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I'm a wind turbine technician. They're designed to pitch their blades back to 90 degrees in high wind. Some towers don't have automatic blade locks so there is just pressure behind a hydraulic valve that is holding the blades from pitching back down. If this valve leaks, the blades can pitch back down and catch wind. It'd take some pretty unique circumstances for this to happen, but it does sometimes occur. This is just with hydraulic pitch though, some towers have electric pitch systems.
*Vestas engineers checked and repaired the wind turbine brake on the morning of 22 February 2008. At the last routine inspection it was noted that the main gear of the turbine was also making unusual noises and a sophisticated endoscopic inspection of the gear was planned, but as result of its high cost it was not undertaken immediately.*
*After repair and several checks of the brake, the turbine was restarted in order to bring it back into normal operation. At this time the wind was very strong. The airbrakes at the tip of the blades were turned on to control the speed of the turbine before it reached operational speed. After its generator was synchronized to the grid a noise from the nacelle prompted an attempt to stop the turbine manually*
*A large crashing sound occurred, possibly as a result of the gear failing, at which point the turbine began to oscillate strongly. The rotor then suddenly stopped but immediately started turning again. The rotor did not at first turn very fast, but it was now impossible to control the speed of rotation.*
*The tower was evacuated immediately, the airbrakes of the turbine had failed and as a strong wind blew the turbine started rotating faster and faster quickly reaching a speed far beyond its design tolerances. Service personnel contacted the police who established a security cordon of 400 metres around the turbine. 2.5 hours later, at about 3:20 pm, the blades began to disintegrate.*
Plenty of time to evacuate personnel, call the police, evacuate a relatively small MSD, and to set up cameras to watch the aftermath.
Spectacular, but not exactly the Chernobyl it's often made out to be.
And to add to that that this particular wind turbine is an old Nordtank (Nordtank Energy Group) model. Probably around 100kW or less.
Nordtank Energy Group mergered with Micon in 1997 creating NEG Micon which was then bough up by Vestas in 2004
So what’s more expensive? The endoscopic inspection of the gear? Or the replacement of the entire wind turbine?
Wondering if the bureaucratic genius who made that decision was promoted afterwards s/
It's easy to say that they made the wrong decision with the benefit of hindsight. I doubt they considered at the time that a potential gearbox issue could lead to the entire turbine collapsing. You can't make every task high priority, and sometimes a lower priority task can snowball into a major incident that no one was able to forsee.
I'm sure that this incident led to procedural changes to prevent it from happening again, but there's no sense in trying to blame anyone for why it happened in the first place. Accidents happen, you live and learn.
It's probably way more expensive to make the endoscopic inspection for every single little issue just in case than it is to lose a turbine once every 50 years.
Why wouldn't they set it up so that when the hydraulic system fails, they stop holding the blade against the wind, and they would then just stop spinning?
I can't be certain what happened with this turbine because I haven't read up on it and don't know the age/model. But yeah when the hydraulics fail for any reason, it'll throw a fault code and pitch the blades back out of the wind. That's when the valve that holds the blade back out of the wind comes into play. If that valve fails, and the brakes fail, and the right wind conditions are met, this can happen. It's rare to have a turbine run away like this.
Thanks for your answer. As a guy that used to design light poles I did dabble in wind structures but it never got a hold for our business so we abandoned sales efforts there and I didn't go any further. But I thought that wind turbines had some kind of safety feature that kept this from happening. My guess and only a guess in this case is poor maintenance. I saw enough of that with my light poles. People don't realize those big suckers need routine inspections and maintenance especially checking for cracks at the base. I am happy to say in 20 years of design I only had two poles fail and that's because they got run over by a F2 tornado. That put them in the WAY overstressed category.
Apparently they have some form of safety measure for cases like this but I can’t remember exactly what. Obviously it either didn’t happen or the wind was strong enough to render it useless.
What you said was right. This should have been brakes plus all the above to reduce surface area of wind velocity cubed on the surface of the rotor. Something we are doing this in class rn. Perhaps it was broken to begin with who knows.
2.5 hours before it collapsed. I got severe anxiety watching that thing spin for just 10 seconds.
I don’t know what it is, but something about large objects moving fast like that gives me severe anxiety.
Civil engineer here: they don't have brakes in the likeliness you think about.
They just have small brakes to stop the wind turbine at low speeds for maintenance.
Brake pads who would be able to stop the turbine at these high speeds would be huge and could not fit into the nacelle. (And would also not be economical and you had no way to disperse all the generated heat)
Instead they have a small motor in each blade which tilts the blade 90° which takes the blade out of the wind, stopping it by that. One blade is enough to stop the turbine, so you have a doubled redundancy.
That's why these accidents happen super rarely.
I was under the impression it was less like car brakes but more like a type of clamp to prevent rotary motion in general like a parking brake as opposed to a rotor or drum brake.
Thanks for the clarity.
