Flying over water: a century of hydrofoil ships
To be meticulous, we are talking about more than a century. Back in 1869, Parisian Emmanuel Denis Farko received a patent with the formula: "Fastening on the sides and bottom of the vessel inclined planes or wedge-shaped elements, which, when the vessel moves forward, will raise it in the water and thus reduce drag." In the years that followed, many patents were issued relating to various methods of raising a ship (in whole or in part) above water in order to increase its speed or improve its wave behavior. Count de Lambert, a Russian citizen living in Versailles, filed a patent application in 1891. He strengthened several independently adjustable wings (lifting planes) along the sides of the ship, which, as the speed grew, were supposed to raise the ship above the water. However, the very arrangement of these primitive wings, in principle, made it impossible to completely raise the ship above the surface of the water.
But the true story of the hydrofoil begins with the Italian engineer Enrico Forlanini. He began working with a hydrofoil in 1898, and a series of model tests allowed him to derive mathematical laws. Based on the formulas, he set about designing and building a full-scale vessel. Forlanini's designs were distinguished by a "stepwise" arrangement of wings. Experiments with models showed that the lift is proportional to the square of the speed - thus, with increasing speed, a smaller wing area was required. The “step-by-step" scheme was invented precisely in order to ensure automatic reduction of the area. The experimental vessel weighed about 1200 kg, it was equipped with a 60-horsepower engine, which propelled two propellers rotating in opposite directions. The design speed of the vessel was 90 km / h, but during tests on Lake Maggiore in Italy in 1906, a speed of 68 km / h was achieved.
The earliest experiments with hydrofoils brought the greatest fame to one American who lived in Canada. It was Alexander Graham Bell. Together with Frederick W. (Casey) Boldwin and Philip L. Rhodes, he designed and built several hydrofoil ships, including the HD-4, equipped with two Liberty engines. On September 9, 1919, this ship set an official speed record, showing 114 km / h. Later, to improve the driving performance of the HD-4, a lot of changes were made to the design, but this record was never officially surpassed.
The initial stage in the history of hydrofoil ships will be incomplete, if you do not pay tribute to the genius of Baron Hans von Shertel. Baron’s experiments (as his friends called him) with hydrofoils began in 1927. The fact that hydrofoils from an unreliable, unstable exotic toy capable of running only “on smooth water” turned into modern safe, efficient, high-speed vehicles is largely due to von Schertel.
Meanwhile, interest in submarine vessels woke up again in Canada, and a 15-meter five-ton boat was built on Lake Massauippi in Quebec, based on Baldwin’s latest projects. After several demonstration tests in rather stormy weather, the ship was transferred to the Naval Research Institute, where it received the official name R-100. However, the unofficial name - “Massauippi” - was used much more often. The R-100 experiments were deemed successful, and the Canadian government decided to fund the construction of another experimental vessel by Saunders-Roe in England. The R-103 with a displacement of 17 tons had an aluminum body (the R-100 was completely wooden), stacked wings and racks made of sheet aluminum riveted to aluminum ribs and stringers (previously these elements were monolithic). The propulsion unit was organized in a fundamentally new way - transmission shafts through bevel gears connected at right angles, the stern tube, as in an outboard motor, went vertically downward, and at its end there was a fairing with two screws - rear and front. This complex design is radically different from a simple long shaft that slopes downward, as implemented in the R-100. On board were installed two 12-cylinder gasoline engines Rolls Royce Griffon with a capacity of 1, 500 hp.
Then other times came, and the attention of the Canadian military focused on the fight against submarines. The role assigned to hydrofoil vessels in these strategic plans required maximum mobility and versatility. A very economical alternative to the development of powerful long-range sonars, which are installed on large ships, involves the deployment of a large number of low-power devices. In 1964, the hull of the new BRAS D'OR vessel was laid down, however, on November 5, 1966, during the construction work in the main engine room, a devastating fire broke out, which almost led to the cessation of the entire program. Nevertheless, despite all the delays and additional financial costs, the new ship with the FHE-400 index and the same name BRAS D'OR was launched in 1967. Later this ship was used in trials and experiments, and also participated in naval parades.
In Russia, unlike the United States and generally the entire Western world, many thousands of hydrofoil vessels were widely used in regular shipping on many rivers, canals and lakes. This is easy to understand, given that in a huge country with a general shortage of cars and roads there are 150, 000 rivers and 250, 000 lakes. Krasnoe Sormovo in Gorky is one of the oldest shipyards in the Soviet Union. In addition to a variety of displacement vessels for the river fleet, this shipyard also built many hydrofoil passenger vessels, and the variety of models had no analogues worldwide. The father of Soviet hydrofoil boats was Rostislav Alekseev, who had been developing such systems since the early 1940s.
