In my setting, a futuristic North America, the hyperloop is a newfangled mode of long-distance transportation. Basically it's a vacuum tube at low friction and air resistance, which allows pods to glide along until they exit at a terminal. How would a group of Traditionalists, who are resisting modernization efforts of the government, sabotage a hyperloop? They would initially just cause traffic/ slow-downs but eventually do something radical that causes large loss of life.

I have some ideas, but my understanding of engineering is pretty much nil so not sure if they would work. For slowing down traffic, I was thinking it might be possible to increase air pressure in the tube. In a theoretical, working hyperloop:

an electrically driven inlet fan and axial compressor would be placed at the nose of the capsule to "actively transfer high-pressure air from the front to the rear of the vessel", resolving the problem of air pressure building in front of the vehicle, slowing it down.

So my theory is that if they could interfere with fan or compressor, air pressure would build up in front of the pods, slowing them down. But I'm not sure how they could do this or if they would get away with it.

For something more drastic, I'm thinking they could interfere with the vacuum tube of the hyperloop. If air suddenly rushed into the steel tube, would the change be sudden enough for pods to crash, and could this cause loss of life? Alternately, can they somehow pierce the pod without destroying the tube, causing passengers to die from asphyxiation in the vacuum? Or is there another way to sabotage a hyperloop? Fire, explosions?

Any suggestions for ways to sabotage a hyperloop would be helpful.

  • $\begingroup$ How closely does the pod fit in the tube? Any kind of debris might cause a jam. As simple as a workman leaving a tool behind. $\endgroup$
    – FlaStorm32
    Feb 10, 2023 at 18:06
  • 7
    $\begingroup$ The traditional way to stop major infrastructure projects in North America is by using lawyers and political propaganda during the design and construction phase, hoping to outlast the pro-construction politics of the time. One imagines this would appeal to "traditionalists", and it's also quite legal. Waiting for the project to be complete and then resorting to sabotage has historically been ineffective, and just gets your band a rather unfriendly visit-in-kind from the curious police. $\endgroup$
    – user535733
    Feb 10, 2023 at 18:22
  • $\begingroup$ How many times does it loop? $\endgroup$
    – Daron
    Feb 10, 2023 at 18:49
  • $\begingroup$ @FlaStorm32 closely enough that debris could cause a jam. But how would they get the debris into a closed tube? If it’s air-resistant, it’s certainly debris-resistant. Maybe a workman could work once, but I’m sure they wouldn’t get away with disguising lots of rebels as workmen and leaving tools behind consistently? $\endgroup$ Feb 10, 2023 at 20:06
  • $\begingroup$ Honestly the major problem with the hyperloop idea is that it's so prone to disasterous lose of life accidents if something goes wrong it's hard to justify the risk. After all your dependent on a little car providing you with air and protection from a vacuum, if anything happens to your car, if it gets a whole, or gets stuck and you use up all the air, or the antigrav stops working, you run out of electricity, the vacuum tube itself breaks etc. It's doubtful we could make a hyperloop safe enough to build with current tech anyways, so sabotaging such a dangerous device should be easy. $\endgroup$
    – dsollen
    Feb 14, 2023 at 16:31

8 Answers 8


Household chemicals and bits and pieces.

You've asked to find a way to sabotage, at first causing slowing, then when things escalate to stop them dead (very dead). I'll give you a low-ish tech solution, difficult to trace.

Phase 1. Slow them down, raise their maintenance costs.

A diamond-tipped drill-bit, battery-rigged drill, portable gas-cylinder and a fluid reservoir can be managed by a crew of only a couple if necessary.

A tiny, more-or-less very difficult to find hole, or series of holes of only a few millimetres diameter could be drilled in the tunnel wall from outside. Salt water or water containing easy to obtain (and thus untraceable) dilute acids or alkalis would be injected as a mist (drain-cleaners, descalers, caustic soda etc.) - just before and during the passing of a train. This can be accomplished with high-pressure air injected to a stream of the liquid, nebulising the caustic fluid.

This will strip paint, erode metal (such as fan-blades) find its way into electrical-control systems, air-conditioning systems generally increasing part and system-failure and maintenance costs to the transport-system as a whole.

Phase 2. Cause catastrophic failure on-demand.

