On March 5, 2020, the 11th submarine of the Soryu series was launched in the Japanese city of Kobe. The boat will become part of the Japanese naval forces under the designation SS 511 Oryu. The new Japanese diesel-electric submarine became the first combat submarine in the world to receive lithium-ion batteries, and it also became the first such submarine in its series.
According to experts, due to the use of new types of rechargeable batteries, which have long been registered in smartphones, the Japanese will be able to abandon the use of not only traditional lead-acid batteries on submarines, but also air-independent Stirling engines. This is a very curious and significant event for the submarine fleet, since even the air-independent power plants themselves at one time became a real breakthrough for diesel boats, saving submarines from the need to often rise to the surface while sailing. By the way, Russia still does not have a single serial submarine equipped with an air-independent power plant.
Launched a new Japanese submarine with lithium-ion batteries is already the 11th boat in the series. In addition, the Japanese fleet has 11 Oyashio-class submarines (including two training boats), which are also difficult to attribute to the old models, since the boats were designed in the 1990s, and the last of them was transferred to the fleet in 2008 year. It is already known that soon the Japanese fleet will receive another submarine of the Soryu project (SS 512 boat) with lithium-ion batteries, after which Japan will proceed to the construction of submarines of a new project, so far known as 29SS (the first submarine SS 513). In total, the Japanese fleet now includes 22 submarines, the oldest of which entered service in 1998.
First submarine with lithium-ion batteries
The inauguration ceremony of the Japanese Maritime Self-Defense Forces of the first SS 511 Oryu lithium-ion battery combat submarine was held in Kobe on March 5, 2020. The ceremony took place at Kobe Shipyard & Machinery Works, owned by Mitsubishi Heavy Industries, a large corporation that spans a wide variety of industrial fields in Japan. The new boat has become the 11th in a series of boats of the "Soryu" type, and a total of 12 such ships will be built, the last two of them with lithium-ion batteries. Construction of the SS 511 Oryu boat began in March 2015, the boat was launched on October 4, 2018.
It is known that the construction of the 11th boat cost the Japanese taxpayers an amount exceeding the cost of any of the ten built boats of the same project. It is reported that the cost of building the SS 511 submarine was 64.4 billion yen (approximately $ 566 million, according to other sources, the boat cost even more - 66 billion yen). In any case, that's a quarter more than the tenth SS 510 Shoryu submarine (51.7 billion yen or $ 454 million) cost. Almost all the difference in cost between the tenth and eleventh boats of the series is accounted for by the cost of new lithium-ion batteries, as well as reworking the entire accompanying electrical system of the submarine and changing the design.
The twelfth of the planned Soryu boats is due to enter the fleet in 2021. The SS-512 boat has already been launched, it happened back in November last year. Both boats with lithium-ion batteries for the coming years will become a real testing ground for testing batteries and their operation in real operating conditions, including in conditions close to combat. The test results are very important, since they will allow the Japanese admirals to adjust the programs for the construction and development of the submarine fleet, as well as to develop a project for the next generation of strike submarines.
SS 511 Oryu challenges traditional submarines
It is worth noting that the Japanese navy has been hatching plans for the use of lithium-ion batteries in submarines for a long time. The appearance of the SS 511 Oryu was the culmination of research and development that continued for several decades. It is known that Japanese designers began the first work in this direction back in 1962, and the first lithium-ion battery designed to be placed on board a submarine was ready in 1974.
Despite these successes, the first batteries were far from ideal, did not meet the specified operating requirements and did not suit the military in many respects. At the same time, such rechargeable batteries were very expensive for a long time. This was superimposed on the higher danger of such batteries, which were prone to spontaneous combustion and explosions, which on board the submarine was fraught with a real disaster. The accompanying risks and high prices, coupled with not yet sufficiently "mature" technology, forced the Japanese admirals to turn their attention to air-independent power plants (VNEU). In 1986, it was decided to develop and build submarines with the Stirling system VNEU, focusing on the successful Swedish experience.
