Just a few hours after a series of explosions on the Crimean bridge on the night of July 17, the National Anti-Terrorist Committee of the Russian Federation announced that “two Ukrainian unmanned surface vehicles” attacked the crossing. Unofficially, this version was confirmed by the Ukrainian military. However, no additional evidence of the participation of drones in the attack over the past two days has appeared: neither the video of the explosions nor the images of the drones themselves have leaked to the network.
An indirect argument in favor of the version about drones is the video and photos of the consequences of the explosions: we can confidently say that they occurred under the road surface of the bridge. There is also a satellite image taken at 12 am Moscow time on July 16, which shows six unknown boats – in theory, they could be those very drones. The boats are captured in the western part of the Black Sea, about 75 kilometers from Zmeiny Island. Five of them are moving east, and their course suggests that they are going to go around the Crimea. One boat is going in the opposite direction. The distance from the point where the satellite spotted the boats to the Crimean bridge is about 520 kilometers.
This ends even circumstantial evidence in favor of an attack on the bridge by surface (marine) drones. Further consideration remains only guesses – based on the technical capabilities that Ukraine has.
What do we know for sure about Ukrainian sea drones?
The shortest answer is not much. Open sources have so far described naval drones of the Ukrainian army and navy that are not capable of damaging the supports of the Crimean bridge. Until July 17, it was believed that the country had a wide range of such vehicles, but none of them had sufficient range and, probably, the carrying capacity to cause significant damage to the bridge.
The Ukrainian fleet received the first naval drones in April 2022 from the United States. Neither the model of the drones, nor their number were named (in the list of deliveries they appear as Unmanned Coastal Defense Vessels – unmanned vehicles for coast protection). Western experts have suggested that this is probably about unmanned boats Mantas T-12, which are in service with the US Navy.
KnowncharacteristicsAmerican Mantas T-12s make it possible to confidently exclude these drones from the circle of “suspects” in the attack on the bridge: A small boat’s payload of only 64 kilograms is far less than what would be required for a charge that would cause significant damage to such a large object.
In the fall, Ukraine showed – and immediately used against the base of the Black Sea Fleet in Sevastopol – drones of a new, unknown design. One of them ended up on the shore of the Sevastopol Bay (it is not clear why), where it fell into the hands of the Russian military. Ukraine showed the same drones in a crowdfunding campaign to raise funds for the “first fleet of drones”. Then in Kyiv they said thatthe kamikaze drones that will make up this fleet have a warhead weighing up to 200 kilograms, a range of 800 kilometers and a total weight of about one ton. It was, of course, impossible to verify these statements.
Western experts, after examining photographs of the new drones, then came to the conclusion that the device was made of civilian components, except for a contact fuse similar to the fuse of a Soviet high-explosive bomb:
- Judging by the photo from the Sevastopol Bay, the Starlink satellite communications system was installed on the drone. This made it possible to supplement the inertial and satellite (via GPS) navigation systems with “manual” control based on the picture from the camera via the Internet. The only limitation for a drone with such an advanced control system is the capabilities of its engine.
- The engine installed on this mysterious drone was identified by experts as the Rotax 3 gasoline power plant, which is used in Sea Doo jet skis . At a watercraft cruising speed of 56 kilometers per hour, the Rotax 3 engine consumes about 30 liters of gasoline per hour (or half a liter per kilometer).
- To overcome the 800 kilometers declared in the characteristics of the drone, thus, almost 400 liters of fuel (weighing almost 320 kilograms) are required. The weight of fuel for a journey around the Crimea about 600 kilometers long (from Zmeiny Island, where the satellite detected unidentified ships, to the Crimean Bridge) can be estimated at about 240 kilograms. The engine itself and the fuel system weigh another 100 kilograms, the warhead – 200. Thus, less than half the weight of the declared ton remains for all other equipment of the drone and its body.
- It is important to remember that jet skis do not weigh a ton, but from 200 to 450 kilograms. Therefore, it is likely that the fuel consumption of the drone is much higher. This, in principle, casts doubt on the version of the arrival of drones from the Zmiinoye region or from the coast of Ukraine. In the fall of 2022, the Russian military even suggested that drones were launched in Sevastopol from civilian ships that were involved in the export of Ukrainian grain (they did not provide any confirmation of this to the Russian Ministry of Defense).
There are at least two other indications that Ukraine likely possesses a very long-range naval warfare capability.
- November 2022, according to the pro-Kremlin telegram channel Mash, such a drone attacked the Sheskharis oil harbor in Novorossiysk. Mash then published a video of surface explosions in the harbor, but the Transneft company, which owns the terminal, denied the incident altogether.
- May and June 2023Ukrainian drones (different in appearance from the drones of 2022 that attacked Sevastopol) hit two reconnaissance ships of the Russian Black Sea Fleet in the open sea, hundreds of kilometers from Zmeiny Island. The attack turned out to be unsuccessful: some of the drones were shot from the ships at a distance, and one may not have worked.
Whereinit cannot be ruled out that Ukraine has gained access to more powerful and efficient engines and now has drones capable of carrying a larger charge.
Why were the RF Armed Forces unable to defend themselves from the strike?
Russian pro-war media offered a variety of explanations, including exotic ones – for example , the use of British underwater laboratory drones for the attack. The delivery of such drones to Ukraine was not reported, nor was it reported that they could carry a warhead: these are vehicles with scientific and reconnaissance equipment, although their design includes the ability to change the type of payload. British drones are also not equipped with communication systems that allow them to be reliably controlled “manually”. And, most importantly, they are clearly not in the weight category to damage the bridge (even their larger models ).
Probably, in fact, the inability of the Russian Armed Forces to resist the attack is due to the fact that the Russian command did not believe in a strike from the sea at such a distance from the coast that Ukraine controls. In addition, we recall that one of the early drone models fell into the hands of the Russian army. The defense of the bridge (judging by the exercises that the Russian army conducted from time to time) was aimed at repelling attacks from the air.
Meanwhile, the history of the full-scale Russian-Ukrainian war has already shown that explosions under bridges (as was the case with the July 17 attack) are more effective than explosions above them:
- Thus, in 2022, the bridge across the Dniester Estuary in the Odessa region was repeatedly subjected to missile strikes from the Russian side, including missiles with a warhead weight of almost half a ton, and did not receive critical damage that would put it out of action for a long time.
- And in February 2023, the same crossing was attacked by a naval drone that came from the sea (probably sent by the Russian military , but similar in size to the Ukrainian ones). And, despite the visually relatively small power of the explosion, the bridge was partially destroyed and is still not in operation . True, the height of this drawbridge in the unraveled state is only a few meters, while the Crimean one is 35.
Now, probably, the defense against attacks from the sea will also be strengthened, as has already been done in Sevastopol. Booms (floating) barriers can be set up along the entire length of the bridge, as well as a constant watch of Coast Guard ships with heavy machine guns (and, possibly, with special equipment for more effective destruction of small and high-speed targets).
However, it will be difficult to create a system for the early detection of small targets at sea, where navigation continues almost as usual. And the bridge as a whole is more difficult to defend than the harbor of the fleet. The danger of new strikes will remain, especially since Ukraine is creating more and more drones from civilian components.
All of these strikes (together with drone attacks, missile strikes, and so on) are obviously part of the campaign to blockade Crimea. It, according to Western experts, may be an alternative to the operation to liberate the peninsula by force. True, the idea seems dubious: without a decisive defeat on land, the Kremlin is unlikely to want to leave the peninsula, which is critical both for its military machine and for domestic politics.
