The story of the Poseidon's military campaign to the shores of the United States should begin with a method of navigation under water.
Salt sea water is an electrolyte that prevents radio waves from propagating. At the depths at which Poseidon is to operate, external radio control of the device, as well as receiving signals from Glonass / GPS satellites, is not possible.
An autonomous inertial navigation system (INS) is capable of guiding Poseidon throughout the day, but its capabilities are also not endless. Over time, the ANN accumulates error, and the calculations lose their validity. An auxiliary system using external reference points is required.
Installing "hydroacoustic beacons" at the bottom is a senseless event in the face of an enemy who has the ability to immediately track down and disrupt their work.
The problem of underwater navigation for the Poseidon spacecraft can only be solved with the use of a relief-based navigation system. But is it possible to adapt the navigation systems used in cruise missiles to work underwater?
First, a seabed map is required.
Myth number 1. It is impossible to make a map along the entire route of "Poseidon"
Discussions on the Doomsday Torpedo have repeatedly expressed the opinion that mapping the entire floor of the Atlantic Ocean, from the Barents Sea to New York Harbor, can take decades and will require exceptional efforts.
In reality, for a relief-based navigation system, such a volume of work is redundant and simply unnecessary.
The proof is the described operating principle of the TERCOM (Terrain Contour Matching) system for the Tomahawk missile. According to a statement by Western experts, 64 correction areas are selected during a cruise missile flight over land. Sections of 7-8 km in length are selected in advance, for which there is a "reference" digital map stored in the memory of the on-board computer.
Under normal conditions, TERCOM operates only on a quarter of the route (with a range of the KR of about 2000 km), the rest of the time the rocket flies under the control of the INS. Accelerometers and gyroscopes are accurate enough to bring the Tomahawk to the next correction area, where, according to TERCOM, the ANN will be amended.
Reliefometric navigation systems celebrated their 60th anniversary last year. In the late 50s. they have become a worthy replacement for astro correction systems. The cruise missiles had to go to low altitudes, from where the stars were not visible.
Even the strongest storm is unable to disturb the calm of the sea depths. The movement of the underwater vehicle is associated with an order of magnitude smaller perturbations in comparison with the low-altitude flight of the RR in the atmosphere. That is why the data of inertial systems on board submarines remain reliable for a much longer time (day).
The conclusion that can be drawn from the available facts: when laying the Poseidon routes, a significantly lower density of correction areas will be required. Separate squares of the ocean floor. All further questions should be addressed to the Hydrographic Service of the Navy.
Myth number 2. Sonar is not able to provide the required accuracy of bottom scans
The permissible error in measuring the height of the relief during TERCOM operation is no more than 1 meter. What accuracy is provided by modern hydroacoustic tools designed for bottom mapping? Is it possible to place such a sonar in Poseidon's limited-size hull?
The answer to these questions will be sonar images of shipwrecks. On the first - the Japanese cruiser "Mogami", discovered in May at a depth of 1450 m.
The second photo shows the aircraft carrier Hornet, sunk in the battle off the island of Santa Cruz. The remains of the aircraft carrier are at a depth of 5400 meters.
The detail of these images is irrefutable evidence in favor of seabed mapping systems. By the way, the pictures were taken by Paul Allen's team from his yacht, the private oceanographic vessel R / V Petrel.
Myth number 3. The topography of the ocean floor is subject to change
Time will pass, and digital maps of the seabed will lose their relevance. Somewhere in a million years, new ones will need to be composed.
The main changes on the ocean floor are associated with volcanic activity and the accumulation of bottom sediments of organic and inorganic origin.
According to modern observations, the average rate of accumulation of bottom sediments in the mid-Atlantic Ocean is 2 centimeters per 1000 years. For the Pacific Ocean, even lower values are indicated.
It is hard to believe in the reality of these numbers, but the paradox has a simple explanation. No one throws stones in the middle of the ocean, no one throws gravel and M600 rubble into the Mariana Trench. All objects trapped in the ocean first dissolve and decompose in the water. Particles dissolved in the sea mass take millennia to reach the bottom.
In coastal areas, the rate of accumulation of sediments is orders of magnitude higher, due to sediment and sediments brought by the flow of rivers. However, the ocean is too large for this to have any meaning in this case.
Despite the increased tectonic activity, the frequency of cataclysms on the ocean floor, coupled with talus, avalanches and displacement of soil layers, is much lower than, for example, the frequency of avalanches in the mountains. Suppose 100 years ago an earthquake caused an avalanche on the side of a seamount. Now it will take hundreds of thousands of years until enough sediment accumulates on its slopes for the next cataclysm.
Young submarine volcanoes, swell-like structures along the oceanic ridges (formed when the earth's axis is displaced) - all of them are "young" only by the standards of geological eras. The age of these formations is millions of years!
A gloomy calm reigns in the ocean depths. The absence of winds, erosion and any traces of urbanization makes the relief unchanged for millennia.
For comparison. How many problems do cruise missiles flying over land have? The process of compiling digital maps for TERCOM is hampered by seasonal changes in the relief. Forms of monotonous relief are encountered everywhere, in which the use of TERCOM is physically impossible. Routes bypass large bodies of water, rockets avoid snow-covered plains and sand dunes on their way.
In contrast to the listed difficulties, there is always a bottom in the depths of the deepest ocean. Covered with a unique "pattern" of relief details.
The Relief System is the most reliable and realistic way of navigation for the Poseidon submersible.
Why hasn't this method been applied in practice yet? The answer is that there was no need for it. Unlike Poseidon, which is continuously sailing in the depths, submarines regularly rise to the surface to conduct communications. Submariners have the opportunity to obtain precise coordinates using space navigation means (Cyclone, Parus, GLONASS, GPS, NAVSTAR).
