Iron Sonata of World War II

Helena's so-called serialized development idea is actually the idea of ​​cannon familyization.Speaking of which, the Rheinmetall in the last plane is a model of the development of the gun family. The RH120 L44, RH120 L55, and RH120 LLR L47 three 120mm smoothbore tank guns developed by it are different in power and applicability (the first is 44 times the diameter Tank guns, the second is a more powerful 55-caliber tank gun, and the third is a 47-caliber low-recoil smoothbore gun for wheeled vehicles or light tanks).However, these three guns use the same ammunition, and many parts are also common, which greatly reduces the cost of R & D and production and the pressure of logistical maintenance.

The benefits of gun familyization are self-evident, and the development of gun familyization is exactly Helena's plan for the future of the German barrel artillery system.

So we saw a very funny scene: Helena shamelessly plagiarized the future development ideas of the Rheinmetall in the previous plane, and then sold it to the Rheinmetall in the current plane...

In Helena's plan, the 75mm anti-tank gun family will have three members:

48 times diameter 75mm towed anti-tank gun

48 times diameter 75mm tank anti-tank gun

60 times diameter 75mm tank anti-tank gun

Why do you want to arrange it this way?Please listen to the breakdown next time.

The author has something to say: I will introduce Helena's 75mm anti-tank gun family in detail tomorrow.

Chapter 37 Trinity

The reason why Helena wants to divide a caliber of artillery into three sub-models through family design.The main reason is that the application scenarios of these three sub-models are different, and the main contradictions faced during design are also different.If the models are forcibly further degenerated, it seems that the degree of generalization is higher, but different design needs will hinder each other, which will inevitably lead to the inability to optimize the performance of some models. On the whole, it is not conducive to the efficient allocation of resources. .

Let me talk about the 48 times diameter 75mm towed anti-tank gun.Helena believes that for the towed anti-tank guns of World War II, the most important contradiction in the design is undoubtedly the weight control.

In the arsenal of a powerful army in the 21st century, towed anti-tank guns have basically disappeared or relegated to the second line. Everyone has installed their own anti-tank guns (including 105mm, 115mm, 120mm, 125mm and other calibers) on tracked guns. chassis or wheeled chassis.In this case, it may not be a big problem if the artillery weight is slightly larger, but we cannot use today's mechanization level to look at the level of mechanization during World War II.

Here we need to clarify the concepts of "mechanization" and "motorization". "Mechanized troops" refer to troops in which soldiers mainly maneuver and fight on armored vehicles (tanks, infantry fighting vehicles, self-propelled artillery, etc.); vehicles), but dismounted combat is the main method of combat troops.

In fact, during World War II, no country was able to truly achieve mechanization!Even Uncle Sam, who is not bad at fuel, has basically realized motorized mobility!As for other countries, especially Germany and the Soviet Union, which have large armies and are relatively short of fuel, they cannot even be motorized.

Although in the last plane, military fans always talked about the mechanized warfare between Germany and the Soviet Union in World War II, this is not the whole picture of the Soviet-German battlefield.In World War II on the previous plane, whether in Germany or the Soviet Union, "mechanization" was a luxury only available to a few elite troops.In fact, there are not many troops in Germany and the Soviet Union that can fully realize motorization. More troops actually use the half-motor half-mule method for mobility.

You read that right, in the previous plane, most of the combat units on the Soviet-German battlefield were half-motorized and half-mule troops. The precious motorized power needed to be used to pull the "big guys" in the army, such as large-caliber Howitzers, heavy antiaircraft guns, etc.Mules and horses are responsible for carrying other baggage.As for ordinary soldiers, you'd better take your No. 11 battlefield taxi (referring to two legs) and go to the front line.

The battlefield environment of World War II was such that the 75mm towed anti-tank gun, as the main anti-tank gun in the hands of future infantry, should not be too heavy.In terms of strategic mobility, it is necessary to rely on mules and horses to maneuver when necessary; in terms of tactical mobility, it is necessary to consider relying on artillery squad members to pull cannons into the battlefield and transfer positions by manpower (even if the U.S. military is basically motorized, the Tank guns also often require manpower for short-distance maneuvers).

