And I mean any Six Flags. I've been to St. Louis, Over Texas, and Hurricane Harbor Concord - all of those parks have their cleanliness and maintenance sliders as close to zero as possible.
@@ZiggyTheHamster Back when Darien Lake was a Six Flags I remember that it cost 7 dollars for a 20 once of coke from a vending machine. I've never seen anything half as crazy as that since.
Even that's pretty generous at this point. I remember going to Great Adventure as a kid before and during the Time Warner era and it was pretty well maintained, but in the Premier era it's more like they don't clean anything until it affects the function of something, and even then they'd sooner just close it until the dirt falls off and it starts working again than actually clean it.
something you should know about coaster tracks, they may seem dirty, but often times it's just the paint chipping off, which. if it's a seasonal park, it's not a very big deal, they can do it in the off season, and odds are, they will, however, if it's a year round park, they can't repaint the tracks unless they take the trains off, which means stopping rides for who knows how long, which a park generally won't do, however, let's go back to the seasonal park for a bit, generally they also won't repaint the tracks unless it looks really bad as in the off season, they're going to want to keep costs as low as possible to help ensure that riders get the best experience they can when the park opens back up
The cost will differ from ride to ride. Also, during that cooldown, a new load of electricity is being built up for the next launch. This, and not overheating, is the biggest cause of a cooldown period.
@@obviouslytwo4u The amount of power needed for a launch is rather large, and because of that you can't just suck it up straight from the electric network. That would result in constant power shortages since the launch itself would need as much electricity as a whole neighborhood while it's launching. That's why manufacturers always work with a technique that can slowly build up energy for the launch, originally with a weight being slowly lifted and then dropped while it was attached to the train. Nowadays, we have hydraulic, pneumatic and electric (like supercapacitors) methods to store this energy, but there is always some form of it.
Several years ago, I worked at Cedar Point in Ohio, and the ride I worked on was exactly like this one, only a little taller. I can say that the ride is served by a 400-volt transformer (European standards I guess, since Intamin is Swiss) and the park had this ride hooked up to a 1.5 MW line coming into the park. The LIM's are 3-phase motors fed by a variable-frequency AC drive system, which is how they're controlling the speed of the train. I happened to catch the MFR name on a sticker in the electrical building ("Integral Drive Systems"). There is an ammeter on the cabinet, and during launch it pulls 3500 to 4000 amps. During the subsequent passes, it uses less power, presumably since the train's already moving. Edit: You can see the black "comb" thing on top of the train, and it slides through some metal device affixed to the track. That device has a laser in it that "counts" the teeth coming through, and so it's able to tell how far the train is and when to have it stop.
state side here we supply stuff like this with 480V AC and yeah 1.5 MW sounds about right for the incoming line. though depending on how fast they want the train to launch, it could get as high as 4 to 5 MW and several thousand amps current is absolutely insane, but can understand that.
Just realized how old this video and comment are but still wanted to say I'm also an Ohioan and used to go to Cedar Point every year. One thing I heard in the past is that they actually have huge backup power generators to keep certain things functioning if they lose power from the grid. Also a bit curious as to which coaster you worked on exactly, I'd guess Twister but I think there may be another ride that moves back and forth as well (I'm more of a coaster fanatic and don't ride those ones as much).
Chain tensioner: Theory is correct, reasoning is wrong. The control system will be programmed so that the chain is ever so slightly faster than the speed the train travels through the drives, and after the dog engages the work is transferred from the drive motors to the lift motor. Since the drive only puts out a frequency to the motors to spin at a certain speed, which is slower than the chain, all of the energy is transferred from the drive tires to the chain the instant the dog engages . The reason the counterweight drops slowly is because there is only a portion of the train on the incline. As the entire train begins to go vertical, the chain will eventually meet the force needed to lift the full train on the incline. Making some rough assumptions can yield a number that will simulate the effect of a coaster with nearly the same characteristics. So assuming: Overall length of chain = 275m (appx 3500 links) Lowest cross sectional area of steel link = 0.00129 m^2 (appx 2 square inches) Force applied to link = 83240 N (train weighing 13 tons on a lift with 40deg incline) Our equation is Y = (F/A) / (dL/L) Therefore our dL (the length the chain stretches total) in this hypothetical (very similar to a B&M hyper) is about 131mm or 5.1 inches. Even though each link only stretches one ten-thousandth of an inch (0.0001") that still adds up. The only section of the chain that has tension begins at the train dog, wraps over the top of the lift hill, and touches the drive sprocket. Everything behind the train has 0 tension. The tensioner keeps tension on that side of the chain which would otherwise be 5 inches of slack, which would cause it to skip links around the drive sprocket.Therefore weight is applied. Some coasters use pneumatic cylinders or airbags to tension chains. A weight is obviously the most simple fail-safe solution. Valravn at Cedar Point has no such drives to guide the motion of the engagement. Find a video of that counterweight! It really bounces!
I'd guess the counterweight is a dynamic tensioner. Which accounts for the slightly different load due to the riders. It would be interesting to see if the weight's movement was different with a ride with lots of smaller riders or a half empty ride. But I'm thinking if the chain's tension is predictable, the pick up clunk can be eliminated. Interesting video and I enjoyed the turn signal video.
Justme Asifyoudidntalreadyknow I know that steel cables stretch but for some reason, it never occurred to me that a metal chain could stretch as well...
This. I ride a motor bike and if the chain tension gets to low you end up with backlash when you put a load on it. keeping it taught eliminates that backlash. The chain will stretch over time, so you have to adjust the rear wheel occasionally to re tension it within speck. Roller coasters with that back lash will be within speck, but they will not be adjusted until it is needed within its maintenance timetable. The mechanism seems to be a way to keep the chain fully taught within its maintenance timetable, where the chain is in speck but some stretch has occurred.
I see what looks like a linear encoder up there, too, so the computer can know the train's speed and get the LIM timing right. I have been fascinated by ride control systems since I was a kid going to Disney, but the interest was extra fired up when I worked in the electrical department at Six Flags New England almost two decades ago (wow, time flies...). I had keys to the whole park (even though my super entry level job didn't require such access, but I guess they trusted me). It was tons of fun going into all the control bunkers and checking things out, without touching anything of course. Some rides ran on 600 V, which kinda blew my mind at the time. It was cool reading the huge binder -sized user manuals for the rides, too, especially the crisis/failure management section. The engineers really put a lot of thought into the possible failure modes and how to recover from such failures safely. There is so much redundancy in these rides!
I read the specs of the ride on the manufacturer website and it says the ride uses lsm motors (linear synchronous motor) so i don't think this ride has a complex control system
@@francoelektro7700 LSMs require more advanced control systems than LIMs, LIMs use a a moving electromagnetic field while LSMs synchronize itself with the location of the plates on the train. Also existing Intimin Impulse coasters use LIMs, Intimin's website labels all of their launch coasters as using LSMs because they discontinued their LIM and Hydraulic launches and now only build LSM launch coasters.
the weight that lowers as the train engages, is taking the slack of the return portion of the chain (the under side kind of hangs until tensioned) and all the chain links have a very small amount of give for freedom of movement, that give adds up when tensioned multiplied by the number of chain links. If you look at a bicycle chain the bottom of the loop has a little hang to it, otherwise the bearings have an additional loading adding to the torque when applied.
This is along the lines I was thinking as well. The motor is probably run continuously as repeatedly starting and stopping increases changes of failure, but keeping the chain at max tension all the time also likely puts unnecessary constant stress on the motor. This is probably why most "cheap" coasters have a noticeable amount of slack chain hanging under the track, which is pulled tighter when loaded. A variable tension device (like the counterweight) would help to extend the life of the motor and provide a smoother lift. Keeping the chain at a more "correct" tension (using C to C calculations, or simply pulling until tight) under load also likely reduces friction losses while pulling the train up the hill.
Your example shows that the sprockets are both fixed to the frame. That is probably only to make the chain engage with more teeth on the drive sprocket.
I agree. In addition thinking of the conservation of energy, it takes a lot less energy to speed up the chain that is already moving than the energy required to start a chain moving from a dead stop repeatedly, without the risk of the chain seizing. The auto oiler for the chain can also spread lubrication easier and more even as the chain is moving.
Everyone is correct about the chain tension but, everyone is missing the thing. That is the friction wheels at the beginning of the lift, are run at the same speed has the chain motor. They're controlled by two different VFD's which use the same signal from the PLC thats running the ride. How I know this is I was full time electrician was a Six Flags park in Maryland in 98.
Comments on the questions you had: -V2 (at least the one near me) uses about 6000A when launching. This is fairly normal for an older launch coaster. -That weight and tensioner is for lift acknowledge and for lift faults such as sensing that the train has stopped on the lift or, in the ultra-rare case, that the chain has snapped. It's attached to a plate with a proximity sensor as you can see. -The pricing at Six Flags is undeniably to push for pass/membership sales as well as parking pass, meal and jump-the-line passes. It's Six Flags, they're still paying off their debts.
One could do a whole channel on the engineering behind modern thrill rides, and how the engineering makes the ride so fast and safe at the same time, with only a handful of barely trained monkeys operating it. While we were next in line for X-flight it broke down right in front of us. It came to a stop just before the chain lift and the monkeys were locked out from being able to restart it. Two men in black arrived (not making this up) and they pulled out very heavy keychains to unlock and open the electrical panels near the control cab. The tall one reached in and immediately the train full of people began to inch towards the lift chain. After a minute of very slow motion the train resumed normal speed--the passengers waiting locked into the train for about 15 minutes were unsure if the ride was going to be safe. The train went through the ride with gravity taking over and the fail-safe braking system keeping the trains from colliding. Once the train was through the ride, they restarted the ride by cycling the power disconnect panels. After about a minute of boot up the waiting train was allowed into the station and the passengers were unloaded. Everyone stuck on the ride got free flash passes for their ordeal. This shows just how well engineered the SYSTEM was--fail safe systems keep anyone from being hurt on a rides that run pretty much non-stop.
And then you have the media making it seem like the rides are doing something wrong when they stop a train on the lift hill or a break run. They should do their research before publishing articles like that.
I worked at Hersheypark in Ride Operations over a ten year period, where I operated every roller coaster they had as of 2010 (predates Skyrush, Cocoa Cruiser, and Laff Trakk). So I am very happy to see a video about a roller coaster. The coaster I operated the most was Great Bear.
Tatsh2DX How to properly operate the ride, how to load and unload trains, general safety and unusual situations, height checking requirements, ADA accessibility, etc.
Awesome, I remember when that was new. I was so amazed how it was "upside down" haha. Unfortunately I was still a kid and afraid to ride roller coasters, but I loved watching it
I know this was 4 years ago but if anyone is reading this - the reason you dont get a "clunk" going onto a b&m lift hill is because they (most of the time, if you go on a coaster that doesnt have this, for example Nemesis Inferno at Thorpe Park in the UK, you will feel the jerk as the train engages) most of the time use drive tyres before the chain and the tyres move at the same speed as the chain, meaning when the chain dog engages with the chain, it doesnt suddenly engage causing the train to jerk about. The reason the weight goes down is because it is what keeps the chain tought - so when the train goes onto the chain it streches a bit, meaning the weight does down as there is more length to the chain. Any questions let me know : )
I live about 15 miles from you, I work on their POS terminals for hp, never had a need to go into the park to do any work but seems it would be interesting. I can tell you their IT people are very good. Can't vouch for the rides. :).
