Comments on: Extreme playground

Question: Extreme playground

A Terrible Llama — Sat, 12 Jan 2013 10:32:29 -0800

Given optimal circumstance, could a person on a swing set swing 360 degrees, over the overhead bar? If not, what would the circumstances be,on this planet, where they could?

By: supercres

supercres — Sat, 12 Jan 2013 10:35:39 -0800

Mythbusters tested it. Required rockets, IIRC.

By: supercres

supercres — Sat, 12 Jan 2013 10:40:34 -0800

(That is, it's impossible with a swing on chains. It's totally possible with a rigid-arm swing. Ignore the title: MBs mentioned that in the episode.)

By: pipeski

pipeski — Sat, 12 Jan 2013 10:42:32 -0800

The problem is that, to get the swing to do a 360, against the pull of gravity, you're going to have to be moving much faster than you'd be swinging normally.

When you're self-propelled, the reason that you can build up a greater and greater amplitude is that you're shifting your centre of mass by swinging your legs. But this only adds a relatively small amount to your momentum on each swing - which is why you have to swing back and forth many, many times to get a good arc. The maximum arc you're going to achieve by swinging your legs is somewhere around 180 degrees (the bottom half of the circle). To suddenly go from that 180 degree arc to a full 360, you're going to have to inject a massive amount of extra momentum into your motion in a single swing; the only way you can do that is to have some extra driving force (a rocket, for example).

By: fshgrl

fshgrl — Sat, 12 Jan 2013 11:06:31 -0800

No. If you get much above horizontal the chains go slack and you free fall for a bit and lose all your hard won momentum. Or fall out of the seat and knock yourself out. You can safely do this on a rope swing for kicks but chains are more unpredictable.

And yeah, you really need several bigger kids to push you to get high enough.

By: easily confused

easily confused — Sat, 12 Jan 2013 11:42:48 -0800

Anecdotally, I've seen kids go over the top; yes the chains sagged somewhat, so it certainly wasn't a 'perfect' 360-degree circle, but it was a full forward over-the-top-and-back-down-the-rear ride, with the swinger's butt still in their seat. It's been decades, but as I recall the swingset feet were cemented in place, plus the chains probably weren't more than 8-10 feet from the top crossbar to the seat. Nobody fell out, nobody got any more mangled than usual at an elementary-school. I didn't try it myself --- I was a 'scairdy-cat! --- but I seem to recall that at least three or four other kids did it successfully.

By: ctmf

ctmf — Sat, 12 Jan 2013 12:26:51 -0800

You'd need a big, big push at just the right time.

As you start swinging, each swing gets incrementally higher. At some point, you're doing a 180 degree arc from horizontally out forward to horizontally out backward.

So if you think about it, even if you could continue to incrementally swing higher and higher each swing, at some point you're going to have to pass through not-quite-there-yet territory. That's when you fall back down onto the crossbar and maim yourself.

Even before that, as you pass above chains-horizontal, your track along the ground has to start moving back toward the point on the ground below the bar. So even if you could keep it up, you'd shift from a semicircular side-view swing motion, to more of a sideways figure-8, free-falling from the top to the bottom each time. That would be pretty punishing, even if you stayed in the seat, could keep adding momentum, and missed the bar.

By: NailsTheCat

NailsTheCat — Sat, 12 Jan 2013 13:09:33 -0800

I agree with ctmf's logic.

If it were possible I am sure Youtube would be full of videos of kids both doing it successfully and failing brutally. The closest I could find in an admittedly quick search was this.

By: Ms. Toad

Ms. Toad — Sat, 12 Jan 2013 15:21:20 -0800

Here's a BBC version of the Mythbusters experiment that also suggests it's not possible, unless you basically have rocket propulsion, a helmet, and a braking system of some kind.

By: emilyw

emilyw — Sat, 12 Jan 2013 15:41:23 -0800

I have seen this done, on a swing set with chains, but only by people standing on the swing, reaching up and holding the bar.

By: 256

256 — Sat, 12 Jan 2013 18:01:03 -0800

I am an excellent swinger and I have hurt myself, both as a child and an adult by venturing above the 180 degree limit. I'll just come right out and say that there is no way this is possible in a roped or chained swing by leg-pumping alone. As soon as you go above 180 degrees, it's game over. For this to work you would need to get up to 179 degrees or so and then somehow, in a single swing, add enough momentum for the full other 180. Your legs just can't do that.

By: Kadin2048

Kadin2048 — Sat, 12 Jan 2013 20:48:14 -0800

The only time I've ever seen someone break the horizontal / 180-degree barrier on a swing was due to the unintended effect of a safety device: to prevent kids from getting their fingers caught in the chains, someone put plastic (or maybe aluminum) pipe around the chain on both sides of the swing, about 6 feet or so feet on each side. If you then took the swing and threw it around the bar a few times, to take up all of the non-piped chain (the pipe chain-protectors were only on the little-kid swings, so you had to do this to raise them up anyway) you could then swing beyond horizontal and vertical.

I'd never given much thought to why this was possible until now, nor that it might have been theoretically possible to go "over the bar" on that particular swing. It was just one of those secrets that all the kids in town knew; if you wanted the best swing, that was the one. Eventually the chain protectors were shortened so that it didn't work anymore, IIRC.

But if anyone has a swingset and wants to make it "extreme", that would probably do the trick.

It does, however, stop you from spinning on the swing and making the chains coil around each other and then letting them uncoil and spin you around in the other direction really fast until you barf. This may be a bug or a feature depending on whether you're the one responsible for cleaning up said barf, and come to think of it might be related to why the really long chain protectors were installed in the first place.

By: windykites

windykites — Sat, 12 Jan 2013 21:02:13 -0800

I could swear that i'd seen someone go over the bar as a kid. But it could be false memory; I really can't tell. I've certainly seen the chains wrapped around the bar and been told that it was from someone going over, and believed it.

By: flabdablet

flabdablet — Sun, 13 Jan 2013 00:19:44 -0800

It's a hell of a lot easier to impart a bar-wrapping amount of energy to an empty swing seat than to a person.

By: Rash

Rash — Sun, 13 Jan 2013 09:13:14 -0800

Agree with those upthread (especially 256) -- if this was possible, we'd have YouTube video.

By: ShutterBun

ShutterBun — Mon, 14 Jan 2013 01:04:42 -0800

Anecdotally, I've seen kids go over the top; yes the chains sagged somewhat, so it certainly wasn't a 'perfect' 360-degree circle, but it was a full forward over-the-top-and-back-down-the-rear ride, with the swinger's butt still in their seat.

I gotta call "no way" on this.

The previously mentioned Mythbusters episode should be enough to convince anyone who claims to have seen it happen that their memory is playing tricks on them.