So what is the upper limit of the weight of an artillery that can be pulled by mules and horses and can be maneuvered for short distances by manpower?According to the experience of the last plane, Helena believes that the upper limit is about 2 tons (not to say that it is absolutely impossible to exceed 2 tons, but it will be very difficult to drag more than this weight by mules, horses and manpower).For the existence of towed anti-tank guns that need to be frequently moved, Helena believes that unless there is a compelling reason (for example, the power is an order of magnitude greater), otherwise its weight is best controlled at 1.5 tons or a little more. .

Why did the pak40 46-fold 75mm anti-tank gun in the previous plane become one of the anti-tank guns that the German army relied on most in the middle and late stages of the war?It's not because of how outstanding its power is, but pak40 has a moderate balance between power and weight.

The 48-diameter 75mm towed anti-tank gun envisioned by Helena on this plane uses a barrel length of 48 times the diameter, an efficient muzzle brake, and a long recoil stroke. Basically, it is the pak40 in the previous plane. There are two main optimization measures for the further optimized product:

40. Compared with pak75, the 48mmL40 of the original plane reasonably expands the volume of the propellant chamber, increases the propellant amount, and improves the muzzle kinetic energy.

40. Compared with the thin and long chamber of pak75 ammunition, the ammunition chamber of 48mmL40 ammunition on the original plane has become thicker and shorter. 714mm, after adding the warhead, the length of the whole shell exceeds 900mm, which is not very friendly to loading in a small tank, so the length of the ammunition chamber of the 75mmL43/48 is shortened to 495mm).

After talking about the towed gun, let's talk about the tank gun.

战车炮分为两型，分别是48倍径的短炮和60倍径的长炮。其中48倍径型战车炮采用和48倍径型牵引炮相同的火炮身管。60倍径型则采用改进自莱茵金属的59倍径75mm高炮的长身管，炮口无制退器。

The recoil stroke of these two types of tank guns is the same and much shorter than that of the towed type. The gun mounts used are also exactly the same. The difference is the power and retreat resistance: the 48-diameter type has a shorter barrel and has a muzzle brake. The 60 times the diameter of the barrel is longer and there is no muzzle brake, the resistance of the retreat is relatively large. The 48-fold diameter is suitable for tanks with a lighter total weight, and the 60-fold diameter is suitable for tanks with a larger tonnage.

To sum up the characteristics of these three artillery are:

48. Common ammunition for three kinds of artillery, 48 times diameter towed gun and 48 times diameter tank gun common barrel, 60 times diameter tank gun and [-] times diameter tank gun common retreat and gun mount (only in the retreat resistance adjusted).

60. The 48-caliber tank gun is more powerful, and the cost is correspondingly higher; the 48-caliber towed gun and the [-]-caliber tank gun are moderately powerful, but the cost is lower.

Helena explained her grand vision to Rheinmetall's designers in detail and exhorted her. In her opinion, as long as Rheinmetall can implement all these well, Germany's big hole in the 75mm anti-tank gun will be regarded as a failure by her own. Filled up.But then Helena found that she still looked up to the Germans.

……

small theater:

One day a few years later, Helena went to the Rheinland company's shooting range to visit the bench test of the 75mm anti-tank gun family. The power was very satisfying, but when Helena came closer and took a look, her face immediately turned black.

Helena: "What process is used to manufacture the muzzle brake for your 48-diameter type?"

Rheinmetall: "It's precisely forged with the barrel, what's the matter?"

Helena: "Why not use the casting process? Precise forging is expensive and labor-intensive!"

Rheinmetall: "The cast muzzle brake has a short lifespan. If it wants to match the lifespan of the gun barrel, it must be thicker, and the weight will increase."

Helena: "Life is short, why don't you just make it detachable?"

Rheinmetall: "In this case, the muzzle brake needs to be replaced four or five times throughout the life of the gun, and customers will question our quality."

Helena: "The casting retreater is only one iron lump, how much is four or five iron lumps worth?"

Rheinmetall: "But..."

Helena was really angry now: "Shut up, I know what you want to say! You must be thinking in your heart that casting muzzle brakes is not good enough for your noble and glamorous Rhinemetal, right? You must Think it's smart to use some integrated precision forging on the muzzle brake, don't you?"

