the existing trenches and cat's ear holes. Considering the continuous rainy season and the softness of the ground, the division decided to repair these fortifications by means of reinforcement. Deploying a large number of engineers and equipment, they began to dig deeper and wider trenches, and set up reinforced wooden piles and sandbags at the edges of the trenches.
The new trench design is more complex to adapt to changing battlefield needs. Not only did the depth and width of these trenches increase, but a number of communication trenches were specially added so that soldiers could move quickly and safely to different combat positions during the battle. In addition, in order to enhance the survivability of soldiers under enemy fire, the 32nd Division also specially designed a number of new shelters. These shelters are stronger than before and are able to withstand stronger shelling and blast impacts.
On the basis of the trenches and shelters, the 32nd Division also focused on the construction of new cat's ear holes. These cat ear piercings are designed to go deeper underground for better protection. Their entrances are cleverly designed to reduce the threat of direct explosions, and are equipped with blast doors and ventilation systems to ensure internal air circulation and a living environment for soldiers.
2. Heavy artillery shelling by the Vietnamese army
Since November 17, the 32nd Company of the 3rd Battalion of the 96th Regiment of the 96th Division has encountered great challenges in the defensive tasks it undertook. The areas they were assigned to defend included key highland locations: 142, 145, and 146, which were strategically important but therefore the focus of Vietnamese attacks.
As the Vietnamese offensive intensified, these heights came under frequent and intensive shelling. The 160 mortars used by the Vietnamese army, especially those equipped with delayed fuses, are designed to be able to explode after reaching a depth of about 2 meters into the ground, and this tactic of deep burial and explosion greatly increases the destructive power of underground facilities. Whenever a shell hits the ground, its explosive force penetrates deep into the ground, causing serious structural damage to the defense tunnel system.
In response to this new threat, the 7th Company had to adjust its defensive strategy and fortifications. Under constant artillery fire, the company's soldiers and engineers had to move quickly, repair the damaged tunnels, and strengthen their structures to withstand more shelling. Not only do these tunnels provide shelter for soldiers, but they also have to ensure smooth communication and chain of command, so every repair is critical.
Engineers quickly dispatched between artillery fires, using sandbags, planks and clods of earth to quickly block the entrance to the blasted tunnel while checking the strength of the support structure. In some severely damaged areas, they had to carry out deeper excavations and reinforcements. These tasks were often carried out under the cover of enemy fire, and soldiers needed to complete their tasks quickly while remaining alert.
At the same time, the commanders are also closely monitoring the firepower deployment of the Vietnamese army, and maintain contact with superiors and adjacent units through radio to transmit battlefield information and adjust defensive measures in a timely manner. This high-pressure and high-stakes environment requires every soldier to demonstrate extraordinary endurance and determination.
3. Engineering reinforcement and innovative measures
Faced with the severe challenge of the Vietnamese artillery bombardment, the engineer contingent of the 32nd Division was quickly mobilized and carried out a series of urgent and systematic reinforcement measures. Company Commander Chen Qianming played a key role in this process, not only as a commander, but also as a technical advisor, ensuring that every task was executed accurately to deal with the immediate threat of enemy artillery fire.
Under the guidance of Chen Qianming, the mechanical company of the engineer battalion began to adopt a new strategy of quickly building a field shelter. They chose I-beam steel plates as the main material, which was considered ideal for building a bullet shield due to its high strength and load-bearing capacity. The I-beam plate is not only able to withstand a direct blow from above, but also effectively disperses the force of the explosion and reduces direct damage.
The decision to adopt I-beams was based on a series of on-site assessments and quantity calculations. The engineering team first carried out a detailed inspection of the existing shelter, analysing the stability of the structure and possible weak links. They then calculated the number and size of the required plates, as well as how to quickly install them without compromising the use of the shelter. These calculations not only focus on the need for materials, but also carefully consider the rational allocation of human resources to ensure that the construction team can complete the reinforcement task in the shortest possible time.
After the construction began, the sappers quickly transported the I-beams to the designated shelter. At each selected location, they use specialized equipment to precisely mount the steel plates on top of the shelter or at important support points. These plates are installed in a multi-layer structure, and each layer is firmly connected to each other by special joints and welding techniques to increase the overall stability and durability.