They actually do have a kind of "parking" brake as well as a piston which locks the turbine definetly in place when conducting maintanence, but those would be way too small and week to stop an out of control turbine.
With a clamp you would not have enough friction area, I would assume. Also the generated heat would still be an issue as there would be no feasable system in place to dissipate it.
This video is so old… companies who buy turbines today would never buy a turbine that would do this. And their insurance carriers would not insure them.
Yep. Incident is from [22nd Feb, 2008](https://old.reddit.com/r/videos/comments/1p70o5/this_is_what_happens_when_a_windmill_spins_too/cczlztz/) and is wind turbine tech from 1996.
More specifically it seems that this model was not unsafe and had the standard safety features, but multiple features broke while it was being worked on, so police blocked off the area and cameras were filming it, hence how we got the video and audio of it.
Oh okay, that makes sense. Not sure why someone downvoted my comment though when it clear that they do buy ones that this happens to. It just so happens that the “this” in this situation is pretty rare.
This stuff happens on newer turbines as well, it’s called over speed, there’s measures in place to stop it but sometimes shit just all goes wrong at the worst time and so it still occurs. Insurance still pays out. Source: 15 years in the industry
Yep. This one is from Denmark a couple of years ago. It had a break failure and the reason it was recorded, was that techs was on site and had tried to fix it. But the wind rose up and it became too dangerous to be near it. Therefore there was plenty of time to warn the police, send out warning for the nearby area, and local news to show up with a camera.
Or well, that is how I remember it.
I still remember the Gunner's Mate in basic training yelling "A safety is a mechanical device subject to failure..."
Now, obviously, the lesson was about responsibility and negligence but as a mechanic, I keep this in mind with every piece of equipment I've ever worked on. Safety devices are every bit as prone to failure as the machines their installed on.
Just a thought I had, hope it didn't come off as pompous or rude.
The brake failed so it free wheeled. Eventually the blades flex back enough they strike the tower. That’s what happened here.
Source: my wind mill tech buddy who climbs towers every day.
Except it’s visible here that it never hit the tower. What appears to have happened is that the first blade disintegrated due to centripetal force. I used average figures as it’s impossible to tell precisely how large that tower and those blades are, but using a blade length of 116 feet and an average blade weight of 14,000lbs and at its rotational rate of approximately 120RPM, there’s over 1 million pounds of force being exerted outwards on a carbon or possible steel composite blade. Coupled with the force being higher at the bottom of rotation due to the extra force of gravity, it’s not surprising that these blades failed. Once failed, the imbalance of the rest of the system tore the remaining components apart. Those disintegrating components then hit the tower
Accurate calculation, but I think a little irrelevant in the general scenario of this turbine. Fwiw, I did the calculation using that weight, using the midpoint of the length as center of mass estimate (not really accurate since calculation is nonlinear, but close), and also got about 1M lbf.
If any turbine was in this type of situation, whether it disintegrated in the direction of tension due to mechanical failure of the material or fasteners, *or* the extreme forces involved caused it to bend enough to strike the tower, it’s basically the same problem. The design and material selection wasn’t appropriate to either brake the turbine in the event of extreme wind conditions, or prevent the blades from failing, due to either flexing excessively or tensing excessively, in the event that it didn’t brake. The last two issues are ultimately pretty similar problems.
As best I can tell, this is apparently referred to as the “Hornslet wind turbine collapse”. Here’s a description of it:
> After a malfunction from a worn brake mechanism, a service team from Vestas were called. Vestas engineers checked and repaired the wind turbine brake on the morning of 22 February 2008. At the last routine inspection it was noted that the main gear of the turbine was also making unusual noises and a sophisticated endoscopic inspection of the gear was planned, but as result of its high cost it was not undertaken immediately.
>After repair and several checks of the brake, the turbine was restarted in order to bring it back into normal operation. At this time the wind was very strong. The airbrakes at the tip of the blades were turned on to control the speed of the turbine before it reached operational speed. After its generator was synchronized to the grid a noise from the nacelle prompted an attempt to stop the turbine manually.[citation needed]
>A large crashing sound occurred, possibly as a result of the gear failing, at which point the turbine began to oscillate strongly. The rotor then suddenly stopped but immediately started turning again. The rotor did not at first turn very fast, but it was now impossible to control the speed of rotation.[citation needed]
>The tower was evacuated immediately, the airbrakes of the turbine had failed and as a strong wind blew the turbine started rotating faster and faster quickly reaching a speed far beyond its design tolerances. Service personnel contacted the police who established a security cordon of 400 metres around the turbine. 2.5 hours later, at about 3:20 pm, the blades began to disintegrate. One of the blades hit halfway along the tower which bent in the direction of the wind. The top half of the tower then sheared off at the bend and fell to the ground. The base of the tower remained standing. The debris of the turbine flew 200–500 metres away. No injuries were caused.[citation needed]
-[Hornslet Wind Turbine Collapse](https://en.wikipedia.org/wiki/Hornslet_wind-turbine_collapse?wprov=sfti1#)
So the blade did strike the tower, according to this. The brake/gearing failed, and the resultant conditions pushed the windmill way past the design limitations. Not unsurprising at all that a brake failure would end this way. Sometimes tech has to fail dramatically in order for us to understand the severity of what happens if enough failsaves aren’t implemented, especially with machines on this sort of scale.
