- Decrease Dwell Times – Current dwell times can reach up to 60 seconds for cable systems. Engineers I’ve talked to, however, have said that 3S dwell times can be reduced to 20 seconds. 20 seconds is far more palatable from a transit planning perspective and should become a more standard feature of cable systems.
- Increase Capacity – Despite the fact that cable is more than capable of handling the moderate capacities witnessed by most of the world’s LRT systems, there is still a perception out there that cable just can’t handle that many people. Maybe it’s a psychological issue. What would happen if the industry were able to eclipse the 10,000 pphpd barrier?
- Make Air-Conditioned and Heated Cabins Standard – While available, they aren’t common. Meanwhile, air-conditioning and heating in transit systems is practically standard nowadays. It isn’t a frill, it’s a necessity. All urban gondola systems should be equipped with these systems.
- Gather Safety Stats – Most of the evidence of gondola’s and cable’s safety is anecdotal. Ironically, so too are most people’s concern about cable’s safety. A comprehensive study should be undertaken by the industry to actually gather the numbers and report on the technology’s excellent safety record.
- Plan For Expandability – Due to a lack of foresight, systems like the Medellin Metrocable and the Funivia del Renon suffer from over-crowding at peak times. This isn’t the fault of the technology, rather it was the fault of the planning and execution. Systems should be designed such that they can be expanded quickly, easily and cheaply in the future with minimal disruption. This would be a good back-stop against inevitable human forecasting errors.
I’m sure there are others. What do you all think?
17 Comments
I think it would be in the interest of one of the big players to build a line below cost in a western English speaking nation. Once one line has been built other city’s will copy, it will be awesome advertising for the company who builds the first system.
No, South America is not good enough. The western world does not aspire to be like those city’s.
5 seems tricky to implement.
Scott,
Couldn’t agree more. Why do you think 5 is “tricky”?
To be more like traditional public transit it would be cool if cable had a local vs express system option or the ability to skip stops when a cabin is full and no one wants to get out.
Frankie,
re: local vs. express
That’s the holy grail of transit. Currently, only bus technology can accomplish “off-line” stations. Subways can, but with huge additional cost. I intentionally didn’t include off-line stations because it seems so pie in the sky right now.
Probably the biggest deterrent for a long distance (more than like 5km) high capacity line is probably speed. What’s the fastest they can go?
So one could think more about the possibility of feeder lines into a higher capacity/faster network. I.e. support good connections to heavy rail, and multi-modality.
Ant6n,
MDG: 23 km/hr
3S: 28 km/hr
Aerial Tram: 35 km/hr
Cable Liner: 45 km/hr
But again, max speed really isn’t the issue. Speed of a transit system has virtually nothing to do with the top speed of a transit vehicle. Station spacing and right of way are really the only issues that matter.
As an addition to 1: Full stop in stations. Crawling trough the station is annoying for everybody and not suitable for seniors, people in wheelchairs or parents with a pram.
Important will be free routing. Go around curves and corners without having a bulky infrastructure.
And small stations which can fit into an already built up area would be nice.
I think 5 is tricky because i haven’t seen an example where it has been done and i cant think of a cheep way to implement it.
I can think of the following ways, each with problems.
1: Design towers/stations to allow another similar system to be built on top. issue: the “upgrade” will cost a similar amount to a second line which would improve service.
2: Buy less than the maximum number of cabins. I understand that cabins make up a trivial portion of the cost of the system. As such you are really just lowering capacity to make the system appear full (and hence successful) in its early days. This provides trivial cost savings over just buying the max number of cabins.
3: Buy smaller cabins than the max size/weight for the rest of the system; same disadvantages as 2
4: over spec some components; i.e. towers and track wires allowing the moving parts to be upgraded. This would mean a long shot down period and expansive upgrade.
Can anybody think of a way expandability can be increased without initially footing the bill for a system similar in cost to one which would have a larger capacity anyway.
Btw I hate it how Public transport has to be crush loaded to be seen as successful, while a motorway which is built way over its needed capacity is seen as a success.
“Heating and air conditioning is available”..?!
Like, show us EVEN ONE! The best the industry can now muster is piddly little fans and butt warmers.
Scott’s right. No one in the ‘civilized’ world aspires to South American standards.
As for safety stats, gondolas are like airplanes. It doesn’t have to be something major. A plane – even a small private jobbie – can’t lower a nose gear, and it’s on the national news until it skids to a showery halt. The slightest hiccup with a gondola and it, too, is center of attention. Wikipedia lists every major accident.
