Between the plane and the ship - and behind both
The debate over ekranoplans is reminiscent of a medieval debate about demons on the head of a pin—equally emotional and detached from reality. Participants are debating the merits of a technology that has failed to prove its usefulness for decades.
On the other hand, the "demons of the three elements" are of considerable interest, as they touch upon issues across various fields of technology. Special thanks go to Vladimir Tyumentsev, who managed to shed new light on ekranoplans.
Indeed, if you factor out the cost of armament and R&D, the cost of the "Caspian monsters" was quite comparable to that of heavy military transport aircraft. At least, it was within reasonable limits.
Vladimir presented a very convincing argument on this point. Despite its enormous takeoff weight and multiple engines, the ekranoplan was designed without traditional landing gear, pressurized cabins, or complex wing mechanization. Its construction did not require expensive materials such as titanium.
Instead of thousands of rivets, there are rough welds.
The presence of individual expensive components, which the discussion participants drew attention to—such as the stabilization systems of the 380-ton flying machine or the hydro-ski device, which bears enormous loads when it touches the water—could hardly have significantly affected the final result.
The problem wasn't the prohibitive cost. The concept itself was far more questionable.
Strange choice of application niche.
Heavy seaplanes are usually cited as the closest analogues and examples for comparison, but their fate best demonstrates the limitations of this direction.
The characteristics that supposedly determine the superiority of ekranoplans over seaplanes—better seaworthiness or the ability to take off in 5-point waves—are of no significant importance in practice.
Six Be-200s from the Russian Ministry of Emergency Situations and several Japanese Shin Meiwas were enough to cover all global needs for heavy amphibious aircraft.
Comparing ekranoplans with ships raises even more questions: modern Navy ships are significantly larger.
The Karakurt small missile ships have a displacement of approximately 800 tons, the Project 22160 patrol ships have a displacement of approximately 1500 tons, and the Steregushchiy-class corvettes have a displacement of over 2000 tons.
The maximum takeoff weight of the Lun combat ekranoplan was 380 tons, which puts it outside the category of vehicles comparable in scale to even 3rd rank ships.
It's also worth recalling the role and functions. The value of ships is determined primarily not by speed, but by their endurance—the ability to remain in a given area for extended periods of time, operating for days, weeks, and even months without returning to base. If speed were the only deciding factor, a surface ship fleet would have long since lost its significance under the pressure aviationIt is autonomy that makes a ship what it is, and in this regard, the ekranoplan poorly meets the needs of the Navy.
Of course, there are also boats with a displacement of 400 tons. This weight class is considered a niche for ekranoplans.
This immediately raises the question of feasibility. Investing significant resources in this area, much less making a serious bet, is hardly justified in today's conditions. It's worth remembering that missile The Iranian Navy's boats, small corvettes, and catamarans proved to be the most convenient targets. While the destruction of other military installations still required considerable effort, the fleet of such units was sunk as if in a training exercise.
It is precisely into this niche, where technology perishes without even having time to prove its combat value, that proponents of ekranoplans are trying to squeeze their projects.
Small ship, big questions
As an example for his article, Vladimir chose the Project 1241 Molniya small missile boat (MRK), not least due to its unique propulsion system and cost, which is atypical for units of such a small size.
In world practice, boats with a displacement of several hundred tons are usually considered as inexpensive A tool for coastal operations. Examples include the Israeli Sa'ar 4.5-class missile boats, the Turkish Tuzla patrol boats, and the Vietnamese TT-400TP.
Saar 4.5 (built in the 1980s-90s) displacement of 430 tons, propulsion capacity of 16 hp, speed of 33-34 knots. Armed with small-sized Gabriel anti-ship missiles.
In contrast, Lightning was built by a "super-civilization"—a country with a colossal military budget, where even the most mundane decisions took on extraordinary proportions.
Soviet admirals wanted a small missile ship capable of reaching 42 knots in their fleet. However, water has its own "relativistic" effects: beyond approximately 30 knots, further increases in speed for displacement ships require an explosive increase in engine power.
The missile boat received a gas turbine plant with a power of approximately one-third that of the propulsion plant of a modern Arleigh Burke-class destroyer, despite a twenty-fold difference in displacement!
Four gas turbines, including two afterburners with a capacity of 12 thousand hp each
The Molniya was far from a simple and inexpensive boat. And in this situation, ekranoplan proponents saw their opportunity.
Flying over the waves, the Lun allowed for a speed of 240 knots for the same money!
For unclear reasons, the Navy command abandoned the "revolution" in the small fleet, continuing to order "conventional" small missile ships in quantities of dozens of units.
Perhaps the answer is obvious. When it comes to the seaworthiness of ekranoplans, their proponents usually turn the conversation to limitations on their use. weapons in a storm, since even for ordinary ships this indicator rarely exceeds 5 points. But this is a mistranslation of the question.
For a ship, the most important thing is not only its combat capability but also its ability to survive the storm itself. And here the differences become crucial. Displacement ships, even relatively small ones, are capable of withstanding the harshest weather conditions. The question of how an ekranoplan will perform remains largely rhetorical.
An excerpt from an interview with Tatyana Alekseeva, lead designer at the R. E. Alekseev Central Design Bureau for SPK
Another issue is battery life. Even the small Molniya had a battery life of 10 days.