Fastest underwater
In this part of the article, we will not discuss specific technical solutions, the design of the "Poseidon" is covered with a veil of military secrecy.
However, we have the opportunity, based on the declassified characteristics, to calculate other interrelated parameters of an unmanned underwater vehicle with a nuclear power plant.
For example, the declared speed is known - 100 knots. What is the power of the Poseidon's power plant?
There is a rule of thumb. For any displacement object, the power of the power plant increases to the third power of speed.
Example. The Soviet torpedo "53-38" (53 - a reference to the caliber, 38 - the year of adoption) had three speed modes: 30, 34 and 44, 5 knots with engine power 112, 160 and 318 hp. respectively. As you can see, the rule doesn't lie.
And the age of the torpedo itself has absolutely nothing to do with it. One and the same torpedo required three times more power to increase the travel speed by 1.5 times.
The next example is more interesting. Heavy torpedo "65-73" caliber 650 mm had a length of 11 meters and a weight of 5 tons. The torpedo was equipped with a short-life gas turbine engine 2DT with a capacity of 1.07 MW (1450 hp) - one of the most powerful ever used in a torpedo weapon. With it, the design speed of the product "65-73" could reach 50 knots.
Theoretical question: what engine power could provide a speed of 100 knots for a 65-73 torpedo?
The speed will double, which means that the required power of the power plant will increase eightfold. Instead of 1450 hp we get the value 11 600 hp.
Now is the time to turn to the Poseidon nuclear torpedo.
Based on the information about the purpose of the "nuclear torpedo" and the fact that it is planned to be launched from carrier submarines (for example, information about the launch from the experimental diesel-electric submarine "Sarov"), it should be noted that the size of the "Poseidon" is much more consistent with the torpedo weapon than the size of submarines. The smallest of which (domestic "Lira" and French "Ruby") had a displacement of about 2.5 thousand tons.
The caliber, length and displacement of the Poseidon can be many times higher than the performance of 650-mm torpedoes. The exact values are unknown to us. But in this case, the differences do not matter much when assessing the required power of the power plant. To reach a speed of 50 knots, the Poseidon, like the 65-73 torpedo, requires at least 1450 hp, for 100 knots it would take at least 11,600 hp. (8.5 MW) useful power.
How is the engine of the same power sufficient for devices of different sizes?
For displacement objects, whose dimensions differ within the same order of magnitude, the difference in displacement does not require a sharp increase in the power of the power plant. A striking example is at the same travel speed the power plants of a typical destroyer and an aircraft carrier differ by only two times, with a 10-fold difference in the displacement of these ships! Much more problems arise from the desire to increase the speed by 3 knots.
Let's summarize. When traveling at the declared speed of 100 knots (185.2 km / h), the Poseidon vehicle will need a power plant with a useful power of at least 8.5 MW (11,600 hp).
Let us fix this value as the lower bound and we will be guided by it in the future.
Is 8, 5 megawatts a lot or a little? How does this indicator compare with the characteristics of other ships and naval weapons?
For an underwater vehicle with a displacement of several tens of tons, 8.5 MW is a monstrous amount. More than the nuclear power plant of the Ryubi multipurpose submarine can develop.
7 MW (9,500 hp) on the propeller shaft allows the 2,500-ton French submarine to develop an underwater speed of 25 knots.
However, the miniature "Rube" was not built for records, but to save money. A much more significant example is the Soviet multipurpose submarine pr. 705 (K) "Lira"!
Despite its significantly large dimensions, "Lyra" approximately corresponded to the "Ryubi" in displacement. Surface ship - 2300 tons, underwater - 3000 tons. The titanium case was lighter than the steel one. And Lyra herself was a star of the first magnitude. Equipped with a reactor with a liquid metal coolant, she developed a speed of over 40 knots under water!
1.6 times faster than Rube. What power did the Lyra's power plant have? That's right, 1, 6 cubed.
29 megawatts (40,000 hp) with a reactor thermal power of 155 MW. Outstanding performance for a submarine of such a small size.
Nowadays, the creators of Poseidon face an even more difficult and non-trivial task. Place a nuclear power plant with 3, 4 times less power (8.5 MW) in a case with approximately 50-60 times less displacement.
In other words, the specific energy indicators of the Poseidon nuclear reactor should be 15 times higher than that of the reactor with a liquid metal coolant (LMC), which was used on Project 705 (K) submarines. The same, 15 times greater specific efficiency should be demonstrated by all the mechanisms associated with the conversion of the thermal energy of the reactor into the translational energy of the movement of the underwater vehicle.
100 knots is a very high speed in the water, requiring EXCLUSIVE energy costs. Probably those who drew the beautiful figure “100 knots” did not fully realize the paradoxical nature of the situation.
Unlike the Shkval submarine missile, the use of a solid-propellant rocket engine for the Poseidon is out of the question - it has a declared cruising range of 10,000 kilometers. The "torpedo of the Apocalypse" requires a nuclear installation that provides 15 times more power density than all known reactors with liquid metal fuel.
The main discussions related to the appearance of the Poseidon nuclear torpedo are conducted in the plane of the economy and the military-industrial complex. Loud statements about the creation of miracle weapons were made against the background of, to put it mildly, modest successes in the creation of traditional weapons. Since 2014, not a single nuclear submarine has been accepted into the Navy.
On the other hand, as you know, everything is possible if you wish. But to create technologies that provide a multiple increase in opportunities, desire alone may not be enough. As a rule, such studies are accompanied by intermediate results, but Poseidon is surrounded by an impenetrable veil of secrecy.
