In 2000, the first trimaran, which became part of the naval forces, was launched - the ship of the Royal Navy of Great Britain Triton, the construction and testing process of which attracted close attention of both military specialists and everyone who is interested in the prospects for the development of military shipbuilding. Immediately after launching it, journalists dubbed the Triton the battleship of the future - the progenitor of a new generation of platforms that will be used in the world's navies.
Today, interest in ships of a similar scheme has increased again. Domestic designers are also working in this direction. For example, Zelenodolsk PKB offers a whole family of trimaranes for various purposes and displacement: from 650 to 1000 tons. It should be recalled here that the Northern PKB was also in the late 80s - early 90s. last century developed several projects of multihull ships, including aircraft carriers.
But back to the Triton trimaran. More than ten years have passed since its launch. The ship has passed comprehensive tests, and, probably, the time has come to draw some conclusions about the prospects and feasibility of building combat units of such a scheme.
Let's make a reservation right away that in fact Triton is not a combat ship, but an experimental one - about 2/3 of the life size of a real ship. It was created specifically for testing and testing in practice the capabilities and potential of innovative technologies, as well as the subsequent reduction of the risks of using trimaran-type hulls for promising warships of the 21st century. In the British navy, it went under the designation "trimaran demonstrator" (demonstration trimaran) or "RV - research vessel" (research vessel). The United States took an active part in its creation. The US Navy has provided a complete set of sensors and recording equipment for taking data during sea trials in high seas.
The contract for the construction of Triton was signed in the fall of 1998. The ship was launched in May 2000. In September of the same year, the ship was handed over to the British Defense Research and Evaluation Agency (DERA, now QinetiQ), and the tests started in October 2000. It was assumed that not an experimental, but a real ship in 2013 will become part of the Royal Navy and will become the ancestor of a whole series of promising combat trimaran Future Surface Combatant (FSC), which will replace the frigates of projects 22 and 23.
Over the course of two years, Triton has participated in a large number of tests, including tests of structures in a dry dock, towing, sea trials, helicopter acceptance, sea trials, including in rough seas up to 7 points, tests of power supply systems, crossing the Atlantic Ocean. A series of mooring maneuvers to the pilot boat, the Argyll frigate and the Brambleleaf supply vehicle was practiced.
Numerous sensors and recorders installed on the ship made it possible to make measurements during the tests, conditionally divided into three categories: ship and navigation systems, ship movement and the reaction of structures. From the ship control systems for mechanisms, information was received about the electricity generated by the generators and consumed by the actuators, fuel consumption, etc. From navigation systems - information about the speed and heading of the vessel. The pitching and rolling angles were also measured. Instruments for measuring the dynamic characteristics of structures provided a large amount of data recording - the characteristics of longitudinal and transverse deformation, measuring the deformation of bulkheads, torques of the main body, stress concentration, as well as the dynamic characteristics of structures arising from shock waves.
Triton's tests have not only tested its driving performance in practice. The ship has undergone extensive testing of a diesel-electric installation. A propeller with a diameter of 2.9 m, made of composite materials, was used as a propeller. The use of composites made it possible to make the propeller blades thicker, and, consequently, to reduce vibration and change the acoustic signature of the ship. To reduce the heat footprint, the gas exhaust from the diesel generators were brought out into the space between the main building and the outriggers.
A couple of years after the completion of the tests, the British Ministry of Defense decided on the further fate of the ship. The trimaran was transferred to the British ocean research organization Gardline Marine Sciences Ltd. and converted into a research vessel. They began to operate it for conducting hydrographic research. However, in December 2006, Triton was handed over to the Australian Customs Service for patrolling in the northern territorial waters of that country. The ship was converted to accommodate an additional 28 customs officers and equipped with two machine guns. In addition, an infirmary, a quarantine station and an isolation ward appeared on board, as well as two seven-meter high-speed rigid inflatable boats. The trimaran started performing customs functions in January 2007 and is still in service today.
In other words, the Triton never became the progenitor of a new class of ships for the British Navy, although several variants of a new type of corvette with a trimaran hull were worked out. But the US Navy, which initially invested large funds in the project and took part in the tests of the ship, drew the appropriate conclusions and used them to create their trimaran, the littoral battleship LCS-2 Independence.
