German Researchers Fire Steel Chains to Down Drones

Germany’s Karlsruhe Institute of Technology (KIT) has proposed something that sounds like medieval warfare with a modern twist. Their answer to the country’s growing drone problem? Fire steel chains at quadcopters from a 40mm launcher and let physics do the rest, as reported by Tom’s Hardware.

The research, led by Professor Claus Mattheck at KIT’s Institute for Applied Materials, was published in the journals Aerospace & Defence and Konstruktionspraxis. The timing isn’t accidental. Germany logged over 1,000 suspicious drone flights above military facilities, airports, and other critical infrastructure in 2025 alone, and the Bundestag has approved more than 100 million euros ($116 million) in counter-drone funding for 2025 and 2026.

How the Chain Weapon Works

The concept borrows from the bola, the weighted throwing weapon South American herders used for centuries to bring down livestock and game. Instead of weighted cords, the KIT team uses lightweight steel chains with link diameters of 3 to 4 millimeters (0.12 to 0.16 inches). The chain is fired from a 40mm caliber launcher at 80 meters per second (179 mph).

When the chain hits a drone, it wraps around the airframe and propeller blades. The rotors lock up. The drone drops.

Simulation and Live Trials

Mattheck’s team modeled the impact using Abaqus finite element analysis software. They simulated a 70-gram (2.5 oz) chain measuring 2,000mm (6.5 feet) striking a 1 kg (2.2 lb) model quadcopter, accounting for friction between the steel chain and drone body, propeller geometry, and rotational dynamics.

Three scenarios were tested: a horizontally approaching chain hitting a stationary hovering drone, the same scenario using a chain launched from the 40mm tube, and a third variant with the drone tilted 30 degrees and moving at 25 m/s (56 mph).

Live firing trials happened at the Sternenfels ballistics center in Baden-Württemberg using a catapult-based launcher. These were designed as basic viability tests. The researchers acknowledge they didn’t factor air resistance into their computational models, which matters because the ring vortex generated at the launcher’s muzzle could affect how the chain spreads after firing.

How This Stacks Up Against Lasers

The chain weapon sits at the opposite end of the anti-drone spectrum from directed-energy and electronic warfare systems. The UK’s DragonFire laser, scheduled for installation on Royal Navy destroyers by 2027, uses a 50 kW fiber-combined beam to burn through targets at the speed of light. That kind of system costs thousands of dollars per engagement and demands substantial power infrastructure.

The KIT team’s chain projectile weighs 70 grams and fires from a portable launcher. Mattheck noted that a falling chain poses less risk of collateral damage than a solid projectile of equal mass. The steel chain also outperformed textile nets in initial range tests.

The biggest tradeoff is range. Like a shotgun, the system only works at short distances.

The Hardware Itself

The system is mechanically simple. A 40mm caliber launcher (the same family as standard low-velocity grenade tubes) fires a steel chain weighing 70 grams (2.5 oz) and measuring 2,000mm (6.5 feet) at a muzzle velocity of 80 m/s (179 mph). The chain links themselves are thin, between 3 and 4mm (0.12 to 0.16 inches) in diameter, which keeps the projectile light enough to stay portable while giving it enough mass to foul rotors on contact.

KIT’s simulations targeted a 1 kg (2.2 lb) quadcopter, which covers most off-the-shelf consumer drones and a fair chunk of small commercial models. Range is shotgun-equivalent (short), and that’s the price of admission. What you trade for range, you get back in cost: there are no electronics, no optics, and no power requirements beyond whatever propels the chain out of the tube.

DroneXL’s Take

Here’s what matters: this isn’t about replacing lasers or jammers. It’s about adding a cheap, dumb, mechanical option to a defense stack that currently relies on expensive systems demanding power, optics, and software.

A 70-gram steel chain doesn’t care about EMP shielding. It doesn’t care about encrypted control links. It doesn’t need GPS denial. If you get within range and aim it right, the drone goes down. That’s it.

The short range is the obvious limitation, and skeptics are right to point it out. You’re not stopping a Shahed from 5 miles out with a chain launcher. But for perimeter defense at airports, prisons, or critical infrastructure where engagement happens at a few hundred meters? This could actually work. And it works without a kilowatt of power, without a fire control computer, without a $50,000 maintenance cycle.

The same week NATO countries are spending billions on directed-energy weapons, German researchers basically reinvented the bola. There’s something to that.

Photo credit: Germany’s Karlsruhe Institute of Technology (KIT)