MAGNETIC LAUNCH SYSTEMS 3: Linear Synchronous Motors and how they work

[@connorscottcook]

this clarified the topic so much for me, thanks ryan!

[@ryantheridemechanic]

Your welcome.

[@kohowch]

Some of the best park content on KZbin, thanks for pulling back the veil for us

[@HaroldKuilman]

You might also like " theme park science " bit less technical but high production value

[@natekeeley1706]

Great breakdown-- I knew they had something to do with magnets but this was really helpful in understanding exactly how

[@ryantheridemechanic]

Great thank you!

[@jeverett59]

Ryan, As a machinst by trade. They are now using this technology for axis movements on CNC machines. Very fast, super accurate. It is definately wild technology

[@TheKnexMaker]

this is so funny you made this video. because im making a home made LSM for my knex coaster lol

[@ryantheridemechanic]

Good luck!

[@Carter-nl2]

Best visual aid of all time

[@dannyj.246]

I had a breif understanding how these might work but this is a great explanation 😊

[@ryantheridemechanic]

Awesome.

[@engi98]

Such an interesting and informative series for me, thank you for making these!

[@chadbroderick160]

So glad to hear someone go in depth into this stuff. Thank you!

[@ryantheridemechanic]

Welcome

[@LTCoasters]

This video is very timely with all the chatter in the coaster community about Top Thrill 2 aka 2.0. Thanks Ryan glad you went over this system.

[@ryantheridemechanic]

@@LTCoasters your welcome.

[@UnlikelyHiker]

I don’t always completely understand everything you discuss but I definitely enjoy watching your videos!

[@ryantheridemechanic]

Thank you

[@IRDeady]

I remember when super man was first built I watched this news special about it and it absolutely blew my young mind and honestly the tech still blows my old mind almost 30 years later. The concept is so elegant and the execution is so precise. Like I can know that these polarity changes happen in milliseconds, perfectly synced up to the point that a load of thousands of pounds can be pushed to 70+ miles in a second or two, and that they can do this thousands of times a day, for decades...but I mean it's like trying to really comprehend a billion dollars, or the true scale of the universe. Really glad I subbed to your channel. The engineering of roller coasters is one of the most fascinating things in the world to me, but my limited education has left me at a huge disadvantage when it comes to understanding how it all works. Really hope you keep going with videos like this, you're good at explaining technical things in a way that doesn't require a degree to learn from.

[@ryantheridemechanic]

Thank you so much for the comment. These launch systems are very fascinating to me as well if you ever fell like you masters the theory just dig in a little bit then everything comes undone gain. So much science.

[@michaeltaylor1603]

i designed a coaster in the early 80's Magna! it was to go nearly 90 mph! no inversions....just fast with turns and magnetically levitated. i was about 14 yrs old!

[@thijmendevalk]

I made an audible "oooooh" sound when you explained the breaking mechanism. Finally understood how LSMs can act as break in their safety default mode. Thank you for the amazing explanation!

[@ryantheridemechanic]

Your welcome!

[@Colaholiker]

Makes me wonder if in normal mode (not emergency braking), they also use the gurrent generated by the "LSM brake" to feed back into the main bus capacitors, much like regenerative braking on an EV would do. Or course, you can't fully recover all the energy that a moving train has, but it could sure lower the amount of grid energy used by the next launch. But maybe doing this is just way more expensive than the potential savings.. 🤔

[@ryantheridemechanic]

@@Colaholiker you are correct. It can be done but an entire separate drive system needs to be build to develop the storage of the created power. I’m guessing only a guess. The braking power generated is probably not even enough to move the train forward one train length. A lot of braking is less than 2 seconds when you think about it.