Desperately suppressing the urge to kill, Helena went on to say: "Imagine, if there is a war on the front line and there is an urgent need for a batch of anti-tank vehicles, now we have exactly 100 captured light tracked vehicles that can be used Modification, but compared to the recoil of 75mmL48, the carrying capacity of these chassis is a bit low, what are you going to do?"

Helena's voice was full of sarcasm: "Change the barrel? Change the gun mount? Or change the travel of the rear seat? You must think so, right? Then open a production line to modify these 100 cars, right? "

Helena said coldly: "But if our muzzle brake is not forged in one piece, but a detachable cast muzzle brake, we only need to replace it with a muffler brake with higher braking efficiency. Re-opening a new model can be done. In this way, we can send the light self-propelled anti-tank guns of the two battalions to the battlefield at least one month earlier! On the key battlefield, the self-propelled anti-tank guns of the two battalions are enough to determine the balance of victory Which side! Now, maybe because of your mind-stopping operation, our soldiers need to rely on flesh and blood to resist the enemy's tank tracks!"

"You say, should the person who made such a brainless design be shot?" Helena finally concluded.

……

Considering that it is a time of peace, Rheinmetall and Helena finally took a step back, and the muzzle brake was changed to replaceable, but the extrusion molding process was used in the process (this is also the German military brake of World War II on the last plane. The common process), the cost is lower than forging, and the life is not as good as precision forging, but better than casting.However, Helena still requested the development of a cast muzzle solution as a backup.

On the way back, Helena couldn't help but hold her forehead, thinking: It's too difficult, it's too difficult for me, every muzzle brake has Hans' brain hole, and I don't know how many German brain holes are waiting in front of me Follow me!Mama, I want to go home...

Chapter 38 Composite Tubes

Helena introduced her family development idea of ​​75mm anti-tank gun to Rheinmetall, and Rheinmetall was very surprised by this "great idea".To be honest, the idea of ​​artillery familyization actually had some sporadic practice in the World War II on the last plane, and there are many successful cases.But like Helena, systematic blueprint planning from the top level from the beginning of the design is indeed a thought that transcends the times.

What Rheinmetall didn't know was that this was just the tip of the iceberg of Helena's ideas about the development of the artillery family!If Rheinmetall could see Helena's panorama of Germany's future development of barrel artillery, they would be shocked!Because Helena's ambition is much bigger than they imagined!

Helena's plan for the development of artillery serialization is not just as simple as familyizing artillery with the same caliber and similar diameter to meet different usage occasions!That's just the longitudinal warp of Helena's artillery family, and Helena's artillery family also has a vertical latitude.

If the warp is to install artillery of the same caliber on different gun mounts to form a family of artillery.The latitude is to install artillery of different calibers on the same gun mount to form an artillery family.For example, a 48-caliber 75mm towed anti-tank gun can use the same type of gun mount as a 32-caliber 105mm towed howitzer.

This kind of gun with different calibers mounted on the same gun mount is called a sister gun.In fact, Germany used the same gun mounts on pak40 and Le.FH18 during World War II, but due to the lack of system planning, there were still many problems in use (such as the lightweight gun mounts were not strong enough).To tackle this problem from the top, Helena proposes three measures:

The first measure is to make the multiple diameter of the large-caliber artillery lower, and the multiple diameter of the small-caliber artillery higher, so that the difference in the suitable firing charge of the two types of artillery will not be too large.

The second measure is to make the efficiency of the muzzle brake of the large-caliber artillery higher, and the efficiency of the muzzle brake of the smaller-caliber artillery is lower. Combining the first measure, the kinetic energy of the free recoil end of different artillery at the end of the post-effect period is similar.

The third measure is implemented when the above two still cannot meet the needs, that is, the artillery mount is divided into a lower mount and an upper mount. When most of the accessories are the same, the compatibility with different artillery can be achieved by adjusting the recoil module and pitch module.

However, such a grand blueprint for cannon familyization cannot be completed by Helena alone. It requires a lot of demonstration and practical work. Helena can only provide a general idea, and the rest needs to be left to experts We went to further argumentation and refinement.Now Helena has set her sights on a small German company: Loewe.