This may not be the transformers you are used to. I do not know, however the voltage of this ride could be much higher voltage than typical housing requirements. This is likely 480v 3 phase by the look of the padmount enclosures. Absolutely a high draw machine, but I am not certain it's quite the scale you worked out despite the extra size for the 3 phases. The lower voltage output of the transformers in condos will also require a physically larger transformer because of the relative amperage continuous 480v takes half the amperage per volt as 220 to create the same wattage, and have that again for 110. So at 60hz continuous the transformers will need to be sized larger to handle the load and heat dissapation needs vs a large draw for relatively short bursts with time to cool. If factor in the efficiency benefits of 3 phase which may or may not apply given the solid state pulse drive these rides sound like they employ. These enclosures seem to have a larger cable area than transformer so there may be additional hardware in them as well. Short version: Yeah pretty high draw, but I don't think it is quite the scale you convey.
Transformer sizes are based on VA requirements, not amperage. A 500 VA transformer, being for 12V or 220V is the same size, the windings are different, but the core and magnetic flux capacity (which determines the size), is dependent on VA (apparent power).
They would be 3 phase transformers, so the 6 diodes in the rectifier module would be under a lot less strain than if it was single phase. As well with 360Hz ripple current the capacitor bank ( probably rated for 800VDC and running at around 600VDC in use, using 400VAC phase voltages, as most IGBT devices are 800V rated) can be quite large, but the ripple current will be low for the power. More for riding out short mains power failures, and still having enough energy to safely brake the car string to a stop even if the power goes out totally, than to store the energy to drive it. The power required is I would guess around 500kW peak, but only in bursts, and having 2 big transformers is to have redundant network connections so one going down ( or being off for maintenance) does not stop the ride. They probably have separate rectifiers, fuses and only connect to the main DC bus via some big fuses. Smaller transformer is probably only powering the ride lights, aircons and the park area around it, not the ride direct, though it might do the control room and passage lights. Cooling fans for the ride will be powered from the big transformers, 400VAC 3 phase motors are very much more reliable than 120VAC single phase ones, and can be much smaller for the power output. You would also have associated with the ride a very large force air cooled resistor bank, to dump the power the linear motors absorb when they are used as brakes. In that control room you will have a resistor bank capable of dissipating 1MW or so of power, though it only has to do that at the end of the ride, or on emergency stop conditions. It will be direct on the DC bus, and use another big power controller ( more IGBT modules) to keep the bus voltage during braking from rising too high.
I'm not sure the LIMs are actually used as brakes at all. In the section past the station, there are gaps between the LIMs that have a pneumatically actuated brake device that is raised up before launch, and lowered back down when the train has made its final pass through the station. I'm guessing these are standard magnetic brakes and would be the main braking mechanism, with the LIMs simply idle.
The Incredible Hulk Coaster at Universal's Islands of Adventure uses 8MW for its launch system. That isn't using LIMs, so it's probably less efficient, but that's the kind of power required. The Hulk uses flywheels to store the power for launch.
The chain tensioner is designed to keep the chain tight, to prevent "throbbing" as the car is pulled up the lift hill. The sound you hear is the electricity surge through the system. They do use capacitors, and a dedicated line from the power company (I was told this when talking to a Cedar Point engineer about Wicked Twister). As for not hearing the standard "clickity clack" of the anti-roll-back device, that's because they now install a piece of rubber inside the catch on the underside (or top side on inverted) of the car. This eventually has to be replaced or you will hear it again. Roller coasters like Millennium Force use a cog wheel instead of a latch mechanism, so you'll never hear it on that one.
I thought the screeching noise was made by the passengers as the 'train' departed at high speed? Another great video - many thanks for creating this and sharing it with us. Bruce.
Every time I can only perceive a low-pitched fwoooooom noise, which I've heard some Subway trains make as well. I think my brain is telling me the rest is coming from the "track" and filtering it out?
My guess is that as the weight of the train stretches the chain, the weight pulls on a tensioning sprocket. You can see a smaller chain that translates the downward gravitational force to a diagonal force on something in that greasy slot. Or maybe the chain is intentionally slack until the train comes along.
Yes! I LOOOVE that sound too. I'm closest to the other V2 which is slightly modified, but still makes that noise. Such a great sound. I use to dream 'I should build a drivable car that's powered by LIMs and makes that noise'.
Thumbs up for that ending. Don't know about the other 6 Flags parks but for a while the one in CA had their employees telling people to "Have a Six Flags day!" which I took as an offense.
As someone who works at Six Flags America (near Washington and Baltimore, not the park in the video), I agree with everything. We had our 480V power cut out for a second recently and it was total chaos for us in maintenance.
I seen linear elevators that draw more power. The VFD is so big it gets put in a separate room. So there is a machine room and a vfd room. When the machine starts up and slows down it the sound it makes is amazing. And when the thing stops and the breaks engage it sounds like a bell (the breaks are huge) I am talking about high speed high rise lifts.
I’m a mechanic on Wildfire at SDC. The counterweight holds tension on the tensioner sprocket. When a train is engaged and the load is transferred from the booster wheels onto the chain, what you’re seeing is the chain stretching slightly as it’s loaded. The counterweight moves to accommodate this and maintain the required tension on the chain.
As someone who rides Raging Bull at least 10 times every summer, I think your theory is correct. When sitting in the first 2-3 rows, you can actually feel the train get tugged by the faster moving chain during the transition onto the lift hill. Thank you for talking about some of the cool things (and not so cool things) about the park though! Great America is my home park as well, and I love to learn more about the rides I'm familiar with
Excellent sub-channel. We were at SFGA just last month and had a blast. It is a playground for engineers fascinated by technology. The chain stretches by that much when the train load is added. Hard to believe, but it really does. Raging bull is the only super coaster at SFGA which means it is in the top class for speed and consequently requires the highest lift (and hence longest chain). Some of the stretch comes from the bearings in the chain links relaxing between trains due to grease pressure and not just stretch of the steel. Your 'ka-chunk' observation is spot on, but the shock is removed by matching the speed of the chain to the speed of the approaching train to minimize the mismatch. Notice how the chain slows down between trains but never stops. This is to save electricity and reduce wear. It never completely stops moving because the energy to overcome the 'stiction' or static friction negates the energy savings and wear reduction.
It's definitely a tensioner that picks up slack on the chain. About your comment on how B&M can smoothly transition onto the lift... You got it correct!! The drive tires at the foot of the lift bring the train to the same speed as the lift. B&M is very good for this!!
A lot of the early launched shuttle loop coasters made by Anton Schwarzkopf actually used either a weight drop (usually indicated by a tower behind the main spike) or a flywheel system to launch their rides before LIM and LSM launches were popular on coasters (though LIMS have seen use on other attractions, such as the PeopleMover at Magic Kingdom). I also believe that the Incredible Hulk coaster here in Florida was designed in such as way to be easy on the grid by storing power prior to a launch. Also, as a word of advice, don't go to Six Flags America
Just guesses. But in this scenario, I'd say it would be on the safe side to push these transformers near their limit, since their duty cycle is quite small. They may run at 80% capacity, but for only 5% of the time. That is of course if the ride is operated directly from grid power--if it has its own storage like a capacitor bank, then the transformers are probably loaded more consistently.
I love the launch mechanism of the Hulk coaster at Islands of Adventure. It’s basically a huge baseball batting cage launcher, and it’s the only ride lift I can think of that pulls off a surprise plot twist. It acts like it’s going to be a traditional drop coaster until it flings you over the top of the hill at the last second. Usually the pretend emergency/accident/shark-attack of a ride is the whole pretext for the ride itself.
That's another B&M coaster, but I recall hearing somewhere that they didn't build the launch mechanism themselves as they don't (or didn't, at the time) do launched coasters. Physically it's just a great big rubber-tire launch. The launches in Escape from Gringotts work the same way.
A couple other tidbits about Wicked Twister at Cedar Point (and probably the others): * When the launch button is pressed, it takes 2 seconds to actually launch. * There is a safety light curtain enclosing the train's footprint in the station. If anything crosses, it E-stops the ride. One time a guest's ride photo blew off the shelves where they set their items down, because of the gust of wind caused by the train coming through the station, and it tripped the beam and stopped the ride. * The year I worked on the ride, the main transformer lost a phase and it was down for 2 weeks while they had a rental transformer brought in. With the rental, they couldn't get the voltage quite right and it behaved quite weirdly and was down all the time. "High Voltage" and "Insufficient Launch Speed" were common error messages seen. They eventually received a replacement transformer from the manufacturer. * There is a "manual" mode where an operator can move the train forward and backward at slow speed by holding down a button, and an "auto" mode where the computer executes the normal ride program. Press the button once and it does its thing. * The ride is incapable of launching less than 60 seconds after the train gets back from the previous cycle. * There are no brakes behind the station. Once on the back tower, the train will go through the station.
Hi there! I worked at SFGAm for 5 seasons as a ride op and in maintenance. My second season was spent entirely at Raging Bull. From what I understand, when the train engages with the chain, it adds an incredible amount of weight to the system, taking out all the slack between the motor and the train (i.e. the entire length of chain running from the train all the way up the hill and back down to the motor). In order for the chain to not become loose between the motor and the rear of the train, the motor end sprocket has that counterweight to pull out the slack. As for the unfriendly signage, during my time working at Six Flags, there were several incidents throughout the country of people who were either injured or killed by roller coasters because they hopped fences. People cried out that Six Flags didn't do enough to discourage people from climbing over the 6+ foot tall fences with warning signage on them into dangerous areas. So I guess since I left, they've added more signage. Unsightly? Maybe. Trying to avoid lawsuits? Definitely.
I was fortunate enough to ride the very first Intamin impulse built, Superman Ultimate Escape. It was at my now defunct Six Flags Worlds Of Adventure in Cleveland, Ohio.
Woo-Hoo, roller coasters, one of my faforite subjects. You are absolutely right about the B&M lift hills that always engage carefully. I have never had a single one of them (and I have been on a lot of B&M coasters) that would get a "bump" when attaching to the lift chain. From what I was told, your assumption is guite right. The chain moves slightly faster than the "booster wheels" just prior to entering the lift hill. The important thing is that there is a clutch between the motors and their "booster wheels" that allows the wheels to turn faster than the motor when the train has engaged to the chain and is pulled by it. On Arrow coasters, famous for their violent engaging of the lift hill, your train basically travels down a slope out of the station towards the lift hill, shoots up a bit and may roll back before it engages. The speeds are not synchronized and you clearly feel it. The counter weight is, as others have stated, a tensioner. Since the motor is mounted on the bottom (other manufacturers place them on the top of the lift hill), and a chain can't transmit a pushing force, it is pulling on the lower "return" part of the chain, over the pulley on top of the lift and all the way down to where the train engages. With the little bit of play in each chain link this can give some significant lengthening of the chain when a train engages. So the lower pulley can move back and forth and is tensioned by that weight. Sorry for being metric now, but I am from Germany, the coaster was designed in Switzerland, so that is what the coaster and me are used to. Judging by the photos and the known height of the coaster, I would estimate that the chain has a total length of roughly 250 meters. Now let's assume a minimal chain temperature of 10°C and a maximal of 30°C (depending on the climate this might be a conservative guess). Given the coefficient of thermal expansion for steel (those chains are usualy not any fancy alloy, they are properly greased so they won't rust and the loads are not extremely high), this would make a difference in length of ~60 millimeters (a bit less than 2.5" if I am not totally wrong) between this temperatures. Of course there has to be some device taking care of that expansion, otherwise somebody would have to readjust tension all the time. Of course these figures have to be taken with a grain of salt since they are based on assumptions I have made looking at pictures, but the order of magnitude should be clear. About your six flags rant, I couldn't agree more. As a roller coaster enthusiast, I visit the US every once in a while to ride some coasters, and of course, if there is a Six Flags park nearby, we are going to visit it. But we don't really enjoy, mostly due to the facts that you have mentioned. When we visited Gread America, we got rid of the parking fees since we stayed in a "nearby" hotel, which was a ~15 minute walk to the park entrance, but hey, $25 saved by just walking a little. Or recently we have been to Six Flags St. Louis, it was a day with not too many guests, so we had been on all the rides in less than three hours. We did not spend a single penny on food or drinks in the park, but instead went to a nearby Denny's where we got much better food at a lower price. Plus nice service. There's one more thing to rant about you did not mention - single train operations. Of course, shuttle coasters like the one you portrayed or their infamous armada of Vekoma Boomerangs can't operate more than one train, but also coasters that could theoretically provide a high capacity like their Batman the Ride B&M inverters, are often run using a single train only, even if the length of the line would allow for a second train to be run. I assume they want to make people pay for their Flash Pass or what it's called. (Dislike! No, not your video, that behavior of Six Flags!) Hmm, I could add tons of other stuff, but looking at my longest UA-cam comment ever written, I doubt anyone would ever read up to this point, so I better hit the submit button now...