[@Colaholiker]

@@ryantheridemechanic There is significant energy in a train rushing into the brake run. Just think of the weight and speed we are dealing with here. The problem is that it needs to be converted back to electric energy in very little time and you would need some really big capacitors to store it. That's what makes it so expensive and therefore not being done. Roughly speaking, if we assume that you get about 75% of the kinetic energy of the train hitting the brakes harvested, and another 75% of the electricity you put in the launch actually make the train go. That means 56% of the incoming train's energy can be used for the launch. A train hitting the brakes at half the launch speed would therefore provide 28% of the required electric launch energy. That's not a small number. But like we said before, it's a lot of extra equipment needed to make it work. I am not too sure about LSMs, but I think the efficiency numbers I assume are actually lower than reality.

[@ryantheridemechanic]

@@Colaholiker yea the return on investment would be so May years down the road I don’t think any park would do it. I’m not an electrical engineer but I would use capacitors as the filter then step voltage down and store in battery’s. Might be something if you had lot of rides using a center return. I also came up with a way to retrofit an old ride to do the same thing with mechanical brakes.

[@skeletor325]

Great video Ryan

[@ryantheridemechanic]

Thank you

[@RanHam]

I was really bored one day and read the lsm manual at work. The way the theory of operation described it was the magnet passing over a single point created a theoretical frequency and the system would try to keep the stator frequency either 17 or 19 degrees ahead of phase. Eventually they got rid of our Hall effects sensors and added current transformers on the drive. Apparently they can use that to determine where the train is. When they did that they did have to add a comb sensor to determine parking. I thought this was going to be the standard, so I was surprised when I saw Intrasys still used hall effects. But I’m sure they no longer use a windows95 computer to interface with the sensors anymore.😂

[@ryantheridemechanic]

Industry is on windows 97 now haha!!!! The manuals are great but they are very hard to follow most of the time. Mainly because they reference things we have no control over. Drive set up stuff where those parameters have already been set in stone.

[@jjhatch69]

All the LSM manufacturers are fully back on hall sensors and have been for about a decade now. The only one that has a really strange set up is Velocity Magnetics, as they have horizontal hall sensors in the base of the stator, which is not great if you don't have the correct tension on your upstop wheels. We have single cart vehicles with the VM system and they try to pull a little wheelie as they launch, so we sometimes get position errors. If they were vertical hall sensors, like intrasys and Indrivetech, it wouldn't be a problem. The good thing is that VM have patented the horizontal hall sensors, so nobody can copy it and make the same screw up. 🤣 I just put an Intamin ride in and I am sure the controls engineer was up to windows XP, so they are progressing.

[@ryantheridemechanic]

@@jjhatch69 windows revisions are so funny in these comments because it painful to think of! Haha! I figured new stators had the hall sensors built in. Guessing they went with horizontal because they could say their stator was shorter and you could make a stronger motor with ore of them. Probably easier to deal with when the roads loose some urethane and get the train a little closer. Thanks for the insight.

[@Jenlovescoasters]

I love Full Throttle!

[@ryantheridemechanic]

Like most sky rocket rides. Fun but short.

[@LTCoasters]

Wow, simple and so complex at the same time. Thanks, you answered a few questions Ive had about this type of ride.

[@ryantheridemechanic]

Glad you enjoyed it! Thank you.

[@Roadhardd]

Thanks for all of your insight, and all you teach us!

[@ryantheridemechanic]

Your welcome!

[@Calakapepe]

great video! Makes you really appreciate the amount of intricacy happening when you are simply moving 1 direction! Esp with what will soon be the fastest lsm launch!

[@ryantheridemechanic]

For sure!

[@garywillis7253]

Another great video Ryan...keep em coming

[@ryantheridemechanic]

Thanks! Will do!

[@Deurklink]

Very informative video, I think you did a great explanation!

[@ryantheridemechanic]

Thank you!

[@alexlail7481]

I'd love to see a video about the weight launched system used on a few old shuttle coasters. I realize that you likely haven't had alot of experience with them because I believe they were always kinda rare.... I understand how it should work but have never seen much on the actual execution... Love the videos

[@ryantheridemechanic]

Ooohhh one of my favorite things as a weight drop shuttle coaster was my favorite growing up. I’ll put a video together with what I understand to be correct. My old manager actually worked on one so he could fill in some blanks for me.

