Russian Troops Once Again Used an Underground Pipe. Is This Tactic Really Effective?

A few days ago, the Russian army once again used underground pipes to redeploy troops near the front line — this time near Kupyansk in Kharkiv Oblast. This is not the first such operation. In 2024, Russian forces used a pipe during the assault on Avdiivka, and this year — near Sudzha.

IStories recalled the details of these operations and asked military experts how effective they really are.

What is known about the pipe passage near Kupyansk

On September 12, the OSINT project DeepState, affiliated with the AFU, reported that near Kupyansk, Russian troops established supply lines for their group through a gas pipeline. The Russians entered the pipe near the settlement of Lyman Pershyi and exited in the village of Radkivka, which borders Kupyansk from the north. After that, the troops infiltrated the city and regrouped there. In the DeepState video, a Russian soldier is shown emerging to the surface in the Radkivka area.

As seen on the map, Kupyansk is divided by the Oskil River into eastern and western parts. To the east of the city, the AFU hold the enemy at a distance of several kilometers. However, to the north, Russian forces have crossed the Oskil and are advancing on Kupyansk along the western bank of the river, and Radkivka is under their control.

The direct distance from Lyman Pershyi to Radkivka is about 10 km. According to DeepState, for movement through the pipe, the Russians use special wheeled stretchers, and where the height allows — electric scooters. The entire journey takes about four days, with rest areas and food supplies arranged inside the pipe.

The news was picked up by Z-media, which wrote that Russian troops entered Kupyansk through the pipe (here are some examples: 1, 2, 3, 4). They began circulating videos showing Russian troops moving through the pipe on carts resembling the “wheeled stretchers” mentioned in the DeepState report. However, this footage appeared on Telegram as early as September 2, when the authors of the Para Pax channel claimed the events were taking place in a sewer collector in the Pokrovsk direction.

On September 13, the AFU General Staff announced that the exit from the pipeline used by Russian troops to redeploy personnel near Kupyansk “is under the control” of Ukrainian forces. In total, there are four such exits in the city area; the other three are destroyed and flooded, according to the statement. That same day, a video appeared online showing barbed wire installed inside the pipe. “The Ukrainians stuffed a lot of barbed wire in there. And not just like in World War I — this wire is really sharp. And if you get tangled up in there, it’s almost impossible to get out on your own. You’ll get seriously injured, it’s a real hellish story,” said former Security Service of Ukraine officer Ivan Stupak.

Military experts emphasize that the pipe exit is outside Kupyansk on territory controlled by Russian forces, so there is no question of a breakthrough into the AFU rear. The point is that the pipe allows the Russians to bring in reinforcements without coming under fire from Ukrainian drones and artillery, explains Conflict Intelligence Team founder Ruslan Leviev. For the advancing army near Kupyansk, the situation is complicated by the need to cross the Oskil River when redeploying reserves.

How Russians have used pipes before

Avdiivka. In January 2024, Russian troops, after moving through a sewer pipe, captured the AFU stronghold Tsarskaya Okhota (the name of a recreation base) south of Avdiivka in Donetsk Oblast. Details of the operation are known mainly from Russian troops and military correspondents.

The pipe was discovered back in February 2023, recounted by “contract deputy” Eduard Sharafeev from the State Council of Tatarstan. According to him, during preparations for the assault, the AFU detected a concentration of Russian troops and shelled them with artillery, resulting in “wounded soldiers.” The first attack failed because too many people were sent into the pipe. “Due to the limited space in the pipe, there was a lack of oxygen. Many soldiers began to lose consciousness. As a result, this assault operation turned into an evacuation,” Sharafeev said. Soon after, spring flooding submerged the pipe, and the operation was postponed.

For the second assault, Russian forces prepared for several weeks, wrote war correspondent Alexander Kots. To mask the noise during the clearing of debris and welding of seams, artillery was used. After traveling two kilometers through the pipe, Russian troops emerged behind enemy lines and captured the stronghold. Z-channels claimed that the Ukrainian defenders of the stronghold were killed or surrendered, and this information was confirmed by DeepState.

