What actually causes roll backs?
Вставка
- Опубліковано 30 лип 2024
- Thorpe Park are having an absolute nightmare with they're brand new Mack Rides Hypercoaster, Hyperia at the moment, and earlier this week they had to shut it again when a train failed to make it all the way round the layout. As enthusiasts, we all know what a rollback is, and might even hope to experience one at some point, but I don't think the reason why they happen is that well understood.
Timestamps:
00:00 - Intro
00:33 - Mythbusting
01:12 - The man, the myth, the legend: Brian Cox
02:41 - That's why they call me Mr. Farenheit
Note that none of the footage used in this video was my own, but the originals can be found using the links below:
Hyperia POV: • Hyperia at Thorpe Park...
Red Force: • Rollback launch in Por...
Brian Cox: • Brian Cox visits the w...
Blue Fire: • Blue Fire Rollback - 0...
Hyperia: • Hyperia Off-Ride Foota...
#hyperia #thorpepark #thorpeparkresort #themepark #rollercoaster #mackrides #hypercoaster - Розваги
Thank you so much for clearing this up, I knew about this ages ago but every time I saw someone talking about the rollback, they always blamed gravity which I had to restrain myself from correcting them, hopefully a lot of people see this and then begin to understand why trains rollback. I will admit i haven't been able to ride Hyperia yet but hopefully Thorpe and Mack sort out these issues soon, apparently a similar thing happened on DC rivals in Australia so this doesn't seem too uncommon.
Hahaha I'm glad I'm not the only one that was annoyed! Yeah, I'm hoping it's just bad luck rather than an inherent issue with the design...
a lot of people wont understand how many things affect the speed of a coaster. on my knex models adding just 50 grams extra of weight can make a huge difference. and also taking the same coaster out side vs indoors can make it no longer complete the layouts I build. I assume because of temp or air moisture levels. but its crazy how much it affects it.
It's crazy that moving it outside can have such an effect, but I guess it's just really sensitive to small breezes? Can you vary the amount of ballast in your trains then, or do you just design them to be different weights?
@coaster_shark na knex has a lot of limits. You can't build big or the track gets too flexible and loses speed
Oh fair enough! Are trains like those on Eurofighters harder to work with then? Since you can't distribute the weight across a long train
Another way to think about it is that the work done against the weight force increases linearly with mass whereas the work done against air resistance is constant. So as the mass increases, the work done against air resistance becomes insignificant compared to the work done against weight. So the air resistance has less effect with higher mass trains.
Yeah, that works
Hopefully this doesn't happen again... Brilliant video as always!
Thanks, hopefully not! Although unless the trims are adjustable, I'm not sure what can be done to stop it. I expected better from Mack in the first place to be honest
This was really helpful thanks!
No worries! I'm glad you liked it
I'm not an engineer but I made the assumption - we talk about coasters 'warming up' through the day, that isn't just a saying.. the wheels warm up throughout the day and Fury 325 FLIES in the afternoon! It's why I don't rush, generally, for morning rides on things... even if I beat a queue, the ride will be slower than normal so what's the point unless you like that ha
Hahaha good point, I can imagine!
For potential energy, the calculation is mgh. Mass x Gravity x height. Whilst you mentioned air resistance, which is correct, mass is an important factor on roller coasters because it is running in a fluid. (Air is a fluid) A larger mass will generate greater kinetic energy, so a heavier train will run faster as it has more potential energy at the top of the lift hill. So for coasters weight is important. Everything else you stated in correct but heavier trains run faster and there is evidence based practice for this, so unfortunately Digital Dan is correct. Any coaster manufacturer will have loaded and unloaded calculations and the time difference can be a few seconds.
Ah, but kinetic energy is 0.5 x mass x velocity squared, so the mass cancels out there. I'm not denying that mass is important. What I was trying to get across with the feather was that it's not gravity that causes the trains to run slower, it's the air resistance. The real equation that determines this is Force = mass x acceleration, so the same resistance causes a greater deceleration on the lighter trains.
Although reading this again I think we might just be in violent agreement hahaha
@@coaster_shark I am a theme park engineer, so I may be cheating a little. The reason it stalled is because it is the morning, but it also suggests the train is not within expected parameters. An empty train should get back with relative ease and hyperia has looked very lazy from the start. Could probably have done with 1000 weighted cycles per train before opening, just to bed everything in. The best time to go on a coaster is on a warm summer afternoon in the rain with a full load. This is the fastest it will ever go but it will be trim braked all the way.
