The twentieth century has become a breakthrough in many areas of technological progress, in particular in increasing the speed of vehicles. For ground vehicles, these speeds have increased significantly, for air - by orders of magnitude. But on the sea, humanity ran into a dead end.
The main qualitative leap took place back in the nineteenth century, when steam ships appeared instead of sailing ships. But very soon it became clear that the main speed limiter for sea vessels is not the weakness of the power plant, but the resistance of the water. As a result, the speed record set by the Russian destroyer Novik on August 21, 1913 (37.3 knots) was actually the ultimate dream for large displacement ships (recall that a knot is one nautical mile, that is, 1852 m / h).
This record was broken, of course. Before World War II, Italian and French leaders and destroyers rushed very quickly across the Mediterranean, sometimes reaching as much as 45 knots. It is not clear, however, why they needed this speed, since it was the Italian and French fleets that fought the worst in World War II. Broke Novik's record, winning the Blue Ribbon of the Atlantic in the early 1950s, the American liner United States (38, 5 knots). But even these speeds were achieved by a few ships and at very short distances. In general, for warships, the maximum speed today rarely exceeds 32 knots, and the cruising speed (at which the maximum cruising range is reached) has always been below 30 knots. For transport ships and 25 knots was a unique achievement, most of them are still dragged across the seas at speeds not exceeding 20 knots, that is, less than 40 km / h.
The appearance of diesel, gas turbine, even nuclear engines, at best, gave an increase in speed by several knots (another thing is that diesel engines and nuclear power plants made it possible to dramatically increase the cruising range). The impedance grew like a wall. The most important means of dealing with it was to increase the ratio of the ship's hull length to its width. Too narrow a ship, however, had poor stability, in a storm it could easily roll over. In addition, it was difficult to fit various systems and mechanisms into the narrow body. Therefore, only some destroyers, due to the narrowness of the hulls, set their speed records, this did not become a trend even for warships, and for cargo ships, narrowing of the hulls was in principle unacceptable.
Aviation has almost completely replaced sea vessels in terms of passenger traffic, but as far as cargo transportation is concerned, almost all of them still account for water and rail transport. Carrying capacity for aircraft remains nearly as critical as speed for ships. Therefore, engineers continue to struggle to solve both problems.
For commercial shipping, the problem of low speeds is largely mitigated by the large number of vessels on the lines. If tankers (container ships, banana carriers, timber carriers, etc.) leave point A every day, then they will come to point B every day, regardless of the speed of each individual vessel. The main thing is that there are enough ships to maintain such a schedule.
For the Navy, speed is, of course, much more important. And for warships (here explanations, perhaps, are superfluous), and for transport and landing ships carrying troops. Moreover, the latter now, when wars have acquired a global scale, has become more important than the first (especially since for warships, some compensation for their own low speed was the presence of missile weapons: the rocket will catch up with anyone).
Since the unsolvability of the problem of wave resistance became clear long ago, then, along with the pursuit of units of nodes by improving the hull contours and the shape of the propellers, strengthening the power plants on ordinary ships, the search for something unusual began.
At the end of the 19th century, the effect of the lifting force on a plate towed under water at a slight angle of inclination to the horizon was discovered. This effect is analogous to the aerodynamic effect that acts on the wing of an airplane and allows it to fly. Since water is about 800 times denser than air, the area of the hydrofoil could be as much less than the area of an airplane wing. If you put a ship on the wings, then at a sufficiently high speed the lifting force will lift it above the water, only the wings will remain under it. This will significantly reduce the resistance of the water and, accordingly, increase the speed of movement.
The first experiments with hydrofoils were carried out in France and Italy, but they reached the greatest development in the USSR. The chief designer of such ships was Rostislav Alekseev, who headed the corresponding Central Design Bureau (it was located in Gorky). A number of passenger ships and combat hydrofoils were created. However, it quickly became clear that the displacement of hydrofoils was very limited. The higher it is, the larger size and mass the hydrofoil should reach and the more powerful the power plant should be. Because of which, even a hydrofoil frigate is almost impossible to create.
As a result, the matter did not go beyond "suburban transport" - "Rockets", "Comet" and "Meteors" - and a number of combat boats on hydrofoils. For the Soviet Navy and the border troops, 2 anti-submarine hydrofoil ships, pr. 1145 and 1 pr. 1141, 1 small missile ship (MRK), pr. 1240, 16 patrol boats, pr. 133, 18 missile boats, pr. 206MR were built. Most of them have now been decommissioned. One missile ship on hydrofoils of the project 206MR turned out to be the very Georgian boat "Tbilisi", which in August 2008, in accordance with the legends and myths of agitprop, was sunk by the Russian MRC "Mirage" in a sea battle, but in fact was thrown by its crew in Poti and blown up by our paratroopers.
