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Underwater drones would be a rather easy way, no deep sea divers needed. Just have a drone pull a mine-clearing charge (a long flexible hose filled with high ex

Underwater drones would be a rather easy way, no deep sea divers needed. Just have a drone pull a mine-clearing charge (a long flexible hose filled with high explosives) and drop it next to the pipe and detonate it. These pipes lay at ~70 m depth so the drones can be wire-controlled. A small fishing vessel would be enough to deliver them.

treis 4y ago
These are several inch thick pipes encased in a foot of concrete. And they made 4 holes IIRC. So we're talking probably a ton or so of explosives. That's not drag a hose behind a commercial drone. That's specialized equipment with trained operators. I just don't see Ukraine being able to pull that off.
- the_third_wave 4y ago
  I think you underestimate the efficacy of explosives under water: ...since an underwater explosion (particularly one underneath a hull) can produce greater damage than an above-surface one of the same explosive size. Initial damage to a target will be caused by the first shockwave; this damage will be amplified by the subsequent physical movement of water and by the repeated secondary shockwaves or bubble pulse. Additionally, charge detonation away from the target can result in damage over a larger hull area. [1] The pipes have ...two layers; the inner pipe steel which is between 27-41mm thick with antifriction coating and a concrete steel outer coating between 60-110mm thick with corrosion protection... [2], far from the 'several inch thick pipes encased in a foot of concrete' you mention. They were also under high pressure, probably around 200 bar at point of attack [3]. Given that the pipes are at a depth of around 70 meters there this means they had an overpressure of around 193 bar so it would not have taken that much of a crack to cause them to rupture. Once ruptured the whiplashing effect - think what happens to a water hose when you turn open the tap but now with 193 bar of pressure behind it - would take care of the rest. [1] https://wikiless.org/wiki/Underwater_explosion?lang=en https://wikiless.org/wiki/Underwater_explosion?lang=en [2] https://www.newcivilengineer.com/latest/nord-stream-risk-of-gas-pipeline-leak-was-estimated-to-be-one-in-100000-year-event-30-09-2022/ https://www.newcivilengineer.com/latest/nord-stream-risk-of-... [3] https://www.wermac.org/nordstream/nordstream_part3.html https://www.wermac.org/nordstream/nordstream_part3.html

treis 4y ago

These are several inch thick pipes encased in a foot of concrete. And they made 4 holes IIRC. So we're talking probably a ton or so of explosives. That's not drag a hose behind a commercial drone. That's specialized equipment with trained operators. I just don't see Ukraine being able to pull that off.

the_third_wave 4y ago
I think you underestimate the efficacy of explosives under water: ...since an underwater explosion (particularly one underneath a hull) can produce greater damage than an above-surface one of the same explosive size. Initial damage to a target will be caused by the first shockwave; this damage will be amplified by the subsequent physical movement of water and by the repeated secondary shockwaves or bubble pulse. Additionally, charge detonation away from the target can result in damage over a larger hull area. [1] The pipes have ...two layers; the inner pipe steel which is between 27-41mm thick with antifriction coating and a concrete steel outer coating between 60-110mm thick with corrosion protection... [2], far from the 'several inch thick pipes encased in a foot of concrete' you mention. They were also under high pressure, probably around 200 bar at point of attack [3]. Given that the pipes are at a depth of around 70 meters there this means they had an overpressure of around 193 bar so it would not have taken that much of a crack to cause them to rupture. Once ruptured the whiplashing effect - think what happens to a water hose when you turn open the tap but now with 193 bar of pressure behind it - would take care of the rest. [1] https://wikiless.org/wiki/Underwater_explosion?lang=en https://wikiless.org/wiki/Underwater_explosion?lang=en [2] https://www.newcivilengineer.com/latest/nord-stream-risk-of-gas-pipeline-leak-was-estimated-to-be-one-in-100000-year-event-30-09-2022/ https://www.newcivilengineer.com/latest/nord-stream-risk-of-... [3] https://www.wermac.org/nordstream/nordstream_part3.html https://www.wermac.org/nordstream/nordstream_part3.html