The real issue is friction, not so much from air resistance but rolling resistance. Temperature, grease viscosity and tyre composition are areas to look at but mass is the easiest way of overcoming this inefficiency during initial testing. In reality an empty train should be able to fall off the lift hill at the slowest speed possible on a cold morning and still make it back to the station, so they need to work on all of the above until it happens.
Yeah that all makes sense, it wouldn't be a well designed coaster if an empty train couldn't plop over the top of the lift and make it round! Going on the rain is an odd one though, although it will be faster it could be painful! I love when parks give up on using the trims, some of the craziest rides I've been on have looked pretty standard but have been insane without the trims
I dont know how true this is but i heard with hyperia that with the immelmann just before that outerbank section being so much shorter than the actual outerbank turn that the train while being empty can struggle to make it up there, now im sure this is something Mack would have considered that it may make the train lose some momentum and as it hasnt happened prior to this i will take it as just that, a speculation, but if you think about it it kinda makes sense, even on the first few test runs that always did seem to be the section it seems to slow down through
It's always a bit riskier having a bigger element after a smaller one, but you're right that they would have considered it in the design, and it's not like it's a super unusual feature in coaster design. Chances are everything wrong just aligned that morning with temperature, wind, humidity, etc so hopefully it's a rate occurrence
awesome video, thanks for making this. as a new enthusiast, it's nice to learn all this information that is probably basic knowledge to every other enthusiast. out of curiosity, is wind resistance also why coasters shut down when it's especially windy?
Thanks, and no worries! Yeah pretty much. I think it might be a comfot thing as well, especially with taller rides, as it would probably put a lot of people off if they could feel it swaying slightly in the wind, but I think this is probably secondary
Nice vid bud
Thanks!
if the trims do exist on the exit of the immelman hopefully they remove it to reduce the risk of rollbacks and maybe introduce wheel heaters in the station? i remember something like i305 had that it would probably help a lot with this issue
Hahaha I've never heard of wheel heaters before! Removing or reducing the trims would be the obvious answer, but I'm not sure how much control they have over them. I wouldn't complain if they got rid of them though!
@@coaster_shark i think there is no direct control for the trims i think it is only dependent on the material of the fins which determine how much resistance is given at a given speed hopefully they replace the ones on the splashdown with less hard hitting trims and if there is a trim on immelman remove it and normalise water dummy testing to reduce risk of this happening. thanks for clarifying why rollbacks happen btw great explanation hope to see your channel grow more
Ahh fair enough, I know you can get actuated trims, but I wasn't sure if they were on Hyperia. I guess they could chop some of the material off but that's a bit extreme... yeahh the splashdown brakes are a bit harsh aren't they. Thanks, I'm glad you enjoyed it!
@@coaster_shark There aren't actually any trims on the exit of the non-inverting immelmann, just the brackets to put them in if needed.
Oh fair enough, guess I need to pay more attention!
Thanks for explaining 😊
My pleasure!
What explanations is it that other enthusiasts have given? Are they thinking gravity varies or something?
This is meant to be the purpose of the trim after the immelman, so it can modulate the speed around the outer bank. An empty train in high wind should do the element a the correct speed and all other cases should require a small trim so they all traverse it at the same speed. Even if I would prefer it to just run full nylons, lightweight bearing grease, and trimless!
The explanations I've heard usually only get as far as lighter = less gravity, and that's where they stop. Some of the craziest rides I've been on have been when the trims have been turned off, so I definitely wouldn't complain if they did the same here!
@@coaster_shark less gravity haha, I suppose it's a lay person's understanding
Yeahhh it's one of those that makes sense as long as you don't think about it isn't it
Wait so does that mean having my hands in the air is causing drag?!?
Technically, yes, putting your hands up slows you down... but it is only tiny. For max speed, you want to be in an aero tuck like a cyclist, but that probably wouldn't be very comfortable haha
So for the wheels;:;,(
Hahaha well it would definitely make the coaster more interesting to watch!
Hellooo
I hope all is well
Helloooo! I'm good thanks, hope you're doing well too!