A new type of barrier developed in Ukraine defends against fibre-guided attack drones by literally cutting their communications.
Radio-frequency jamming stops most small drones. In response, drone designers have begun using fibre-optic cable instead of radio to communicate with the crafts. The fibre-optic cable unspools as the drone flies.
Russia produced very few of these drones in 2024, and each could only reach a few kilometres. 20-kilometre-range versions are now common, with 50-km ones also appearing. The drones have become far more abundant, too, with some 60 per cent of Russian FPV attack drones now fibre guided. In places the landscape is draped with discarded fibre cables.
The Ukrainian forces have been to cut the strong fibre-optic cables. One video shared by a Ukrainian government-led platform has shown civilians how to break a line by hand by looping it and snapping the brittle fibre. But other methods for breaking the cables are needed.
“The most reliable defences against fibre-optic FPVs have been passive barrier systems such as the net tunnels installed over key roads,” says Roy Gardiner, Intel Director at the group Defense Tech for Ukraine. Hundreds of kilometres of roads in Ukraine are now covered with these tunnels, which are physical barriers that catch drones or cause them to explode prematurely.
The Chaharnyk (“Shrubbery”), developed by Logika Design Bureau in Kyiv, offers an alternative. An acoustic sensor picks up the sound of a drone passing overhead and activates the barrier. This is a motorised wire fence in which the wire moves like a conveyor belt with hooks to trap any fibre-optic cable laid over it. The hooks carry the fibre to a cutting block where it is severed.
Chaharnyk is supplied as two 50-metre sections, which two people can set up in less than an hour. It is battery-powered and weatherproof, and can be turned on or off remotely as needed – for example, while friendly drones are passing over.
Barriers can be placed across known lines of approach used by drones, or as a perimeter to protect a fighting position or a facility.
“Vulnerable installations in the rear, such as electrical substations that are too extensive to cover with netting, could be given significant protection against long-range fibre FPVs by the Chaharnyk system,” says Gardiner.
Breaking the fibre cable generally disables a fibre drone, and the makers claim that Chaharnyk has a 95 per cent success rate in cutting the cable of any drone flying over. But it only works if it detects the drone.
“The reliability of the acoustic detection system to distinguish threats in the cacophony of the battlefield needs to be proven,” says Gardiner.
Logika Design Bureau didn’t respond to a request for an interview about the Chaharnyk system.