Clearance Envelopes

[shadox17]

So I had some general questions about clearance envelopes:

 

1. I know they differ from country to country, but as far as the US, is there an standard clearance distance from seat to obstruction?

 

2. Are there actual laws in place, or just an industry standard?

 

3. How far around the side/bottom of the train does the clearance usually go?

 

Thanks for any answers

[coasterbill]

So I had some general questions about clearance envelopes:

 

1. I know they differ from country to country, but as far as the US, is there an standard clearance distance from seat to obstruction?

 

2. Are there actual laws in place, or just an industry standard?

 

3. How far around the side/bottom of the train does the clearance usually go?

 

Thanks for any answers

 

On Kumba I have managed to both smack a metal pole on the way up the lift and the drag my hand along the ground at full speed during the helix. Both times because I wasn't paying attention and was being an idiot, so I doubt that there's a specific safety envelope size. It's probably determined by some combination of the individual parks and manufacturers.

Edited September 28, 2016 by coasterbill

[shadox17]

That's cool, I knew Kumba's helix was close to the ground but woah! Yeah, my only experience with something like that is figuring out that you can drag your hands along the tunnels on space mountain (WDW), which is incidentally quite painful lol

[PKI Jizzman]

If your arms are long enough and you're dumb enough, you can touch the (left side) tunnel's walls in the Beast's final helix.

[Physical]

I'm pretty sure each manufacturer determines clearance envelopes based on rider position. If I remember correctly B&M uses average height plus an extra foot on all sides.

 

That being said I've managed to touch supports on a few coasters. Mostly older ones (Runaway Mine Train at Gradv, Thunderhawk at Dorney)

[Comeagain?]

Not really a legal requirement (in the US at least). Nor is there really a set distance because it depends on the restraint system. GIBs have significantly smaller envelopes than PTC wooden coasters.

[rcjp]

My foot once touched some pine tree needles while riding batman at Warner Madrid. I suppose that things like trees are harder to "control" so I don't know what margin there usually is. I was really stretching my feet and it was a very small scratch so nothing special.

[imagineerz]

There are no laws that regulate envelopes, however, there is a lengthy section in ASTM F2291 about them. For those who are not familiar, ASTM is a standards and testing methods group, of which the amusement device subcommittee F24 is a part of. Industry professionals write these design and safety standards, and while they are not law by any means, they are generally followed pretty well.

 

The way that an envelope is created depends on the type of restraint. Different class restraints allow differing degrees of freedom, so each different type of restraint has a different general shape (IIRC over the shoulder restraints have more of a rounded rectangle shape, while lap bars have more of a rounded trapezoid shape). The actual dimensions are determined by using a standardized human scale at the 95th percentile, using the given envelope geometry from the restraints, and then adding a few inches on top of that for extreme cases.

 

Again, manufacturers are in no way obligated to follow that method, so there's probably some variance, but manufacturers are often the ones writing these standards.

[A.J.]

Just put the wooden tunnel on a NoLimits track and go from there. Done.

[DoinItForTheFame]

How far around the side/bottom of the train does the clearance usually go?

 

Not really the "bottom" of the train, but this photo shows how tight the clearance envelope can be around an inverted train.

 

[AndrewRnR]

On Millennium Force's first turn people were hitting their hand on one of the supports so they cut out part of the one beam after the first year. (Last horizontal beam before diving out of the turn).

[djcoastermark]

Envelope was much higher on Kumba and wider on Space Mountain when they opened. Why you ask? WELL, Kumba is sinking (into a sinkhole) and Space Mountain is shrinking in the heat. Ya know, these things happen .

[cedarpointguru]

On Millennium Force's first turn people were hitting their hand on one of the supports so they cut out part of the one beam after the first year. (Last horizontal beam before diving out of the turn).

 

Come to think of it, has there ever been an Intamin coaster that hasn't needed modifications from the initial design?

[Myself]

If you're on the right-hand side of the train, you can touch the grass during Trailblazer's final helix. A friend found out the hard way that you can also touch the bushes to the right of the turn off the lift...though I don't recommend that.

[Physical]

Envelope was much higher on Kumba and wider on Space Mountain when they opened. Why you ask? WELL, Kumba is sinking (into a sinkhole) and Space Mountain is shrinking in the heat. Ya know, these things happen .

 

Kinda off topic but has anybody else noticed (it seems like) every single park has at least one rumor of a coaster "sinking?"

[DoinItForTheFame]

On Millennium Force's first turn people were hitting their hand on one of the supports so they cut out part of the one beam after the first year. (Last horizontal beam before diving out of the turn).

 

Powder Keg had a similar support change. . .

Screenshot from TPR's POV.

[FSUFanChris]

The Coaster formerly known as Shockwave also had a support altered.

[RollerManic]

dalebrumfield.net

Edited May 19, 2016 by RollerManic

[Swede]

All I know is that I'm not allowed to ride Steel Dragon 2000 after they changed trains. The max height of a rider now is just 6 foot (185cm) which is plain ridiculous for a northern European. I hope Godzilla ruins your park.

[Rill'o'beily]

Soo these have to be changed basically because idiots don't follow the "keep your hands inside the cars" rule?

Ffs.

[DoinItForTheFame]

Soo these have to be changed basically because idiots don't follow the "keep your hands inside the cars" rule?

Ffs.

 

Have you ever put your arms up at any point on any roller coaster??

[coasterer]

I remember back in the day (like 10 years ago) on my first ride on the Beast, I smacked my fingers overhead as we entered the tunnel after the second lift and drop, and spent the next helix and a half in the dark in excruciating pain, wondering if my fingers were still attached to my body. I'm not even thaaaat tall, only 6' 3".

[viking86]

On Kumba I have managed to both smack a metal pole on the way up the lift and the drag my hand along the ground at full speed during the helix. Both times because I want paying attention and was being an idiot, so I doubt that there's a specific safety envelope size. It's probably determined by some combination of the individual parks and manufacturers.

 

When sitting in the left seat on Kumba I smacked my left hand on some branches while starting the climb into the dive loop. This was in a "normal hands up" position and I wasn't trying to reach for it. Seems to be quite common on rides with a lot of vegetation near the track.

[savetheclocktower]

I remember back in the day (like 10 years ago) on my first ride on the Beast, I smacked my fingers overhead as we entered the tunnel after the second lift and drop, and spent the next helix and a half in the dark in excruciating pain, wondering if my fingers were still attached to my body. I'm not even thaaaat tall, only 6' 3".

 

Same here, though I'm 6' 2" and it was 4 years ago for me. From then on, I've always just not put my arms up on coasters. I still raise my arms slightly to let myself "float", but I no longer put my hands above my head.

 

Follow the safety rules and nobody gets hurt! Besides, putting your arms in the air just increases wind resistance and slows the ride down!

[shadox17]

Soo these have to be changed basically because idiots don't follow the "keep your hands inside the cars" rule?

Ffs.

 

Have you ever put your arms up at any point on any roller coaster??

 

In all seriousness, I'm pretty sure most coasters are designed with the idea of people putting their hands up in mind.

 

Also, just remember that it is very fun to touch the trees while riding Blackbeard's Los... I mean Harley Beard's Crazy Treasure Train