Chain tensioner.... Much like the belt tensioner on a car.... When the chain takes on a load the tensioner will will take up the slack... That being said.... The upper sprocket has a large spring that will absorb the impact of the train latching the chain.causing the chain to slack out... The reason for the tensioner.
So what makes the sound on the LIM coaster? I've heard a very similar sound on electric subways (Montreal for example) and they definitely don't use LIM for those...
You're exactly right about the counterweight being responsible for the smooth engagement with the lift chain. Older coasters have more primitive tensioners which is why you get a jerky engagement and a bit of lurching until the train gets up to speed. You can really see the effect on some old Arrow coasters. Rather than weights, Arrow used a couple of gears at the base of the chain lift, one of which is on an arm that can move slightly back and forth to tighten the chain as the train latches on. Watch the tensioner bounce back and forth as a train engages on an old arrow and notice that it's timed perfectly with the lurching motion of the train (or, more visibly, the riders on the train). Unfortunately, that will be hard to observe at that particular park since your only Arrow is Demon and it's actually one of the better ones (despite it also being one of the older ones...)
I think my favorite LIM (besides the PeopleMover) is California Screamin' (now The Incredicoaster?) at Disney California Adventure. I always loved that WHOOOOOP sound it made on takeoff after Neil Patrick Harris's (very forced) enthusiastic introduction. I'll have to get up to SFGA at some point to check this one out!
I agree with many of your complaints and comments on Six Flags Great America. it's my home park, too, and I decided to get a season pass this year to go as often as I want. I've been going for as long as I can remember, and my girlfriend has been working there for three years now. It's definitely not the cleanest park in the world, but they can claim that based on a single year that they were the cleanest, even if it was in the past. there's no guidelines stating that it has to be a recent "award" or anything. Additionally, I might seem biased, but I talk down on six flags all the time and I love the place. the food is incredibly expensive, as is most of the merchandise. I do get free parking as a passholder, but to be fair, I haven't had to pay for parking for a few years now, because of my girlfriend taking me in though the employee parking entrance (as visitors that day, we still had to enter through the guest entrance). I'm also a huge coaster nut, and dearly wish that SFGAm would update some of their rides even slightly. for example, I love Demon, but I feel it needs some major track refurbishments. American Eagle could use some smoothing out, due to how rough it is. and for the amount of times I've gone this season already, Joker is down far too often and needs some retooling, but that's my opinion, it's probably just riders being dumb. and that's more than enough of my rambling in youtube comments for a while.
I believe the counterweight is a dynamic chain tensioner. They are used to tighten the chain, and because the chain is so large, they account for different speed of the train/coach and rider’s weight. If there wasn’t a dynamic chain tensioner, the chain, huge chain motor, and chain sprockets would get weaker over time due to a several ton car getting slammed back against it every 2 minutes. The moving tires next to the chain press against the train’s break fin on the bottom of the car. The tires have springs and hydraulic cylinders under them to prevent them from wearing out or being jerky. The tires also have eddy braking, on the tire axle. When the tire turns, magnets oppose the turning and slow the car down to the same speed of the chain. If it is going too fast the hydraulic cylinders push against the tire and putting the car more on the tire, slowing it down, and if it is going too slow, a high torque motor kicks in and gives it a bit of speed to get to the speed of the chain. The reason for the 3 huge transformers if for the insane load of over 2000 amps when the upside down car is on the linear inductive motors. Some roller coasters also have regenerative inductive braking. So when a car is stopped, the energy left in the car is stored in high voltage super capacitors to use for the next car launch. Shout out to Maxx B who said the same as me, he was first on the subject, I just wanted to broaden information. Source- Uncle is an engineer for Arrow Dynamics in California, one of the most popular roller coaster builders in the country.
Very cool! Check out Vancouver, BC's SkyTrain system. It's been in service since 1986, has been expanded several times, and is entirely LIM powered. The trains have a similar but much lower pitched whine as they accelerate. The MK1s have an especially strange crescendo, as they change the pulse width of the current driving the coils in the motor -- the MK1 trains were built before MOSFET technology matured, so they had to use a semiconductor which had fairly slow on/off times, and used frequencies well within audible range. MK2 and MK3 trains are all very quiet and smooth in comparison.
as far as the two "large" transformers, my guess is they are 480 VOLT transformers, used only for the launch and recovery of the train, the smaller one is likely for the ride computer as well as lighting in and around the station plus the audio (if any) and PLC's. It is likely a 120/240 Volt transformer. depending on how much current draw there is from the ride, its possible that it is using something like a capacitor, but on a much larger scale, think lightning generator and you get the idea.
You would be correct. The reason B&M coasters engage the lift so smoothly is because of the feed tires. However, there are a couple of B&M's that don't have feed tires that do in fact "klunk" onto the chain. Valravn at Cedar Point and Griffon at Busch Gardens Williamsburg are two examples of this. There is also another exception to the feed tire method on Mako at Seaworld Orlando. Instead of feed tires, the lead in to the lift is sloped slightly such that gravity feeds the train onto the lift, but without as much of a klunk.
I don't have any experience with a sit-down B&M, but I'm pretty sure I remember the chain of the lift-hill of Swarm at Thorpe Park (a winged B&M coaster) running faster before it attaches, tho that could very well be different for other B&M models. The only other one that I have experience with is Nemesis Inferno, which's a B&M inverted coaster, but that actually has a notably long pre-lift-hill section that actually causes the cart to drag the chain at a faster speed than it's running at up the hill for a short bit before the chain starts to carry the weight of the cart.
The Swarm's lift chain runs faster when the entire train is on a perfectly straight piece of track and slows down when the train starts curving up or levelling out. No idea why, just is. When the chain isn't hauling up a train, it goes into an idling pace.
The stack of weight is rather simple in it function, yet long winded to explain. Considering a chain can only pull and the drive works are at ground level the tension placed on the chain by the train loading it will put tension on the entire loop of chain except the very short piece between the drive sprocket (which is mounted to the shaft we can see vary its speed with the bolt heads showing) and the point the trains pawl engages with the chain. So to make a long story short several hundred feet of chain are placed under tension by the train, this tension yields some slack. The weights keep an idler sprocket pulled in the direction to take up this slack. A similar system (spring loaded rather than weighted) that simply demonstrates this is in the rear derailer of a multi speed bicycle, a (relatively) light tension is kept on the chain all the time to keep things moving thru the sprockets correctly. Imagine a chain with too much slack it tends to fall off the sprockets. the weights job in this coasters case is simply to apply this small amount of tension to the entire chain and to take up any slack made from the load stretching the chain. Most one direction only systems employ this movable idler system for the base load tension that keeps the chain on its sprockets, (unrelated) two way systems like motorcycle chains must transmit power from shaft to shaft both forward when accelerating and the opposite when using the engine to slow the motorcycle down; the base tension often comes from catenary in the chain, but this requires periodic adjustment and who wants that. Note: the limit switch (mounted directly above the aperture that grease is coming out of) that can detect a problem with the tension. If the idler moves back and forth in its housing too far in either direction the upturned ends of that siding part will trip that limit switch, indicating tension has been lost (chain breakage) or a sprocket binding problem (chain gets carried around stuck to the sprocket). I Hope This is clear and helps
My guess on the lift chain is that the chain motor runs slow until the train engages, when this happens the length of the chain tightens up leaving slack from behind the motor sprocket and below the train. The counterweight is on this slack and the position of the counterweight could be controlling a variable frequency drive which speeds up the motor. This way the chain runs the same speed as the idler wheels then speeds up slightly once the train engages. Once the train is off the top, the tension drops, the chain returning from the top sags down, the counterweight goes up and the chain slows back down.
small correction, LIMs and LSMs do sound the same, if you listen to the sound of the launch on the ride you were showing, and compare it to the sound when Wicked launches (Wicked being a launch coaster at Lagoon which uses LSMs) they both have the same screech which is synonomous with launch coasters that use magnets for the launch (LIMs and LSMs) then, another small thing, no, it doesn't use flywheels, the only launches that will use those are the flywheel launches (not very common, and not made anymore) and hydraulic launches such as the launches on Top Thrill Dragster and Kingda Ka, but that's an entirely different type of launch that I don't feel like getting into, so, anyone who read this whole thing, kudos to you, that's a whole spiel about coasters from a coaster enthusiast read
They really don’t sound the same. LSMs have more of a smooth screech (see Taron or Red Force) as opposed to LIMs which sound more mechanical (see Joker’s Jinx or Speed: The Ride). And flywheel launches absolutely are still made, mostly by Zamperla on their Moto Coaster model, the most recent of which opened only three years ago in 2018. Golden Horse also has a flywheel coaster model, with the most recent one opening only 14 days ago.
The counterweight is adjusting the chain tension to make up for the fact that the chain stretches slightly and gets longer when an train is being pulled to the top. It isn't much, but if it isn't accounted for, the chain will either jump off its driving gear or have to have an unacceptably high rest tension.
Your idea was almost entirely correct, the couter weight helps align the chain with the hook system b&m uses on it's trains. If you notice it will not move the same amount depending on how far off the alignment is
My first Great America! I built a show for them the year the double eagle wooden coaster opened. WOW. [that show came here to Santa Clara later]. I think what you are seeing on the chain lift is the idler or tensioning gear relaxing as the chain takes up the load it was mimicking. [not balancing, just tensioning it slightly during slack time]
The counterweight keeps tension on the driving gear for the chain. To achieve the smooth transition, a series of drive wheels are used. A great example of the drive wheels are on Apollo’s Chariot at Busch gardens Williamsburg. Look at a POV and you’ll notice that the chain is moving slightly faster than the drive tires are moving. This eliminates the “clunk” at the start of the lift hill.
I think the counterweight is attached to the chain sprocket and acts as a pretensioner on the chain and motor. When the train engages, the chain stretches out a few inches (over a long, relatively lightweight chain), causing the weight to lower. I bet if you were to watch the weight as the train goes up the track, it would slowly return to it's unloaded position as less of the chain comes under the full weight of the car.