Now there are probably not many people who know Loewe (I am afraid that only a few tube radio enthusiasts have heard of it), but Loewe still has a high status in the history of electronic tube development, because Loewe is the inventor of composite tubes.

When it comes to the invention of composite pipes by Loewe, one interesting thing has to be mentioned.At that time, the tax standard for tube radios in Germany was based on the number of tubes, which made the tax burden on tube radios quite heavy.

But it is said that there are policies at the top and countermeasures at the bottom. In 1926, the Loewe company came up with a very chicken thief invention: composite electronic tube!Loewe has integrated the functions of 2HF and 3NF into the same tube, which would have required two tubes.This reduces the number of electronic tubes on the basis of ensuring the function, which is also the originator of all composite electronic tubes.

Although Luo Yiwei's invention was only made for tax evasion at the beginning, Luo Yiwei soon discovered that although the cost of a single composite tube is higher than that of ordinary electronic tubes in terms of production costs, the total number of tubes is reduced. The total cost has dropped instead!The reduction in the total number of tubes also brings other benefits, such as a reduction in the size of the entire circuit system, such as increased reliability and maintainability...

Take apart an old tube radio and you can see various types of tubes inside, many of which are composite tubes.Although from today's point of view, these small light bulb-like electronic components are big and stupid, but in terms of that year, the emergence of composite tubes was indeed the product of the development of electronic tubes to the peak.

In fact, Helena originally planned to skip the tube and directly install the transistor.However, in practice, it is found that it does not work at all. Although Helena knows the basic principles of transistors, the current level of the German chemical industry cannot purify the high-purity silicon that Helena needs. In terms of technology, it cannot comprehensively outperform electronic tubes that have already matured.

Helena finally gave up the idea of ​​reaching the sky in one step, and instead pulled Loewe and Siemens into the scientific research project of the "Peace and Development Fund". It is more appropriate for us to make the electron tube better first.

The author has something to say: Helena tinkering with electron tubes and transistors is naturally preparing for the development of electronic technology in the future.

Computers actually rely on a series of switches controlled by programs to complete computing tasks.The earliest was a mechanical computer, relying on mechanical switches; then evolved to relays (although relays are controlled by electricity, there are still mechanical components, not electronic computers in the true sense); and then evolved to the familiar electronic tubes and transistors ( This is the full sense of the "electronic computer").

"Father of the world's computer" - Konrad Zuse began with mechanical computing units, and later with relay computing units.As far as the computing unit is concerned, it is actually mechanical and semi-mechanical.However, he is known as the "father of computers" mainly because he was the first to use "binary" on computers and the first to propose the concept of "computer program control".

But now that he is still in high school, Helena should not disturb him for now.

Chapter 39 Another pitfall

When you gaze into the abyss, the abyss gazes into you.

—— Nietzsche

Helena finally filled the minds of German artillery designers through the artillery family design. This should be a happy thing, but at this time, Helena's heart is not fluctuating. Helena was educated once and for all, that is, every time you fill in a brain hole for the Germans, there will always be a bigger hole waiting for you in front of you.

Now Helena is facing a bottomless pit. As the wheel of history enters 1927, it is time for Helena to plan for the power of German tanks in the future.

The German designer's brain hole in tank power is estimated to be the most harmful of all the weapon design brain holes of the Third Reich. Combined with the history of the previous plane, Helena believes that if all the weapon designers of the Third Reich are shot , there may be a few wrongdoers, but if all the Maybach tank engine designers are shot, it is estimated that there will be no wrongdoers.

……

Many people like to debate whether it is better to use gasoline engines or diesel engines for combat vehicles during World War II, although after the 60s, diesel engines eventually became the mainstream power of combat vehicles.However, during World War II, the competition between gasoline engines and diesel engines on tanks was still in a state of close competition.Although the diesel engine has the advantages of high torque, low fuel consumption, and low fire resistance, the advantages of the gasoline engine, such as small size, light weight, and low noise, cannot be ignored.

