The history of military shipbuilding has given us many unusual projects that never cease to amaze us decades later. Interesting bold ideas visited the minds of many designers around the world. In this regard, the Soviet shipbuilding school was no exception. Unusual unrealized projects of the Soviet period include the Project 1231 Dolphin submersible missile boat, which was a hybrid of a missile ship and a submarine.
The birth of the idea of a diving missile carrier
It is worth noting that Soviet designers were not the first to propose a project that combined the qualities of a surface and submarine ship. The first attempts to create such a ship were made at the end of the 19th century. Despite a fairly large number of projects and ideas, no one succeeded in creating a surface submarine ship. Some success in this field of experiments was achieved by the French, who, even before the outbreak of World War II, created an unusual submarine - the submarine "Surkuf", which, in addition to the torpedo armament characteristic of submarines, carried a turret with two 203-mm guns on board. The boat, commissioned in 1929, remained one of a kind, holding the record for size and displacement until the very end of World War II. The French did not abandon the idea of creating such ships today. So, in 2010, at the EURONAVALE-2010 exhibition, a project of the future warship was presented - the diving frigate SMX-25, which combines the features of surface warships and submarines.
In the Soviet Union, Nikita Sergeevich Khrushchev personally submitted the idea of creating such a ship. Examining the high-speed boats based in Balaklava (designed by engineers TsKB-5 and TsKB-19) and the submarines located there, the secretary general proposed to combine their qualities in a new ship. The idea expressed by Khrushchev was to ensure the secrecy of the fleet's actions, this was especially important in the context of a possible atomic war. At the same time, they decided to "submerge" one of the existing or promising missile boats.
The idea expressed by the first person in the state was taken seriously. Specialists from TsKB-19 were involved in the work on the creation of a diving missile carrier. The chief designer of the future small submersible rocket ship was the head of the bureau, Igor Kostetsky. The project was planned to be implemented at the Leningrad Marine Plant, which was the construction and experimental base of TsKB-19. Later, after the merger of TsKB-19 and TsKB-5, work on the project was headed by the head of TsKB-5, Evgeny Yukhin. It is believed that the unusual project 1231 "Dolphin" played an important role in the unification of the two Soviet design bureaus, which in the future became the Almaz Central Marine Design Bureau, which still exists today.
It is worth noting that even in the pre-war years in the USSR there was a project to create a diving boat. It is believed that the first Soviet designer to present such a project was Valerian Brzezinski, who in 1939 worked in a special technical bureau of the NKVD. This bureau worked in Leningrad at the plant number 196. The submitted project of a submersible torpedo boat received the designation M-400 "Bloch". According to the plans of the developers, the unusual ship was supposed to develop a speed of 33 knots in the surface position, and 11 knots in the submerged position. It was planned to arm the boat with a displacement of 35, 3 tons with two 450-mm torpedo tubes. The construction of the experimental ship began in Leningrad in 1939 at the A. Marty plant. By the beginning of World War II, the project was completed by 60 percent, but under the blockade, the project was frozen, and after damage to the boat as a result of artillery shelling in 1942, it was completely curtailed. As conceived by the developers of "Blokha", the boat was supposed to approach the enemy ships in a submerged position, and after a torpedo salvo, emerge and leave the battle already in the surface position.
What tasks did Dolphin have to solve?
The main advantage of all projects of submerged warships implemented in different years was stealth. The ships approached the enemy underwater, so it was difficult to detect them. At the same time, it was planned to place weapons on board that were used on conventional surface ships. All projects combined the secrecy, and sometimes the possibility of underwater use of weapons, characteristic of submarines, with high firepower and speed, as in surface warships.
The Soviet project of the submersible small missile boat "Dolphin" fit into this concept. According to the plans of the developers, the boat of project 1231 was supposed to specialize in delivering surprise missile attacks on warships and transport ships of a potential enemy. It was planned to use small submersible missile boats on the approaches to naval bases and large ports of the enemy, in narrow places. It was assumed that the ships will be able to solve the tasks of repelling landings on the coast, will participate in the defense of the coast and the bases of the Soviet fleet, carry out radar and sonar patrol in the basing areas, operate on enemy sea lanes, interfering with the transportation of weapons and cargo.
The creators hoped that a group of missile boats would be deployed in advance in a given area, where it could remain unnoticed by the enemy, being submerged for a long time. To approach enemy ships for attack, the submersible missile boats were also submerged. Having approached the enemy, the ships surfaced and at high speed reached the line of attack. After launching the missiles, the boats were again submerged under water or, having reached their maximum speed, they left the battle site on the surface. The high speed and the ability to submerge were supposed to reduce the time the ship was under enemy fire and protect the ship from air strikes.
