Public Transit Ziplines?

Post by Steven Dale

Ryan sends a link to an op-ed piece in the Waterloo Record:

“Truly innovative ideas for public transit are needed to make progress. . . A zipline is a version of a ropeway. They originated to cross valleys and gorges because they are safe, easy to operate, and inexpensive to build.”

The author goes on to talk about cable transit as well, but it’s the zipline component that clearly stands out.

Having ziplined myself a few times, I’ll admit the idea has a certain steampunk appeal. It’s just . . . cool. But that’s about as far as the idea goes.

Any new idea has to pass a smell test. If well-outside the mainstream, the idea has to provide a comparable or superior level of service to that which is currently used at a price the market is willing to pay. If not, then what’s the point of making the switch?

If it weren’t for the fact that Cable Propelled Transit and Urban Gondolas repeatedly passed the smell, I wouldn’t have spent the last year working on this site.

Ziplines, however, don’t pass the smell test for one simple reason: Capacity.

I’ll admit that ziplines could quite easily be the cheapest, fastest, most environmentally-friendly form of transit ever built, but the technology’s ability to move large numbers of people just isn’t there.

As per my understanding (which is limited, I’ll admit) ziplines are meant to carry one person at a time per line segment. Assume that your average travel time per segment to be anywhere from 30 seconds to 1 minute, and you’ve got a whopping capacity of 60 – 120 pphpd.

There are bus routes in suburban Nebraska that carry more people in off-peak times.

Nothing wrong with new and innovative ideas, but they have to exist somewhere within the realm of practicality. Are ziplines a cool idea? Yes. Are they transit? Not right now and not in the foreseeable future.

"These rush hour crowds are killing me!"

Want more? Purchase Cable Car Confidential: The Essential Guide to Cable Cars, Urban Gondolas & Cable Propelled Transit and start learning about the world's fastest growing transportation technologies.

Want more? Purchase Cable Car Confidential: The Essential Guide to Cable Cars, Urban Gondolas & Cable Propelled Transit and start learning about the world's fastest growing transportation technologies.