So in Helena's view, in terms of performance alone, there is no problem that tanks in World War II must use gasoline engines or diesel engines.Compared with the performance of gasoline engines and diesel engines, each country's own technical level, resource status, and combat environment are the first factors to be considered when choosing.In World War II on the last plane, the Soviet Union and Japan chose diesel engines, while Britain, the United States, and Germany mainly used gasoline engines.The choice of each country is basically the result of comprehensive consideration based on the resource endowment and technical level of each country.

Germany in the previous plane was hesitant on whether to use gasoline or diesel engines for chariot power, but in the end Germany still chose gasoline engines. This is largely the same as the coal liquefaction process of Germany in the previous plane. It is mainly more suitable for production. It is related to the direct liquefaction process of gasoline.

However, in this plane, due to Helena's advance development of the "iron-zinc oxide-potassium oxide" catalyst, coupled with the day and night research of the two great chemical industry gods, Fischer and Tropsch, the speed of progress in the indirect coal liquefaction process With rapid progress, compared with the direct coal liquefaction process, it has the momentum of catching up from behind!Since the coal indirect synthesis method is more suitable for the production of high-quality diesel oil, the balance in the heart of the hesitant German military finally fell to the diesel power plant.

Helena has no objection to the choice of diesel power for internal combustion engines in German vehicles.I dare not say that the diesel engine will definitely overwhelm the gasoline engine in World War II, but it is not a bad choice in terms of overall performance.What Helena is more concerned about now is the choice of the future German vehicle diesel engine technology route.

When it comes to the classic vehicle diesel engine in World War II in the last plane, the first thing that comes to mind is the B-34 diesel engine, the power of the Soviet T-2 tank.This proven engine not only equipped tens of thousands of Soviet tanks in World War II, but its descendants continued to write legends after the war, T-54, T-55, T-62, T-72 and other models The source of the most famous Soviet tank engine can be traced back to this engine.It can be said that without the B-2, there would be no "steel torrent" of the Red Empire!

The B-2 is good, but Helena is not going to let the German car diesels follow the calculated route of the B-2.

Don't think that Helena can't eat wine and say sour grapes!In fact, with Germany's technical capabilities, it is not difficult to produce a diesel engine that exceeds the B-2 along the B-2 technical route.

This is not Helena's empty talk. In the history of the last plane, Germany really developed such a diesel engine. This is the OF-1936 diesel engine successfully developed by Daimler-Benz in 2 (interestingly, OF -2, like the B-2, has an aero-engine pedigree). Both the OF-2 and B-2 cylinders have an included angle of 60 degrees, both have long piston strokes, and both have aluminum bodies.So how does this OF-2 perform compared to the B-2?Let's look at the following data:

Its maximum power is 800 horsepower, which is 2% higher than the 500 horsepower of the B-60 engine;

Its liter power is 14.85 horsepower/liter, which is 2% higher than the 12.86 horsepower/liter of the B-15.5 engine;

Its power-to-weight ratio is 0.856 hp/kg, which is 2% higher than B-0.572's 49.7 hp/kg!

你以为OF-2又是一台迈巴赫式的高速低扭矩发动机？你错了！OF-2在800马力时，转速只有1790转，比B-2的1800转还要低，因此其最大功率时扭矩比B-2高出61%。另外OF-2的单位体积功率也不错，和号称紧凑的B-2基本相当。

In short, in Helena's opinion, the Soviet B-2 engine is very good, and if the Germans operate it, it can do better than the B-2.But despite this, Helena still "stubbornly" believes that the B-2's technical route is not suitable for future Germany.

You may have doubts: You Helena said that the technical route of Maybach should be shot, and Helena said that the technical route of B-2 is not suitable for Germany, so which technical route are you going to arrange for the future Germany?

Helena said that everyone should not be in a hurry, this matter still needs to be explained in detail.

The author has something to say: Whether it is for Helena or for me, the car engine is really a big hole, and I may need to use a few chapters to fill the hole.

Chapter 40 The Golden Mean

If you want to design an engine with a power that meets the standard, you first need to understand what the power of an engine is mainly determined by.There are three main parameters that determine the power of an engine: displacement, speed, and mean effective pressure.

Displacement refers to the volume of space that the piston passes through when it moves between the upper and lower dead centers.For a multi-cylinder engine, the displacement is determined by multiplying the volume of a single cylinder (determined by the bore and stroke of the piston) by the number of cylinders.The greater the displacement, the greater the volume of gas drawn in and expelled by the engine per revolution.