After the I-plates were installed in place, the sappers further covered them with a thick layer of soil and sandbags. The purpose of this is to add an additional layer of cushioning to absorb and disperse the shock wave due to the explosion of the mortar shell. The mulching of soil and sandbags not only enhances the protective capabilities of the shelter, but also helps the shelter better integrate into the surrounding environment, reducing the risk of being directly targeted by the enemy.
4. Implement the "steel plate cover" technology
After completing the laying of the I-beams, Company Commander Chen Qianming organized the sappers to begin to implement the next important reinforcement measure - covering the protective layer. They used a large number of earth-filled sacks, which were carefully stacked on top of the steel plates to form a layer at least one meter thick. This construction not only improves the overall robustness of the structure, but also increases the absorption capacity of the blast wave.
During the operation, the sappers systematically stacked sacks filled with earth and stones layer by layer. Each sack is tightly packed and ensured with no gaps to prevent any direct penetration. Not only do these sacks provide additional mass to resist the force of the explosion, but their flexible material and internal earth and stone are also ideal shock wave absorbing media. With such a layout, even in the case of a direct hit by a shell, the upper layer of earth and stone sacks can effectively disperse and absorb part of the impact force, reducing the burden on the lower structure.
In addition, Chen Qianming also paid special attention to the uniformity and thickness of the overburden. The sappers were instructed to ensure that the sacks on each plate were of the same thickness in case of weakness. In key areas, such as areas where more frequent or heavy artillery fire is expected, they have even added additional layers of sacks to provide more enhanced protection.
As the last layer of the sack was laid, the appearance of the entire shelter changed significantly. This new perimeter not only makes the shelter stronger, but also allows it to better blend in with the surrounding natural environment, reducing the likelihood of being detected by enemy reconnaissance. The sappers made sure that all sacks and earth and rocks were properly secured to prevent displacement by shaking or other external forces in the heat of battle.
When the Vietnamese shells finally hit these cleverly reinforced shelters, the effect was immediate. The shell exploded the moment it touched the steel plate, and the huge blast wave was strongly absorbed and dispersed by the upper layer of earth and stone sacks after penetrating the steel plate. This double-layer protective structure effectively reduces the damage to the internal structure of the tunnel by direct impact force, thereby significantly improving the overall safety of the tunnel and shelter.
This technology, known as the "steel plate cover", not only provides soldiers with safer protective measures, but also reflects the innovative thinking and practical operation ability of the 32nd Division in dealing with high-intensity battlefield challenges. Through these consistent construction and reinforcement work, the soldiers were able to be more effectively protected in the face of heavy artillery fire and continue to carry out their defensive tasks while maintaining combat effectiveness and morale.
5. Combat testing of fortifications
With the widespread implementation of the "steel plate roof" technology, the 32nd Division's shelters and tunnels have been significantly reinforced. Each time the Vietnamese launched an artillery bombardment, although the momentum was huge, when the shells hit the reinforced shelter, its destructive power was greatly reduced. The fortifications were not only effective against direct hits from shells, but also protected soldiers from the direct impact of the shock wave after the explosion. These shelters served as fortified fortresses on the battlefield, providing soldiers with a relatively safe environment in which they could remain able to fight and survive under artillery fire.
In the ever-changing battlefield environment, this rapid adaptation and technological innovation of the 32nd Division has demonstrated its superior tactical flexibility. This flexibility is not limited to the use of technology or materials, but also reflects the ability to respond quickly to battlefield situations and adjust tactics. The commanders and engineer units of the 32nd Division are able to quickly adjust the defensive structure and tactical layout according to the immediate needs of the battlefield, ensuring that each adjustment maximizes the defensive effect and the safety of soldiers.
Other units also began to imitate and adopt this method as an important means of improving their own defense capabilities. The successful application of this technology has improved the defense capability of the entire division, enabling it to more firmly and effectively protect the lives of soldiers in the face of increasingly complex battlefield challenges.
Pan Kaien.Return to the Historical Scene——The 35th Anniversary of the Self-Defense Counterattack War against Vietnam[J].Social Observation,2014(3):75-77