Slingshot ride cable snap

Not sure which Clickbait website to link, but here's the story from a source in London, where the accident happened:

https://www.dailymail.co.uk/news/article-11540089/Slingshot-ride-Hy...NSIDE.html

Who's the manufacturer of this? The standard models I've seen all have redundant cables. It's unlikely for both to break if they're properly maintained.

I admit I haven't looked at the technical specs for the ride, but generally, elastics don't perform as well in cold temperatures. Running that ride at night in unseasonably cold London seems like it might be pushing the ride's operational envelope...

That's my point, the US rides I've seen don't use any kind of elastic, it's a pair of steel cables to each side. The tension is in springs in a box on the ground.

They used to be a lot more common here in the US with the bungee cord style launch.

These are more common on fair and traveling circuits, and often referred to as “reverse bungee”. I even remember back in the early 2000’s, the Ohio state fair had a “cage-less” version where single riders were strapped into a harness and launched upward. I would never even consider such a thing.

Having watched the video a few more times, I concede Jeff's design concept of tension loaded cables is probably right as opposed to my original concept of bungee cords. If you look near the top of the cables, you can see a sphere attached to the line. This makes sense to stop a cable being pulled through the support legs, but I can't justify a large weight on a bungee cord.

What are the release mechanisms on these rides like? I don't think I am being overly clever in asking as a safety advocate (whether it be the inevitable government or insurance agent) "Well, what happens if in a tensioned state you have a catastrophic failure? (ie. this example)" My expectation is that the release mechanism would be designed to hold an asymmetric load from either side, holding the cage in place until the ride can be e-stopped and detensioned. In this case it doesn't seem the release mechanism even tried to maintain the load.

There are two variants of these in service.

The modern type has the "cage of springs" that Jeff talks about. These are made (in the main) by Funtime.

The older style does indeed have bungee cords, and when they snap, this is more or less what happens.

Having ridden both over the years, the spring-loaded versions are somewhat less intense than the older models, but more than intense enough to make for a superb ride. I wasn't planning to do another bungee model even before this accident happened because they're far too aggressive for my liking.

This isn’t an isolated incident. You’d think they’d give up on the bungee cords after the first two, three, four, five occurrences…

Unless someone else has the patent for the spring cage...or you don't have money to design, test, and get certified for a new design, or the cost of insurance is less than the cost to do all that...

Per the video that is a bungee catapult which is actually illegal in many places. Elastic bands...essentially oversized bungee-jumping cords...are attached to the gondola and to wire rope, the wire rope is pulled to tension the elastics, then the gondola is cut loose. Notice also that the holding mechanism at the base (I'll guess this thing is trailer mounted) has an arm that allows the gondola to come up about 6', rather than launching from the ground as the spring-cabinet models do. This is so that even if the elastics reach full extension, the gondola can't hit the ground until the tensioning ropes are backed off. The spring-cabinets handle this by adjusting the position of the spring carriers so that again, even if the springs reach full extension, the gondola won't reach the ground.

It's not clear what exactly happened. It doesn't look like the elastic rope actually failed; it seems more likely that it detached from the tensioning rope. That, not the elastic rope itself, seems to be the weak point on these things, and it is necessarily a single point failure opportunity.

--Dave Althoff, Jr.