[@alexlail7481]

@@ryantheridemechanic cool thanks 😊

[@Colaholiker]

Great explanation, Ryan! I wonder how long it will take until you will have the inevitable person show up in the comment section of your videos telling you that "You have no idea what you are talking about". 😂 If that happens, please don't feel discouraged... Anyhow, the LSM principle really reminds me a lot of how brushless DC motors work. At work, i am currently involved in developing firmware for a product that uses this motor technology (though not on the actual motor control, this far exceeds my math skills😅) and the only difference seems to be geometrical (round rotor with the stator windings wrapping around in the motor housing vs. linear magnet under the train and stator windings spread out along the launch track. I was able to witness the importance of the sensors a few years ago when I visited Holiday World in Indiana. Just as we got to the station, they couldn't launch the train - it would dispatch, move a bit on the launch track, and then the ride would shut down with an error. We used the opportunity to get out of the heat and watched the park's maintenance team as they tried to get it up and running again, and after going back and forth a lot, they found that someone must have lost their phone on the ride and it had ended up blocking a sensor. I assume the magnets in your typical iPhone aren't strong enough to interfere with the hall effect sensors, but of course it can block an optical sensor or just trigger a prox sensor easily. After they removed the phone, things worked again. (Keep your darn phones in a closed zipper pocket or don't take them on rides at all, kids!) Anyhow, I imagine it's kind of tricky working on LSM trains. Those Neodymium magnets are extremely strong, so I can imagine that they would also try to yank the wrench out of your hand if you come too close.😂 There's just one thing I would like to kindly ask you for, in order to improve your next videos. Please crank up the audio level, there were a few sections that I had to rewind to understand what you were saying. And I already have the KZbin player on max volume and also my laptop's sound mixer. As long as it doesn't clip, as higher audio level is not much of a problem as people can reduce the volume during playback, but there's only so far you can turn it up until you max out. Thanks a lot! A man like you, who has mastered the special effects needed to support the explanation should also be heard 😁

[@ryantheridemechanic]

Thanks for the comments. Magnets are quite nerve racking to work around for sure. I don’t mind when people att a ton of info in the comments I don’t feel like it is a big deal. I know there is way more information than I give when it comes to theory on anything. But I make the videos they way I do because that text book theory goes over most peoples heads and they don’t understand. I make these videos the same way I gave tours and learned what to explain and what just needed to be touched on momentarily. My hearing isn’t the best so I try and “place” the volume where I think it should be. Definitely don’t want quiet though that’s no fun at all. I also do want to pop in and have people lungeing for the it volume because I’m yelling. Haha. I’m also trying to be conscious of where my mic is and where I am.

[@nicksvlogs2426]

I like your videos

[@ryantheridemechanic]

Thank you

[@TheParkPlanet]

How strong are these permanent magnets? How much kilos can they lift theoretically?

[@ryantheridemechanic]

Depends on how you use them? Pull strength against a carbon plate? Force from an Eddie on copper? A single magnet that’s used inside a brake shoe has about 400lb pull force. And the shoe uses about 12 of these.

[@LSM_Lover]

Awesome

[@__-cb3co]

I love your content keep posting!!!!

[@TrueLies23]

Love the content you put out there. I have a bit of a technical question... so obviously cedar point announced top thrill 2 and some stats. A lot of people are disappointed in the speed of the launches and are wondering "is this even a rollback?" "Whats the point of a 420 ft spike if i wont go higher than 370 ft?" Can the rate of acceleration be altered without having to replace componenets of the launch system? Is it reasonable to suggest that after the ride is up and running, within a few years they could increase the speeds of the first and second launch and allow the 3rd launch to just make sure the train will make it over the tophat? It would be great to get you out here to America's rockin roller coast!

[@ryantheridemechanic]

Great question. Speeds are set during installation. When you send a ride up a spike you must have a safety barrier to prevent the train from impacting the top. Because there are no motors up there the safety envelope is a guess based on friction. And worst case drive speed +/- tolerance. The final speeds will be matched with the original so the ejector g force is not to high going over the top hat. These rides the profiles are called swings In this case, only If swing 3 failed to go over, that’s a true rollback in my book.