Needed: A bigger crew, a bigger drill-bit, a wide flexible tube and funnel, and as many bags of pea-sized gravel as they can carry - the sort you find on people's driveways and paths. (Say a metric ton or more, 20 * 50 kg bags should do it) A poking-stick, broom-handle like thing.

First drill your hole. Fit flexible pipe into hole, hold funnel in mouth of pipe, add gravel, using a feeder-stick to push it through if necessary.

The fan at the front colliding with the pile at 300 miles per hour or more (~ 500kph) will cause destructive-failure of the fan, and may stove-in the front of the train releasing a hail of pea-sized rocks inside the carriages to the front. This will kill, maim and cause more mechanical mayhem, tearing the carriage to pieces from the inside, with a similar and decreasing effect on the next carriage.

The train will grind to a halt, blocking the tunnel with casualties and mixed wreckage.

As an alternative to gravel, wet sand or even marine-grit could have similar stopping power, but possibly be less destructive of life. Experimentation might be needed to sort-out teething problems with the plan.

  • $\begingroup$ Recommend changing name to Crazy Harry ;-) That Muppet's name is more apt considering the way your mind works. However, consider that for hyperloop to work it must be vacuum- "filled" (ROTFL) tube, so if it's anywhere on the surface it will be heavily reinforced (vacuum inside plus atmosphere outside equals very high pressure that loop tube must withstand). Which means drilling may be a challenge. $\endgroup$
    – AcePL
    Feb 13, 2023 at 9:39

A simple explosive on the surface of the loop's track.

To function, hyperloops need to be in an enclosed air-tight tube at near vacuum: break the tube, pressurize the tube, and cripple the entire line. Since you can't just switch tubes, that entire line is out of commission until it's repaired.

Bonus points if your bomb is planted in an area that's hell to work in (e.g. a desert).

  • $\begingroup$ While hyperloops have higher maintenance concerns than traditional rail, most/many rail lines in the US are single track only as well, so this isn't any different from traditional rail in that respect. $\endgroup$ Feb 11, 2023 at 20:38
  • $\begingroup$ @Clockwork-Muse which is easier to fix? 2 steal bars attached to some wood or a complex vacuum tube? $\endgroup$ Feb 13, 2023 at 14:40


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Hyperloop is a train in a vacuum tube. Anything that will sabotage a normal train also works on a hyperloop. i.e blow it up.

If you have your heart set on something essential to the vacuum-train and not normal train, I suggest use the vacuum part. Make a hole in the side of the carriage so the breathable air escapes and the passengers drown.

Boats have life jackets and lifeboats. Airplanes have oxygen masks. The train has safety features for this sort of eventuality. Goggles On!

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Sabotage the safety features too. Tamper with the emergency airtight seals between railcars. Hide all the breathing goggles.

. . . can they somehow pierce the pod without destroying the tube?

They can if you say they can. Hyperloops are not real so you get to decide how hard they are to blow up.

The bomb is specially designed and positioned to puncture the hull of the carriage but not the tube. It was made by smart people. The engineering details are left out since they are not relevant to the story.

The guys who know about the bomb don't need to explain it to each other. They already know how it works.

The guy who plants the bomb doesn't explain it to herself. She doesn't need to know how the bomb works.


Ball Bearings, Lots of Ball Bearings.

At the speeds that pods in the hyperloop are travelling at - a Ball Bearing through the windshield would be akin to getting shot with a high power rifle.

a Chrome hardened Ball Bearing is extremely hard and can get big enough to have enough mass to cause havoc.

Reasons they are great:

1: They are cheap. 2: They aren't suspicious. 3: They are easily portable. 4: They are available everywhere.

Get enough Ball Bearings into the loop and they will cause mayhem.



Do you know what 3 hundred tonnes of air does when your hypersonic capsule slams into it? It would be absolutely horrific. All your saboteurs would need to do is burst a pipe and the air will hit the capsules like a brick wall.

They will crumple like a tin can and kill everyone inside, instantly. It would be brutal and extremely easy. Just blow a hole anywhere ahead of a capsule, even at the surface-level stations, if your tubes run underground. The second issue would be pile-ups. When one crashes, if another capsule cant brake in time, and survives the atmosphere, it will hit the crash and start a pile-up.

Something less drastic

You say this isn't the first time they tried something like this, so I will briefly explain how a hyper loop works. First there would be a vacuum tube that would probably run underground in metropolitan areas, and as above-ground tubes on concrete pillars like a monorail.

