Russia hit the South Bridge in Kyiv with jet drones for the first time

On October 1 and 2, Russia for the first time carried out rocket-propelled drone strikes on the South Bridge in Kyiv. At least three UAVs hit the structure. The city authorities announced that the bridge was closed to traffic.

(The original of this article in Ukrainian is here.)

The first Russian drone hit since the beginning of the war on the Kiev bridge across the Dnieper was reported around noon on October 1.

Mayor Vitaliy Klitschko said that two UAV hits were recorded near the support part of the South Bridge. At that moment, a metro train was moving along the stretch.

Serious damage was avoided, Kyiv authorities said.

On Wednesday evening, the mayor of the Ukrainian capital reported another attack on the bridge. According to him, the drone damaged the roadway.

However, Klitschko later wrote that the consequences were more significant: the support, bump stop, road surface and protective concrete fence of the metro line were damaged.

Another blow was struck on the morning of October 2. About five o'clock, a Russian UAV hit the South Bridge, damaging, judging by the photo of the State Emergency Service, the bridge fence, bump stop and metro line structures.

The movement of the metro and other transport on the South Bridge was suspended. The authorities also restricted traffic on two more capital bridges that had long been recognized as unsafe - the Metro Bridge, through which trains of the Svyatoshinsko-Brovarskaya Line run, and the Paton Bridge.

What is special about the South Bridge

The Southern Bridge, connecting the densely populated areas of the left bank of Kyiv and the right bank microdistrict of Vydubychi, began to be designed in 1983.

It was supposed to become the shortest route from the Boryspil airport to the center of Kyiv, as well as relieve congestion on other bridges, which by that time could no longer cope with the capital’s car traffic.

Now this bridge is critically important not only for Kyiv, but also for the whole of Ukraine, providing one of the largest road transits of people and goods from the right to the left bank of the Dnieper. In addition, the green metro line, which runs along the South Bridge, is the only one that can (more precisely, could until October 2) transport passengers across the Dnieper during an air raid.

The design of this bridge was carried out by the outstanding Ukrainian engineer Georgy Fuks. He developed four of the five Kyiv bridges - South, North, Podolsko-Voskresensky and Metromost.

During the construction of the South Bridge, as the engineer himself wrote, “the latest technologies were used, designed to increase the pace of construction, its industrialization, reliability and durability of structures.”

“The bridge across the Dnieper became the testing ground where so-called flexible or universal technology was introduced on a large scale,” this is how engineer Fuchs described the feature of the South Bridge.

Vehicle traffic on the bridge was opened in December 1990. Two years later, metro trains began running across the bridge.

One of the features of the South Bridge is the cable-stayed system. There are only two bridges in Kyiv that were built using this technology - South and North. They are also called extracurricular.

Cable stays—steel cables stretched between the road surface and the pylon (vertical support)—not only look aesthetically pleasing, but also perform important functions as a counterweight, balancer, and support for bridge spans.

On the South Bridge of Kyiv there are two tension planes, each of which has 72 cables - 36 cables to support the large span of the bridge and 36 guy cables. They are located in the dividing strips between the subway rails and the car parts located on the sides.

Closed galvanized ropes with a diameter of 62 mm with a breaking force of 350 tons were used for the stay cables. Each cable consists of two such ropes.

The video, which was distributed by telegram channels on October 1, shows how a UAV, probably Geranium-4, hits the South Bridge in the area of ​​the pylon support part.

Considering that the warhead of such a drone - about 50 kg of explosives - is not enough to destroy the strong steel and reinforced concrete structures of the pylon, the cables were probably the target of the UAV.

In addition, according to Advisor to the President of Ukraine Sergei Beskrestnov (“Flash”), in recent raids the Russians began to use modernized Geranium drones.

They have special “whiskers” that serve as detonators, and a new cumulative-cutting special load ammunition (KRSN). It consists of a main warhead weighing 40 kg and four destruction modules.

“Such a warhead was created specifically for the destruction of high-voltage poles and iron bridge structures,” noted Flash.

Can a drone destroy shrouds?

The BBC Ukrainian service spoke with a Ukrainian expert in the field of urban planning, who in past years was involved in the repair and inspection of Kyiv bridges.

Due to the sensitivity of the topic, he agreed to comment on the matter only on condition of complete anonymity.

According to him, it is theoretically possible to damage or break several cable stays with UAV strikes, but when creating and designing the bridge, its stability was calculated with a margin.

“There is a large supply there. That is, if one or two shrouds are interrupted, nothing will happen. But if you break more cables and, God forbid, destroy the pylon, these will be very big problems,” the expert notes.

According to him, two or three UAV strikes cannot have a significant impact on the functional state of the bridge. It will be another matter if the attacks are systematic and hundreds of drones or dozens of missiles are used.

“Depending on where they hit and which shrouds they damaged, there may be different limitations in operation. But this will not completely destroy the bridge, there will be no “domino effect” when one cable is torn off and others begin to crumble immediately. This can only happen with very severe destruction.”

However, there are problems with possible repair or replacement of the cables if they are damaged.

“There is a question of restoration, because some structures are no longer produced in our country. For example, the same cable stays for the South Bridge were not made in Ukraine. As far as I know, they were ordered abroad even when it was being built. And this is not a product that can be ordered and delivered very quickly, much less repaired later,” the expert notes.

According to him, even in the event of significant damage to the South Bridge, already working technologies can be used. For example, special arch supports, which are already used to maintain the functionality of the emergency Metro bridge.

“The Metro Bridge has a different system, but they made these supports and completely redistributed the load. The same can be done here, since it is the bridge deck that is very difficult to destroy, but it can be damaged... And if something happens, for example, problems with the cables, it will be possible, so to speak, to change the technical operation of the bridge. And it will function a little differently. It’s difficult, it’s expensive, but it’s possible,” says the specialist.

Despite the fact that the South Bridge is one of the newest in Kyiv (later only the Darnitsky Automobile Bridge and the Podolsko-Voskresensky Bridge were put into operation), over 36 years of operation it has worn out, experts say. Almost every year renovations are carried out there.

All this leads to the fact that the South Bridge, as Fedorenko noted, “suffers from dynamic loads and vibrations from heavy-tonnage transport.”

However, it remains one of the most important transport arteries of the Ukrainian capital.