Design features of the boat of project 1231 "Dolphin"
Almost from the very beginning of the design, the main feature of the project was the movement on hydrofoils, the designers settled on such a scheme to provide the boat with a high speed. At the same time, within the framework of the work, various options for combinations of the shape of the boat hull and hydrofoils were considered. For testing, models were built, which were sent to a wind tunnel and an experimental pool, and tests were also carried out on the lake. In total, three main options for the shape of the hull and hydrofoils were presented: without hydrofoils (displacement up to 600 tons), with one bow hydrofoil (displacement 440 tons) and with two hydrofoils (displacement 450 tons). At the same time, the width of the hull of boats with wings was 9, 12 meters, in the version without wings - 8, 46 meters. The main differences between the options presented were surface speed, size and displacement. The length of variants with hydrofoils was just over 50 meters, without wings - 63 meters.
In the course of the work, the designers came to the conclusion that the most suitable for development is the project of a small missile boat equipped with one bow wing. This project was chosen even despite the lower travel speed. The maximum surface speed is 38 knots versus 42 knots for the variant with two wings. Under water, the ship was supposed to develop a speed of 4-5 knots. In favor of this project was the fact that the boat could reach full speed without overloading the main power plant. At the same time, the characteristics of balancing and controllability of the boat in the submerged position were higher than that of the faster version equipped with two hydrofoils.
During the design process, the designers settled on a model with two compartments located in a durable welded body. In the bow compartment, the designers placed the central post of the ship, the posts of the acoustician and the radio operator, the room for the electric power industry, and also the battery pit. It was from this compartment that the commander controlled the missile boat, from here the power plant, missile weapons and radio equipment were controlled. The second sturdy compartment housed the main engines and electric motors, a diesel generator and other equipment. In the superstructure of the boat, in a separate strong container, the designers placed the living compartment of the ship, which had 6 berths (for half the crew), a galley, provisions and fresh water. In an emergency, the living compartment was planned to be used to rescue the personnel of the boat from a submerged position. In the event of damage to the living compartment, it was possible to evacuate from the central post, but by the method of free ascent to the surface or climbing the buirep. In the superstructure of the boat there was a permeable wheelhouse, in which there was a second control post for the main engines of the ship, used in the surface mode.
The main armament of the project 1231 "Dolphin" boat was to be four P-25 cruise missiles, the maximum firing range of which reached 40 kilometers. The missiles were housed in single container-type launchers (sealed), located at a constant slope to the horizon. All launchers were located outside the rugged hull of the boat and could withstand the pressure of the vessel's maximum immersion depth. Additional weapons, including air defense systems, were not provided on the ship. The stake was placed on the surprise of the attack and the speed of withdrawal from the battle.
The engineers chose the M507 diesel engine as the power plant. This unit was a pair of serial M504 engines mastered by the Soviet industry. Wide-bladed fixed-pitch propellers were used as propellers on the boat. The design feature of the project was the ability to purge the main ballast tanks with exhaust gases from diesel engines, this solution ensured a quick ascent of a submersible missile boat.
According to design calculations, all three variants of missile boats could dive to a working depth of 70 meters, the maximum depth was 112 meters. An unusual ship could be under water continuously for no more than two days. The total autonomy of the boat did not exceed five days. Seaworthiness did not exceed 3-4 points. For variants with hydrofoils, the cruising range was 700 nautical miles, underwater - no more than 25 miles. The boat's crew consisted of 12 people.
The fate of the "Dolphin"
As specialists later noted, the key point in the design of any warship is the planned tactics of its combat use. At the same time, in relation to a submersible small missile boat, such a tactic of use has not been comprehensively worked out and studied, especially taking into account possible opposition from a potential enemy. The tactical and technical assignment for the design of a new missile boat was not fully justified from the outset. The technical characteristics, composition and capabilities of the installed missile weapons obtained in the process of designing a unique ship allowed the military and designers to better assess the options for the combat use of the ship. It became obvious that in real combat conditions the losses of the Dolphins would be no less than the losses of conventional surface small missile boats of the Soviet Navy. At the same time, the cost of building ships of project 1231 would obviously be higher than the cost of building traditional ships, and the military-economic effect of the use of submersible missile boats was considered doubtful.
The design of a small submersible missile boat was carried out in the USSR from January 1959 to the end of 1964. After leaving the post of General Secretary Nikita Khrushchev, work was stopped. At the same time, the suspension of work on the 1231 project was not so much a political as a purely practical context. Despite all the dedication of Soviet designers and consideration of various concepts, the work could hardly have ended successfully. The creation of such ships is associated with insoluble technical problems that arise due to completely different requirements for submarines and surface ships. Previously, none of the projects (the Soviet Dolphin was no exception) was not brought to its logical conclusion or, like the French boat Surkuf, was not successful, yielding in everything to specialized ships.