Tsarskaya Okhota was one of the main strongholds on the southern flank of Avdiivka’s defenses; soon after its capture, fighting began in the private sector on the outskirts of the city. A lieutenant of the Russian Armed Forces who participated in the capture of the city recounted that Russian forces used the pipe for supply and evacuation even after it became widely known.

Sudzha. In March 2025, during a counteroffensive in Kursk Oblast, Russian troops attempted to infiltrate the rear of AFU units in Sudzha through the disabled Urengoy–Pomary–Uzhhorod gas pipeline.

According to the version of the Russian side, the troops traveled 12–15 km through the pipe (depending on the entry point), emerged behind enemy lines “and took control of the settlement of Mirny, Sudzha, and the main road.” To confuse the AFU, Russian troops tied blue tape to their uniforms, which is usually worn by Ukrainian forces. The Russians “accumulated” in the pipe for four days, and the assault began on the fifth day. Many were wounded while exiting the pipe, according to the Russians themselves. Five days after reports of the operation, Russian forces liberated Sudzha.

Even Russian sources gave varying figures for the number of participants in the operation. Chief of the General Staff Valery Gerasimov spoke of more than 600 soldiers; in a propaganda film by Channel One, it was said there were 800 servicemen, there were reports of a hundred.

The AFU General Staff confirmed an attempt by Russian forces to reach the outskirts of Sudzha via the gas pipeline. However, the Ukrainians claim they quickly detected the sabotage groups and inflicted heavy losses on them with drone and artillery strikes.

The Russians suffered losses not only in battle but also while inside the pipe.

The most vivid evidence — the story of a soldier who claims he was in the pipe. According to him, there was not enough oxygen or water, and many soldiers died: “People just lost their minds in there. One shot himself. One... pointed his rifle at himself. Another smashed his own head. A third crashed into a wall. Panic set in.” He also claims that water was taken by fighters from the Akhmat unit. The soldier says he himself only made it halfway before crawling back. The man’s identity was confirmed by Astra, which found he was a resident of St. Petersburg and told journalists that everything he had previously described was true.

“I couldn’t sleep at night because of the coughing. Only now, with the help of doctors, has it become easier. Black phlegm started coming out of my lungs,” recounted another participant in the operation who ended up in the hospital.

“Everyone who was in the pipe suffered lung damage. The soldiers were suffocating. Some have already died,” wrote propagandist Anastasia Kashevarova. “The question is — will anyone be held accountable for those who suffocated?” — wondered Z-blogger Vladimir Romanov.

How effective are assaults through pipes

Operations using underground communications are not always equally effective, and their impact on the course of combat is exaggerated by the Russian side, military experts say.

If in Avdiivka the capture of the Tsarskaya Okhota stronghold somewhat accelerated the advance of the Russian army, the operation near Sudzha had no effect, says Ruslan Leviev of Conflict Intelligence Team: “We remember that operation, <...> in the following days, the situation in the combat zone did not really change. The Operation Pipe in Sudzha was not as successful as Z-bloggers portray.” As for Kupyansk, there is currently no reason to say that the Russian passage through the pipe has seriously affected or will affect the situation, Leviev adds.

The use of the pipe near Kupyansk is a minor episode, and overall the significance of such operations is exaggerated, says a Russian military expert who requested anonymity. “This can be a factor at the tactical level — nothing more,” he believes.

It is difficult for Ukrainian forces to block all underground communications, because there are so many such facilities in industrial areas, and commanders at the operational and tactical level may not know about them, the expert explains. Most pipes were laid in Soviet times, and documentation about them may well be in Moscow.

The main thing in operations using pipes is how many people and how much ammunition the Russians can transfer, says Johan Norberg, senior military analyst at the Swedish Defence Research Agency (FOI). “If it’s a small group, its impact will be very insignificant. For a serious tactical success, you need several hundred soldiers,” the expert believes. In addition, the effect depends on the overall situation on the front and the features of the terrain — on how they can be used.