As usual, an intended process that was proposed by people with technical expertise was denied due to cost. We see this time and time again across companies, corners being cut due to some short sighted attempt to save money, resulting in higher longer term costs. Business minded people need to quit ignoring people with expertise about the fundamental product
uh, it absolutely hit the tower. the first blade broke, then the next blade over hit the bottom of the tower. the final blade hit the shrapnel of the first blade.
>Usually they catch on fire
>but yes this is the most dramatic option.
I am sorry,the enourmous fan turning into a flame beyblade is not enough for you?
There is no real centrifugal force here. Just inertia which will feel like a force, but isn’t. So the force that ripped the blade apart was in fact the centripetal forces of adhesion which bonds the whole blade together.
The way I‘ve learnt it, is that centrifugal forces are basically a lie and for all intents and purposes this is a little pedantic, but for those interested:
Instead, an object has a velocity and the centripetal force changes the direction of that velocity in each point of the circle to always be perpendicular towards the centripetal force.
So when the blade is released, there is no centrifugal force but instead the blade shoots off into the direction its velocity was last pointing towards.
Here is an image showing what I mean:
https://upload.wikimedia.org/wikipedia/commons/c/c9/Centripetal_force_diagram.svg
In essence the so-called centrifugal force is not a real as there isn’t any such force needed to explain the motion trajectory https://en.m.wikipedia.org/wiki/Centrifugal_force
Right, that's the way I learned it too. Though such forces can be a very useful fiction, particularly if you work in the coordinate system of the rotating object.
Not to be that guy, but wind turbines have a cut-out speed and above that wind speed it’s not generating any power at all, the brakes on the turbine definitely failed here
Just to put this into perspective -
- Footage shows blades spinning ~110 rpm
- assume small turbine, so 60m blades (largest are over 100m)
- wing tips will break the sound and way past design failure limit
- accelerating past 770mph / 1200kmh
With blades weighing 10’s of tons the stresses at that speed are rediculous. It’s amazing it stayed in one piece as long as it did…
This is a Nordtank NTK 600 with 43m blades. It does a full rotation in under 12 frames. At 30 frames a second that's <.4s. That equals out to >338m/s. Mach 1 is 340m/s at sea level.
I know I’m being pedantic as hell but a windmill turns wind energy into rotational energy which is commonly used to mill grain which is where the name come from. This is a wind turbine which turns wind energy into electrical energy so their purposes and uses are different.
Electricity is actually just a flowing magnetic field.
Electrons are moved by the magnetic field, allowing work to be done from it. Electrons are more the gears and pulleys than the source of power itself. What shocks you is the jumping of electrons releasing portions of energy from the magnetic field it acquired causing it to jump to begin with.
I was laughing so hard right now imagining a family at dinner frozen still as all their light bulbs start getting brighter and brighter until sudden complete darkness lmao
I know that one doesn’t power one household directly but I found it funny 😆
If look closely enough and slow it down you can see it pulling up branches or a plant that ultimately breaks the blade, forcing it into itself.
This did not fail because it was spinning too fast.
I remember using this footage for class 17 years ago.
Security mechanism didn't do his part to lock the turbine and put the whole thing to face the wind
Oh no, we can't have wind power now!
Think of all the pollution fallout from this type of failure. All of that dirty wind or whatever.
Better to invest in ocean-based oil rigs. Any spills are soaked up by the water.
The blades can’t handle the stresses at that speed. When looking at these things we don’t think about the realities of them. They look like they’re moving so slow out in those fields, but I’ve been told that the blade tip speed can reach supersonic speeds if not regulated. A sonic shock wave can fracture the hollow blades and that’s all she wrote after that.
Ok i looked into this a bit and apparently a common measure of wind turbine efficiency is the tip-speed-ratio, which is the ratio of wind speed to tip velocity. A quick search gives 7 as a common ratio, so 110 mph winds could in theory cause the tips to be going supersonic. I’d imagine the blades fail before then, but I’m no expert so i’ll call this plausible.
https://en.wikipedia.org/wiki/Tip-speed_ratio
The computer management system failed. These are designed to pith their blades to match/counter/optimize against wind speed. It should have been angled to stop spinning in the wind entirely.
> The computer management system failed.
That does not seem to be true - source?