Abroad, hydrofoil boats also practically did not receive development. The USA built 6 Pegasus missile ships on hydrofoils, Italy - 7 Sparviero-type missiles, Israel - 3 M161-type missile launchers, and Japan - 3 PG01-type missile launchers. Now all of them, except for the Japanese ones, have been decommissioned. China stamped more than 200 Huchuan-class hydrofoil torpedo boats, they were also exported to Romania, Albania, Tanzania, Pakistan, which then transferred them to Bangladesh. Now in the ranks there are only 4 Bangladeshi and 2 Tanzanian "Huchuan". In general, for the naval forces of the whole world, the CPC turned out to be a dead-end branch of development.
Hovercraft (KVP) became somewhat more promising. This very cushion is created by blowing compressed air under the bottom of the ship by fans, due to which the ship rises above the water and the wave drag disappears completely. That allows not only to develop a tremendous speed (50-60 knots), but also to go ashore.
Hovercraft were most developed again in the USSR (starting from the 1920s). The West began to develop this direction only in the late 1950s. It soon became clear that for such ships there is almost the same fundamental problem as for hydrofoil ships - their useful mass cannot be large. To support the weight of a heavy ship, you need to install very powerful fans. And for the movement of the ship, huge and powerful propellers are needed, which take up a lot of space and are extremely vulnerable in battle.
As a result, the scope of such ships turned out to be very limited. In the USSR, quite a few amphibious air cushion ships (DKVP) of various types were built. The possibility (thanks to the ability of such ships to go ashore) seemed very attractive to land troops "without getting their feet wet." True, their landing capacity was rather limited, and the vulnerability to fire even from small arms was extremely high (it was the propellers that were especially vulnerable). The largest steel DKVP pr. 12322 "Zubr" (displacement more than 500 tons, length 56 m, speed up to 60 knots, capable of taking on board 3 tanks or 140 marines). Russia now has only 2 of these ships, but we sold 3 to Greece. We now have about 10 old DKVP pr. 12321, 1206 and 1205 smaller.
In addition to Russia, the LCAC air cushion landing craft (150 tons, 50 knots, carries 1 tank) was created in the USA. About a hundred such boats have been built, they are based on American universal amphibious ships and amphibious dock ships. Landing craft project 724 in the amount of about 30 pieces were built in the PRC. These are probably the smallest hovercraft in the world: 6.5 tons, length 12 m, they take 10 paratroopers on board.
Small (from 15 to 100 tons) air cushion patrol boats were built by the British in the 1970s, including for sale to Iran (even under the Shah) and Saudi Arabia. One British-built Iranian KVP VN.7 type died during the war with Iraq.
In the end, both domestic and foreign designers came to the idea of replacing the rubber "skirt" supporting the air cushion with rigid plates called skegs. They keep the air inside the pillow much better than the "skirt", which makes it possible to increase the mass of the ship. In addition, since the skegs enter the water, propellers or water cannons can be installed on them, removing bulky and vulnerable propellers from the deck of the ship. At the same time, the resistance of the skegs is, of course, greater than that of the "skirt", but much lower than that of hydrofoils. Their only drawback is that the ship is deprived of the opportunity to go ashore. Therefore, it is advisable to build skeg KVP in the form of shock ships or minesweepers. In the latter case, the advantage is that the smaller part of the ship is in the water and the higher its speed, the less chance of being blown up by a mine.
So far, Russia and Norway have a monopoly on such ships. In the Black Sea Fleet we have 2 skeg MRK pr. 1239 ("Bora" and "Samum"), the largest hovercraft in the world (displacement over 1,000 tons). They have tremendous striking power (8 supersonic Moskit anti-ship missiles) and a speed of 53 knots. The disadvantage of these ships is weak air defense and, most importantly, extreme difficulty in operation.
The Norwegian Navy includes 6 Skjold-type skeg missile boats and Oxøy-type minesweepers. They are much smaller than our RTOs (250-400 tons). At the same time, the missile boats carry 8 NSM supersonic anti-ship missiles. It can be noted that (except for Russia and Norway), only China has supersonic anti-ship missiles.
Although hovercraft are more promising than hydrofoils, they in no way solve the problem of speed because of the many restrictions described above, as well as the high cost and complexity of operation.
