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Ukraine has led the world in the development of combat drones, with small FPVs and larger bombers inflicting the majority of Russian losses. Ukrainian robot boats have scored some notable successes in the Black Sea. Now Ukraine is moving into the underwater domain with the unveiling of a giant new robot submarine at an exhibition in Lviv.
The underwater drone has a five-ton payload and is designed for minelaying and the "destruction of large stationary targets." This sounds like a direct threat to Russia's Kerch Bridge.
Robot submarines have been around for decades; not counting torpedoes, they go back to the 1950s. Many navies operate Uncrewed Underwater Vehicles or UUVs of different shapes and sizes for a variety of missions, generally in a supporting role such as mapping, intelligence gathering and counter-mine warfare. The U.S. Navy has recently stepped up activity in this area and uses underwater drones like the 500-pound Remus 600.
The U.S. navy is also testing the Orca XLUUV, a submarine believed to be 85 feet long and with an endurance of several months. Orca will be able to launch smaller robot subs, as well as dropping off sensors and mines. Development started in 2017 and the first deployment is expected sometime next year.
War has forced Ukraine to move faster. Tech accelerator Brave1 announced the TLK-150 model in April 2023. While the U.S has been cautious with UUVs, assigning them to auxiliary roles, Ukraine has taken a more robust approach and used drones for attack missions. The TK-150 is no exception: armed with a 33-pound warhead, it is effectively a smart, electrically powered torpedo which can loiter for days at a time waiting for a target. It has a range of 60 miles.
The TLK-150 is not a true submarine, as it relies on a mast above water for sensing and communication. However, with the body submerged it is much harder to spot than the high-speed drone attack boats which Ukraine has used so effectively. It is questionable how much damage the small warhead would do, even below the waterline, but this looks like a first experimental effort at weaponizing UUVs. Bigger and better designs were soon to follow.
In 2024, the makers were talking about an entire family of underwater drones. The TLK 150 was joined by the TLK- 400 and TLK 1000; in each case the suffix seems to indicate the diameter of the vessel in centimeters.
By this time the TLK 150 had been upgraded with a warhead of 45 - 110 pounds of explosives, as much as a U.S. Mk. 54 lightweight torpedo. No details have been shared of combat missions.
The Toloka 400 is around forty feet long, and has a hybrid propulsion system giving it a range of around 800 miles and an endurance of two months. A true submarine, the TLK 400 can operate at depts of up to 1,000 feet. Typical missions include reconnaissance, minelaying, communications relay, and of course direct attack. The TLK 400 can carry a 1,000-pound warhead, making it more powerful than the U.S. Mk48 heavyweight torpedo.
At the top end of the range is the TK 1000, which looks like a scaled-up TK 400 with a payload of five tons, and which was shown at Lviv for the first time. Typical missions are given as "destruction of large stationary targets" as well as laying mines. Its endurance and range are similar to the smaller version. This was seen for the first time in Lviv.
The makers say their UUVs are highly autonomous, with neural-network based AI for sensing and navigation. This is a complex field and no details have been given or testing or limitations, but if the UUVs are simply going to a spot and laying a mine or detonating they may not need to be too sophisticated.
Naval mines are much underrated weapons. They lack the glamor of aircraft and missiles, but they are extremely effective. In WWII, U.S. mining sunk more than a thousand enemy vessels, with no submarines or shops lost while mining. Mine countermeasures take up a significant amount of naval effort, and the presence of mines will hamper and delays operations even when they cause no damage. But it will be those stationary targets that Putin will be worrying about.
The Kerch Bridge which links Russia with occupied Crimea is a major strategic and symbolic target. Ukraine has attacked it before. In October 2022 a truck bomb detonated on the bridge, damaging three spans; repairs were completed in May 2023. In August 2023 a robot boat ran into one of the bridge supports with over 1,700 pounds of explosions but failed to bring it down. This June an underwater explosion, this time over 2,200 pounds of explosives again failed to bring down a support.
The TK 1000, able to bring a charge almost five times as big, might finally be the bridge dropper that Ukraine needs. Russia has deployed a wide range of defensive measures both above and below the water and would hope to detect and counter an attack. But the fact that previous efforts got through suggests that another effort might succeed.
There are other targets too, not just bridges but platforms in the Black Sea, originally built for oil and gas but now used as radar and air defence bases. The Russian fleet is now largely confined to port, sheltering behind booms and other defenses to keep the robots boats out. A big enough explosive charge could be covertly placed to blast a way through for an attack either over or under the water. It could also act as a carrier for squadrons of FPVs or other aerial drones.
As with aerial drones, robot submarines have tended to be elbowed aside by crewed platforms. That may change soon. And while many nations are developing giant XLUUVs at varying rates -- including the U.S., U.K., Australia, China , France , Israel - these are generally sophisticated, expensive exquisite systems. Ukraine , which sees drones more as low-cost expendable units , may lead the world in a new type of underwater warfare.