In the courts, the effect of the underweight hydrofoil (Alekseev effect) was used. Alekseev’s underwater wing consists of two main horizontal bearing planes - one in front and one in the back. When converging, the dihedral angle is either small or absent; the weight distribution is approximately equal between the front and rear planes. A submerged hydrofoil, rising to the surface, gradually loses its lifting force, and at a depth approximately equal to the length of the wing chord, the lifting force approaches zero.
It is thanks to this effect that a submerged wing is not able to fully surface. At the same time, a relatively small hydroplanning (sliding on the surface of the water) wing liner is used to help with the "exit to the wing", and also does not allow the vessel to return to the displacement mode. These fenders are located in close proximity to the front struts and are mounted so that they touch the surface of the water on the fly, while the load-bearing wings are submerged approximately to a depth equal to the length of their chords. The whole system was first tested on a small boat, which set in motion a 77-horsepower car engine.
On the basis of Alekseev’s developments, a large number of commercial hydrofoil vessels were built in Russia: Rocket, Strela, Sputnik, Meteor, Comet, Cyclone, Petrel, Sunrise ... military vessels, including the largest vessel of this class in the world - the Butterfly, it was preceded by the Bee, Turia and Locust.
The essence of the concept is to raise the hull of the vessel from the water and maintain it in this position in a dynamic mode, using for this purpose planes, which are commonly called hydrofoils. As a result, it is possible to reduce the influence of waves and reduce energy consumption when driving at high speed, often unattainable in the usual (displacement) mode. It is necessary to pay with increased draft at low speeds and stability problems. For vessels with completely submerged wings, which almost completely “isolate” the hull of the vessel from the influence of waves, but are devoid of self-stabilization, an “autopilot” is needed that monitors the position of the vessel and adjusts the lift of the wings by changing the angle of attack and deflecting the flaps.
Western Europe also did not stand aside. Gustoverft in the Netherlands, Westermoen in Norway, Vosper Thornycroft in the UK are actively engaged in the design and construction of hydrofoils. But the most successful commercial projects designed and built in Western Europe are, of course, the works of the Italian Rodriquez Centieri Navali. Among its many products, it would be worth noting the RHS series of commercial vessels. Over the years, ships of this series grew in size and dared to go into those waters where their wings, in principle designed to glide over the surface, were subjected to such loads that could not be found in rivers, lakes and coastal lagoons. To create acceptable conditions for passengers, Rodriquez developed the “Seakeeping Augmentation System (SAS)”, which, as practice has shown, successfully fights vertical, keel and side-to-side rolls with sufficiently strong excitement.
In the early 1950s, New York shipbuilding company Gibbs & Cox joined forces with a team of specialists from the US Navy to create a versatile hydrofoil pilot. The device was built by Bath Iron Works and named BIW. It was a boat 6 m long, one and a half wide and a displacement of 0.8 tons, with a 22-horsepower outboard engine. BIW is very useful for testing various layouts of hydrofoils, control systems, various sensors. The most important result of this work was the foundations for the development of an electro-hydraulic autopilot, as well as the decision to build a new vessel of this series - SEA LEGS (“Gait of a Sailor”). An electronic autopilot containing 160 radio tubes was developed by Draper Laboratory in collaboration with the Massachusetts Institute of Technology. In 1957, SEA LEGS made its first voyage, demonstrating excellent seaworthiness with a high wave at speeds of up to 27 knots.
This success inspired the shipbuilders, and in the American Navy seriously engaged in experimental hydrofoils. These were Little Squirt, Hydrodynamic Test System (HTS), Foil Research Experimental Supercavitating Hydrofoil (FRESH-1). Several experimental devices were built by Boeing and Grumman / Lockheed Shipbuilding - High Point (PCH-1), Flagstaff (PGH-1), Tucumcari (PGH-2) and Plainview (AGEH-1). All devices, from Flagstaff with a displacement of 57 tons to Plainview with a displacement of 320 tons, clearly demonstrated the capabilities and potential applications of hydrofoils in military operations. As a result, the Boeing Marine Systems division built a patrol vessel PHM (Patrol Hydrofoil Missile Ship) specifically for the US Navy. According to NATO plans, it was planned to build 26 of these ships, however, Germany and Italy refused to participate in this project, so that from 1977 to 1982 only six ships named after the constellations came into operation: PHM-1 PEGASUS (Pegasus), PHM -2 HERCULES ("Hercules"), PHM-3 TAURUS ("Taurus"), PHM-4 AQUILA ("Eagle"), PHM-5 ARIES ("Aries") and PHM-6 GEMINI ("Gemini").
Vessels, in the construction of which two or more methods of maintaining on water (or above water) in most modes are simultaneously used, are usually called hybrid. The hydrofoils in them are used to form lift, complementing the usual buoyancy.