I worked on an lsm coaster. We had a special 2000amp 720 3 phase service to power it. The stator motors were wired up to an off the shelf vfd nothing special about it. VFDs do use igbts. All the magic was in a computer system that would do the calculations to control the vfd. The stator motors had thyristors that would short them out. They did this to take the stator motors out of the system when the train isn't present on that stator motor to save energy.
The counter weight is just that, a counter weight. It isn't controlled except by gravity. As the chain begins pulling the trail up the hill, the weight of the train provides tension to the entire length of the chain, which causes it to stretch and become longer (mostly compressing the lubricant between the chain elements, but also stretching the metal). The counter weight uses gravity to take up this slack. The smooth transition is being created by the driven tires pushing on the back of the train which keep the train from slowing down while it transitions up the hill until after the chain is attached to the front of the train. To get them to link, the chain moves slightly faster than the tires until the chain grips on the train, when they two settle at the same speed.
I would assume that weight is what tensions the chain and when the coaster gets grabbed by the chain the extra weight makes the chain "stretch", increasing the overall length of the chain and making the weight drop a little.
Launch coasters do not have all the complex machinery of other coasters, but you are correct in that they use a butt load of electricity! They also create a butt load of heat. There are other models including one from Mack which actually have coolant systems for the metal components. Your theory for the clunkless chain lift is correct. The set of friction drives, or idler tires that you pointed out, are synchronized to ease the train onto the chain in a manner where the chain dog can connect to it silently. You may have also noticed that this coaster does not have the clickety-clack sound that older coasters have as they ascend the lift hill. Most modern coasters have a glide finger that raises the anti-rollback dog up and off of the sawtooth that is visible in your video. In the event of a lift chain failure, as the train begins to roll backwards down the hill, the glide finger would automatically reverse direction and lower the anti-rollback dog onto the sawtooth, thus freezing the train in its tracks.
Some rides actually drive the chain TOWARD the hill, and loop the chain 180 degrees around a "dancer" idler. This idler is tensioned by weights and shock absorber. This was the case for Superman ride in 6 flags in Md. The dancer oscillated when the train engaged. Regarding the drive tires, I would say the train is driven a little faster then the chain, and as the tires disengage, the train settles back against the chain, at the moment that the speeds match. If the tires drove slower, you would have a guaranteed velocity mismatch at engagement. Many rides use a small downhill to provide this match.
The common theory of the counterweight serving the purpose of a chain tensioner makes sense to me, but there's an additional element of curiosity added by what appears to be a position sensor above part of the tensioning stay. Could this possibly be used to calculate the weight of the train, and thus perfect the amount of braking applied later on in the ride?
Re: Raging Bull's lift counterweight... chain stretch. That movement represents how much the chain stretches from the drive sprocket (at the bottom), going all the way up the return pan under the lift, over the bullwheel at the top, all the way back down, and finally to the train. As the train moves from horizontal to the angle of the lift, more and more tension is applied.
All chain lifts will have this type of system to tension the chain as it needs to not be loose around the sprockets. Also, for the no ka-chunk sound, there are guide wheels that bring the train to the chain at the same speed as the chain.
Over here at six flags over Texas Mr. Freeze (a premier rides shuttle) also uses liner induction motors for its launch. Costs the park about $5000 a day in electricity.
At Valley Fair in Shakopee, MN, there is a coaster called Steel Venom that appears to be a carbon copy of Vertical Velocity, even down to the size and shape of the supports holding the twisted tower. Very cool to have some insight into how it works. Thanks! Edit: Looking further I see that Possessed at Dorney Park is also *exactly* the same. I didn't expect them to all be exactly the same.
If my motorcycle experience is anything to go by, chains can stretch slightly especially over very long distances like on a roller coaster lift, so the counter weight could just be a sophisticated tensioning system.
probably 480v at a couple thousand amps. Best guess and yes banks of capacitors but not like the ones you see in modern electronics, those are going to be able to dump the voltage and amperage is a few miliseconds.
The reason B&M's have that "perfectly smooth transition" onto the lift is because of those wheels just before it, they call that a "lift feed". Other manufacturers use them at times as well, but they're most commonly found on B&M's. Never noticed that counterweight though, I'll have to keep an eye out for them in the future
You’re very correct, the counterweight acts as a dynamic chain tensioner. Also, I’ve noticed that other parks suck in cleanliness. Cedar point is by far the cleanest park (non Disney/universal) that I’ve been too. Dollywood is a close second. However, Kings island which is another cedar fair property isn’t nearly as clean as cedar point. It must be a park management thing.
The weight is a chain tensioner. But the pickup on that one is smoother because it's a B&M, their lift motors have 3 speeds while most have 2. It has an idle and an active speed like most but on the B&M's the lift motor also has an engage speed. That's why the speed increases after its latched. The lift can also vary speed depending on how far through the course the train infront is.
Interesting. Could you point to video how Impulse Roller Coaster goes all the way, POV if available? google search finds only some Impulse Roller Coaster at Knoebels as all first page results for videos, and it does not look as one, because it has a chain and slow lift. Thanx!
As mentioned, the linear coaster is likely 480v, as that is the standard for anything commercial/industrial. The cables in the framing might look thick from the outside, but there are likely many smaller cables inside the jacket instead of some 4/0 gauge wire. Each “cell” of the linear motor probably needs its own circuit in order to control the timing/speed. As for the lift chain, steel does not stretch that much. Also, the chain underneath the track is the portion under tension, not slack (the car is pulled from the top, not pushed from the bottom). That being said, getting the chain under enough tension to not have any play at all would need some major forces, so instead they just designed a way to keep the loose portion under control (motor to the bottom of the train). When the counterweight raises, it is actually decreasing the length between pulleys (“loosening the chain”) since the force of gravity on the weight would pull the chain tighter in the down position (gravitational tensioner). Motor-> pulley at top-> train will always be self tensioning and holding the weight of the passengers. Train->pulley tensioner at bottom -> motor is the “slack” portion, so the counterweight system is just keeping it under control. Before the train arrives, the entire chain is under the same tension. Then, when the weight is taken, 2/3 of the chain is now under (30 people x 175 lbs) 5,250 lbs of tension, so all the slack goes to the portion with the tensioner hence why it increases in length (pulls the slack/gets tighter).
Can I just say, looking at what UA-cam is recommending as the "next" video, that you have some of the best Thumbnails on UA-cam? The faces you make are priceless. :D
Couple notes from this video 1. Go to Silver Dollar City and Dollywood because they are amazing parks owned by Herschend and are clean, have a great atmosphere, and good food. But with Silver Dollar City I think you would love watching the new for 2018 Time Traveler Coaster. Its a controlled spinning coaster and It’s using new technology to make it work. It cost $26 million. It’s the tallest, fastest, steepest, first double launching and first inverting spinning coaster. It starts with you dropping 10-story’s right out of the station. 2. The launch you heard was nice and all but the Premier rides LIM launch sounds are way cooler. Look up either of the Mr. Freeze reverse blast or poltergeist at fiesta Texas or Jokers jinx. They make a lower frequency buzzing sound are a lot more forceful than the Intamin LIM launchers. 3. B&M’s do have a anti rollback system like the old woodies do but they have learned how to keep it quiet unlike RMC who wants people in Mexico to know when Steel Vengeance is climbing the lift. I notice this on the Batman inverts and Wildfire at Silver Dollar city. 4. I agree with everything you said about Six Flags.
Would guess that the counter weight is keeping the chain tension constant. As the chain takes up the load it stretches a bit, and the weight moves down to compensate. Those transformers are usually marked with KVA and primary voltage, possibly secondary voltage. Those big ones look like perhaps 500 KVA. Realize that such a transformer can supply considerable overload for short duration, easily twice the continuous rating.
The smooth engagement of the train onto the chain is most likely due to the coupler that hooks on to the chain being mounted to the car with a spring and damper. At least that's how I would design it. It's possible that the idler tires are powered/braked and they are used to smoothly match the speed of the train and chain, then slow the train slightly to allow a simi-ridgidly mounted coupler (just a plain rubber shock mount) to grab a chain link. There is plenty of time for the speed adjustments to be made unnoticeable. The counter weight is just taking up the extra length of chain due to the load as the train grabs it. The weight of the train is nothing for a chain of that size, but there is always some stretching. If each link stretched .0001" that add up over probably thousands of links.
The chain clutch is *really* simple. It's literally a large metal hook biased by gravity into a 'down' position, but able to rotate upward to roll over the chain links if the train is moving faster than the chain, both at engagement and at release. The only difference between the chain clutch and the safety pawls is that the chain clutch has a curved cutout on the end to engage with the chain roller, while the safeties have an angled end to positively hook into the lift sawtooth. Also, the safeties have a resilient pad on the bottom to cut down on the noise.
I would have to agree with most everyone else and say that the counterweight is a dynamic tensioner that takes the slack out as the train engages, which is what causes the "cachunk" on other rides
"Six Flags doesn't clean anything unless it affects the function of something"
This is a universal truth.
And I mean any Six Flags. I've been to St. Louis, Over Texas, and Hurricane Harbor Concord - all of those parks have their cleanliness and maintenance sliders as close to zero as possible.
@@ZiggyTheHamster Back when Darien Lake was a Six Flags I remember that it cost 7 dollars for a 20 once of coke from a vending machine. I've never seen anything half as crazy as that since.
I thought he was gonna say that they didn't clean anything until it was puked upon!
Even that's pretty generous at this point. I remember going to Great Adventure as a kid before and during the Time Warner era and it was pretty well maintained, but in the Premier era it's more like they don't clean anything until it affects the function of something, and even then they'd sooner just close it until the dirt falls off and it starts working again than actually clean it.
something you should know about coaster tracks, they may seem dirty, but often times it's just the paint chipping off, which. if it's a seasonal park, it's not a very big deal, they can do it in the off season, and odds are, they will, however, if it's a year round park, they can't repaint the tracks unless they take the trains off, which means stopping rides for who knows how long, which a park generally won't do, however, let's go back to the seasonal park for a bit, generally they also won't repaint the tracks unless it looks really bad as in the off season, they're going to want to keep costs as low as possible to help ensure that riders get the best experience they can when the park opens back up
fun fact every launch costs $60 and there is 115-second cooldown to prevent the LIMs from blowing up.
The cost will differ from ride to ride. Also, during that cooldown, a new load of electricity is being built up for the next launch. This, and not overheating, is the biggest cause of a cooldown period.
@@Filipolis its not a flash to a camera mate, there's nothing to store its all ac power
@@obviouslytwo4u The amount of power needed for a launch is rather large, and because of that you can't just suck it up straight from the electric network. That would result in constant power shortages since the launch itself would need as much electricity as a whole neighborhood while it's launching. That's why manufacturers always work with a technique that can slowly build up energy for the launch, originally with a weight being slowly lifted and then dropped while it was attached to the train. Nowadays, we have hydraulic, pneumatic and electric (like supercapacitors) methods to store this energy, but there is always some form of it.
That's... A lot of gigajoules.
Wow ur dumb and ignorant. Lmfao.
Several years ago, I worked at Cedar Point in Ohio, and the ride I worked on was exactly like this one, only a little taller. I can say that the ride is served by a 400-volt transformer (European standards I guess, since Intamin is Swiss) and the park had this ride hooked up to a 1.5 MW line coming into the park. The LIM's are 3-phase motors fed by a variable-frequency AC drive system, which is how they're controlling the speed of the train. I happened to catch the MFR name on a sticker in the electrical building ("Integral Drive Systems"). There is an ammeter on the cabinet, and during launch it pulls 3500 to 4000 amps. During the subsequent passes, it uses less power, presumably since the train's already moving.
