It's better to conquer them than to command the steel torrent

Chapter 219 | Prototype Car
"...Especially to address the problem of poor heat dissipation, the No. 3 prototype vehicle enlarged the ventilation openings, and the (engine) operating temperature became very stable."

Xu Zhiyuan, the chief designer of Hualian Industrial's 175 Project, perfectly embodied the stereotypical image of a middle-aged engineer. He briefly explained the key improvements of the prototype vehicle to the officers present.

Did Huaxia United Industrial Group really produce such a car in 1940? And did they not encounter any technical difficulties that needed to be overcome?
The process went so smoothly that even Shank found it unbelievable.

The prototype vehicle in front of us has a rugged design, with a predominantly straight-line silhouette and a large, centrally mounted turret. Its key technical and tactical specifications are:
Empty weight -29.8 tons

Members - 5 people

Power - 350 horsepower V12 gasoline engine

Top speed: 45 km/h on road, 22 km/h off-road
Running gear - 6 pairs of road wheels, torsion bar suspension, 450 mm wide tracks
Turret rotation speed -23 degrees/second

Armament: 75mm 42-caliber tank cannon, 3 x 7.36mm machine guns
Armor penetration depth - 1000 meters, 106 mm vertical steel plate
[Room allocation weight: 4.3]

The vehicle's protective capabilities are what Shank is most concerned about; its firepower is not a concern.

Given the turret's size, as long as a long-barreled gun can be inserted, the firepower won't be too bad. The best indicator of the difference between good and bad design is the ability to protect the turret.

In terms of frontal protection, this vehicle achieves a considerable level of effectiveness.

Frontal view of the vehicle body -55 mm -55 degree angle
Turret front - 70mm - 15-degree angle
Side profile of vehicle body - 40 mm - 0 degree vertical tilt
Turret side - 55mm - vertical 0-degree inclination
In short, it's passable, but the other aspects are a bit weak.

The technical and tactical specifications given by the Equipment Bureau clearly required that the sides of the medium-sized tank be immune to attacks from Russian-made anti-tank rifles; however, Hualian Industrial's work... was somewhat of a stretch.

In his previous life, as a student at Nanjing University of Science and Technology, Shang Ke had a deep impression of this annoying thing, and could recite its key parameters by heart.

It is well known that the Russian-made 14.5mm bullet is notorious for its terrifying kinetic energy and excellent penetrating power. The 14.5mm bullet was one of the direct reasons for the significant increase in the weight of NATO armored vehicles during the Cold War.

The development of the 14.5×114mm machine gun bullet is quite interesting. It was initially designed for use in anti-aircraft machine guns because the military believed that the 12.7mm bullet was insufficient to deal with increasingly faster aircraft, so they requested the development of bullets with higher muzzle velocities, and the 14.5mm bullet was born.

Simply put, it's like mounting a 14.5mm projectile on the cartridge case of a 20mm artillery shell, achieving an initial velocity of 1010 m/s. Although initially conceived for use against aircraft, the military quickly discovered that it was well-suited for attacking tanks because of its small diameter, high kinetic energy, and extremely strong penetration capability. This concept is similar to the steel needle—also known as an armor-piercing discarding sabot projectile.

Russian-made 14.5mm bullets come in various types, and even the most common (copper-plated steel) steel-core armor-piercing bullet can penetrate a 35mm thick steel plate at a distance of 100 meters.

If it is a tungsten-core armor-piercing projectile, it can penetrate a 40mm thick vertical steel plate at a distance of 100 meters, which is extremely powerful.

It should be noted that when the Hungarian army was in Hungary, the Sulotun S-18 anti-tank gun (cannon) equipped by the Hungarian infantry could only penetrate 25 mm of vertical steel plate at a distance of 100 meters when firing 20×105 mm armor-piercing incendiary rounds, and it weighed 100 kilograms.

Compared to the other two, it pales in comparison.

Perhaps the Ivanross did indeed possess a unique talent for weapon design, achieving greater armor-piercing power with a lighter weight?
However, coincidentally, his own country also had a similar design, and Shank knew that the Great Unified Federation had developed a similar bullet around the same time.

That was the 15.5×100mm machine gun round. Back then, the Equipment Bureau believed that small-caliber anti-aircraft weapons should have the characteristics of "two fasts and one lightness"—fast rate of fire, fast muzzle velocity, and light weight. However, the 20mm anti-aircraft gun did not meet the requirements. Therefore, the cartridge case of the 20mm shell was necked, and the 20mm bullet was replaced with a 15.5mm bullet, which significantly increased the muzzle velocity, but the explosive power (destructive capability) was also reduced.

The Type 38 15.5mm anti-aircraft machine gun, currently in service, has long been in mass production and is gradually replacing the older Type 24 20mm autocannon.

The Equipment Bureau was convinced it was worthwhile; for small-caliber air defense weapons, firepower density was more important than destructive capability. When the prototype was first unveiled last month, Shank, who was also present, immediately noticed its significant weakness in side protection.

He suggested thickening the side armor of the vehicle body, or adopting a more ingenious solution—pre-installing armor skirt brackets so that they can be installed when needed and easily replaced if damaged.

Two years ago, the Liaoyang Federal Arsenal conducted a similar experiment. Placing a thin steel plate in front of a thick steel plate could effectively remove the cap of an incoming small-caliber projectile, significantly reducing its penetrating power.

Therefore, at Mr. Shang's strong insistence, Hualian Industrial listened to advice and adopted the second solution.

The prototype vehicle has an additional 6mm thick steel plate on its side, which is high-hardness armor steel with a Brinell hardness of 490-520.

This type of armor steel is very difficult to weld and is only suitable for riveting, but since it is used as a skirt panel, it doesn't matter.

Mr. Shang was quite satisfied with this improvement.

Adding skirts has an unexpected benefit: it helps improve the tank's protection against shaped charge anti-tank projectiles. When the projectile touches the skirts, it is detonated prematurely, reducing the penetrating power of the metal jet.

Subsequently, the improved prototype vehicle underwent obstacle crossing demonstrations and hill climbing tests.

Then they demonstrated their firepower, with gunfire erupting and distant targets sparking as they were hit.

Qian Changxuan, the commander of the Tank Training Division, was also in the crowd. Several army generals, including him, were extremely satisfied and immediately expressed their intention to place an order for 5,000 vehicles.

People from the Equipment Bureau were also there, all with cold faces, but seeing a group of army generals in high spirits, they didn't want to dampen their spirits.

The representative of Hualian Industrial Group looked delighted, thinking to himself that this was a sure thing. If they won, a large order for tens of thousands of vehicles would be within reach.

Competitors? Let them be envious!
at this time……

Shang Ke was an expert in artillery, and suddenly asked the chief designer a question.

"By the way, Chief Engineer Xu, how much propellant is loaded into the armor-piercing shells of this 42-caliber gun?"

Without hesitation, Xu Zhiyuan replied, "Two thousand three hundred grams, nitrocellulose mono-based drug."

Shang Ke hissed and hesitated before saying, "The initial velocity is 720, which still feels a bit slow. The landing velocity at a distance of 1,000 meters... can barely penetrate the Russian Special Type 34, and it will be very difficult to penetrate it at any further."

As the chief designer, Xu Zhiyuan did not deny the problems pointed out by Shang, but he was not comfortable speaking up in front of so many people.

He seemed a little embarrassed and said in a low voice, "This cannon was handled by the Liaoyang Arsenal, and it passed the equipment bureau's acceptance test."

"Meets the standard?" Shang Ke blurted out immediately, "I don't think so."

(End of this chapter)