But Matthias nailed it. Full stop, on demand, free routing, handling curves and corners without bulky infrastructure, and small stations that can fit into an already built up area. Combine that the high cost, ‘peeping tom’ syndrome, and lack of heating and AC and you begin to understand why gondola can’t (and won’t) make it in any urban street setting other than those with major geographical barriers.
Which is why your thinking will start to shift to suspended PRT.
Dave,
With all due respect:
1. Full stop, on demand, free routing doesn’t exist with any transit technology (except buses). You’re applying a standard to cable that you don’t to any other technology.
2. Cable is consistently shown to be one of the cheapest transit options on a per kilometer per rider basis. Your claim of “high cost” is off the mark.
3. I respectfully disagree with your assessment that “gondola(s) can’t (and won’t) make it in any urban street setting other than those with major geographical barriers.” Are traffic, intersections and buildings not geographical barriers? How you define a “geographic barrier” dramatically effects your argument. And even if you’re right, what does it matter? Even if the technology only manages to fill in the natural geographical gaps you allude to, is that not important?
4. Until I’ve seen an actual, operational PRT system I’ll wait to start shifting my thinking, thanks.
1 & 2. Decrease Dwell Times, Increase Capacity – 20 seconds is pushing it to the limit. 10,000 pphpd = 56 person cabins, 3 per minute. That’s 56 people filing into a cabin in 20 seconds? Hard to maintain. And yes cabins should stop completely. But in order to decelerate and accelerate from 10 to 0 to 10 metres per second (36 kph) pushes station length. Maximum acceptable rate of change of speed is 0.5m/s²
3. Make Air-Conditioned and Heated Cabins Standard – Impracticable: fuel sources aren’t allowed on cabins in many jurisdictions and batteries still too heavy. “Third rail” is not being done.
4. Gather Safety Stats – Certainly. And advertise them. The positive statistics are overwhelming. The few scary stories of course stand on record but people are surprisingly “game”. Cable really is very very safe.
5. Plan For Expandability – see #2
@ off the cuff
1 Even if the cabin has 56 people in it, only a few will want to get on/off at each station. Also, there is no reason the cabins couldn’t have really big doors, or multiple doors. I think 20 second dwell times are totally reasonable.
3 Third rail could be done easily enough, one of the large CPT companies just needs to engineer and market it. That is the point of the post, these are things that could and should be done, not things that are done.
Kelly,
I think that’s a strong point: This is about where things should go, not where they are.
Why my comment has been deleted? A full stop for vehicles is a necessity to comply the current law in many countries. A system with gondolas crawling trough stations simply will not match the criteria for a public transit system. New trams and buses need to be low floor to provide level access. stations must be built with ramps and lift to provide access for everybody And cable system used in transit are built to have a full stop and many have a level access. Thats why funiculars or aerial tramways are used for those applications even if a gondola system would be more appropriate.
I have to agree with Ant6n. It’s sort of like capacity, even though cable’s limit here isn’t going to matter in most cases, the perception that there is this limit hurts cable. So aerial trams can go 22 mph. Most people regularly drive 3 times faster than that in their cars. It sounds slow. Never mind that if you’re in city traffic hitting lots of stop lights you may average only 12 mph, no one believes they’re really going that slow, and their road rage would only increase if they realized they do. It would really help cable’s cause if someone would demonstrate an aerial tram that hit 50 MPH or higher, even if it would rarely be practical or necessary to design one for that speed, it would help with the perception that these things are slow.
I have to agree with Ant6n. It’s sort of like capacity, even though cable’s limit here isn’t going to matter in most cases, the perception that there is this limit hurts cable. So aerial trams can go 22 mph. Most people regularly drive 3 times faster than that in their cars. It sounds slow. Never mind that if you’re in city traffic hitting lots of stop lights you may average only 12 mph, no one believes they’re really going that slow, and their road rage would only increase if they realized they do. It would really help cable’s cause if someone would demonstrate an aerial tram that hit 50 MPH or higher, even if it would rarely be practical or necessary to design one for that speed, it would help with the perception that these things are slow.
@ Kelly
True, I agree it’s possible. I simply pointed out that it will be hard to maintain.
I should have been more clear, when talking about third rail issues i was referring to aerial technologies, not rail-based CPT
@ Steven D
True that this is about all where things should go, not where they are. There are just two major conglomerates that are in the CPT business and as you’ve pointed out so well, they’re just waking up to the potential of the urban market. It’s potentially huge and hasn’t really been marketed to. It is so much bigger than the tourist and recreation sector and less prone to bumps in the economy.
What’s also interesting is that in having had the rare opportunity to be an insider in the cable industry, I have noticed how closely these european conglomerates resemble cooperatives. related article: http://www.huffingtonpost.com/georgia-kelly/an-alternative-to-cutthro_b_759546.html