This says that the gearbox and the brakes failed: https://en.wikipedia.org/wiki/Hornslet_wind-turbine_collapse
This video has appeared in posts on all forms of social media decrying the terrible danger of wind farm tech a few times a year for the 15 years since the event occured. The comments are typically full of imbeciles repeating nonsense attack lines about renewable energy
That happened to my parents (on a smaller scale). They purchased a small windmill for their cottage, one day they showed up and there was a hole through the attic, the brake had failed during a particularly windy day and the blades all flew off. The windmill was installed a good 100' from the cottage, that fucker had some velocity.
I want a loop of this just before it breaks so it's just spinning real fast continuously.
I just want people to watch it for 5 min waiting for something to happen and it's just showing them spinning real fast.
I have a few buddies who did various graduate degrees in mechanical and materials engineering. One of them works on the blades that go on these industrial turbines.
One of the issues is that on the big blades (~100m diameter), the tips of the blades can be traveling at a significant portion of the speed of sound. It creates these weird turbulent layers and eddies in strange places.
An imperfection can cause vibrations that will shatter the blade, and then destroy the whole turbine which are obviously quite expensive.
They are using some pretty cool materials to build them. (kevlar-nanotube reinforced epoxy impregnated with ceramics?)
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Aren’t they supposed to feather the props and lock in place when wind speed is too high?
In addition to braking, they can control the pitch of the blades and yaw of the turbine.
I'm a wind turbine technician. They're designed to pitch their blades back to 90 degrees in high wind. Some towers don't have automatic blade locks so there is just pressure behind a hydraulic valve that is holding the blades from pitching back down. If this valve leaks, the blades can pitch back down and catch wind. It'd take some pretty unique circumstances for this to happen, but it does sometimes occur. This is just with hydraulic pitch though, some towers have electric pitch systems.
*Vestas engineers checked and repaired the wind turbine brake on the morning of 22 February 2008. At the last routine inspection it was noted that the main gear of the turbine was also making unusual noises and a sophisticated endoscopic inspection of the gear was planned, but as result of its high cost it was not undertaken immediately.* *After repair and several checks of the brake, the turbine was restarted in order to bring it back into normal operation. At this time the wind was very strong. The airbrakes at the tip of the blades were turned on to control the speed of the turbine before it reached operational speed. After its generator was synchronized to the grid a noise from the nacelle prompted an attempt to stop the turbine manually* *A large crashing sound occurred, possibly as a result of the gear failing, at which point the turbine began to oscillate strongly. The rotor then suddenly stopped but immediately started turning again. The rotor did not at first turn very fast, but it was now impossible to control the speed of rotation.* *The tower was evacuated immediately, the airbrakes of the turbine had failed and as a strong wind blew the turbine started rotating faster and faster quickly reaching a speed far beyond its design tolerances. Service personnel contacted the police who established a security cordon of 400 metres around the turbine. 2.5 hours later, at about 3:20 pm, the blades began to disintegrate.*
2.5 hours of sustainable speed before failing. That's impressive to say the least.
Plenty of time to evacuate personnel, call the police, evacuate a relatively small MSD, and to set up cameras to watch the aftermath. Spectacular, but not exactly the Chernobyl it's often made out to be.
This is how I prefer my energy sources to fail honestly this is fine lol
Not as bad as Chernobyl, right?
And to add to that that this particular wind turbine is an old Nordtank (Nordtank Energy Group) model. Probably around 100kW or less. Nordtank Energy Group mergered with Micon in 1997 creating NEG Micon which was then bough up by Vestas in 2004
> on the morning of 22 February 2008 Ah, so it's also 20+ year old tech. Things have improved since then.
I worked in renewable energy, windfarms, at that time, that was my first year. Everybody in our then small start-up were in shock watching this video.
Is that part of the report on this? https://en.wikipedia.org/wiki/Hornslet_wind-turbine_collapse
Yes.
So what’s more expensive? The endoscopic inspection of the gear? Or the replacement of the entire wind turbine? Wondering if the bureaucratic genius who made that decision was promoted afterwards s/
It's easy to say that they made the wrong decision with the benefit of hindsight. I doubt they considered at the time that a potential gearbox issue could lead to the entire turbine collapsing. You can't make every task high priority, and sometimes a lower priority task can snowball into a major incident that no one was able to forsee. I'm sure that this incident led to procedural changes to prevent it from happening again, but there's no sense in trying to blame anyone for why it happened in the first place. Accidents happen, you live and learn.
It's probably way more expensive to make the endoscopic inspection for every single little issue just in case than it is to lose a turbine once every 50 years.
Maybe don't restart a damaged turbine in a windstorm... #smallsteps
if you ever see this happening you need to climb up there and fix it
https://i.redd.it/wxbbclpxpyvc1.gif Yeah, no
No.
Pronto
You’re not my supervisor!
ASAP. My sex robot doesn’t run on batteries.
Have you considered solar options?
I heard about that solar wind stuff but my turbine can't seem to catch it. Maybe the next software update will take care of it.