But Independence is fundamentally different from its British counterpart primarily in the ideology of use. If Triton was to become the prototype of promising corvettes and frigates, the Independence is designed to gain dominance in coastal waters, as well as to quickly transfer forces and equipment to almost anywhere in the oceans. This is why the American ship has a very high speed of travel, as well as extensive rooms designed to accommodate special equipment and weapons in removable containers.
Without denying the positive qualities of the multihull scheme as such, as well as the possibility of its use for such specific ships as aircraft carriers, high-speed landing ships and ferries (for example, Benchijigua Express, HSV-2 Swift), as well as ships of the rapid reaction forces, which should be able to maximum speed to move to the area of hostilities (LCS-2 Independence), I would like to consider how rational is the use of a multihull scheme in the construction of ships such as a corvette with a displacement of up to 2000 tons.
Certainly, the multihull design has a number of advantages over the traditional monohull for ships of similar or close displacement. The trimaran hull allows you to reduce the resistance of the water, and accordingly the speed of the full speed of the ship increases. All multihull ships and ships are more or less distinguished by increased seaworthiness. For example, a catamaran has a lower roll with almost the same pitching as a single-hull ship. Higher stability of the ship as a weapon carrier platform makes it possible to expand the possibilities of using additional equipment and weapons.
All multihull architectural and structural schemes are characterized by increased, to one degree or another, deck area per ton of displacement. Therefore, it is the multihull schemes that are the most convenient from the point of view of providing a given deck area. This is especially important for promising ships, on which aircraft weapons will be used much more widely than today. The multi-case scheme allows realizing such areas of stealth technology as, for example, reducing the heat trace due to the organization of the gas exhaust of the power plant into the space between the cases.
At the same time, the considered scheme for ships of the corvette class has its drawbacks. Firstly, this is a much higher cost due to the more complex construction technology. It is clear that for the construction of corvettes, which should be massive ships and as cheap as possible, this factor, especially in modern conditions, may turn out to be critical.
To the greatest extent, the running advantages of trimaran are manifested at sufficiently high speeds. So, during the tests of Triton, it turned out that in all weather conditions the ship behaved best at speeds over 12 knots. At the same time, corvettes should spend most of their combat service in patrolling the water area at low speeds. Accordingly, the shape of their body should be optimized for this condition.
All domestic ships are designed taking into account the possibility of their service in low temperatures, including in ice. Even broken ice and sludge will pose a serious problem for a multihull ship, since they will accumulate and get stuck between the hulls, negating all the advantages of the adopted scheme.
Research has shown that, ideally, the trimaran outriggers should be located outside the area of the waves generated by the central body. This minimizes the wave interaction of the main body and outriggers, but results in a very significant, about 35% of the length, overall width. It can be concluded that such a scheme, due to its large width, is suitable specifically for small ships - with a displacement of up to 2000 tons, that is, precisely for corvettes. However, it is on small ships that it is most problematic to realize the possible favorable wave interaction of the hull and outriggers.
Docking conditions for a multihull ship are more difficult than for a single-hull. In addition, the absence of the docks themselves of the required dimensions will lead to the impossibility of servicing the ships.
A trimaran with a scheme adopted by the British, and in domestic designs, is distinguished by short side outriggers. This will lead to serious problems with mooring - both stern and side, which is unacceptable, since corvettes as mass ships must be serviced by crews with a basic (medium) level of training. Hence the difficulty of basing such ships.
One of the most serious problems of multihull ships and vessels is slamming, and in this case it is more correct to speak not about the classic bottom slamming (the impact of the bottom part of the bow end of the hull on the water during the longitudinal rolling of the vessel - editor's note), but about the shock of waves affecting the structure connecting outriggers or side hulls to the main hull. In this case, the shock loads can be so high that the entire structure can be severely damaged. This also affects the habitability of the crew.
Thus, it can be assumed that for ships of the corvette class, the multi-hull scheme will bring more disadvantages than advantages. Apparently, such conclusions forced the British to abandon plans to create trimaran corvettes.
At the same time, one cannot ignore the fact that in modern conditions of many alternative options, in no case can one new type of ship be introduced by voluntaristic methods. Real competition of several types of ships is needed at the stage of a preliminary design, bringing several alternative options to a technical design - only with such an organization will it be possible to implement new technical solutions.
