"Poseidon" will go into battle, guided by the seabed
The story of the Poseidon’s military campaign to the US coast should begin with a way to navigate under water.
Salt seawater is an electrolyte that prevents the spread of radio waves. At the depths at which Poseidon will operate, the external radio control of the device, as well as the reception of signals from Glonass / GPS satellites, is not possible.
An autonomous inertial navigation system (ANN) is capable of leading the Poseidon throughout the day, but its capabilities are also not unlimited. Over time, the ANN accumulates an error, and the calculations lose their reliability. An auxiliary system using external landmarks is required.
The installation of “hydroacoustic beacons” at the bottom is a meaningless event in the face of the enemy, who is able to immediately track and disrupt their work.
The problem of underwater navigation for the Poseidon apparatus can only be solved with the use of a relief navigation system. But is it possible to adapt the navigation systems used in cruise missiles to work underwater?
Firstly, you need a map of the seabed.
Myth No.1. It is impossible to make a map along the entire route of Poseidon
In discussions on the Doomsday Torpedo, it has been repeatedly believed that mapping the entire bottom of the Atlantic Ocean, from the Barents Sea to New York Harbor, can take more than a decade and will require extraordinary effort.
In reality, for a relief-based navigation system, this amount of work is redundant and simply unnecessary.
The proof is the described principle of the TERCOM (Terrain Contour Matching) system for the Tomahawk missile. According to the statement of Western experts, when flying a cruise missile over land, 64 correction areas are selected. 7-8 km lengths 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 only works on a quarter of the route (with a range of KR about 2000 km), the rest of the time the rocket flies under the control of the ANN. The accuracy of accelerometers and gyroscopes is enough to bring Tomahawk to the next correction area, where, according to TERCOM, the ANN will be amended.
Last year, relief navigation systems celebrated their 60 anniversary. At the end of the 50's. they have become a worthy replacement for astrocorrection systems. Cruise missiles needed to go to low altitudes, from where the stars were not visible.
Even the most severe storm is unable to disturb the calm of the deep sea. The movement of the underwater vehicle is associated with less perturbations than the low-altitude flight of the RS in the atmosphere. That is why the data of inertial systems on board submarines remain valid for a significantly longer time (days).
The conclusion that can be drawn from the available facts: when laying the routes of Poseidon, 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 No.2. Sonar is not able to provide the necessary accuracy of scanning the bottom
The permissible error in measuring the height of the relief during TERCOM operation is not more than 1 meters. What accuracy do modern sonar products designed for bottom mapping provide? Is it possible to place such a sonar in a limited-sized Poseidon case?
The answer to these questions will be sonar images of the remains of ships. At the first is the Japanese Mogami cruiser, discovered in May of this at a depth of 1450 m.
The second image shows the Hornet aircraft carrier sunk in battle near Santa Cruz Island. The remains of the aircraft carrier are at a depth of 5400 meters.
The detail of these images is conclusive evidence in favor of seabed mapping systems. By the way, the pictures were taken by Paul Allen’s team from his side
Myth No.3. The bottom topography is subject to change
Time will pass, and digital bottom cards will lose their relevance. Somewhere in a million years, it will be necessary to compose new ones.
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 middle part of the Atlantic Ocean is 2 centimeters over 1000 years. For the Pacific, even lower values are indicated.
It is hard to believe the reality of these numbers, but the paradox has a simple explanation. Nobody throws stones in the middle of the ocean, spills gravel and gravel M600 into the Mariana Trench. All objects that have fallen into the ocean are first dissolved and decomposed in water. Particles dissolved in the sea thickness take millennia to reach the bottom.
In coastal areas, the rate of sediment accumulation is orders of magnitude higher due to sediment load and sediment brought by rivers. However, the ocean is too large to make any difference in this case.
Despite the increased tectonic activity, the frequency of cataclysms on the ocean floor, associated with talus, avalanches and displacements 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-like descent on the side of a seamount. Now it will take hundreds of thousands of years until enough deposits are accumulated on its slopes for the next cataclysm.
Young underwater volcanoes, swell-like structures along the ocean ridges (formed when the Earth's axis is displaced) are all “young” only by the standards of geological eras. The age of these formations is millions of years!
Gloomy calm reigns in the ocean depths. The absence of winds, erosion and any signs of urbanization makes the terrain unchanged for millennia.
For comparison. How many problems do cruise missiles fly over land? The digital mapping process for TERCOM is hampered by seasonal changes in terrain. Everywhere there are uniform forms of relief in which the use of TERCOM is physically impossible. Routes bypass large ponds, missiles avoid snow-covered plains and sand dunes on their way.
Unlike 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 navigation method for the Poseidon underwater vehicle.
