Underwater novelties of the Celestial Empire
At one time (in the 30s of the last century), competition between the imperial army and the imperial fleet determined the vector of Japan's external expansion. Having tried their hand at Lake Khasan and Khalkhin Gol, the Japanese decided that fighting at sea with the Anglo-Saxons was more profitable than breaking spears with the Red Army and its allies in the vastness of China and Mongolia.
For a self-respecting Chinese, comparison with Japanese militarists is extremely insulting, but... The fact that the PRC today is investing enormous amounts of money and effort in building up its naval power also quite clearly shows that the Chinese see the Americans as their enemy...
What motivates the PLA Navy's "non-nuclear" submarine? A mystery wrapped in a secret...
Particular attention should be paid to the development of the submarine forces of the PLA Navy, and most importantly, their non-nuclear component.
The fact is that in terms of building submarines with a nuclear power plant, our southern neighbors are quite far behind both the Russian Navy and the US Navy. The same can be said about diesel-electric submarines. However, at present, technologies that are unconventional in underwater shipbuilding are being developed, which enable the PRC to get ahead, at least in this matter. We are talking about the so-called “Stirling engines”...
Reverend Robert Stirling
It’s hard to call this technology new. Reverend Robert Stirling (who worked as a priest in Scotland) patented his vision of heat engines more than two hundred years ago - in 1816. This advanced and good shepherd proposed, as a replacement for steam engines, which at that time often exploded, killed and maimed drivers and stokers, a design that generated energy by heating and cooling the working fluid in a cylinder.
The Stirling machine had a number of advantages: it was quieter, safer, more economical, had a longer service life, but... It had low efficiency and required the use of massive cooling radiators, and as a working fluid - such expensive and rare (at the time of development) chemical elements, like hydrogen or helium. As a result, at that time it didn’t work out.
But times are changing, and in the 1816st century, submarine designers paid attention to Stirling engines. Here, the disadvantages of the Stirlings have become less noticeable (cooling radiators on submarines work perfectly on sea water, which means they are much smaller than on land, and hydrogen and helium have become much more accessible than in XNUMX), but the advantages ... The Stirling engine is much quieter than any internal combustion engine, and for a submarine, low noise is one of the main characteristics! Yes, both efficiency and increased resource will not be superfluous.
Gotland class submarine – Scandinavian design!
In general, the Swedes took the first step in this direction. In 1988, the Swedish Nakken-class submarine received the first Stirling. And those commissioned in 1996–1997. Three Gotland-class submarines became the first production boats equipped with this type of air-independent power plant. But Sweden is not serious! Because then the PLA Navy began experimenting with Stirlings, and China is on a completely different scale!
True, one can only judge the real state of affairs in the Chinese fleet very approximately - give or take a bast shoe: everything is in order with the secrecy regime in the PRC. Therefore, we can only reason on the basis of data from open sources, mostly Western ones. For example, Thomas Newdick from the Warzone project analyzes satellite images of the Wuchang shipyard in Wuhan. In the photographs you can make out a submarine standing on the slipway.
Project 039A submarines are being built at this shipyard, but the new building has clear differences from this project. Thus, the author points out that the boat is significantly longer than the Project 039A submarines, and also has newfangled (and not yet seen in the PLA Navy) x-shaped rudders. The author estimates that the submarine is approximately 82,4–94,5 meters (272–279 ft) long, versus 76,7 meters (253 ft) for Project 039A.
Project 613 submarine – Soviet roots of the Chinese submarine...
It's worth making a digression here.
Initially, the submarine forces of the PLA Navy were built on the basis of submarines of Soviet designs. At first these were boats of Project 613 (in China - type 03) - a Soviet version of the German XXI series, which did not have time to enter service en masse by May 9, 1945. Subsequently, they were replaced by diesel-electric submarines of Project 633 (033 “Wuhan” according to the Chinese classification). The Chinese reworking of this project became known as Type 035 “Ming”. Finally, the first independent development of Chinese engineers was the Type 039 Song submarines...
The Hangor submarine is an export (for the Pakistani Navy) version of the Chinese Type 039 submarine
The new boat (the first copy was launched in 1999) had a teardrop-shaped hull with a rubber coating, engines mounted on rubber shock absorbers... However, the first pancake, apparently, turned out to be lumpy - only one submarine was built according to the original drawings.
The main series of seven submarines, designated 039G, was significantly improved. How? You can only judge by the shape of the felling fence - the Chinese know how to keep military secrets. Well, because the tests of the first option were long and painful. The next version of the project, type 039A, does not have horizontal rudders. But... All these boats, apparently, are diesel-electric.
But in 2023, there were reports that the PRC had created the world's most powerful Stirling engine. They write that the engine produced a power of 102 kW, breaking the 100-watt mark for the first time. The engine uses helium at a pressure of 15 MPa as the working fluid. Professor Hu Jianying notes that the efficiency of thermoelectric conversion was 28% at a working fluid temperature of 523 degrees Celsius, and if the temperature can be raised to 600 degrees, then the efficiency will increase to 34 percent.