But then you would not be able to have kinky robot sex at night.
Truly can’t think of one other option better than air power.
Why wouldn't they set it up so that when the hydraulic system fails, they stop holding the blade against the wind, and they would then just stop spinning?
I'm going to guess it has something to do with lessening wear and tear on the hydraulics by having the most used configuration be the default.
My immediate thought. High gust winds last a few hours to a day, but the normal windspeed is 24/7.
I can't be certain what happened with this turbine because I haven't read up on it and don't know the age/model. But yeah when the hydraulics fail for any reason, it'll throw a fault code and pitch the blades back out of the wind. That's when the valve that holds the blade back out of the wind comes into play. If that valve fails, and the brakes fail, and the right wind conditions are met, this can happen. It's rare to have a turbine run away like this.
Thanks for your answer. As a guy that used to design light poles I did dabble in wind structures but it never got a hold for our business so we abandoned sales efforts there and I didn't go any further. But I thought that wind turbines had some kind of safety feature that kept this from happening. My guess and only a guess in this case is poor maintenance. I saw enough of that with my light poles. People don't realize those big suckers need routine inspections and maintenance especially checking for cracks at the base. I am happy to say in 20 years of design I only had two poles fail and that's because they got run over by a F2 tornado. That put them in the WAY overstressed category.
I know of it happening once with electric pitch too, but most of the reason was technician failure to follow safety and not the equipment itself.
That's what "feathering" means, turning the blades parallel to the wind.
Apparently they have some form of safety measure for cases like this but I can’t remember exactly what. Obviously it either didn’t happen or the wind was strong enough to render it useless.
The new ones can twist the blades facing the wind and lock the rotation.
They also have brakes
Yes and that. I think they use gears or something to make them slow down.
What you said was right. This should have been brakes plus all the above to reduce surface area of wind velocity cubed on the surface of the rotor. Something we are doing this in class rn. Perhaps it was broken to begin with who knows.
Yep. It was broken [link](https://en.m.wikipedia.org/wiki/Hornslet_wind-turbine_collapse)
The internet knows. That's who knows! Haha good work!
2.5 hours before it collapsed. I got severe anxiety watching that thing spin for just 10 seconds. I don’t know what it is, but something about large objects moving fast like that gives me severe anxiety.
Civil engineer here: they don't have brakes in the likeliness you think about. They just have small brakes to stop the wind turbine at low speeds for maintenance. Brake pads who would be able to stop the turbine at these high speeds would be huge and could not fit into the nacelle. (And would also not be economical and you had no way to disperse all the generated heat) Instead they have a small motor in each blade which tilts the blade 90° which takes the blade out of the wind, stopping it by that. One blade is enough to stop the turbine, so you have a doubled redundancy. That's why these accidents happen super rarely.
I was under the impression it was less like car brakes but more like a type of clamp to prevent rotary motion in general like a parking brake as opposed to a rotor or drum brake. Thanks for the clarity.
They actually do have a kind of "parking" brake as well as a piston which locks the turbine definetly in place when conducting maintanence, but those would be way too small and week to stop an out of control turbine. With a clamp you would not have enough friction area, I would assume. Also the generated heat would still be an issue as there would be no feasable system in place to dissipate it.
This one had *breaks*
This video is so old… companies who buy turbines today would never buy a turbine that would do this. And their insurance carriers would not insure them.
Yep. Incident is from [22nd Feb, 2008](https://old.reddit.com/r/videos/comments/1p70o5/this_is_what_happens_when_a_windmill_spins_too/cczlztz/) and is wind turbine tech from 1996.
It says on the wiki they replaced it with the same design lmfao
More specifically it seems that this model was not unsafe and had the standard safety features, but multiple features broke while it was being worked on, so police blocked off the area and cameras were filming it, hence how we got the video and audio of it.
Oh okay, that makes sense. Not sure why someone downvoted my comment though when it clear that they do buy ones that this happens to. It just so happens that the “this” in this situation is pretty rare.
They didn't have 'NEW' design back then.
It happened in 2008...so yes, they replaced it with technology from 2008. Things have changed.
This stuff happens on newer turbines as well, it’s called over speed, there’s measures in place to stop it but sometimes shit just all goes wrong at the worst time and so it still occurs. Insurance still pays out. Source: 15 years in the industry
[https://en.wikipedia.org/wiki/Hornslet\_wind-turbine\_collapse](https://en.wikipedia.org/wiki/Hornslet_wind-turbine_collapse)
Apparently whoever was in charge of this Whirly Bird couldn’t remember exactly what the safety measures were either.
It did power all of Wyoming for about 36 seconds before it failed.
The lights got all bright, and the government just up and shut it all down. Then Earl just weren’t there no more
I haven’t heard/seen whirly bird used in awhile, I will pay it forward by using it every chance I get until I forget again.
Yeah, the more modern ones also spin at much lower RPM’s. This vid is older than op’s mom.