Edit: You can see the black "comb" thing on top of the train, and it slides through some metal device affixed to the track. That device has a laser in it that "counts" the teeth coming through, and so it's able to tell how far the train is and when to have it stop.
state side here we supply stuff like this with 480V AC and yeah 1.5 MW sounds about right for the incoming line. though depending on how fast they want the train to launch, it could get as high as 4 to 5 MW and several thousand amps current is absolutely insane, but can understand that.
Just realized how old this video and comment are but still wanted to say I'm also an Ohioan and used to go to Cedar Point every year. One thing I heard in the past is that they actually have huge backup power generators to keep certain things functioning if they lose power from the grid. Also a bit curious as to which coaster you worked on exactly, I'd guess Twister but I think there may be another ride that moves back and forth as well (I'm more of a coaster fanatic and don't ride those ones as much).
@@grn1 Yeah, Wicked Twister is in fact one of these 7 Impulse Coasters. That current at said voltage would be just a touch over 1.5 MW too.
How does that not upset the local grid? Capacitors?
@@nthgth I'd imagine it's just part of the cost of business. They designed their feed to be enough for what they need. 🤷♂️
Chain tensioner: Theory is correct, reasoning is wrong. The control system will be programmed so that the chain is ever so slightly faster than the speed the train travels through the drives, and after the dog engages the work is transferred from the drive motors to the lift motor. Since the drive only puts out a frequency to the motors to spin at a certain speed, which is slower than the chain, all of the energy is transferred from the drive tires to the chain the instant the dog engages . The reason the counterweight drops slowly is because there is only a portion of the train on the incline. As the entire train begins to go vertical, the chain will eventually meet the force needed to lift the full train on the incline.
Making some rough assumptions can yield a number that will simulate the effect of a coaster with nearly the same characteristics. So assuming:
Overall length of chain = 275m (appx 3500 links)
Lowest cross sectional area of steel link = 0.00129 m^2 (appx 2 square inches)
Force applied to link = 83240 N (train weighing 13 tons on a lift with 40deg incline)
Our equation is Y = (F/A) / (dL/L)
Therefore our dL (the length the chain stretches total) in this hypothetical (very similar to a B&M hyper) is about 131mm or 5.1 inches. Even though each link only stretches one ten-thousandth of an inch (0.0001") that still adds up. The only section of the chain that has tension begins at the train dog, wraps over the top of the lift hill, and touches the drive sprocket. Everything behind the train has 0 tension. The tensioner keeps tension on that side of the chain which would otherwise be 5 inches of slack, which would cause it to skip links around the drive sprocket.Therefore weight is applied. Some coasters use pneumatic cylinders or airbags to tension chains. A weight is obviously the most simple fail-safe solution.
Valravn at Cedar Point has no such drives to guide the motion of the engagement. Find a video of that counterweight! It really bounces!
I had to read that twice and watch that segment twice to understand, but I think I got it. Thanks for the explanation.
I'd guess the counterweight is a dynamic tensioner. Which accounts for the slightly different load due to the riders. It would be interesting to see if the weight's movement was different with a ride with lots of smaller riders or a half empty ride.
But I'm thinking if the chain's tension is predictable, the pick up clunk can be eliminated.
Interesting video and I enjoyed the turn signal video.
Maxx B exactly correct.
Same kind of thing for the San Francisco trams cable tension system, but on a much smaller scale
Justme Asifyoudidntalreadyknow I know that steel cables stretch but for some reason, it never occurred to me that a metal chain could stretch as well...
This. I ride a motor bike and if the chain tension gets to low you end up with backlash when you put a load on it. keeping it taught eliminates that backlash. The chain will stretch over time, so you have to adjust the rear wheel occasionally to re tension it within speck.
Roller coasters with that back lash will be within speck, but they will not be adjusted until it is needed within its maintenance timetable. The mechanism seems to be a way to keep the chain fully taught within its maintenance timetable, where the chain is in speck but some stretch has occurred.
This is the correct answer.
It's only 5 flags unless you pay $27 for the 6th flag and a $14 flag cleaning fee
And they really clean the flags enough for them to work again.
EA: The Park
I see what looks like a linear encoder up there, too, so the computer can know the train's speed and get the LIM timing right. I have been fascinated by ride control systems since I was a kid going to Disney, but the interest was extra fired up when I worked in the electrical department at Six Flags New England almost two decades ago (wow, time flies...). I had keys to the whole park (even though my super entry level job didn't require such access, but I guess they trusted me). It was tons of fun going into all the control bunkers and checking things out, without touching anything of course. Some rides ran on 600 V, which kinda blew my mind at the time. It was cool reading the huge binder -sized user manuals for the rides, too, especially the crisis/failure management section. The engineers really put a lot of thought into the possible failure modes and how to recover from such failures safely. There is so much redundancy in these rides!
I read the specs of the ride on the manufacturer website and it says the ride uses lsm motors (linear synchronous motor) so i don't think this ride has a complex control system
@@francoelektro7700 LSMs require more advanced control systems than LIMs, LIMs use a a moving electromagnetic field while LSMs synchronize itself with the location of the plates on the train. Also existing Intimin Impulse coasters use LIMs, Intimin's website labels all of their launch coasters as using LSMs because they discontinued their LIM and Hydraulic launches and now only build LSM launch coasters.
1. This is also my local Six Flags, and I love it!
2. 10:04 THANK YOU FOR SAYING WHAT EVERY GUEST THERE EVER HAS THOUGHT!
the weight that lowers as the train engages, is taking the slack of the return portion of the chain (the under side kind of hangs until tensioned) and all the chain links have a very small amount of give for freedom of movement, that give adds up when tensioned multiplied by the number of chain links. If you look at a bicycle chain the bottom of the loop has a little hang to it, otherwise the bearings have an additional loading adding to the torque when applied.
I found a video example, at the beginning you can see the chain tension up as the train loads on. ua-cam.com/video/Gfn4kS2NGV8/v-deo.html
This is along the lines I was thinking as well. The motor is probably run continuously as repeatedly starting and stopping increases changes of failure, but keeping the chain at max tension all the time also likely puts unnecessary constant stress on the motor. This is probably why most "cheap" coasters have a noticeable amount of slack chain hanging under the track, which is pulled tighter when loaded. A variable tension device (like the counterweight) would help to extend the life of the motor and provide a smoother lift. Keeping the chain at a more "correct" tension (using C to C calculations, or simply pulling until tight) under load also likely reduces friction losses while pulling the train up the hill.
Your example shows that the sprockets are both fixed to the frame. That is probably only to make the chain engage with more teeth on the drive sprocket.
I agree. In addition thinking of the conservation of energy, it takes a lot less energy to speed up the chain that is already moving than the energy required to start a chain moving from a dead stop repeatedly, without the risk of the chain seizing. The auto oiler for the chain can also spread lubrication easier and more even as the chain is moving.
Everyone is correct about the chain tension but, everyone is missing the thing. That is the friction wheels at the beginning of the lift, are run at the same speed has the chain motor. They're controlled by two different VFD's which use the same signal from the PLC thats running the ride.
How I know this is I was full time electrician was a Six Flags park in Maryland in 98.
"Cleanest theme park in the world" I'd like to know who told them that and how much they were paid to say it
It was the signage company. They are well known prostitutes.
lmao thier pr Department
@@GreenBoxMedia bruh, water you doing over here? 😂😂
@@TS_Mind_Swept enjoying someone rambling on about technology topics without a script?
That's a Six Flags day for you.
"Half-a-Dozen Flags", Amazing.
Comments on the questions you had:
-V2 (at least the one near me) uses about 6000A when launching. This is fairly normal for an older launch coaster.
-That weight and tensioner is for lift acknowledge and for lift faults such as sensing that the train has stopped on the lift or, in the ultra-rare case, that the chain has snapped. It's attached to a plate with a proximity sensor as you can see.
-The pricing at Six Flags is undeniably to push for pass/membership sales as well as parking pass, meal and jump-the-line passes. It's Six Flags, they're still paying off their debts.
One could do a whole channel on the engineering behind modern thrill rides, and how the engineering makes the ride so fast and safe at the same time, with only a handful of barely trained monkeys operating it. While we were next in line for X-flight it broke down right in front of us. It came to a stop just before the chain lift and the monkeys were locked out from being able to restart it. Two men in black arrived (not making this up) and they pulled out very heavy keychains to unlock and open the electrical panels near the control cab. The tall one reached in and immediately the train full of people began to inch towards the lift chain. After a minute of very slow motion the train resumed normal speed--the passengers waiting locked into the train for about 15 minutes were unsure if the ride was going to be safe. The train went through the ride with gravity taking over and the fail-safe braking system keeping the trains from colliding. Once the train was through the ride, they restarted the ride by cycling the power disconnect panels. After about a minute of boot up the waiting train was allowed into the station and the passengers were unloaded. Everyone stuck on the ride got free flash passes for their ordeal. This shows just how well engineered the SYSTEM was--fail safe systems keep anyone from being hurt on a rides that run pretty much non-stop.
And then you have the media making it seem like the rides are doing something wrong when they stop a train on the lift hill or a break run. They should do their research before publishing articles like that.
@@davidfrischknecht8261 the media does that with just about everything
The YT channel GP to Enthusiast - this is one of their pet peeves. I recommend checking them out, really good info on coasters and other rides
I worked at Hersheypark in Ride Operations over a ten year period, where I operated every roller coaster they had as of 2010 (predates Skyrush, Cocoa Cruiser, and Laff Trakk). So I am very happy to see a video about a roller coaster. The coaster I operated the most was Great Bear.
Harry Michelson what does the training involve?
Tatsh2DX How to properly operate the ride, how to load and unload trains, general safety and unusual situations, height checking requirements, ADA accessibility, etc.
Awesome, I remember when that was new. I was so amazed how it was "upside down" haha. Unfortunately I was still a kid and afraid to ride roller coasters, but I loved watching it
I know this was 4 years ago but if anyone is reading this - the reason you dont get a "clunk" going onto a b&m lift hill is because they (most of the time, if you go on a coaster that doesnt have this, for example Nemesis Inferno at Thorpe Park in the UK, you will feel the jerk as the train engages) most of the time use drive tyres before the chain and the tyres move at the same speed as the chain, meaning when the chain dog engages with the chain, it doesnt suddenly engage causing the train to jerk about. The reason the weight goes down is because it is what keeps the chain tought - so when the train goes onto the chain it streches a bit, meaning the weight does down as there is more length to the chain. Any questions let me know : )
I live about 15 miles from you, I work on their POS terminals for hp, never had a need to go into the park to do any work but seems it would be interesting. I can tell you their IT people are very good. Can't vouch for the rides. :).
Love the ending! Had me laughing.
NO IT F**KING ISN'T!
This may not be the transformers you are used to. I do not know, however the voltage of this ride could be much higher voltage than typical housing requirements. This is likely 480v 3 phase by the look of the padmount enclosures. Absolutely a high draw machine, but I am not certain it's quite the scale you worked out despite the extra size for the 3 phases. The lower voltage output of the transformers in condos will also require a physically larger transformer because of the relative amperage continuous 480v takes half the amperage per volt as 220 to create the same wattage, and have that again for 110. So at 60hz continuous the transformers will need to be sized larger to handle the load and heat dissapation needs vs a large draw for relatively short bursts with time to cool. If factor in the efficiency benefits of 3 phase which may or may not apply given the solid state pulse drive these rides sound like they employ. These enclosures seem to have a larger cable area than transformer so there may be additional hardware in them as well. Short version: Yeah pretty high draw, but I don't think it is quite the scale you convey.
