Meta Description: Discover the reasons behind the impenetrability of aircraft carriers to ground-penetrating bombs. Explore the physics, design considerations, and damage control measures that make it difficult for these bombs to penetrate these naval giants directly.
1. The Functioning of Ground-Penetrating Bombs
Many enthusiasts who raise this question have limited knowledge about the combat capabilities of ground-penetrating bombs. Their understanding often revolves around the depth to which these bombs can penetrate the ground and explode. However, the true nature of ground-penetrating bombs extends beyond mere surface-level information.
2. How Ground-Penetrating Bombs Operate
Ordinarily, ground-penetrating bombs are deployed by carrier aircraft from high altitudes. To comprehend their functioning, we must consider the bomb’s energy during the release process, including its potential energy and the initial kinetic energy acquired from the carrier aircraft’s flight speed upon delivery.
For instance, let’s examine the GUB-57A/B. Typically dropped by a B-52 or B-2 bomber from an altitude of 20,000 meters, this ground-penetrating bomb carries significant kinetic energy due to its flight alongside the carrier aircraft.
By applying the kinetic energy formula, we can calculate the B-52’s cruising speed at 480 km/h, allowing it to cover approximately 133 meters in just one second. The resulting calculation yields a kinetic energy of 120,959,940 joules (J) for the bomb.
Thus, the bomb’s final mechanical energy amounts to 2.78812794 x 10^9 joules. However, it is worth noting that the kinetic energy imparted by the aircraft is negligible when considering the total mechanical energy.
Converting this energy into TNT equivalent, each ton of TNT can release 4.184 megajoules of energy. Therefore, the mechanical energy contained in the bomb when it is deployed is equivalent to the energy released by detonating 666.3 tons of TNT explosives—an astounding manifestation of fundamental physics.
Nevertheless, during the bomb’s descent, initial mechanical energy is depleted due to air resistance and other factors. Accounting for air resistance, the bomb’s mechanical energy upon impact with the ground is estimated to be around 427 tons of TNT equivalent.
3. The Challenge of Directly Blowing Through the Ground
Some individuals wonder why not load ground-penetrating bombs with more explosives to facilitate direct penetration. However, achieving the objective of blowing through the ground necessitates meticulous energy transfer and concentration.
While increasing the explosive charge can enhance the bomb’s energy, several factors must be considered, such as the distribution of explosives and the precise direction and location of the explosion. These considerations are crucial for effectively transferring energy to the ground and concentrating it at a specific point.
It is essential to note that the primary design purpose of ground-penetrating bombs is to reach and destroy underground structures rather than causing direct ground explosions.
For instance, to create a direct 60-meter-deep hole on the ground, a nuclear bomb with a TNT equivalent of approximately 300,000 tons would be required. Only a surface explosion of this magnitude can achieve such penetration, albeit resulting in a crater with a diameter of roughly 260 meters.
Distinguishing mechanical energy (kinetic energy) from explosive energy lies in their respective directionalities. Mechanical energy pertains to an object’s energy due to its velocity, possessing definite directionality. On the other hand, explosion energy spreads in all directions through shock waves and heat energy.
The primary goal of ground-penetrating bombs is to penetrate underground structures rather than cause direct ground explosions.
These bombs employ various design measures, including special shapes, dense materials, and reinforced structures, to enhance penetration and destructive power. Their blast energy predominantly damages subsurface targets by utilizing shock waves and concussion effects.
4. The Penetrator Head: A Vital Component
Ground-penetrating bombs possess a flattened cylindrical punch at their head. When these bombs strike the ground, the punch compresses and expels loose dirt, rocks, and cement debris sideways.
This process creates space for the bomb to advance underground—an action akin to a punching machine that creates holes in metal parts. This “punching” operation’s efficacy depends on the material’s modulus.
Typically, the punching modulus of soils ranges from 1 to 10 MPa, with 1 MPa representing an average value for basic soil. In contrast, the modulus of steel ranges from hundreds of megapascals to even gigapascals.
By employing ground-penetrating bombs to puncture an aircraft carrier’s deck, it is feasible to penetrate around 4-5 layers. However, achieving such penetration is undoubtedly more challenging than penetrating the ground.
5. Damage Control Measures and Attack Density
One might argue that drilling inside an aircraft carrier and detonating 2 tons of explosives would cause fatal damage. However, this perspective fails to consider the warships’ damage control measures.
Warships comprise numerous watertight compartments, enabling isolation of damages incurred in specific directions by closing the corresponding compartments.
Throughout history, multiple decks of aircraft carriers have been pierced, yet these naval giants have withstood internal explosions by implementing damage control measures and effectively isolating the affected areas.
Saturating an aircraft carrier’s defenses and ultimately sinking it necessitates an exceptionally intensive attack. Therefore, the core challenge lies in achieving the required attack density.
It becomes arduous for large bombers carrying substantial ground-penetrating bombs to approach the aircraft carrier with sufficient density to drop the bombs.
Furthermore, if one’s own aircraft can fly over the opponent’s aircraft carrier, it signifies that the opponent’s carrier has already lost its combat effectiveness. In such scenarios, most individuals would retrieve and salvage the carrier rather than leave it bombed and sunk.