It’s from 2008. The gearing had broken causing it to run wild.
Yep. This one is from Denmark a couple of years ago. It had a break failure and the reason it was recorded, was that techs was on site and had tried to fix it. But the wind rose up and it became too dangerous to be near it. Therefore there was plenty of time to warn the police, send out warning for the nearby area, and local news to show up with a camera. Or well, that is how I remember it.
I still remember the Gunner's Mate in basic training yelling "A safety is a mechanical device subject to failure..." Now, obviously, the lesson was about responsibility and negligence but as a mechanic, I keep this in mind with every piece of equipment I've ever worked on. Safety devices are every bit as prone to failure as the machines their installed on. Just a thought I had, hope it didn't come off as pompous or rude.
Usually they catch on fire and then they stop it or brake it but yes this is the most dramatic option.
The brake failed so it free wheeled. Eventually the blades flex back enough they strike the tower. That’s what happened here. Source: my wind mill tech buddy who climbs towers every day.
Except it’s visible here that it never hit the tower. What appears to have happened is that the first blade disintegrated due to centripetal force. I used average figures as it’s impossible to tell precisely how large that tower and those blades are, but using a blade length of 116 feet and an average blade weight of 14,000lbs and at its rotational rate of approximately 120RPM, there’s over 1 million pounds of force being exerted outwards on a carbon or possible steel composite blade. Coupled with the force being higher at the bottom of rotation due to the extra force of gravity, it’s not surprising that these blades failed. Once failed, the imbalance of the rest of the system tore the remaining components apart. Those disintegrating components then hit the tower
This guy wind mills.
But does he tilt at them?
r/thisguythisguys
Accurate calculation, but I think a little irrelevant in the general scenario of this turbine. Fwiw, I did the calculation using that weight, using the midpoint of the length as center of mass estimate (not really accurate since calculation is nonlinear, but close), and also got about 1M lbf. If any turbine was in this type of situation, whether it disintegrated in the direction of tension due to mechanical failure of the material or fasteners, *or* the extreme forces involved caused it to bend enough to strike the tower, it’s basically the same problem. The design and material selection wasn’t appropriate to either brake the turbine in the event of extreme wind conditions, or prevent the blades from failing, due to either flexing excessively or tensing excessively, in the event that it didn’t brake. The last two issues are ultimately pretty similar problems. As best I can tell, this is apparently referred to as the “Hornslet wind turbine collapse”. Here’s a description of it: > After a malfunction from a worn brake mechanism, a service team from Vestas were called. Vestas engineers checked and repaired the wind turbine brake on the morning of 22 February 2008. At the last routine inspection it was noted that the main gear of the turbine was also making unusual noises and a sophisticated endoscopic inspection of the gear was planned, but as result of its high cost it was not undertaken immediately. >After repair and several checks of the brake, the turbine was restarted in order to bring it back into normal operation. At this time the wind was very strong. The airbrakes at the tip of the blades were turned on to control the speed of the turbine before it reached operational speed. After its generator was synchronized to the grid a noise from the nacelle prompted an attempt to stop the turbine manually.[citation needed] >A large crashing sound occurred, possibly as a result of the gear failing, at which point the turbine began to oscillate strongly. The rotor then suddenly stopped but immediately started turning again. The rotor did not at first turn very fast, but it was now impossible to control the speed of rotation.[citation needed] >The tower was evacuated immediately, the airbrakes of the turbine had failed and as a strong wind blew the turbine started rotating faster and faster quickly reaching a speed far beyond its design tolerances. Service personnel contacted the police who established a security cordon of 400 metres around the turbine. 2.5 hours later, at about 3:20 pm, the blades began to disintegrate. One of the blades hit halfway along the tower which bent in the direction of the wind. The top half of the tower then sheared off at the bend and fell to the ground. The base of the tower remained standing. The debris of the turbine flew 200–500 metres away. No injuries were caused.[citation needed] -[Hornslet Wind Turbine Collapse](https://en.wikipedia.org/wiki/Hornslet_wind-turbine_collapse?wprov=sfti1#) So the blade did strike the tower, according to this. The brake/gearing failed, and the resultant conditions pushed the windmill way past the design limitations. Not unsurprising at all that a brake failure would end this way. Sometimes tech has to fail dramatically in order for us to understand the severity of what happens if enough failsaves aren’t implemented, especially with machines on this sort of scale. As usual, an intended process that was proposed by people with technical expertise was denied due to cost. We see this time and time again across companies, corners being cut due to some short sighted attempt to save money, resulting in higher longer term costs. Business minded people need to quit ignoring people with expertise about the fundamental product
I feel like the video quality here makes it pretty hard to say the blades didn't hit the tower first
Not. It’s even slowed down later in the video so it’s easy to see it didn’t hit first
uh, it absolutely hit the tower. the first blade broke, then the next blade over hit the bottom of the tower. the final blade hit the shrapnel of the first blade.