[@LTCoasters]

@@ryantheridemechanic Thanks Ryan for confirming two posts I did recently. The first was to ask was a true rollback even possible now. Meaning is it possible that a train full of larger adults would cause a rollback between all the forces acting on it if you can't adjust the launch speed on the 3rd launch. The last one was quickly telling people you don't want it hitting the top of the spike for the safety of your trains and possibly you. I mean I will take a 370 foot plunge there are only 2 hills higher right now and 1 is on the other end of the coaster.

[@ryantheridemechanic]

@@LTCoasters it will still be super fun.

[@nedmickey8237]

@@ryantheridemechanic I understand that the train could not go too fast on the second launch going backwards because it could risk going to close to the top of the spike and it couldn’t go too fast on the third launch because the stress on the track going over the top hat would be too much. but could they alter the speed of the first launch that goes partway up the top hat to be a little faster while keeping the speeds of the other two launches the same

[@ryantheridemechanic]

@@nedmickey8237 absolutely it just takes the speed increase out of the next launch which drops down how the ride feels a little bit so it will mainly be how they want the entire package to come across

[@bpark10001]

There is no iron in LSM stator coils. (If there were iron, there would be horrendous side forces if there were the slightest side-to-side misalignment. Since the mechanical alignment of a coaster train/stator is much poorer than in normal rotary motor, it is not practical to put iron in the stator. (Remember your comment about putting plywood in magnet gap to prevent wrench from being sucked in?) Conversely, in LIM, all the iron is in the stator & none is on the mover (fin on the train) for the same reason. Because of the large gap without iron, it requires HUGE power just to set up the magnetic field. (This power is not required for LSM because the "work" is being done by the permanent magnets.) Both motor types would benefit from having iron in both the mover & the stator, as "pushing" magnetic field through air is difficult. Result is weaker field & less force per amp drawn in both motor types. You do not mention why LSM cannot rival hydraulic or pneumatic launch. To get more acceleration, you need more current or more magnets, or both. Even with WATER cooling, there is only so much current you can push through the coils before the coils MELT. Adding more magnets gives more force (for a given current), but the magnets are HEAVY. More force does little good if you have to add to the mass to be accelerated! There is a point of diminishing returns. This is why Top Thrill 2 can't use the original "one pass" launch as Top Thrill Dragster did. The same goes for King Da Ka. There was one coaster that used LSM on the lift hill (superman?), but they abandoned this for chain lift because of reliability problems. Exploded LSM coil structure is shown in this video: kzbin.info/www/bejne/nJfHdqeYd7aMbK8 Note the WATER COOLING layer in the coil set. There are 3 phases so there are no "dead spots" in the magnetic force & uniform current draw.

[@ryantheridemechanic]

Thanks for all the cool info. As far as the iron on the inside, I don’t make them, I was just told that’s what’s in there. You can also see the slight outline with an FLIR as well so I take it a face value. Not saying all are exactly the same either. I know they weigh as much as a 19mm plate of steel, need 2-3 people to lift one. Are you in design of these stators? So far (me personally) I haven’t seen an internal water cooled stator. The stators intamin makes looks like they could use a shell cooling. Closest I’ve ever seen is when they sprayed water on the outside of lightning rods lift base motors. I know the old lIM/ LSM stators were made from the manufacturer with either being an option but they were much larger.

[@bpark10001]

@@ryantheridemechanic A FLIR shows TEMPERATURE differences, not iron. What you are seeing is the hot copper loops, not iron. The next time you are working on LSM coaster, take a magnet with you & place it on the stator (with the current off) to see if it is magnetic. It won't be! If it were, the coaster would LOCK to it when it tries to pass over. I don't design coaster stators, but I have designed synchronous permanent magnet motors (one much smaller for military, the entire motor fitting inside 0.2 inch cube). The other thing you mention is hall sensors & the timing criticality. The one shown in the link I sent has the sensors where they belong: INSIDE THE COIL STRUCTURE, directly connected to the motor controller. Incidentally, once the coaster gets moving > 10MPH, the back EMF from the coils gives more accurate timing information. This is sensed directly from the coil drivers in the electronics. The same scheme is done in rotary synchronous motors used in RC electric airplanes & is referred to as "sensorless" synchronous drive. Also, you need to look for water cooling lines & a radiator located near the driver cabinet. There should be a pair of hoses going to each stator. After running, the hot hoses should show on your FLIR.

