25
Nov

2015

Maximum Travel Speed for a Cable Car

Post by Nick Chu

We recently received a great question from reader Roberto:

I was wondering what is the maximum speed now registered in the world for a cable car. So far I know, reversible cable cars (43 kph, Portland, USA) go faster than the well known loop cable cars (27 kph, Val d’Isère, France), which is not clear to me why. If you could also explain this issue, that would be great. Thank you in advance.

By the way, what can we expect in the near future for maximum speeds?

These are great questions Roberto. To start, it’s important to remember that Cable Propelled Transit (CPT) can be broken down into top-supported and bottom-supported systems. For bottom-supported systems, the fastest cable technology are funiculars which can travel at maximum speeds of 14 m/s (50km/h).

For top-supported systems such as the Aerial Tram and Gondola, maximum speeds are 12.5m/s (45km/h) and 8.5m/s (30km/h) respectively. Maximum gondola speeds as high as 9 m/s are rumoured but not confirmed.

Why detachable gondolas (“loop cable cars”) travel at lower maximum speeds is partially related to issues of design and economics. For a detachable gondola to reach higher speeds, it would require enormous stations to accelerate and decelerate cabins.

For most gondola systems — which travel in relatively short distances — the increase in speeds would only result in marginal time savings but result in much greater station costs, energy demands, system wear and tear, and etc etc. Aerial trams in comparison, are fixed-grip systems. They simply come to a full stop in a station which enables them to travel at higher maximum speeds. Also, aerial trams typically use larger cabins which are able to provide greater comfort and stability during high speed operations.

As for the future, high speed cable test facilities have reportedly designed ropeways operating at speeds of 18m/s (65km/h). While this is exciting, it’s important to note that before maximum speeds change, it must meet a series of stringent technical and legal requirements to ensure maximum passenger safety.


——————————————————————


Got a technical question about ropeways you want answered? Send your questions to 
gondola (at) creativeurbanprojects (dot) com in the subject heading and we’ll try to answer it.

Related Posts Plugin for WordPress, Blogger...

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.

Comments

  1. Great post. I'd add that a (the) major limitation to increasing speed is the ability of the lift system to safely deal with a sudden stop when operating at full speed. The length of the carrier arm (between the cable grip and the gondola cabin) and the weight of individual gondola cabins is currently a major limiting factor to increasing system speed. Light monocable gondola systems cannot operate at the higher speeds of larger heavier tram systems because during a sudden stop the lightweight cabins would swing up into the overhead cable(s). There is a tremendous amount of kinetic energy that needs to be absorbed when a lift system stops quickly and unexpectedly. The potential loading conditions of circulating detachable-grip systems are also much more complicated to anticipate and design for as compared to jig-back tram systems which have only one or two cabins. I imagine that future higher speed mono cable detachable grip systems will have a way to provide a damper between the cable grip and gondola cabin which will allow light weight gondola cabins to travel at higher speeds without swinging and bouncing all over the place during an emergency stop. FYI, when travelling at 6 m/s an eight or ten passenger gondola cabin can really swing around during an emergency stop. Although chairlift systems could technically travel at 6 m/s, the limit for those systems is 5 m/s because of the potential to eject passengers. Gondolas have the advantage over chair lifts of containing passengers safely within an enclosed cabin.
  2. Thanks for adding to the comments Eric. You mentioned a damper mechanism for future monocable detachable gondolas, any idea what this might be?
  3. Passengers at cable cars are not much slower than passengers at subways or tramways. A) Faster subways or tramways cannot drive long time at their maximum velocity, then they must brake. B) You have to calculate or compare total travelling time of pedestrians from point to point. C) Cable cars must not drive detours like tramways. So velocity is not a problem,
  4. Eric Callender
    Hi Nick, not really, I'm only imagining/ speculating. I've had the problem explained to me by lift engineers, but not a solution :) It's a big problem to solve, given that velocity is squared i.e. by doubling the speed of the system there is four times as much force to deal with. Some systems currently use a viscous fluid damper to reduce lateral sway caused by high crosswind, but I would guess that a different type of damper would be required to inhibit cabin swinging from a fast system deceleration. Springs? Torsion bars? Pneumatic? Something else entirely? It will be interesting to see, and I suppose that different manufacturers will come up with different solutions.
  5. You have to "store" the energy, you have to turn kinetic energy to thermal energy. I believe, dampers would fulfill the task. At the new Stanserhorn-cable car (Switzerland) there are hydraulic cylinders. Have a look to http://www.funivie.org/funigallery/albums/userpics/10101/stanserhorn_Cabrio_eng.pdf
  6. Speed has to be reduced when passing the masts. Aerial tramways have only two cabins and few masts, so the control system slows them down when one is passing a mast. Detachable system have more masts and more gondolas so there is always a gondola passing a mast,. Thus the s speed cannot be increased. Bi and Tricable systems can pass masts at a higher speed, than moncable systems.