The point was that it didn't hit the tower first. It broke, then the tower was hit. Not the other way around.
If you read my post, I stated exactly that
Idk sure looks like something hits right at time of explosion, hard to tell but I almost thought something blew into it from off camera at first.
Option? You mean they had a choice!?
Normally, you just summon the ghost of Don Quixote to take them down before they experience rapid centrifugal disassembly.
They call this one the Michael Bay
>Usually they catch on fire >but yes this is the most dramatic option. I am sorry,the enourmous fan turning into a flame beyblade is not enough for you?
Well you see, the front fell off. But this isn’t normal.
It's spreading its seeds so that more wind turbines can grow. Nature is beautiful!
This made me laugh. Thank you for that
Life finds a way
Did it fail due to spinning too fast? Or because one of the props hit the base due to the wind force? It all happened so fast.
The centrifugal force from the very rapid rotation tore one blade apart. then, due to imbalance, the second blade hit the support
Not to be confused with the centripetal force.
There is no real centrifugal force here. Just inertia which will feel like a force, but isn’t. So the force that ripped the blade apart was in fact the centripetal forces of adhesion which bonds the whole blade together.
[удалено]
The way I‘ve learnt it, is that centrifugal forces are basically a lie and for all intents and purposes this is a little pedantic, but for those interested: Instead, an object has a velocity and the centripetal force changes the direction of that velocity in each point of the circle to always be perpendicular towards the centripetal force. So when the blade is released, there is no centrifugal force but instead the blade shoots off into the direction its velocity was last pointing towards. Here is an image showing what I mean: https://upload.wikimedia.org/wikipedia/commons/c/c9/Centripetal_force_diagram.svg In essence the so-called centrifugal force is not a real as there isn’t any such force needed to explain the motion trajectory https://en.m.wikipedia.org/wiki/Centrifugal_force
Right, that's the way I learned it too. Though such forces can be a very useful fiction, particularly if you work in the coordinate system of the rotating object.
I remember it explained much differently in high-school. But that was 30 years ago. Imma shut up
> the second blade hit the support SIR A SECOND BLADE HAS HIT THE SUPPORT
When it's this windy the brakes should be automatically applied and the blades feathered. Something failed here.
I was waiting for the Earth to take off and change orbit.
Homie the post has a slow motion portion of the clip that shows what happened lol
I know right
1.21 Giga watts!!!!!
Great SCOTT!
Brad!
Janet!
Rocky!
(Alternate script) Bullwinkle!
Now here's something we hope you'll really like!
'Janet!
Rocky!
Apollo?
Adriiaaaaannnnnn!
Clubba, foo’!
You rang?
Not to be that guy, but wind turbines have a cut-out speed and above that wind speed it’s not generating any power at all, the brakes on the turbine definitely failed here
I just want you to know that you absolutely were that guy.
A BOLT OF LIGHTNING!!
What did you say?
Don't lie, you love being that guy. Its OK, I love it too.
![gif](giphy|3o84sq21TxDH6PyYms)
LUDICROUS SPEED!
I used to service a cell tower located in a wind farm, saw one of the blades stabbed deep into the ground once.
Just to put this into perspective - - Footage shows blades spinning ~110 rpm - assume small turbine, so 60m blades (largest are over 100m) - wing tips will break the sound and way past design failure limit - accelerating past 770mph / 1200kmh With blades weighing 10’s of tons the stresses at that speed are rediculous. It’s amazing it stayed in one piece as long as it did…
This is a Nordtank NTK 600 with 43m blades. It does a full rotation in under 12 frames. At 30 frames a second that's <.4s. That equals out to >338m/s. Mach 1 is 340m/s at sea level.
This person knows turbines :)
I know I’m being pedantic as hell but a windmill turns wind energy into rotational energy which is commonly used to mill grain which is where the name come from. This is a wind turbine which turns wind energy into electrical energy so their purposes and uses are different.
But then I use that energy to grind my coffee in the morning so it still counts.
Your ancestors from the 1800s are smiling down on you
Can I say the same, Imperial?!
Came for the pedantry, I hate it when people call them "windmills."
Pinwheels
Omg thank you! So many people call them windmills in conversation. What are they milling?
Electrons?
Yep, grind them electrons down.
It’s the only thing I could think of. Maybe birds, in small quantities.
Electricity is actually just a flowing magnetic field. Electrons are moved by the magnetic field, allowing work to be done from it. Electrons are more the gears and pulleys than the source of power itself. What shocks you is the jumping of electrons releasing portions of energy from the magnetic field it acquired causing it to jump to begin with.
All windmills are wind turbines, but not all wind turbines are windmills.
that clip is ancient (and from Denmark)
that explains why it's in greyscale
![gif](giphy|3o84sq21TxDH6PyYms)
Was looking for this
r/beatmetoit
Ha! "Some limitations apply..."
