Midorizaka Skyrail. Image from Wikipedia.
They called it the Skyrail. It operates at 18 km/hr, has three stations and is 1.3 km long.
For all intents and purposes, the Skyrail is nothing remarkable. Every technique on display – at least from a layman’s perspective – has been accomplished before:
- Cable Propulsion.
- Detachable grips.
- Acceleration and deceleration in the stations.
- Support from above via steel truss.
- Acceleration and deceleration via linear motors.
Midorizaka Skyrail gondola. Image from wikipedia.
What was unique is how the various components were brought together. Never has such a bizarre combination of transport technologies been slammed together and I don’t think such a combination has been built since.
As with so many of these “one-off” installations, they’re often in far off places in languages I don’t understand. Beyond the cursory information one can find on wikipedia, most information about the Midorizaka Skyrail is in Japanese. The most important piece of information I (of course) cannot find: are the linear motors located on-vehicle or in-station?
This would have a major impact on vehicle weight and cost: Rather than have a heavy linear motor on every vehicle, one would only require a motor at every station. As linear motors are relatively common in train-based installations, one could then speculate/imagine a train of detachable gondolas, which would dramatically increasing the upper limits of cable’s capacity.
(Note: As far as I understand, a train of detachable gondolas has never been designed due to concerns about acceleration and deceleration. Pulsed systems are “train-based”, but due to their lack of detachability they suffer from extremely poor capacity levels.)
Leaving aside the linear motor issue, what we do know is this:
The combination of cable propulsion and support from above via steel trusses means this system can ascend and descend virtually any incline plus it can navigate complex turns without need of any angle stations. It really is the best of both worlds.
Unfortunately, it’s not particularly attractive:
The steel truss guideway. Image from u-netsurf.ne.jp.
Descending the Midorizaka line. Image via u-netsurf.ne.jp.
More info about this system clearly needs to be generated. The potential this system holds could be enormous.
13 Comments
I can not explain, but when I look at this thing I get a strange feeling. Maybe it is the fact every technology is put in one piece together or the fact the line looks to big for just that few small cabins (more like a people mover – but hanging).
But it does curves!
Hmm, I will spend a little more time into looking a little deeper. Hopefully that strange feeling will disappear. (but I believe if a product doesn’t make sense at first sight – first there is an explanation for it and second this product will have a hard time to become popular or convince someone)
@ LX,
Yeah, the headways are ridiculously slow. But the idea is there. Does anybody know if Mitsubishi went anywhere with this?
Hi, I’m a regular reader of this blog, and I grew up in Japan so I have some knowledge of Japanese, here’s what I was able to get from the Japanese article on the skyrail service (Wikipedia article here: http://tinyurl.com/4p9zs5)
-Totally vertical extent 160m.
-Electrified at 440V DC.
-Ability to climb up to a 27% incline (actual maximum is 26.3%).
-Most of the line is built along roads.
-Connects a development built on top of steep hills that is otherwise unreachable by rail, etc.
-Trip duration from one end to the other is about 5 minutes.
-Runs from 6:40am to 10pm. Every 15 minutes from 10am to 4pm. Every 7 minutes during peak hours.
-Connection to Sanyo-main line of the JR rail network.
-Used by elementary school students to get to school. Has a special service for only elementary school students Elementary school students can only ride this. (i.e. can’t ride at other times of day alone?) Students and other riders are completely separated. New school to be built in the development itself in 2011.
-System has the theoretical ability to be operated at 75 second headways.
-Opened in 8/28/1998.
-Fare: Adults: 150 yen, children: 80 yen
-Automatic fare machines and ticket wickets, has non-touch IC fare cards for monthly pass holders. Tickets collected upon entry, tickets not checked when exiting the system.
-After system closes at 10pm, a “jumbo-taxi” makes six runs from 10:25pm to 0:30am. Fare is adults: 300 yen, children: 160 yen. Unless you are a monthly pass holder, then it is just adults: 150 yen, children: 80 yen.
-In August 1997 a construction work gondola lost control a crashed into a station killing two workers and seriously injuring seven.
@ Jeffrey Bridgman,
Thanks so much for this!
The linear motor is in the vehicle whereas the track has just the reaction plate.
The massive power pickup would be needed if the active linear motor is built into the track.
I think this system could lead to the development of a new generation of gondola system. It should be possible to have a gondola that can run on cables as well as on rails. Gondolas run on rails in stations.
@ Matthias,
How do you know the linear motor is in the vehicle. Why could you not build it into the track instead?
Looks kinda pricey to me, particularly if you had to cross a significant river, ravine, or so on.
What’s the advantage over, say, an elevated, cable-propelled, APM system? Is it just a grade issue?
@BrianTH
the tracks look like they’re for taking curves. just cross a ravine or river on a straight line and you can get rid of the tracks … then the price goes down. an APM would need tracks for the entire route, this one is more like a hybrid.
In the pictures (here and at the linked website) it look like the tracks are used on the straights as well, and I couldn’t find any shot without the tracks being used. If you could get rid of the tracks except in curves, then I could see the appeal. And if this particular system doesn’t work that way . . . someone should invent one that does!
@BrianTH
Good point. Using the track in the non-curved sections is extraneous. It costs too much money and becomes much more of an eyesore. How to do the track in the curves, but not in the straightaways would be fascinating.
Perhaps the transition from track to none track section required complications (slowing down, etc.) so they opted to just build track for the whole thing?
Re. curved sections, does a cable that suspends a gondola require more tension than a cable that “rides” guide wheels and only provides propulsion?
@ Ken,
As I’m not an engineer, I don’t know. I would assume it is different in an MDG, BDG, or 3S situation. Maybe some of the engineers who read the site can help answer your question?