The capsules would levitate on superconductive magnets and glide down the loops at hundreds of kilometers per second, depending on how far the track runs and how wide you are willing to make the curves. You can go upwards of 400 to 600 kilometers per hour on long, strait stretches.

The stations would need a way to either cut itself off from the vacuum network or bridge the station to the capsules, thus keeping the air in and the vacuum out. I would imagine it would be some kind of docking and sealing system derived from space capsules, as it's basically the same thing.

So the docking tunnel extends and pressurizes, your people get in, it gets evacuated and disengaged and your train takes off. Every few dozen kilometers you will need a vacuum pumping station and power substation for the magnetic engines (linear motors) and to keep the low pressure in the tube.

If you opt for a less extreme low-vacuum, then you do need a way to bypass the air, and thus a turbine, which decreases the track cost but makes the train slower and more complicated. Everything above still applies.


In many ways your train is identical to a spacecraft, except it isn't in space, but it's the same idea. If you shut off the turbo-molecular pumps, spinning at thousands of revolutions per second, air will start seeping in and slowing down or damaging capsules. Sabotage part of the network in a city and traffic will pile up as trains are diverted to other tracks, avoiding repair sites.

Do note that the trains will still be in vacuum, but just not perfect vacuum, theres a big difference between low and high vacuum, but a colossal difference between low vacuum and atmospheric pressure.

Most cities would probably be connected by a web of loops, and so if one direct track between two cities is offline, you can just take an alternate route, probably passing through a different city on the way. An inconvenience, but not a major threat.

Throwing debris into the pipes would also work, or making tiny holes that ever-so-slowly deplete the vacuum. Another option is to damage the capsules themselves while in the station, or the maglev system so that they come to a stop half-way through the track. It will be a royal pain in the rear end to rescue them in the middle of a vacuum filled track.

Or just kill them

If you really want to, then just let air into the track. Just go see the scene from the expanse. (Major gore warning at the end.)


I know that Elon Musk has done a really good job at selling the idea of a hyperloop to people... many of whom should know better, but the truth of the matter is that Nature abhors a vacuum.

If you were to blow a hole in the side of the hyperloop vacuum tube:

There is then a tube with extremely low pressure gas on one side (the vacuum), and high pressure gas (the atmosphere) on the other side. The atmosphere will rush into the tube and could accelerate beyond supersonic speeds (because of the vacuum). The air shock blast-wave's effect will depend on the distance from the break and could range from hitting a minor speed bump to pancaked passengers.

See Hyper loop catastrophe


As regards safety from catastrophic failure, hyperloops are diaperpoops. A vacuum is a fragile thing, and the moment the skin of the tube has a rupture of any real size, the air from outside will rush in, catastrophically braking any carriage and ruining the system.

Ways to rupture the skin –

  • Bomb inside the carriage.

  • Bomb outside the tube.

  • Anti-materiel rifle from outside the tube (this is the stealthiest, the attackers don't have to get close to the system)

  • Corrosive chemicals outside the tube (cost pennies)

  • Crash a vehicle into the pipe

Supposing I took you to a metal pipe in a field and said, "How can you smash this?" it's pretty easy to think of ways.



Every single day I get news from somewhere in the world, about lots of people who die because some company went cheap on their building materials.

Latest round was about some engineers and building companies executives in Turkeye who were arrested. There was a huge Earthquake there, and upwards of 20,000 people lost their lives. Apparently less people would have died if some buildings were built to code.

A few years ago in my home country, an airplane carrying a whole soccer team crashed because the air company went cheap on fuel. They filled the airplane with just enough fuel for the trip. The destination airport had too much traffic and the tower ordered the plane to fly in circles a bit before getting cleared for landing. The pilot signaled a fuel leak in order to obtain priority landing, but still didn't have enough fuel and... You know.

I also remember Titanic... The builders thought it was invincible, so they didn't put enough lifeboats for everybody. And the lifeboats that they used were not filled up to capacity. Hundreds of people died because of this oversight.

If you wish to cause a lot of disruption and loss of human life, just cater to corporate greed and a general lack of empathy that seems so natural to humans. One cheaper component here, one breach of procedure there, saves you tons in costs which goes to shareholders pockets and eventually gets the terrorists' job done.


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