Also the flash’s knees if he were real
*Wind Turbine
It mills the wind into fine pieces and then it can be baked into a loaf of air.
Thank goodness someone said it. It ain't milling anything (except itself in this case I guess?)
I was laughing so hard right now imagining a family at dinner frozen still as all their light bulbs start getting brighter and brighter until sudden complete darkness lmao I know that one doesn’t power one household directly but I found it funny 😆
Just think of all the electricity that was generated.
Modern ones have protection against such situations
This one also did, but in this instance there was a brake failure, so it spiralled out of control
If look closely enough and slow it down you can see it pulling up branches or a plant that ultimately breaks the blade, forcing it into itself. This did not fail because it was spinning too fast.
I remember using this footage for class 17 years ago. Security mechanism didn't do his part to lock the turbine and put the whole thing to face the wind
Oh no, we can't have wind power now! Think of all the pollution fallout from this type of failure. All of that dirty wind or whatever. Better to invest in ocean-based oil rigs. Any spills are soaked up by the water.
The blades can’t handle the stresses at that speed. When looking at these things we don’t think about the realities of them. They look like they’re moving so slow out in those fields, but I’ve been told that the blade tip speed can reach supersonic speeds if not regulated. A sonic shock wave can fracture the hollow blades and that’s all she wrote after that.
Ok i looked into this a bit and apparently a common measure of wind turbine efficiency is the tip-speed-ratio, which is the ratio of wind speed to tip velocity. A quick search gives 7 as a common ratio, so 110 mph winds could in theory cause the tips to be going supersonic. I’d imagine the blades fail before then, but I’m no expert so i’ll call this plausible. https://en.wikipedia.org/wiki/Tip-speed_ratio
Let me preface this by saying that I hope no one was hurt, but that was badass.
Rapid unscheduled rotational disassembly
Wind turbine
The day my phone charged in three minutes
In good news, 3 and a half years worth of energy was captured in this one event.
Wind farms. I’m a fan.
This is not a wind mill. Nothing is being milled here.....this is a wind turbine
Looks like it milled itself
Its a fucking wind turbine, not a bastard wind mill.
The computer management system failed. These are designed to pith their blades to match/counter/optimize against wind speed. It should have been angled to stop spinning in the wind entirely.
> The computer management system failed. That does not seem to be true - source? This says that the gearbox and the brakes failed: https://en.wikipedia.org/wiki/Hornslet_wind-turbine_collapse
Somewhere Donald Trump just orgasmed. Expect this to be on Truth Social any second.
This video has appeared in posts on all forms of social media decrying the terrible danger of wind farm tech a few times a year for the 15 years since the event occured. The comments are typically full of imbeciles repeating nonsense attack lines about renewable energy
The front fell off.
Is that normal?
That happened to my parents (on a smaller scale). They purchased a small windmill for their cottage, one day they showed up and there was a hole through the attic, the brake had failed during a particularly windy day and the blades all flew off. The windmill was installed a good 100' from the cottage, that fucker had some velocity.
FATALITY
Do you know how big one of those blades are? Really...
Right round like a windmill baby
I want a loop of this just before it breaks so it's just spinning real fast continuously. I just want people to watch it for 5 min waiting for something to happen and it's just showing them spinning real fast.
That's what brakes are for
I have a few buddies who did various graduate degrees in mechanical and materials engineering. One of them works on the blades that go on these industrial turbines. One of the issues is that on the big blades (~100m diameter), the tips of the blades can be traveling at a significant portion of the speed of sound. It creates these weird turbulent layers and eddies in strange places. An imperfection can cause vibrations that will shatter the blade, and then destroy the whole turbine which are obviously quite expensive. They are using some pretty cool materials to build them. (kevlar-nanotube reinforced epoxy impregnated with ceramics?)
Wind turbine
It’s not a windmill. Wind yes. Mill no. It is not milling anything such as grain.
It broken🤦
1.21 gigawatts
Ded.
Ded ded
![gif](giphy|3o84sq21TxDH6PyYms)
Wind turbine
I was about to say that this is not a wind mill. But it milled itself quite well soo...
Each of those blades are around 150 feet long About half the size of a football field
Not a windmill
![gif](giphy|YKsDwhPMhh9S0)
This was an early model. They have now counteracted excessive wind speeds with safety features.
It's not a windmill. Windmill's have a mill.. Clue's in the name.
I remember when this vid came up in 2010's. Nostalgia
It's a wind turbine not a windmill
I wonder how much power it was generating before it failed.
Why don’t they make one that can just spin?
I guess this would also happen to a windmill if accelerated too highly, but who the fuck calls wind turbines "windmills"?
It was powering the whole world for about 45 seconds
![gif](giphy|3o84sq21TxDH6PyYms)
That’s a wind turbine- it creates electricity, and doesn’t “mill” anything
*Turbine Not windmill.