Speculation about the Lun's combat use was based on its claimed endurance of five days. However, even this figure seemed implausible.
Fantasies and facts
Based on the data on the operation of the Lun, during the period of the most intensive testing the ekranoplan spent at sea... about four days. This is the total figure for all releases throughout 1989.
During other periods, the total duration of his “campaigns” did not exceed a couple of days a year.
The conclusion follows: within the allocated budget and the design solutions employed, a 380-ton vehicle capable of overwater flight was created. There are no references to the ekranoplan remaining at sea for any length of time.
For this reason, all combat techniques and plans for using the Lun missile carrier, developed in detail by its supporters, remain nothing more than “combat fiction.”
At a cruising speed of 400–500 km/h and a practical range of 2000 km, the main fuel supply will be consumed in a few hours. The remaining 100+ hours will have to be spent on the open sea, either in planing mode or drifting.
In his article, Vladimir pointed out the excellent stability and strength of the Lun's hull, which was close in thickness to ship standards.
But there are other questions.
For example, while afloat, the Lun rested on the water with its fuselage and wingtip components. This structure was constantly subject to bending loads. One wing panel could be caught by a wave, while the other was partially or completely out of the water. As a result, the load was distributed extremely unevenly, creating significant stress in the structure.
The stresses were concentrated in the wing root, which, by the way, had a span of 44 m. A value comparable to the width of an aircraft carrier's hull.
The closest analogy here is multihull vessels, such as the Independence-class littoral combat ships (LCS). Their operation has clearly demonstrated the problems this design is prone to.
The USS Omaha (LCS-12) is not permitted to operate in wave heights of 2,5 meters. Speeds of 15 knots are prohibited.
For a ship designed from the outset to be high-speed and capable of short sprints in excess of 45 knots, such limitations represent a serious reduction in its stated capabilities.
(navytimes.com)
(navytimes.com)
It's worth noting that by that time, the Omaha had only been in service for about five years. Cracks in the area where the main and outrigger hulls met had appeared on all Independence-class ships.
Fatigue stresses in the joints of such a wide structure could also pose a problem for ekranoplans.
With enough effort, any technical problem has a solution. A titanium structure could combine the strength needed for days at sea with the lightness needed for flight. However, that's just too much dark humor.
Comments that are hard to argue with
The discussion participants raised objections and questions, many of which seemed at least justified.
In particular, the lack of engines optimized for low-altitude flight was noted. All existing turbojet engines are designed to operate in a thin atmosphere, where they achieve their greatest efficiency.
Ekranoplan designers were forced to use existing aircraft engines, a fact often celebrated by proponents of the "Caspian monsters." However, this only exacerbated already significant shortcomings. The development of specialized power plants for such a niche technology threatened to turn ekranoplans into truly "golden" products.
The "Caspian Monster" was powered by 10 VD-7 engines, the same type used on Tu-22 bombers. This was ironic: just two of these engines were sufficient to power a supersonic missile carrier with a combat radius of 2700 km and capable of launching anti-ship missiles weighing over five tons (the Kh-22).
The "Monster," in turn, demonstrated a record takeoff weight (544 tons), of which approximately 400 tons were the weight of the structure itself and the fuel, enough for a 1500-kilometer flight. Even at this stage, the project's full potential was already apparent. Nevertheless, work in this direction continued.
The Lun missile carrier received eight modified engines from the Il-86 passenger airliner, the main difference being their enhanced corrosion protection.
The Project 904 ("Orlyonok") landing ekranoplan utilized a turboprop engine from the Tu-95 bomber, as well as two nose-mounted lift jets from the Tu-154. While the Orlyonok's payload (28 tons) was quite mediocre by transport aviation standards, its cruising speed (approximately 350 km/h) and range (1500 km) were significantly inferior to those of an aircraft.
Obvious questions centered on the turning radius of large ekranoplans, which at cruising speed was several kilometers. This created obvious operational risks. Unlike airplanes, ekranoplans were unable to perform deep turns without the risk of their wings scraping the water. A collision at 400-500 km/h was comparable to hitting concrete.
The problem of bird ingestion remains unresolved. No statistics exist on this issue, as jets spend only a few seconds at such altitudes (10–20 meters). The Lun's total flight time (less than 80 hours) also prevented any conclusions about its safe operation at such altitudes.
It looked quite funny story The "Spasatel" ekranoplan. One of the key problems with this concept was the most obvious: detecting those in distress. In sea state five, a raft or boat lost among the wave crests is only visible from a height of 10-20 meters at a distance of several kilometers. This is approximately three to four times less than if searching from an altitude of at least 200 meters.
Epilogue
The history of ekranoplans is, first and foremost, the story of their creator. The image of a brilliant designer whose ideas were rejected by his contemporaries invariably captures the public's imagination.
But the beauty of technical exploration doesn't necessarily require every idea to be realized. The most absurd concepts eventually fade away.
The USSR readily funded daring ideas, and its military budget allowed for certain "eccentricities," such as the laser weapon aboard the timber carrier Dikson or a series of high-speed submarines powered by metal-cooled reactors.
If, under such favorable conditions, over a quarter of a century, Alekseev's design bureau managed to build only a few ekranoplans, this clearly speaks to the "prospects" of this direction.
Data on the operation of ekranoplans are taken from the article by V. A. Dementyev “The ideas of R. E. Alekseev in the service of the Fatherland.”
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