Transformer sizes are based on VA requirements, not amperage. A 500 VA transformer, being for 12V or 220V is the same size, the windings are different, but the core and magnetic flux capacity (which determines the size), is dependent on VA (apparent power).
They would be 3 phase transformers, so the 6 diodes in the rectifier module would be under a lot less strain than if it was single phase. As well with 360Hz ripple current the capacitor bank ( probably rated for 800VDC and running at around 600VDC in use, using 400VAC phase voltages, as most IGBT devices are 800V rated) can be quite large, but the ripple current will be low for the power. More for riding out short mains power failures, and still having enough energy to safely brake the car string to a stop even if the power goes out totally, than to store the energy to drive it. The power required is I would guess around 500kW peak, but only in bursts, and having 2 big transformers is to have redundant network connections so one going down ( or being off for maintenance) does not stop the ride. They probably have separate rectifiers, fuses and only connect to the main DC bus via some big fuses. Smaller transformer is probably only powering the ride lights, aircons and the park area around it, not the ride direct, though it might do the control room and passage lights. Cooling fans for the ride will be powered from the big transformers, 400VAC 3 phase motors are very much more reliable than 120VAC single phase ones, and can be much smaller for the power output.
You would also have associated with the ride a very large force air cooled resistor bank, to dump the power the linear motors absorb when they are used as brakes. In that control room you will have a resistor bank capable of dissipating 1MW or so of power, though it only has to do that at the end of the ride, or on emergency stop conditions. It will be direct on the DC bus, and use another big power controller ( more IGBT modules) to keep the bus voltage during braking from rising too high.
I'm not sure the LIMs are actually used as brakes at all. In the section past the station, there are gaps between the LIMs that have a pneumatically actuated brake device that is raised up before launch, and lowered back down when the train has made its final pass through the station. I'm guessing these are standard magnetic brakes and would be the main braking mechanism, with the LIMs simply idle.
The Incredible Hulk Coaster at Universal's Islands of Adventure uses 8MW for its launch system. That isn't using LIMs, so it's probably less efficient, but that's the kind of power required. The Hulk uses flywheels to store the power for launch.
Well this really breaks down the tech, problems, and power use of both LIM and LSM systems. www.coastersandmore.de/rides/lim/lim_lsm.shtml
Its a chain tensioner similar to a derailer on the rear wheel of a multi speed bicycle.
that makes sense, to me as well. I could see it being a way to slowly tension the chain as well for a smoother grab, rather than doing it all at once
The chain tensioner is designed to keep the chain tight, to prevent "throbbing" as the car is pulled up the lift hill.
The sound you hear is the electricity surge through the system. They do use capacitors, and a dedicated line from the power company (I was told this when talking to a Cedar Point engineer about Wicked Twister).
As for not hearing the standard "clickity clack" of the anti-roll-back device, that's because they now install a piece of rubber inside the catch on the underside (or top side on inverted) of the car. This eventually has to be replaced or you will hear it again. Roller coasters like Millennium Force use a cog wheel instead of a latch mechanism, so you'll never hear it on that one.
The sound that Premier LIm coasters make is even better. I love the sound of LIM motors. Much cooler than the whine of LSM.
I thought the screeching noise was made by the passengers as the 'train' departed at high speed? Another great video - many thanks for creating this and sharing it with us. Bruce.
You hear a short yelp at launch, but the multi-second screech is the LIM
Every time I can only perceive a low-pitched fwoooooom noise, which I've heard some Subway trains make as well. I think my brain is telling me the rest is coming from the "track" and filtering it out?
Why do you sign off your name at the end of your comment, this isn't a letter
It's like those death skull devices that you can blow in to make them emit a sound similar to a eery scream.
I thought I was the only one who loved the sound of the magnets when the train launches!
I'm in attraction maintenance and get to work on these monster machines all day. Very good explanations I liked the video 👍🏻
My guess is that as the weight of the train stretches the chain, the weight pulls on a tensioning sprocket. You can see a smaller chain that translates the downward gravitational force to a diagonal force on something in that greasy slot. Or maybe the chain is intentionally slack until the train comes along.
This is that time of year where I watch a lot of coaster related videos because I can't wait for it to be spring again.
Yes! I LOOOVE that sound too. I'm closest to the other V2 which is slightly modified, but still makes that noise. Such a great sound. I use to dream 'I should build a drivable car that's powered by LIMs and makes that noise'.
They should call that one "Diagonal Velocity". And next time they should check the local height limits *before* building the ride!
The LIM sound of Joker’s Jinx at Six Flags America is different but also very noticeable!!
Thumbs up for that ending.
Don't know about the other 6 Flags parks but for a while the one in CA had their employees telling people to "Have a Six Flags day!" which I took as an offense.
Lol they still do that. I think it's chain wide. I hear it at Great Adventure too. I'm still not entirely sure what it's supposed to mean.
Yup I always bring subs and chips and a bottle of liquor for the price of park food
As someone who works at Six Flags America (near Washington and Baltimore, not the park in the video), I agree with everything. We had our 480V power cut out for a second recently and it was total chaos for us in maintenance.
I seen linear elevators that draw more power. The VFD is so big it gets put in a separate room. So there is a machine room and a vfd room. When the machine starts up and slows down it the sound it makes is amazing. And when the thing stops and the breaks engage it sounds like a bell (the breaks are huge)
I am talking about high speed high rise lifts.
I’m a mechanic on Wildfire at SDC. The counterweight holds tension on the tensioner sprocket. When a train is engaged and the load is transferred from the booster wheels onto the chain, what you’re seeing is the chain stretching slightly as it’s loaded. The counterweight moves to accommodate this and maintain the required tension on the chain.
As someone who rides Raging Bull at least 10 times every summer, I think your theory is correct. When sitting in the first 2-3 rows, you can actually feel the train get tugged by the faster moving chain during the transition onto the lift hill.
Thank you for talking about some of the cool things (and not so cool things) about the park though! Great America is my home park as well, and I love to learn more about the rides I'm familiar with
Excellent sub-channel. We were at SFGA just last month and had a blast. It is a playground for engineers fascinated by technology. The chain stretches by that much when the train load is added. Hard to believe, but it really does. Raging bull is the only super coaster at SFGA which means it is in the top class for speed and consequently requires the highest lift (and hence longest chain). Some of the stretch comes from the bearings in the chain links relaxing between trains due to grease pressure and not just stretch of the steel. Your 'ka-chunk' observation is spot on, but the shock is removed by matching the speed of the chain to the speed of the approaching train to minimize the mismatch. Notice how the chain slows down between trains but never stops. This is to save electricity and reduce wear. It never completely stops moving because the energy to overcome the 'stiction' or static friction negates the energy savings and wear reduction.
It's definitely a tensioner that picks up slack on the chain.
About your comment on how B&M can smoothly transition onto the lift... You got it correct!! The drive tires at the foot of the lift bring the train to the same speed as the lift. B&M is very good for this!!
5:47 Some fun trivia: American Eagle was also built by Intamin, back in their early days!
Wow I never thought of the power some rides needs that’s insanely cool taking my brain to new levels.
A lot of the early launched shuttle loop coasters made by Anton Schwarzkopf actually used either a weight drop (usually indicated by a tower behind the main spike) or a flywheel system to launch their rides before LIM and LSM launches were popular on coasters (though LIMS have seen use on other attractions, such as the PeopleMover at Magic Kingdom). I also believe that the Incredible Hulk coaster here in Florida was designed in such as way to be easy on the grid by storing power prior to a launch.
Also, as a word of advice, don't go to Six Flags America
Rollercoasters and their mechanisms...I LOVE IT
I'm a budding rollercoaster fanatic, so this interests me immensely
3:50 did you read the actual load and rating or guessing how much by the size of the box?
Just guesses. But in this scenario, I'd say it would be on the safe side to push these transformers near their limit, since their duty cycle is quite small. They may run at 80% capacity, but for only 5% of the time. That is of course if the ride is operated directly from grid power--if it has its own storage like a capacitor bank, then the transformers are probably loaded more consistently.
I love the launch mechanism of the Hulk coaster at Islands of Adventure. It’s basically a huge baseball batting cage launcher, and it’s the only ride lift I can think of that pulls off a surprise plot twist. It acts like it’s going to be a traditional drop coaster until it flings you over the top of the hill at the last second. Usually the pretend emergency/accident/shark-attack of a ride is the whole pretext for the ride itself.
That's another B&M coaster, but I recall hearing somewhere that they didn't build the launch mechanism themselves as they don't (or didn't, at the time) do launched coasters. Physically it's just a great big rubber-tire launch. The launches in Escape from Gringotts work the same way.
A couple other tidbits about Wicked Twister at Cedar Point (and probably the others):
* When the launch button is pressed, it takes 2 seconds to actually launch.
* There is a safety light curtain enclosing the train's footprint in the station. If anything crosses, it E-stops the ride. One time a guest's ride photo blew off the shelves where they set their items down, because of the gust of wind caused by the train coming through the station, and it tripped the beam and stopped the ride.
* The year I worked on the ride, the main transformer lost a phase and it was down for 2 weeks while they had a rental transformer brought in. With the rental, they couldn't get the voltage quite right and it behaved quite weirdly and was down all the time. "High Voltage" and "Insufficient Launch Speed" were common error messages seen. They eventually received a replacement transformer from the manufacturer.
* There is a "manual" mode where an operator can move the train forward and backward at slow speed by holding down a button, and an "auto" mode where the computer executes the normal ride program. Press the button once and it does its thing.
* The ride is incapable of launching less than 60 seconds after the train gets back from the previous cycle.
* There are no brakes behind the station. Once on the back tower, the train will go through the station.
Hi there! I worked at SFGAm for 5 seasons as a ride op and in maintenance. My second season was spent entirely at Raging Bull. From what I understand, when the train engages with the chain, it adds an incredible amount of weight to the system, taking out all the slack between the motor and the train (i.e. the entire length of chain running from the train all the way up the hill and back down to the motor). In order for the chain to not become loose between the motor and the rear of the train, the motor end sprocket has that counterweight to pull out the slack.
As for the unfriendly signage, during my time working at Six Flags, there were several incidents throughout the country of people who were either injured or killed by roller coasters because they hopped fences. People cried out that Six Flags didn't do enough to discourage people from climbing over the 6+ foot tall fences with warning signage on them into dangerous areas. So I guess since I left, they've added more signage. Unsightly? Maybe. Trying to avoid lawsuits? Definitely.
0:00 LOL, I'm imagining him narrating this video live on the scene, and bystanders looking at him confusedly.
I was fortunate enough to ride the very first Intamin impulse built, Superman Ultimate Escape. It was at my now defunct Six Flags Worlds Of Adventure in Cleveland, Ohio.
Woo-Hoo, roller coasters, one of my faforite subjects. You are absolutely right about the B&M lift hills that always engage carefully. I have never had a single one of them (and I have been on a lot of B&M coasters) that would get a "bump" when attaching to the lift chain.
From what I was told, your assumption is guite right. The chain moves slightly faster than the "booster wheels" just prior to entering the lift hill. The important thing is that there is a clutch between the motors and their "booster wheels" that allows the wheels to turn faster than the motor when the train has engaged to the chain and is pulled by it.
