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Nov 23, 2011
Engineering

Could a High Speed Test Installation Result In 65 km/hr Gondolas?

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CC-image via Wikipedia.

Fatzer AG is an 175 year old Swiss manufacturer and supplier of wire ropes and steel cables who’ve provided ropes for thousands of cable transit systems worldwide. They know a thing or two about this stuff.

So it should cause all of us a moment of pause when a company like Fatzer decides to build a high speed cable test installation to test and explore the “effects of speed, brake force, tension of the rope, disk and rope diameter on the durability and wear of the ropes . . . under realistic conditions.”

According to Fatzer, this is the fastest cable car system in the world operating at a top speed of 18 m/s (~ 65 km/hr). That’s fast. Light Rail fast.

Now this comes with a few caveats:

  • The images and video (see below) we’ve witnessed do not suggest this installation has any vehicles in operation – which is strange considering they’ve called this the fastest “cable car” system in the world.
  • The system loop is only 232 meters long with a line length of just 110 meters.
  • This is a test installation for experienmentation and field testing only.

The first caveat is the most important. The cable industry knows they can operate systems at speeds like these, but have yet to address the rider experience issues speeds like these cause.

Issues of rider comfort, speed-over-towers, deceleration, acceleration, boarding and alighting, station size, and spacing all become major issues when we move from a test installation with no cabins and passengers to a real-world example moving tens of thousands of people per day.

Having said that, it is a big development and one that could ultimately open up new markets for the technology in the future.

So let’s just assume just for a moment that 10 years in the future the issues discussed above are addressed. What does that mean for the technology?

Well:

  • System capacity and throughput would be increased dramatically. We’re talking about a pphpd increase on the order of 200-300%. This suddenly makes the technology competitive with heavily-trafficked light rail lines and even moderate subway/metro lines.
  • Long distance “commuting” lines become feasible. The current maximum speed of the technology makes it excellent in circulator/feeder situations, but a non-starter in all but the most specific of long-distance installations. Being able to operate at 65 km/hr allows proposals like City Councillor Brian Tucknott’s Victoria gondola to cross the bridge from misinformed fantasy to realizable possibility.
Check out Fatzer splicing together the cable for this installation (itself an impressive feat) and running it at full speed:


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14 Comments

  • monorail says:

    if proven safe, this has huge implications for urban transit. that cable was flying!

    i imagine you’d need extremely long stations for this to work just for decelerating and accelerating.

    and if the costs turn out to be competitive with LRTs, the transit world might just be turned upside down and might you say, “propelled” into a new age

    EDIT: this is assuming google’s automated cars haven’t come out yet 😉 and by that time, all transit agencies will likely be obsolete.

  • Chip says:

    Do these higher speeds actually increase capacity all that much? The limiting factor in ropeway capacity is how many people you can board per unit of time, and that’s more a function of the design of the terminal and the contour speed than it is of the line speed.

    A fact that surprises some skiers is that detachable-grip chairlifts don’t actually have intrinsically higher uphill capacity than fixed-grip lifts, despite running twice as fast, because neither type can safely load and unload skiers at a faster interval than six seconds. The chairs on a detachable lift are simply further apart on the line. Indeed, all other things being equal, a detachable lift serving a given set of trails will have a longer line when operating at capacity than a fixed-grip in the same place, as the latter has more of the skiers hanging in the air rather than waiting in line.

    • Sam Wong says:

      Higher speeds makes it attractive to long-distance commuters. Commuters don’t want to spend a long period of time on a slow moving gondola going a great distance.

      Impact on system capacity is secondary.

      • Steven Dale says:

        I’d somewhat agree with you on that, Sam. Especially given that short-distance feeder lines tend not to need massive capacity levels. But if we suddenly see long-distance commuter cable lines, they will logically attract more ridership – hence the need for greater capacity. It’s a chicken-or-the-egg sort of situation.

    • Steven Dale says:

      The higher speed will definitely have an impact on line capacity. Of course speed is not the only factor that goes into determining line capacity, but it is a major one.

  • GiorgioXT says:

    Probabily the cabins or chairs will be added later – for testing it makes sense to start with the most simple situation to evaluate and have a basis .