[@nesmanmain0001]

Isn't square wave DC essentially Full Wave Rectified DC? (FWR) Great video as always! Only thing I didn't quite get was the difference in the two sensors you explained. Understood how they worked, just not their separate uses.

[@ryantheridemechanic]

Yes full rectified. Basically get that term from welding. Are you saying hall affect vs tail sensors? Basically the early hall affect have a value feedback vs tai sensor gives an on /off.

[@nesmanmain0001]

@@ryantheridemechanic Ah ok, thank you for the explanation! I've always been into learning the electrical stuff since I was 3 and started collecting fire alarms. Eventually started wiring them up with control panels, senors, and all sorts of devices. Got into coasters in like 2018 and have been hooked ever since. Even got a job in a junior engineering position/program last year at a power supply applications engineering company as a 14 year old. It's been on awesome hobby and always interesting! I can tell you really enjoy learning about this stuff and teaching others, yourself!

[@ryantheridemechanic]

@@nesmanmain0001 it is fun to teach this to people if I can

[@HaroldKuilman]

27:34 if you ever have one thats planned for scrap, you might want to do this with the whole crew... Wear eye and ear protection! 👌🏻 (and have a few co2 extinguishers at hand) I sort of witnessed it going wrong, didn't see it but heard it loud and clear from 150 m (thats about 30 tesla X's long for you americans) away. Gave a nice sharp bang and according to my colleagues a bright blue flash followed by thick black and white smoke

[@ryantheridemechanic]

I almost broke one like that. Shoot the dust off the entire structure.

[@HaroldKuilman]

@@ryantheridemechanic quick cleaning 👍🏻 At ours it did some more then dusting off the tunnel 😅 the ride wasn't back up and running for 14 or 15 months... Officially due to parts delay, but we had the part within a week 🤐 Also ours didn't have hall-effect sensors, it timed the speed of the ride at the end of the tunnel and if the time was too long (aka speed too low) the (friction) brakes would engage at the end of the launch track

[@ryantheridemechanic]

@@HaroldKuilman what a sound it made though. I don’t know to watch, or run.

[@HaroldKuilman]

@@ryantheridemechanic when ours misfired it was over before you could make a decision, the busbar worked as a fuse 😬

[@ryantheridemechanic]

@@HaroldKuilman Ho-LEE-crap that’s scary. I blew a capo stir bank(12igbt) out one time but that was in a closed room and no one was withinn 200 feet. Big boom

[@jamieeast4974]

Try 3 phases in a line 120 degrees apart.

[@TheParkPlanet]

Is the Current going to the Staror windings just DC with fixed amplitude, or does it have a Frequenzy/ is it AC?

[@ryantheridemechanic]

It’s dc where the form is modulated for both current and frequency. But at full speeds it’s more of just dC that looks like square wave AC kind of.

[@HaroldKuilman]

Do you have an affiliate link for those really cool flat yellow magnets that only have a north pole? 😍

[@MaxLib]

Now I think I’m ready to build one in my backyard for my entire family and I to test out and enjoy!

[@SvenDonut]

Another great video, your content is awsome thanks! I'm wondering if you guys had special training dealing with such high Amps or did you hire someone to service the elektrical components?

[@ryantheridemechanic]

Nothing special. Just a lot of instructions from the manufacturer on how to safely take they systems down for service.

[@joeskis]

how does the Kingda Ka launch work? I know it's a sled attached to a cable that pushes the train. Just wondering how they manage to get a winding cable drum to spin so fast so quickly.