Yet the day has arrived for lithium-ion batteries aboard submarines. New technologies can significantly change the entire submarine fleet. Many experts already classify such diesel-electric boats as fifth-generation submarines. At the same time, in order to switch to the use of new storage batteries, Japanese designers had to significantly revise the project of boats of the "Soryu" type. First of all, the new batteries required the project to be reworked to maintain stability and ballasting of the boats, since the lead-acid batteries installed on the first 10 submarines of the series are significantly heavier than lithium-ion batteries. Moreover, part of the weight of the new submarines "went away" at all due to the dismantling of the Stirling engines.
During the work, the engineers had to completely revise the entire power supply system on board the SS 511 Oryu. Also, more powerful diesel generators were installed on the submarine, designed to recharge batteries. Additionally, the designers had to rework the snorkels, this is necessary to increase the volume of air supply and at the same time to remove exhaust gases, since the charging rate of lithium-ion batteries is noticeably higher than standard lead-acid batteries.
Already today, lithium-ion storage batteries provide submarines with a duration of the underwater run comparable to boats using VNEU. And in the future, the technical characteristics of such boats will only grow. At the same time, the high capacity of the batteries allows submarines to move under water for a long time at a high speed - about 20 knots. The long duration of the underwater run at high speed is a very important indicator for submarines. This can help when attacking a surface target and when dodging enemy attacks. The sooner the boat leaves the dangerous area, the better.
At the same time, unlike submarines equipped with VNEU, the new submarine is able to constantly replenish the energy supply in lithium-ion batteries, using battery recharging using a device for operating the engine under water RDP. Also, the advantages of lithium-ion batteries include a longer service life. These batteries do not require maintenance, and the electrical systems built with their help are easier to manage and design. Also, lithium-ion batteries differ from lead-acid batteries in a shorter recharge time due to the higher amperage, which is very important for divers.
Capabilities of Soryu-class submarines
The Soryu-class diesel-electric submarines are strike submarines of the Japan Maritime Self-Defense Forces. These boats are considered one of the most modern and best in the world, they already form the backbone of the submarine forces of the Japanese fleet. The new Japanese boats are quite large, in terms of displacement they surpass all serial Russian diesel-electric submarines of projects 677 "Lada", 636 "Varshavyanka" and 877 "Halibut". Soryu-class boats are considered quite quiet, and in terms of the duration of their submerged navigation they can compete with modern nuclear submarines.
Submarines of the Soryu type with a standard surface displacement of 2900 tons and an underwater one of 4200 tons have been built in Japan since 2005 (the first boat of the series was laid down). The Soryu submarines are 84 meters long, 9.1 meters wide, and have an average draft of 8.5 meters. The boat's crew consists of 65 submariners (including 9 officers).
The first ten diesel-electric submarines built according to this project featured a combined power plant consisting of two Kawasaki 12V25 / 25SB diesel-electric units with a capacity of 3900 hp each and four Kawasaki Kockums V4-275R Stirling engines developing a maximum power of 8000 liters..s (underwater passage). The ship's propulsion system operates on one propeller shaft. The maximum surface speed of the boat is 13 knots (approximately 24 km / h), the maximum underwater speed is 20 knots (approximately 37 km / h).
The operating depth of the Soryu-class submarines is 275-300 meters. Swimming autonomy - up to 45 days. For boats of this project, equipped with an air-independent power plant, the cruising range is estimated at 6100 nautical miles (approximately 11 300 km) at a speed of 6.5 knots (approximately 12 km / h). It is reported that the new submarines, receiving lithium-ion batteries, will be able to stay submerged even longer, in fact, their capabilities will be limited only by the supply of provisions and fresh water on board.
The main armament of Soryu-class boats are anti-ship torpedoes and missiles. The submarine has six 533 mm HU-606 torpedo tubes. The boat's ammunition capacity can consist of 30 Type 89 torpedoes. Modern torpedoes develop a maximum speed of 55 knots (102 km / h), at this speed a torpedo can travel 39 km under water. Also, these torpedo tubes can be used to launch anti-ship US missiles UGM-84 "Harpoon". Modern versions of such missiles can hit targets at a distance of up to 280 kilometers.