On Arrow coasters, famous for their violent engaging of the lift hill, your train basically travels down a slope out of the station towards the lift hill, shoots up a bit and may roll back before it engages. The speeds are not synchronized and you clearly feel it.
The counter weight is, as others have stated, a tensioner. Since the motor is mounted on the bottom (other manufacturers place them on the top of the lift hill), and a chain can't transmit a pushing force, it is pulling on the lower "return" part of the chain, over the pulley on top of the lift and all the way down to where the train engages. With the little bit of play in each chain link this can give some significant lengthening of the chain when a train engages. So the lower pulley can move back and forth and is tensioned by that weight.
Sorry for being metric now, but I am from Germany, the coaster was designed in Switzerland, so that is what the coaster and me are used to. Judging by the photos and the known height of the coaster, I would estimate that the chain has a total length of roughly 250 meters. Now let's assume a minimal chain temperature of 10°C and a maximal of 30°C (depending on the climate this might be a conservative guess). Given the coefficient of thermal expansion for steel (those chains are usualy not any fancy alloy, they are properly greased so they won't rust and the loads are not extremely high), this would make a difference in length of ~60 millimeters (a bit less than 2.5" if I am not totally wrong) between this temperatures. Of course there has to be some device taking care of that expansion, otherwise somebody would have to readjust tension all the time. Of course these figures have to be taken with a grain of salt since they are based on assumptions I have made looking at pictures, but the order of magnitude should be clear.
About your six flags rant, I couldn't agree more. As a roller coaster enthusiast, I visit the US every once in a while to ride some coasters, and of course, if there is a Six Flags park nearby, we are going to visit it. But we don't really enjoy, mostly due to the facts that you have mentioned. When we visited Gread America, we got rid of the parking fees since we stayed in a "nearby" hotel, which was a ~15 minute walk to the park entrance, but hey, $25 saved by just walking a little. Or recently we have been to Six Flags St. Louis, it was a day with not too many guests, so we had been on all the rides in less than three hours. We did not spend a single penny on food or drinks in the park, but instead went to a nearby Denny's where we got much better food at a lower price. Plus nice service. There's one more thing to rant about you did not mention - single train operations. Of course, shuttle coasters like the one you portrayed or their infamous armada of Vekoma Boomerangs can't operate more than one train, but also coasters that could theoretically provide a high capacity like their Batman the Ride B&M inverters, are often run using a single train only, even if the length of the line would allow for a second train to be run. I assume they want to make people pay for their Flash Pass or what it's called. (Dislike! No, not your video, that behavior of Six Flags!)
Hmm, I could add tons of other stuff, but looking at my longest UA-cam comment ever written, I doubt anyone would ever read up to this point, so I better hit the submit button now...
when I first rode this type of coaster at Cedar Point (Wicked Twister), I had thought at first everyone was screaming at the same pitch lol.
Chain tensioner.... Much like the belt tensioner on a car....
When the chain takes on a load the tensioner will will take up the slack...
That being said....
The upper sprocket has a large spring that will absorb the impact of the train latching the chain.causing the chain to slack out... The reason for the tensioner.
RIP Wicked Twister at Cedar Point
So what makes the sound on the LIM coaster? I've heard a very similar sound on electric subways (Montreal for example) and they definitely don't use LIM for those...
You're exactly right about the counterweight being responsible for the smooth engagement with the lift chain. Older coasters have more primitive tensioners which is why you get a jerky engagement and a bit of lurching until the train gets up to speed. You can really see the effect on some old Arrow coasters. Rather than weights, Arrow used a couple of gears at the base of the chain lift, one of which is on an arm that can move slightly back and forth to tighten the chain as the train latches on. Watch the tensioner bounce back and forth as a train engages on an old arrow and notice that it's timed perfectly with the lurching motion of the train (or, more visibly, the riders on the train). Unfortunately, that will be hard to observe at that particular park since your only Arrow is Demon and it's actually one of the better ones (despite it also being one of the older ones...)
I think my favorite LIM (besides the PeopleMover) is California Screamin' (now The Incredicoaster?) at Disney California Adventure. I always loved that WHOOOOOP sound it made on takeoff after Neil Patrick Harris's (very forced) enthusiastic introduction. I'll have to get up to SFGA at some point to check this one out!
I agree with many of your complaints and comments on Six Flags Great America. it's my home park, too, and I decided to get a season pass this year to go as often as I want. I've been going for as long as I can remember, and my girlfriend has been working there for three years now. It's definitely not the cleanest park in the world, but they can claim that based on a single year that they were the cleanest, even if it was in the past. there's no guidelines stating that it has to be a recent "award" or anything. Additionally, I might seem biased, but I talk down on six flags all the time and I love the place. the food is incredibly expensive, as is most of the merchandise. I do get free parking as a passholder, but to be fair, I haven't had to pay for parking for a few years now, because of my girlfriend taking me in though the employee parking entrance (as visitors that day, we still had to enter through the guest entrance). I'm also a huge coaster nut, and dearly wish that SFGAm would update some of their rides even slightly. for example, I love Demon, but I feel it needs some major track refurbishments. American Eagle could use some smoothing out, due to how rough it is. and for the amount of times I've gone this season already, Joker is down far too often and needs some retooling, but that's my opinion, it's probably just riders being dumb.
and that's more than enough of my rambling in youtube comments for a while.
LOL that ending caught me off guard, I love it
I believe the counterweight is a dynamic chain tensioner. They are used to tighten the chain, and because the chain is so large, they account for different speed of the train/coach and rider’s weight. If there wasn’t a dynamic chain tensioner, the chain, huge chain motor, and chain sprockets would get weaker over time due to a several ton car getting slammed back against it every 2 minutes. The moving tires next to the chain press against the train’s break fin on the bottom of the car. The tires have springs and hydraulic cylinders under them to prevent them from wearing out or being jerky. The tires also have eddy braking, on the tire axle. When the tire turns, magnets oppose the turning and slow the car down to the same speed of the chain. If it is going too fast the hydraulic cylinders push against the tire and putting the car more on the tire, slowing it down, and if it is going too slow, a high torque motor kicks in and gives it a bit of speed to get to the speed of the chain. The reason for the 3 huge transformers if for the insane load of over 2000 amps when the upside down car is on the linear inductive motors. Some roller coasters also have regenerative inductive braking. So when a car is stopped, the energy left in the car is stored in high voltage super capacitors to use for the next car launch. Shout out to Maxx B who said the same as me, he was first on the subject, I just wanted to broaden information. Source- Uncle is an engineer for Arrow Dynamics in California, one of the most popular roller coaster builders in the country.
Very cool video - thanks for this. And the end, yes, I laughed. :D
Just loving these free-form TC2 videos - well done! _Especially about coasters BTW!_ Nice juxtaposition to compliment the main channel :)
Very cool! Check out Vancouver, BC's SkyTrain system. It's been in service since 1986, has been expanded several times, and is entirely LIM powered. The trains have a similar but much lower pitched whine as they accelerate. The MK1s have an especially strange crescendo, as they change the pulse width of the current driving the coils in the motor -- the MK1 trains were built before MOSFET technology matured, so they had to use a semiconductor which had fairly slow on/off times, and used frequencies well within audible range. MK2 and MK3 trains are all very quiet and smooth in comparison.
as far as the two "large" transformers, my guess is they are 480 VOLT transformers, used only for the launch and recovery of the train, the smaller one is likely for the ride computer as well as lighting in and around the station plus the audio (if any) and PLC's. It is likely a 120/240 Volt transformer. depending on how much current draw there is from the ride, its possible that it is using something like a capacitor, but on a much larger scale, think lightning generator and you get the idea.
You would be correct. The reason B&M coasters engage the lift so smoothly is because of the feed tires. However, there are a couple of B&M's that don't have feed tires that do in fact "klunk" onto the chain. Valravn at Cedar Point and Griffon at Busch Gardens Williamsburg are two examples of this. There is also another exception to the feed tire method on Mako at Seaworld Orlando. Instead of feed tires, the lead in to the lift is sloped slightly such that gravity feeds the train onto the lift, but without as much of a klunk.
thank you for making a video on a subject ive always been interested in
I don't have any experience with a sit-down B&M, but I'm pretty sure I remember the chain of the lift-hill of Swarm at Thorpe Park (a winged B&M coaster) running faster before it attaches, tho that could very well be different for other B&M models. The only other one that I have experience with is Nemesis Inferno, which's a B&M inverted coaster, but that actually has a notably long pre-lift-hill section that actually causes the cart to drag the chain at a faster speed than it's running at up the hill for a short bit before the chain starts to carry the weight of the cart.
The Swarm's lift chain runs faster when the entire train is on a perfectly straight piece of track and slows down when the train starts curving up or levelling out. No idea why, just is. When the chain isn't hauling up a train, it goes into an idling pace.
The stack of weight is rather simple in it function, yet long winded to explain. Considering a chain can only pull and the drive works are at ground level the tension placed on the chain by the train loading it will put tension on the entire loop of chain except the very short piece between the drive sprocket (which is mounted to the shaft we can see vary its speed with the bolt heads showing) and the point the trains pawl engages with the chain. So to make a long story short several hundred feet of chain are placed under tension by the train, this tension yields some slack. The weights keep an idler sprocket pulled in the direction to take up this slack. A similar system (spring loaded rather than weighted) that simply demonstrates this is in the rear derailer of a multi speed bicycle, a (relatively) light tension is kept on the chain all the time to keep things moving thru the sprockets correctly. Imagine a chain with too much slack it tends to fall off the sprockets. the weights job in this coasters case is simply to apply this small amount of tension to the entire chain and to take up any slack made from the load stretching the chain. Most one direction only systems employ this movable idler system for the base load tension that keeps the chain on its sprockets, (unrelated) two way systems like motorcycle chains must transmit power from shaft to shaft both forward when accelerating and the opposite when using the engine to slow the motorcycle down; the base tension often comes from catenary in the chain, but this requires periodic adjustment and who wants that.
Note: the limit switch (mounted directly above the aperture that grease is coming out of) that can detect a problem with the tension. If the idler moves back and forth in its housing too far in either direction the upturned ends of that siding part will trip that limit switch, indicating tension has been lost (chain breakage) or a sprocket binding problem (chain gets carried around stuck to the sprocket).
I Hope This is clear and helps
My guess on the lift chain is that the chain motor runs slow until the train engages, when this happens the length of the chain tightens up leaving slack from behind the motor sprocket and below the train. The counterweight is on this slack and the position of the counterweight could be controlling a variable frequency drive which speeds up the motor. This way the chain runs the same speed as the idler wheels then speeds up slightly once the train engages. Once the train is off the top, the tension drops, the chain returning from the top sags down, the counterweight goes up and the chain slows back down.
small correction, LIMs and LSMs do sound the same, if you listen to the sound of the launch on the ride you were showing, and compare it to the sound when Wicked launches (Wicked being a launch coaster at Lagoon which uses LSMs) they both have the same screech which is synonomous with launch coasters that use magnets for the launch (LIMs and LSMs) then, another small thing, no, it doesn't use flywheels, the only launches that will use those are the flywheel launches (not very common, and not made anymore) and hydraulic launches such as the launches on Top Thrill Dragster and Kingda Ka, but that's an entirely different type of launch that I don't feel like getting into, so, anyone who read this whole thing, kudos to you, that's a whole spiel about coasters from a coaster enthusiast read
They really don’t sound the same. LSMs have more of a smooth screech (see Taron or Red Force) as opposed to LIMs which sound more mechanical (see Joker’s Jinx or Speed: The Ride). And flywheel launches absolutely are still made, mostly by Zamperla on their Moto Coaster model, the most recent of which opened only three years ago in 2018. Golden Horse also has a flywheel coaster model, with the most recent one opening only 14 days ago.