Type 039G submarine at the pier. Stirling or diesel?
The Chinese have already tested their “Stirling” at their own orbital station, which means... It’s more expensive to launch an untested design into space - the price of a kilogram of cargo launched into orbit is stinging. Therefore, there is talk that the next generation of submarines, tentatively designated as type 039C, will have a Stirling engine. Or maybe it has already been installed - on existing submarines of type 039 - should the Chinese have somehow brought to life the engine that was launched into space?
VLS cells are one of the payload options for Type 039 submarines
However, it is possible that the lengthening of the hull of the new PLA Navy submarine seen on satellite images is associated with the installation of another newfangled device on it - vertical missile launch cells (VLS). Such cells are found on the last of the Israeli Dolphin II-class submarines, the Dragon. Engineers from South Korea are also experimenting with VLS cells, having placed six cells for launching SLBM ballistic missiles on their submarine Dosan Angh Changho (but cruise missiles can also be loaded into them).
Submarine "Soryu" - lithium-ion samurai...
But there are other options for using the additional volume obtained by lengthening the submarine’s hull. Thus, the Japanese, on their Soryu-type boats, are experimenting with using lithium-ion batteries as a battery. It is possible that an additional compartment in the Chinese submarine will be used for these batteries, which will significantly increase the life of the boat under water. Or to accommodate reconnaissance equipment or underwater saboteurs.
The easiest way is with x-shaped rudders: it is believed that they improve the maneuverability of the submarine and also reduce its noise. It is worth noting that Chinese submarines have very mediocre characteristics in terms of noise, therefore, most likely, the use of such rudders, previously uncharacteristic of Chinese-built submarines, is aimed specifically at improving this characteristic. The same goes for using a Stirling engine instead of a traditional diesel engine.
If there were shipyards, there would be boats!
Vysotsky sang “I hate gossip in the form of versions.” Considering the exemplary secrecy regime in the PLA Navy, all that can be extracted from satellite images of the new submarine is the same gossip in the form of versions. It is not even known whether a new type of submarine was captured by a curious satellite, or whether this is another modernization of type 039 with the next letter after the numbers.
One thing can be said with enviable accuracy - the PRC is paying increased attention to the development of its naval forces. Each of the 13 Chinese shipyards is now more powerful than all American shipyards combined. It is clear that most of them build merchant ships to ensure the functioning of trade in the first economy of the world, but...
There is not the slightest doubt that, if necessary, the PRC will be able to bake warships like hot cakes. Their quality today, to put it mildly... cannot be called a masterpiece. But there is no quality that cannot be overwhelmed by quantity. And the PLA Navy will have no problems with this!
For a self-respecting Chinese, comparison with Japanese militarists is extremely insulting, but... The fact that the PRC today is investing enormous amounts of money and effort in building up its naval power also quite clearly shows that the Chinese see the Americans as their enemy...
What motivates the PLA Navy's "non-nuclear" submarine? A mystery wrapped in a secret...
Particular attention should be paid to the development of the submarine forces of the PLA Navy, and most importantly, their non-nuclear component.
The fact is that in terms of building submarines with a nuclear power plant, our southern neighbors are quite far behind both the Russian Navy and the US Navy. The same can be said about diesel-electric submarines. However, at present, technologies that are unconventional in underwater shipbuilding are being developed, which enable the PRC to get ahead, at least in this matter. We are talking about the so-called “Stirling engines”...
Reverend Robert Stirling
It’s hard to call this technology new. Reverend Robert Stirling (who worked as a priest in Scotland) patented his vision of heat engines more than two hundred years ago - in 1816. This advanced and good shepherd proposed, as a replacement for steam engines, which at that time often exploded, killed and maimed drivers and stokers, a design that generated energy by heating and cooling the working fluid in a cylinder.
The Stirling machine had a number of advantages: it was quieter, safer, more economical, had a longer service life, but... It had low efficiency and required the use of massive cooling radiators, and as a working fluid - such expensive and rare (at the time of development) chemical elements, like hydrogen or helium. As a result, at that time it didn’t work out.
But times are changing, and in the 1816st century, submarine designers paid attention to Stirling engines. Here, the disadvantages of the Stirlings have become less noticeable (cooling radiators on submarines work perfectly on sea water, which means they are much smaller than on land, and hydrogen and helium have become much more accessible than in XNUMX), but the advantages ... The Stirling engine is much quieter than any internal combustion engine, and for a submarine, low noise is one of the main characteristics! Yes, both efficiency and increased resource will not be superfluous.
Gotland class submarine – Scandinavian design!
In general, the Swedes took the first step in this direction. In 1988, the Swedish Nakken-class submarine received the first Stirling. And those commissioned in 1996–1997. Three Gotland-class submarines became the first production boats equipped with this type of air-independent power plant. But Sweden is not serious! Because then the PLA Navy began experimenting with Stirlings, and China is on a completely different scale!