[@ryantheridemechanic]

@@joeskis kzbin.info/www/bejne/emWnmJ5prJiXp9ksi=PAMfb6lS4OpQyHW1

[@Hangtime_Davi64]

Would you be able to do a video talking about Lightning Rod's launch system and why it faces so much down time?

[@ryantheridemechanic]

So lightning rods launch system is an LSM drive that this video covers. As far as down time, I can’t speak for something Im uncertain of. I know that year RMC had a ton of restraint issues. And control systems can be a bear but not sure about its particular drive issues. Where is the information coming from that it has drive problems?

[@Hangtime_Davi64]

@ryantheridemechanic I can't think of a specific source at the moment except for a Coaster Studios video where it broke down while they were waiting in line. The train just failed to make it up the lift hill on the first launch, and it took them about fifteen minutes to get it ready to launch again. I've heard it has overheating issues as well, but for all I know, that's just speculation.

[@ryantheridemechanic]

@@Hangtime_Davi64 ok fair enough. Lift hills have a lot of attention due to the visibility across the area. I know the feed stators at the bottom get hot as they are spraying water on them. Hmmm. And I could see having trouble restarting dead weight on a lift, heck big hp lift motors also struggle with it. I’ll have to think on this one.

[@dindog22]

do you have any thoughts on the Top Thrill 2 announcement?

[@ryantheridemechanic]

Not too many but I’ll put out something

[@Jenlovescoasters]

In the control room on A side, an electrician wrote in sharpie pen, "Superman the mistake"😂

[@ryantheridemechanic]

Got to love prototyping! That park is full of prototypes too.

[@dfgwm30]

How much would you esttimate the power bill for one day of operation to be on the LSM launch vs LIM launch?

[@ryantheridemechanic]

I honestly don’t know how high voltage is sold to parks so I’m uncertain how to even guess off that. You could take volts and amps convert to watts and figure out what a Kw is sold for maybe?

[@Bnizzofashizzo]

Always wondered this

[@Coasterteen22]

@@ryantheridemechanic I think this comment was getting at an efficiency comparison between the two technologies. I would assume that LSM stators use between 30-50% less power than a similar LIM system, depending on the acceleration and velocity delta required. LSM systems also lend themselves to using eddy braking with a set of generator stators to recuperate some energy from the train, similar to how electric vehicles can use the traction motor(s) to recharge the high voltage battery.

[@anderfrank1]

What coaster is at 23:00 in the video? It looks like a great ride!

[@rickym7380]

Helix at liseberg

[@TheParkPlanet]

From what Material is the Stator case made?

[@ryantheridemechanic]

I’m not 100% certain as these things are very closely guarded they don’t let much information out. But it appears to be simple high temperature resin like fiberglass would be used. I’m sure it’s stronger than that though.

[@TheParkPlanet]

@@ryantheridemechanic 👍

[@nicksvlogs2426]

U should talk about why coasters have shin guards or shin pads like runaway train at six flags great adventure

[@harikrishnan-ts5ti]

Hai brother one doubt please tell me about the polarity of permanent magnets on the train facing each other . How they are fixed are they fixed as repelling each other all the tym or attracting each other

[@ryantheridemechanic]

They are attracting but every other on is reversed NSNSNSNS SNSNSNSN

[@tubepotato500]

How much does a roller coaster train cost for a 12, 16, 20, 24, 32 and 36 passenger trains?

[@ryantheridemechanic]

Very complex and the cost is not well known because every train built is custom. 28 passenger bare bones train could come in close a million. A train with onboard audio, custom fiberglass along those lines probably closer to 1.4mil. A train like x2 probably comes in closer to 2.5mill

[@tubepotato500]

@ryantheridemechanic How much you think the old Dragster trains were? And what about millennium force trains? And how much do you think the new lightning trains will be for Top Thrill 2?

[@Colaholiker]

@@tubepotato500 For the last part of the question, I wouldn't be surprised if Zamperla gave CP a huge discount on the entire project, to get a foothold in the giant coaster business. They took a huge leap from what they have previously built to this, and sometimes customers need to be convinced ;-) to give a company the opportunity to try something completely different. Therefore, even if anyone knew what they paid, it wouldn't be the price that Zamperla are planning to usually charge.