    The capacity limit on actual lines is mostly due to ski slopes / costs, the economical purpose of a lift is carrying people – when single chairlift became too crowded -> technology offered the double chairlift, and the 2 places gondola …etc etc.
    When capacity needs will rise, like in an urban environment, technology will do the necessary leaps (some of them already disponible)

    Better don’t forget that here we ‘re talking about a technology that born, bred and developed TOTALLY in the private sector, so without the aids (but also the constrains) of military/state , and thus we may be sure that if this technology survives its because it works and make money. (not a thing that could be easily affirmed about other urban transit systems)

    • Steven Dale says:

      Excellent point about how the technology has developed exclusively in the private sector. Do you think that’s a positive or negative for the technology?

      • GiorgioXT says:

        As with most things, in part a blessing, in part a burden.

        Now we could take for granted that a gondola or lift it will work for many , many years producing good margin , if correctly dimensioned and managed.
        This is an important point, since for the SHEER MAJORITY of urban mass transit a profit is just a dream.

        But, I feel that the lack of a “no-limit-spending” politic like the military has surely hindered the potential developments; after all, without the cold war we probabily wouldn’t have commercial jets airliners at end of fifties…

  • One of the lesser known reasons for limiting the speeds of urban cable systems is actually the maintenance/parts replacement requirements. More speed = more wear and tear. That is why the Medellin Metrocables only operate at 17km/h, not 22.5km/h (the top MDG speed). Cables and other components only last so long and replacing them is no easy task when you’re trying to operate to the demands of the public transport timetable. That is a big consideration when setting line speed. The systems are not yet optimized to allow for efficient maintenance in this environment, this is one area the industry needs to focus on. Longer lasting, more robust cables would certainly be a factor in allowing maximum system speeds to become the norm.

  • Very interesting.

    Every 30 seconds a 3S-ropeway starts to the next intermedian station at the distance of 500 m. No support towers are necessary. (18 m/s => 28 seconds for 500 m). The problem at this speed could be the supports, but with a 2S or 3S you don’t need supports. you could construct a safe carriage with sheaves over and under the rope (with towers not possible).

    A detachable 2S or 3S accelerated like an aerial tramway. Very fascinating. Why not?

    • We need to see stations elevated on central support columns if this is to be possible (or close to it) – I think SD has mentioned this possibility before? 3S’s space requirements for traditional intermediate stations are too much in most urban environments at present. While it has never been done, some speculate 120m long mid stations with sub 30km/h speeds. That’s a significant constraint right there! What are peoples thoughts on this issue?

    • GiorgioXT says:

      Why (stiil) not? because in ski intermiediate stops are rare and location-imposed , in urban environment , particularly in modern grid-type cities even-spaced stations are possible (and necessary in this case)-but sought also in underground and LRT , because this simplfy a lot the traffic.
      Currently detachable speed limits are imposed first by rules, second by lenght of stations , but , if we change the rules and accept longer stations (e.g. – tram/LRT size = 30/40 metres) we could at least double the current max speed (6,5/7 to 13/14 m/s) and have also more cabins ready at stations , with some at full stop.

      • GiorgioXT says:

        Forgot an important thing … speed are also ruled by the allowed acceleration/decelaration, thats much less in cable system respect underground for example … in a Gondola you could stay upright even whitout gripping to poles, in underground (or LRT/Tram) definitely not.

    • Eric L says:

      There’s a lot to like about this design. Here’s what I don’t like about it:

      1. How high are you assuming the stations are to not need towers between them? More realistically, the stations should be low and there should be high towers next to them. The acceleration/deceleration could be timed so that the gondola is only going at high speed between the towers, though. If you have multiple intermediate towers, you could slow down at each tower crossing, though all the speeding up and slowing down may make it feel a little like a roller coaster and will hurt your average speed.

      2. Instead of 3S, you will have a 4 rope system unless your stations are roughly evenly spaced. This is because you will need to have individual return ropes so that you don’t need to coordinate the cars going in opposite directions.

      3. What about when you have longer distances between stations? This is precisely when higher speeds are most useful, but if you can only have one car in transit between stations then your capacity is seriously limited. I say this from a Seattle perspective, where I can think of plenty of obstructions more than 2 km across that could be nicely handled by gondola if only they weren’t so slow. So I’m not sure this is the solution I’ve been waiting for. The only thing I can think is to have the line speed up and slow down, like for the multiple intermediate tower case, and have gondolas attach and detach from the rope during the slow phases.

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