1. Hydrofoil vessels with a small waterline area. This is a hybrid of the principle of hydrofoils and the development of SWATH (small waterline vessels), which were conducted in the 1970-1980s at the Center for military research of the surface fleet of the United States. The vessel consists of two hulls: one fully submerged hull with a system of fully recessed wings, and above it another hull supported completely above the water by a thin and long longitudinal strut. At low speed, buoyancy is ensured by the displacement of the lower hull, strut, and a small segment of the upper hull. With increasing speed, the dynamic lift of the wings raises the upper body above the water, and the area along the waterline (horizontal section of the thin pillar) becomes extremely small. In this mode, the lower body and the submerged part of the rack provide 70% of the total buoyancy (due to displacement), and the wing system gives the remaining 30%. In the 1990s, the U.S. Navy funded an attempt to build a demo model called QUEST. Maritime Applied Physics Corporation in Baltimore designed, built, launched and successfully tested this nine-meter ship with a tonnage of 12 tons. QUEST had a stroke of 35 knots with an almost two-meter wave. More recently, Rodriquez developed the Aliswath, using a similar principle. It is reported that this is a large vessel - it will be a car and passenger ferry - should be launched already in 2007.
2. Catamaran hydrofoil. Most of the work on the hydrofoil-driven catamaran concept was done by Dr. Hopp, a shipbuilding engineer at Stellenbosch University in South Africa. This hybrid is a catamaran with completely asymmetric hulls, between which there is a hydrofoil. In English, such catamarans are called Hydrofoil Supported Catamaran, and are abbreviated as HYSUCAT. Variants of this concept are often used in the construction of passenger ferries (such as Foilcat).
3. Gliding bodies / integrated wings. This configuration was proposed by Navatek - it was she who developed and tested various configurations of planing bodies with wings in different combinations. Since 1996, successful demonstrations of this principle have been conducted on pilot vessels Midfoil and Waverider. Using computer programs of hydrodynamic calculations and attracting specialists from the University of California at Long Beach, Navatek took a new step in the development of planing bodies - the integrated wing (Blended Wing Body, BWB). The main purpose of the BWB is to improve seaworthiness and speed for existing or planned types of ships.
4. Ships with a front wing. The stern of such a vessel, as it were, is dragged along the water. A typical example of this approach is the Superfoil 40 catamaran, built by the Almaz Marine Plant under the project of the St. Petersburg branch of the British company MTD (Marine Technology Development) for the Estonian company Linda Lines Express. Это судно является самым быстрым пассажирским паромом в мире, оно способно развивать скорость в 55 узлов (более 100 км/ч), так что поездка по маршруту Таллинн- Хельсинки займет всего 50 минут.
Но вместо того чтобы модернизировать эти корабли, руководство американского флота в 1993 году решило их списать. Позже часть этих катеров распродали с молотка, а часть пустили на лом. С тех пор и по сей день на флоте США только и делают, что строят планы, занимаются «бумажными разработками» и перебирают проекты судов водоизмещением от 615 до 2400 т: Corvette Escort, DBH, PCM, Grumman HYD-2…
В течение 1990-х годов коммерческое направление развивалось своим путем, впитывая в себя новые конструктивные решения из Японии, Норвегии, Швеции, России, Италии и США. Одна из новых российских разработок — судно «Циклон» с крейсерской скоростью 42 узла (78 км/ч) — увеличенный двухпалубный вариант «Кометы», рассчитан на 250 пассажиров и оснащен электронной автоматической системой управления. Еще более новая российская конструкция — судно «Олимпия» — это вершина на пути развития больших судов, способных курсировать на маршрутах практически в открытом море.
Модель Jetfoil компании Boeing была запущена в производство в середине 1970-х и хорошо послужила во многих частях света. По тем временам это был верх совершенства для коммерческих аппаратов на подводных крыльях. В 1989 году Kawasaki приобрела у Boeing лицензию и наладила собственный выпуск модели Jetfoil. Многие аппараты из этой серии до сих пор служат в окрестностях Гонконга. Там же, в Японии, компания Mitsubishi сконструировала и построила несколько пассажирских судов на подводных крыльях, названных Rainbow.
В Швеции и Норвегии аппараты с катамаранным корпусом и крыльями, установленными на относительно коротких стойках, например Foilcat 2900 компании Westamarin, эксплуатировались на балтийских линиях.
В 1994 году итальянская компания Rodriquez выпустила Foilmaster — еще один пример тщательной компоновки толкающего винта с соответствующим профилем крыла для достижения максимальных характеристик, но с традиционной компоновкой кормовых винтов, приводимых в движение длинным наклонным валом.
Автор статьи — эксперт консультационной фирмы High Performance Marine Vehicle, автор книг « Ships That Fly » и « Hybrid Ships and Craft — A New Breed ».Статья опубликована в журнале «Популярная механика» (№11, Ноябрь 2007).