Speed ​​is the number of revolutions per minute of the engine's crankshaft. For a four-stroke engine, there will be one working stroke every two revolutions of the crankshaft (two-stroke engines will do one work per revolution).So the higher the rpm, the more work the engine can do per minute.

The mean effective pressure is the effective work that can be produced per cycle per unit displacement.The average effective pressure is the product of the average indicated pressure and mechanical efficiency, where the average indicated pressure can be regarded as the average pressure of the working fluid on the top of the piston.Since the improvement of mechanical efficiency is relatively difficult and slow, the increase of the average effective pressure of the engine is mainly achieved by increasing the average indicated pressure, that is, the average pressure of the working medium on the top of the piston.Improving the compression ratio and supercharging ratio of the engine is the most effective means to achieve this goal.

Because the power of the engine is directly proportional to the product of displacement, speed and mean effective pressure.When you weaken one of the parameters, if you want to ensure that the power does not drop, you must compensate by strengthening the other two parameters.The design of an internal combustion engine actually requires the designer to dance on the three balls of displacement, speed, and average effective pressure without falling off.

Knowing the above, let's take a look at the Maybach's engine design.During World War II, Maybach was the manufacturer of tank engines such as No. 230, No. [-], No. [-], No. [-], Tiger, Leopard, and King Tiger. It can be said that it almost monopolized the research and development and production of tank engines in the Third Reich. There are many types of chariot engines, so let's choose a representative HL[-] gasoline engine to have a glimpse of Maybach's chariot engine design ideas.

The HL700 series gasoline engine with a maximum power of 230 horsepower is developed from the HL210 series. The main improvement is to change the cylinder block from cast aluminum to cast iron and slightly increase the displacement. The power source of the King Tiger tank.

As mentioned earlier, the power of the engine is mainly determined by three indicators: displacement, speed, and average effective pressure.As the saying goes, the devil always hides in the details. In addition to marveling at the powerful power output of the HL230, we also need to delve into how the amazing power output of 700 horsepower is achieved, and what hidden dangers lie hidden in the technical route of Maybach to achieve this power.

Let us look at the displacement of HL230 first. The displacement of HL230 is 23.88 liters. According to the technical level at that time, it is a proper small displacement engine.Its power per liter is not only much higher than the Soviet B-38.88 diesel engine with a displacement of 500 liters and a power of 2 horsepower, but also higher than that of the Ford GAF ​​V8 engine, which is also a small-displacement gasoline engine (the power of the M26 Pershing, with a power of 500 horsepower, Displacement 18 liters).

Looking at the average effective pressure again, as a naturally aspirated engine, the main means to increase the average effective pressure is to increase the compression ratio, but the inherent characteristics of the gasoline engine make the compression ratio of the gasoline engine unable to match that of the diesel engine, and the German high-octane engine with strong anti-knock ability Gasoline has to be given priority to the aviation unit. In order to prevent deflagration, the compression ratio of HL230 cannot be set too high.

HL230排气量设计得太小堵死了靠排量来拉功率的道路，汽油机的固有属性外加德国高辛烷值燃油的不足又把刷平均有效压力这条路堵死了。如果说排量、转速和平均有效压力是的圆桌三条腿，那么现在三条腿断了两条，只能靠剩下的转速这条腿一柱擎天了！于是HL230转速高达3000转/分，比苏联T-34的B-2发动机足足高了66.7%,比同为高转速小排量的美国M26潘兴的GAF型V8发动机也高了15.4%！

If you ask is there any benefit to high RPM?Yes, of course there is. For example, high speed can bring high power density. Didn’t you see that the high power density engines of sports cars all have high speed?As far as the HL230 engine is concerned, the power density of its body is one of the best in World War II!

But the pitfalls are still behind. The high speed of HL230 brings a very high heat load. In order to prevent the engine from bursting due to overheating, strong heat dissipation measures must be used.If we disassemble the power hatch of the Tiger and Leopard tanks, we can see the three-stage structure inside: the engine body in the middle, and a set of huge radiator fans on both sides.