True, one can only judge the real state of affairs in the Chinese fleet very approximately - give or take a bast shoe: everything is in order with the secrecy regime in the PRC. Therefore, we can only reason on the basis of data from open sources, mostly Western ones. For example, Thomas Newdick from the Warzone project analyzes satellite images of the Wuchang shipyard in Wuhan. In the photographs you can make out a submarine standing on the slipway.
Project 039A submarines are being built at this shipyard, but the new building has clear differences from this project. Thus, the author points out that the boat is significantly longer than the Project 039A submarines, and also has newfangled (and not yet seen in the PLA Navy) x-shaped rudders. The author estimates that the submarine is approximately 82,4–94,5 meters (272–279 ft) long, versus 76,7 meters (253 ft) for Project 039A.
Project 613 submarine – Soviet roots of the Chinese submarine...
It's worth making a digression here.
Initially, the submarine forces of the PLA Navy were built on the basis of submarines of Soviet designs. At first these were boats of Project 613 (in China - type 03) - a Soviet version of the German XXI series, which did not have time to enter service en masse by May 9, 1945. Subsequently, they were replaced by diesel-electric submarines of Project 633 (033 “Wuhan” according to the Chinese classification). The Chinese reworking of this project became known as Type 035 “Ming”. Finally, the first independent development of Chinese engineers was the Type 039 Song submarines...
The Hangor submarine is an export (for the Pakistani Navy) version of the Chinese Type 039 submarine
The new boat (the first copy was launched in 1999) had a teardrop-shaped hull with a rubber coating, engines mounted on rubber shock absorbers... However, the first pancake, apparently, turned out to be lumpy - only one submarine was built according to the original drawings.
The main series of seven submarines, designated 039G, was significantly improved. How? You can only judge by the shape of the felling fence - the Chinese know how to keep military secrets. Well, because the tests of the first option were long and painful. The next version of the project, type 039A, does not have horizontal rudders. But... All these boats, apparently, are diesel-electric.
But in 2023, there were reports that the PRC had created the world's most powerful Stirling engine. They write that the engine produced a power of 102 kW, breaking the 100-watt mark for the first time. The engine uses helium at a pressure of 15 MPa as the working fluid. Professor Hu Jianying notes that the efficiency of thermoelectric conversion was 28% at a working fluid temperature of 523 degrees Celsius, and if the temperature can be raised to 600 degrees, then the efficiency will increase to 34 percent.
Type 039G submarine at the pier. Stirling or diesel?
The Chinese have already tested their “Stirling” at their own orbital station, which means... It’s more expensive to launch an untested design into space - the price of a kilogram of cargo launched into orbit is stinging. Therefore, there is talk that the next generation of submarines, tentatively designated as type 039C, will have a Stirling engine. Or maybe it has already been installed - on existing submarines of type 039 - should the Chinese have somehow brought to life the engine that was launched into space?
VLS cells are one of the payload options for Type 039 submarines
However, it is possible that the lengthening of the hull of the new PLA Navy submarine seen on satellite images is associated with the installation of another newfangled device on it - vertical missile launch cells (VLS). Such cells are found on the last of the Israeli Dolphin II-class submarines, the Dragon. Engineers from South Korea are also experimenting with VLS cells, having placed six cells for launching SLBM ballistic missiles on their submarine Dosan Angh Changho (but cruise missiles can also be loaded into them).
Submarine "Soryu" - lithium-ion samurai...
But there are other options for using the additional volume obtained by lengthening the submarine’s hull. Thus, the Japanese, on their Soryu-type boats, are experimenting with using lithium-ion batteries as a battery. It is possible that an additional compartment in the Chinese submarine will be used for these batteries, which will significantly increase the life of the boat under water. Or to accommodate reconnaissance equipment or underwater saboteurs.
The easiest way is with x-shaped rudders: it is believed that they improve the maneuverability of the submarine and also reduce its noise. It is worth noting that Chinese submarines have very mediocre characteristics in terms of noise, therefore, most likely, the use of such rudders, previously uncharacteristic of Chinese-built submarines, is aimed specifically at improving this characteristic. The same goes for using a Stirling engine instead of a traditional diesel engine.
If there were shipyards, there would be boats!
Vysotsky sang “I hate gossip in the form of versions.” Considering the exemplary secrecy regime in the PLA Navy, all that can be extracted from satellite images of the new submarine is the same gossip in the form of versions. It is not even known whether a new type of submarine was captured by a curious satellite, or whether this is another modernization of type 039 with the next letter after the numbers.
One thing can be said with enviable accuracy - the PRC is paying increased attention to the development of its naval forces. Each of the 13 Chinese shipyards is now more powerful than all American shipyards combined. It is clear that most of them build merchant ships to ensure the functioning of trade in the first economy of the world, but...
There is not the slightest doubt that, if necessary, the PRC will be able to bake warships like hot cakes. Their quality today, to put it mildly... cannot be called a masterpiece. But there is no quality that cannot be overwhelmed by quantity. And the PLA Navy will have no problems with this!
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