  1. I think Kurt was simply making a light-hearted joke.
  2. Really? I'm not so sure about that.
  3. I was left wondering whether the author used the wrong terminology and meant a gondola all along....??? We all know that aerial detachable ropeways (technical term) unfortunately have many different names (gondola, cable car, aerial tram etc). Even worse, contradicting other technologies in the same family. No wonder people are left confused!! He talks about ziplines, but then goes on to moving large numbers of people and freight over flat terrain - which could well mean gondola, and definitely not ziplines. @Mono - whether it is a joke or not probably depends on the reference to the Conestoga Expressway at the start of the piece? A little google search indicated it is considered a model of long-term thinking in the region (may be wrong). If is is a joke, it has been executed terribly ;)
  4. Haven't we discussed this before? I thought we referred it to the TTC?
  5. @ Scott, "Haven't we discussed this before? I thought we referred it to the TTC?" Listen, the TTC already thinks I'm crazy enough proposing gondolas in Toronto. How do you think they'd respond to ziplines ;).
  6. @ Ryan, "No wonder people are left confused!!" I certainly was.
  7. Think about it. A zipline is a "1S" gondola (toss the cabin and the return loop. Just hook on and let gravity do its thing). As for low capacity, au contraire. You could have half-second headway - provided, of course, that you had a way to 'shed' the bodies at the bottom. A good way to grasp headway and shedding is to watch a video of paratroopers exiting a plane. http://www.youtube.com/watch?v=6DH1PBdbuDM Now, try feeding that one to the TTC, eh? Not sure if they'd buy the idea of requiring passengers to attend jump school before they 'ride'. Geronimo!
  8. What you need is a zipline where you hook on multi-person cabins. You would also need some mechanism to hoist the cabins back up the gravity field, and it would probably make sense to use some of the energy from the cabins going down for that purpose. And since the cabins are going both ways anyway, you might as well load them each way. And since you are loading them each way, you can string together sequences where cabins are alternatively going up and down the gravity field. Someone should invent a zipline technology like that.
  9. @ BrianTH" " Someone should invent a zipline technology like that" After 9/11, I drew up a patent for a zipline of sorts that would allow people to escape down the outside of a building. People would don a harness, and just like the zipline, clip onto the line and downward they would go. But (aside from the fact that patent 'art' for similar remedies already existed) there were problems. Like controlling the descent speed (you can build up a lot of speed on a vertical zip line). I'm sure you can visualize one person taking their sweet time down, only to get clobbered by someone a little more anxious to depart the scene. There was thousands of a harnesses needed – one for each person. Then there was the difficulty getting people, particularly handicapped, to actually use the thing. And finally, getting interdiction personnel (firemen, etc.) and equipment up and in to the building. My “Aha!” moment came riding the gondola at Snow Basin (Utah), near my home: use a continuously-moving loop cable with clamp-ons; shed the user from the harness at the bottom; send the harness back up on the return trip. Except that the return trip can also carry the rescuers and their equipment. To increase capacity, two (or more) people could cluster onto one hook, just like tandem skydiving. It could theoretically carry 10,000 pax/hr. Add the helicopter to hoist it and a SAR-tech to the roof and the special truck at the bottom, and you get the idea. The problem, of course, was getting it going. No one (including NYFD) wanted to be first. Holy cow: where have we heard that before?
  10. @ BrianTH, "What you need is a zipline where you hook on multi-person cabins." I think you've put way too much thought into this ;). If this conversation continues much longer, people will begin to suspect we're seriously considering ziplines as public transit. Which we're not. Right? Right?
  11. @ Dave Brough, "It could theoretically carry 10,000 pax/hr" God, I hope you're not serious.
  12. @ Steven: "God, I hope you’re not serious" No and yes. The number (10,000/hr) may be stretching it, but when you see how fast paratroopers can evacuate an aircraft (or firemen drop down a fireman's pole) you can see that you can get 'good numbers' - especially if you could 'cluster' people together a la tandem parachute jump. Probably 3,000 would be max, but by employing multiple units, it could be increased. The idea is, pun intended, deadly 'serious'. The fundamental question I addressed was the conundrum posed by the World Trade Center collapse: people could not get down; rescuers (and their heavy hoses and other equipment) could not get up. The impacts were at the higher floors (85 and 95), but if it had occurred at lower floors, the death toll would have been many times the 2,700 that died. Hence, the higher evac rate. In checking patent databases, I found a lot ideas, including parachutes, of course, but nothing that would both evacuate big numbers while at the same time, permitting rescuers to get in. Combing the zip line (harness and clip on) with the gondola/clothesline endless loop is, in my opinion, not only the fastest possible way to accomplish the objective, but the cheapest. For those interested in the mental exercise, this: a chopper delivers 'starter' kit and SAR tec to the roof of building. A truck carrying the system races to the scene and sets up. SAR tek on roof secures and drops a 'starter' loop cable to ground. Ground sends up the heavier loop cable, which is secured to a predetermined location on building. Rescue harnesses and other personnel are now sent to top, where they suit-up evacuees and guide them into the system, just like paratroop jumpmaster. People are automatically shed from harnesses at the bottom and tumble down air-filled chute (like on airliners). Rescuers and equipment take the return loop to the top. Sounds as crazy as running a ski gondola down the middle of Yonge St., doesn't? :)
  13. Dave Brough, Of course I was being tongue-in-cheek, but your idea is actually interesting. But how would you deal with the likelihood of a variable mismatch between the weights going up and going down? And what happens if the firefighters want to evacuate as well at some point? These aren't hostile questions--I'm just trying to think through what is to me a new idea.
  14. BrianTH Except for the portability, everything is 'stolen' gondola technology, the main difference being that with a gondola, the 'mismatch' is ascending (getting skiers to the top of the hill), while in my ap, it is both. BTW, the concept has others applications - for instance, take a washed out bridge or other disaster scenario where temporary transport is required for both people and 'stuff'. On your mention of 'new idea', add seats or cabins and you now have a carnival/state fair ride - which, BTW, I proposed to DM as a way of promoting urban gondola (but no joy). As a 'toy for tourists', it would make for a highly profitable undertaking. But the price ($10 million) will take some serious coin.
  15. Dave Brough, I see. So it really is more of a portable, quick-assembly gondola system than a zipline. It seems to me the challenge then will be to make it both robust enough and portable/quick-assembly enough to fulfill your vision.

Leave a comment

You can add images to your comment by clicking here.