analysis

Can Aerostats Protect a Bridge? Calculations for Kyiv's Southern Bridge

Outside our usual topic, but asked often in Ukraine right now: could tethered aerostats with a net protect a bridge from Shahed-type drones? First-order estimates for Kyiv's Southern Bridge.

Iurii Vysoven

Iurii Vysoven

— 2 min read
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Wireframe of Kyiv's Southern Bridge with two AB130 aerostats holding a 60 by 150 m net next to the pylon
Two AB130 aerostats and a 60 × 150 m net at the Southern Bridge pylon, Kyiv. Visualization: Aerobavovna

This post is outside the usual topic of this blog, elevated connectivity. We are publishing it because the question is being asked in Ukraine right now.

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Can aerostats protect a bridge? Video: Aerobavovna, 3 min 14 s.

Between 1 and 3 October 2026, Russian drones hit Kyiv's bridges six times. We were asked whether aerostats could shield a bridge the way about 1,750 barrage balloons shielded London in 1944. We made first-order estimates for the Southern Bridge; the video walks through them.

The estimate

  • The pylon rises 135 m above the deck. A 60 × 150 m net of 2.4 mm cord weighs about 71 kg. Shahed-type drones have contact fuses, so the warhead could detonate in the net at a distance from the pylon.
  • A pair of our AB130 aerostats (about 70 kg of lift each, on hydrogen) lifts one net. Two pairs cover the pylon from both sides of the bridge; approaches along the bridge and at angles stay open.
  • Wind tilts our aerostats by up to 45°. Holding the net in place takes guy lines to anchors on the bridge and the bank, and these pull the aerostats down and require more lift.
  • A 200 kg drone at 185 km/h loads the net with about 9 kN, against about 1.4 kN of lift from an AB130 pair. The net and tethers most likely snap on the first drone; the next one on the same course meets no obstacle.
  • A TCOM 71M pair (about 42 kN of lift) tilts about 3° at 10 m/s, but covers one side of the pylon, costs about $19.3M a year to operate, holds 33,400 m³ of gas, and, going by Poland's 2024 order, takes about three years from contract to readiness.
Two nets on four AB130 aerostats on both sides of the bridge
Two nets on four AB130, one on each side of the bridge. Frame from the video. Visualization: Aerobavovna

By our estimate, protecting a bridge with aerostats takes years and millions of dollars, and the net on each covered side would most likely stop no more than the first drone.

Summary figures of the estimate
Summary of the estimate. Frame from the video. Visualization: Aerobavovna

Aerobavovna builds tethered aerostats for Ukraine's Defence Forces. Most of them lift communications relays that extend the range of Ukrainian drones, including drones striking targets in Russia.

Sources: Operation Diver; TCOM brochure 2024; Polskie Radio; LB.ua. Wind tilt and AB130 lift: Aerobavovna field data.

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