The counterweight is adjusting the chain tension to make up for the fact that the chain stretches slightly and gets longer when an train is being pulled to the top. It isn't much, but if it isn't accounted for, the chain will either jump off its driving gear or have to have an unacceptably high rest tension.
Your idea was almost entirely correct, the couter weight helps align the chain with the hook system b&m uses on it's trains. If you notice it will not move the same amount depending on how far off the alignment is
That particular counterweight is all about taking up the slack on the bottom side of the chain when the train stretches the heck out of the top side.
My first Great America! I built a show for them the year the double eagle wooden coaster opened. WOW. [that show came here to Santa Clara later]. I think what you are seeing on the chain lift is the idler or tensioning gear relaxing as the chain takes up the load it was mimicking. [not balancing, just tensioning it slightly during slack time]
The counterweight keeps tension on the driving gear for the chain. To achieve the smooth transition, a series of drive wheels are used. A great example of the drive wheels are on Apollo’s Chariot at Busch gardens Williamsburg. Look at a POV and you’ll notice that the chain is moving slightly faster than the drive tires are moving. This eliminates the “clunk” at the start of the lift hill.
I think the counterweight is attached to the chain sprocket and acts as a pretensioner on the chain and motor. When the train engages, the chain stretches out a few inches (over a long, relatively lightweight chain), causing the weight to lower. I bet if you were to watch the weight as the train goes up the track, it would slowly return to it's unloaded position as less of the chain comes under the full weight of the car.
I worked on an lsm coaster. We had a special 2000amp 720 3 phase service to power it. The stator motors were wired up to an off the shelf vfd nothing special about it. VFDs do use igbts. All the magic was in a computer system that would do the calculations to control the vfd. The stator motors had thyristors that would short them out. They did this to take the stator motors out of the system when the train isn't present on that stator motor to save energy.
The Santa Clara park is pretty spiffy paint wise, but we don't exactly have 'weather' here that you would notice.
The counter weight is just that, a counter weight. It isn't controlled except by gravity. As the chain begins pulling the trail up the hill, the weight of the train provides tension to the entire length of the chain, which causes it to stretch and become longer (mostly compressing the lubricant between the chain elements, but also stretching the metal). The counter weight uses gravity to take up this slack. The smooth transition is being created by the driven tires pushing on the back of the train which keep the train from slowing down while it transitions up the hill until after the chain is attached to the front of the train. To get them to link, the chain moves slightly faster than the tires until the chain grips on the train, when they two settle at the same speed.
I would assume that weight is what tensions the chain and when the coaster gets grabbed by the chain the extra weight makes the chain "stretch", increasing the overall length of the chain and making the weight drop a little.
Launch coasters do not have all the complex machinery of other coasters, but you are correct in that they use a butt load of electricity! They also create a butt load of heat. There are other models including one from Mack which actually have coolant systems for the metal components.
Your theory for the clunkless chain lift is correct. The set of friction drives, or idler tires that you pointed out, are synchronized to ease the train onto the chain in a manner where the chain dog can connect to it silently. You may have also noticed that this coaster does not have the clickety-clack sound that older coasters have as they ascend the lift hill. Most modern coasters have a glide finger that raises the anti-rollback dog up and off of the sawtooth that is visible in your video. In the event of a lift chain failure, as the train begins to roll backwards down the hill, the glide finger would automatically reverse direction and lower the anti-rollback dog onto the sawtooth, thus freezing the train in its tracks.
Some rides actually drive the chain TOWARD the hill, and loop the chain 180 degrees around a "dancer" idler. This idler is tensioned by weights and shock absorber. This was the case for Superman ride in 6 flags in Md. The dancer oscillated when the train engaged.
Regarding the drive tires, I would say the train is driven a little faster then the chain, and as the tires disengage, the train settles back against the chain, at the moment that the speeds match. If the tires drove slower, you would have a guaranteed velocity mismatch at engagement. Many rides use a small downhill to provide this match.
The common theory of the counterweight serving the purpose of a chain tensioner makes sense to me, but there's an additional element of curiosity added by what appears to be a position sensor above part of the tensioning stay. Could this possibly be used to calculate the weight of the train, and thus perfect the amount of braking applied later on in the ride?
Re: Raging Bull's lift counterweight... chain stretch. That movement represents how much the chain stretches from the drive sprocket (at the bottom), going all the way up the return pan under the lift, over the bullwheel at the top, all the way back down, and finally to the train. As the train moves from horizontal to the angle of the lift, more and more tension is applied.
Man I’m just like you-I could be at a broadway musical and get completely caught up in the tech of how things work lol
All chain lifts will have this type of system to tension the chain as it needs to not be loose around the sprockets. Also, for the no ka-chunk sound, there are guide wheels that bring the train to the chain at the same speed as the chain.
Over here at six flags over Texas Mr. Freeze (a premier rides shuttle) also uses liner induction motors for its launch. Costs the park about $5000 a day in electricity.
Intamin uses LSM instead of LIM on their rides.
At Valley Fair in Shakopee, MN, there is a coaster called Steel Venom that appears to be a carbon copy of Vertical Velocity, even down to the size and shape of the supports holding the twisted tower. Very cool to have some insight into how it works. Thanks!
Edit: Looking further I see that Possessed at Dorney Park is also *exactly* the same. I didn't expect them to all be exactly the same.
It's a specific production model, an Intamin Impulse.
The weight is used to tighten the chain which is moving faster than the tires, the weight is accounting for some of the weight of the train.
If my motorcycle experience is anything to go by, chains can stretch slightly especially over very long distances like on a roller coaster lift, so the counter weight could just be a sophisticated tensioning system.
10:07 the lift mechanism is adjusting so the chain isn't slacking. Basically it's keeping the chain tensioned.
probably 480v at a couple thousand amps. Best guess and yes banks of capacitors but not like the ones you see in modern electronics, those are going to be able to dump the voltage and amperage is a few miliseconds.
Cleanest theme park I've ever been to is Holiday World in Santa Claus, IN.
The reason B&M's have that "perfectly smooth transition" onto the lift is because of those wheels just before it, they call that a "lift feed". Other manufacturers use them at times as well, but they're most commonly found on B&M's. Never noticed that counterweight though, I'll have to keep an eye out for them in the future
You’re very correct, the counterweight acts as a dynamic chain tensioner. Also, I’ve noticed that other parks suck in cleanliness. Cedar point is by far the cleanest park (non Disney/universal) that I’ve been too. Dollywood is a close second. However, Kings island which is another cedar fair property isn’t nearly as clean as cedar point. It must be a park management thing.
my suggestion is Holiday World in Indiana as far as best value, I really love that park and a ton of stuff is free like parking and drinks
The weight is a chain tensioner. But the pickup on that one is smoother because it's a B&M, their lift motors have 3 speeds while most have 2. It has an idle and an active speed like most but on the B&M's the lift motor also has an engage speed. That's why the speed increases after its latched. The lift can also vary speed depending on how far through the course the train infront is.
Interesting. Could you point to video how Impulse Roller Coaster goes all the way, POV if available? google search finds only some
Impulse Roller Coaster at Knoebels as all first page results for videos, and it does not look as one, because it has a chain and slow lift. Thanx!
As mentioned, the linear coaster is likely 480v, as that is the standard for anything commercial/industrial. The cables in the framing might look thick from the outside, but there are likely many smaller cables inside the jacket instead of some 4/0 gauge wire. Each “cell” of the linear motor probably needs its own circuit in order to control the timing/speed.
As for the lift chain, steel does not stretch that much. Also, the chain underneath the track is the portion under tension, not slack (the car is pulled from the top, not pushed from the bottom). That being said, getting the chain under enough tension to not have any play at all would need some major forces, so instead they just designed a way to keep the loose portion under control (motor to the bottom of the train). When the counterweight raises, it is actually decreasing the length between pulleys (“loosening the chain”) since the force of gravity on the weight would pull the chain tighter in the down position (gravitational tensioner).
Motor-> pulley at top-> train will always be self tensioning and holding the weight of the passengers. Train->pulley tensioner at bottom -> motor is the “slack” portion, so the counterweight system is just keeping it under control. Before the train arrives, the entire chain is under the same tension. Then, when the weight is taken, 2/3 of the chain is now under (30 people x 175 lbs) 5,250 lbs of tension, so all the slack goes to the portion with the tensioner hence why it increases in length (pulls the slack/gets tighter).
Can I just say, looking at what UA-cam is recommending as the "next" video, that you have some of the best Thumbnails on UA-cam? The faces you make are priceless. :D
Couple notes from this video
1. Go to Silver Dollar City and Dollywood because they are amazing parks owned by Herschend and are clean, have a great atmosphere, and good food. But with Silver Dollar City I think you would love watching the new for 2018 Time Traveler Coaster. Its a controlled spinning coaster and It’s using new technology to make it work. It cost $26 million. It’s the tallest, fastest, steepest, first double launching and first inverting spinning coaster. It starts with you dropping 10-story’s right out of the station.
2. The launch you heard was nice and all but the Premier rides LIM launch sounds are way cooler. Look up either of the Mr. Freeze reverse blast or poltergeist at fiesta Texas or Jokers jinx. They make a lower frequency buzzing sound are a lot more forceful than the Intamin LIM launchers.
3. B&M’s do have a anti rollback system like the old woodies do but they have learned how to keep it quiet unlike RMC who wants people in Mexico to know when Steel Vengeance is climbing the lift. I notice this on the Batman inverts and Wildfire at Silver Dollar city.
4. I agree with everything you said about Six Flags.
Would guess that the counter weight is keeping the chain tension constant. As the chain takes up the load it stretches a bit, and the weight moves down to compensate. Those transformers are usually marked with KVA and primary voltage, possibly secondary voltage. Those big ones look like perhaps 500 KVA. Realize that such a transformer can supply considerable overload for short duration, easily twice the continuous rating.
The smooth engagement of the train onto the chain is most likely due to the coupler that hooks on to the chain being mounted to the car with a spring and damper. At least that's how I would design it. It's possible that the idler tires are powered/braked and they are used to smoothly match the speed of the train and chain, then slow the train slightly to allow a simi-ridgidly mounted coupler (just a plain rubber shock mount) to grab a chain link. There is plenty of time for the speed adjustments to be made unnoticeable.
The counter weight is just taking up the extra length of chain due to the load as the train grabs it. The weight of the train is nothing for a chain of that size, but there is always some stretching. If each link stretched .0001" that add up over probably thousands of links.
The chain clutch is *really* simple. It's literally a large metal hook biased by gravity into a 'down' position, but able to rotate upward to roll over the chain links if the train is moving faster than the chain, both at engagement and at release. The only difference between the chain clutch and the safety pawls is that the chain clutch has a curved cutout on the end to engage with the chain roller, while the safeties have an angled end to positively hook into the lift sawtooth. Also, the safeties have a resilient pad on the bottom to cut down on the noise.
Have you ever been to Holiday World in Santa Claus Indiana? I'm curious of what you think of those coasters, regular and water.
I would have to agree with most everyone else and say that the counterweight is a dynamic tensioner that takes the slack out as the train engages, which is what causes the "cachunk" on other rides