[@ryantheridemechanic]

@@tubepotato500 I’m guessing those intamin trains are about 1.5M each. Zamperlas replacement might be cheaper but probably still around 1M

[@tubepotato500]

@@ryantheridemechanic What about the trains on Cedar Point's Gatekeeper?

[@nicksvlogs2426]

U should talk about why rmc lap bars and shin guards so tight

[@gametime2473]

Because they don't want you going to the moon on those ejector airtime hills :)

[@LTCoasters]

Amen, I swear Steel Vengeance is trying to either drop you or eject you out of its train. I'm very glad for those beefy restraints.

[@Coasterteen22]

TLDR: RMC Restraints are class 5, which either require something over the shoulder, or a tight lap bar and seating system which forces the rider to stay upright. The shin guard is what allows the lap bar to meet these requirements. TL:DR,TL:DR: A shin guard a day keeps the OTSR away! ASTM (American Society for Testing and Materials) has developed a class rating system for ride restraints. These are separated into five classes depending on the severity of the acceleration which a rider experiences. Class 1: No restraint. Think “Bench: The Ride”. Class 2: No restraint, but a grab bar or other point of stability is provided should the rider wish to hold on. (Ex: Fast and Furious: Supercharged, train rides) Class 3: Locking, multi position restraint, which may restrain one or more riders. Ride operators should verify all restraints are locked prior to dispatch/start of ride cycle. (Ex Disko, other rides featuring lap bars without a seatbelt/redundant locking) Class 4: Individual, multi position restraint. Class 4 restraints must automatically lock, with sole unlocking ability given to the ride operator. Does not require external indication of locking, can be checked visually or manually. Class 4 restraints require redundancy, typically in the form of a dual (paralleled) locking mechanism. (Ex: Older B&M restraints) Class 5: Individual, multi position restraint, with a redundant locking mechanism and electronic verification which will inhibit the ability to start the ride if a restraint shows a fault; OR a combination of a class 4 system with an additional seat belt/lap bar. These typically require a sensor to verify locked status, and ride manufacturers like to go above and beyond these baseline requirements. What you see often these days could be called a class 5+. These systems will have sensors to determine position, redundancy built into the locking mechanism (Ex: RMC using two independent hydraulic locking cylinders for each lap bar) AND a seatbelt for good measure. In order to ensure the restraint continues to meet these requirements, the rider must be held in the proper riding position. The shin guards force your legs to bend, putting your body into a position where it cannot slip out from the lap bar. Sources: ASTM F2291-2006: Standard Practice for Design of Amusement Rides and Devices Sources: I worked as a project manager on installations of rides for Busch Gardens and the Mouse. Hope this helps, if you have questions, please let me know!

[@LTCoasters]

​@@Coasterteen22Thank you for that in depth answer, love it.

[@Colaholiker]

@@Coasterteen22 Bench: The Ride looks too intense for me. 😅 Just kidding, thanks for the explanation!

[@harikrishnan-ts5ti]

sir 0ne more doubt so in finally stator is working with DC voltage instead of Ac waves

[@ryantheridemechanic]

Dc current with pulse modulation

[@harikrishnan-ts5ti]

@@ryantheridemechanic thankyou.

[@harikrishnan-ts5ti]

Brother iam also working in theme park abu dhabi. Actually iam from a mechanical background. Iam very curious to study about this all. But in my park lsm stator is powered by Ac

[@ryantheridemechanic]

@@harikrishnan-ts5ti interesting. My old park the drive is given AC power. Power is broken into Dc. Then dc is pulse modulated and given to the stators. The way most people think about it, they would say it’s AC going to the stators but it’s actually DC (AC - drive - DC - stators) But the dc is made into a form that almost looks like AC.

[@TheParkPlanet]

where do you worked i mean which lsm and whick lim coasters

[@ryantheridemechanic]

I had an Intamin Impulse suspended LIM And a Skyrocket LSM