Why is this method not yet applied in practice? The answer is that this was not necessary. Unlike the Poseidon, which is constantly moving in the depths, submarines regularly rise to the surface for communication sessions. The submariners have the opportunity to get the exact coordinates using space navigation aids (Cyclone, Sail, GLONASS, GPS, NAVSTAR).
The fastest under water
In this part of the article we will not discuss specific technical solutions; the design of the Poseidon is covered in a veil of military secrecy.
However, we have the opportunity, on the basis of declassified characteristics, to calculate other interrelated parameters of an unmanned underwater vehicle with a nuclear power plant.
For example, the claimed speed is known - 100 nodes. What is the power of the Poseidon power plant?
There is a rule of thumb. For any displacement object, the power of the power plant increases to a third degree from the speed.
Example. The Soviet torpedo "53-38" (53 - reference to the caliber, 38 - the year of adoption) had three speed modes: 30, 34 and 44,5 units with engine power 112, 160 and 318 hp respectively. As you can see, the rule is not lying.
And the age of the torpedo itself has absolutely nothing to do with it. The same torpedo required three times more power to increase the speed by 1,5 times.
The following example is more interesting. The heavy torpedo "65-73" caliber 650 mm had a length of 11 meters and a mass of 5 tons. The torpedo was equipped with a 2 MW (1,07 hp) 1450DT short-life gas turbine engine - one of the most powerful ever used in a torpedo weapons. With it, the estimated speed of the product "65-73" could reach 50 knots.
Theoretical question: what engine power could provide the 65-73 torpedo with the speed of 100 nodes?
The speed will double, which means that the required power of the power plant will increase eight times. 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 with the Sarov experimental diesel-electric submarine), it should be noted that the dimensions of the Poseidon are much more suitable for torpedo weapons than the size of submarines. The smallest of which (the domestic Lira and the French Rubin) had a displacement of about 2,5 thousand tons.
The caliber, length and displacement of the Poseidon can be several times greater 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 achieve the speed of 50 nodes, the Poseidon, like the 65-73 torpedo, needs at least 1450 hp, for 100 nodes, it would take at least 11600 hp (8,5 MW) net power.
How different in size are the engines of the same power enough?
For displacement objects, whose sizes vary within the same order, the difference in displacement does not require a sharp increase in the power of the power plant. A striking example is at the same speed the power of the power plants of a typical destroyer and an aircraft carrier differ by only two times with an 10-fold difference in the displacement of these ships! Much more problems arise from the desire to increase speed on the 3 node.
We summarize. When driving at a declared speed of 100 knots (185,2 km / h), the Poseidon will require a power plant with a net power of at least 8,5 MW (11 600 hp).
We fix this value as the lower boundary and will focus on it in the future.
8,5 megawatt - is it 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 - this is a monstrous amount. More than the nuclear power plant of the Ryubi multipurpose submarine is capable of developing.
7 MW (9500 hp) on the propeller shaft allow the 2500-ton French submarine to develop underwater speeds at 25 nodes.
However, the miniature "Ryubi" was not built for records, but to save money. A much more significant example is the Soviet multipurpose submarine, etc. 705 (K) Lira!
Despite its significantly large dimensions, the Lira was roughly equivalent in terms of displacement to the Ryubi. Above-water in / and - 2300 tons, underwater - 3000 tons. The titanium case was lighter than steel. And Lira itself was a star of the first magnitude. Equipped with a liquid metal coolant reactor, it developed under water speeds above 40 nodes!
1,6 times faster than Ryubi. What power did the Lira power plant have? Right, 1,6 in a cube.
29 megawatts (40 000 hp) at a thermal power of the 155 MW reactor. Outstanding performance for submarines of such a small size.
Today, the creators of Poseidon are faced with an even more complex and non-trivial task. Place a nuclear power plant with 3,4 times less power (8,5 MW) in a casing with approximately 50-60 times less displacement.
In other words, the specific energy performance of the Poseidon nuclear reactor should be 15 times higher than that of a reactor with a liquid metal coolant (LMT), which was used on submarines of the 705 (K) project. 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 motion of the underwater vehicle.
100 knots - very high speed in water, requiring EXCLUSIVE energy costs. Probably those who drew the beautiful figure “100 knots” did not fully realize the whole paradox of the situation.
Unlike the Shkval submarine rocket, the use of a solid propellant rocket engine for Poseidon is ruled out - it has a range of 10 000 kilometers. “Torpedo of the Apocalypse” requires a nuclear installation that provides 15 times greater specific power than all known reactors with iron-ore fusion.
The main discussions related to the appearance of the Poseidon nuclear torpedo are conducted in the economy and defense industry. Loud statements about the creation of miracle weapons were made against the background, to put it mildly, of 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 desired. But to create technologies that provide multiple growth opportunities, one desire may not be enough. As a rule, such studies are accompanied by intermediate results, but Poseidon is surrounded by an impenetrable veil of secrecy.
Information