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urban ropeways : destination stops

Forschungsprojekte > US

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Detachable ROPEWAY trams
or called "Cable Propelled Transit" or "urban gondolas" ( U.S. / CAN )
as public transport vehicles of the FUTURE ?


PLEASE NOTE: This single page contains suggestions for small details, descriptions, and for a (networked) cable car system of the future, theoretical ideas, that go beyond the state of the art of the present and needs testing and development!

The cable car in the city has a future. Intra-urban gondolas can solve many traffic problems and transport problems, especially in the developing world. Renewable energy can be used for sustainable transport, CO2 emissions will be avoided, exhaust emissions are significantly reduced in the streets and at the same time increasing the quality of life of urban residents.

Presence


Urban Cable cars usually have a launch (starting) station and a terminal station. For longer distances separate sections are linked to a "line" where the passengers ( at some stations ) have to change the gondolas.
Examples at > history < (German language)




AERIAL TRAMS trams as public transport vehicles of the FUTURE ?


PLEASE NOTE: This single page contains suggestions for small details, descriptions, and for a (networked) cable car system of the future, theoretical ideas, that go beyond the state of the art of the present and needs testing and development!

The cable car in the city has a future. Intra-urban gondolas can solve many traffic problems and transport problems, especially in the developing world. Renewable energy can be used for sustainable transport, CO2 emissions will be avoided, exhaust emissions are significantly reduced in the streets and at the same time increasing the quality of life of urban residents.


Future


In 1997 I designed a theoretical system study for gondolas as urban transport. And if a new transportation is introduced, it is to overcome disadvantages of other transport equipment:


Conventional buses (except for low-floor buses with its own "platform") are not very suitable for wheelchair user. At an urban cable car as a newly introduced transportation wheelchair user should conquer only a small gap between the platform and the gondola. It would be ideal if the gondola stops (and drives not in a slow motion like at (winter)sports ropeways).


Passengers have access to subway stations only with longer paths. The optimized transportation should "come to the passenger". A ropeway with a gondola lift to pedestrian level. Conceived in 1997 by lowering the rope, today perhaps more realizable with linear drives (they were not so publicized in 1997). Linear drives now replace the cables and counterweights in elevators and eddy current brakes the cable brakes. The same technology could lift gondolas (or other people-movers) up and down or move it at destination stops.


Mass transportation have their place, they move masses. At the start of school, at lunch, during rush hour at the start and end of work. Most mass transportations push its limits here. Overcrowded buses, trams and suburban trains show this. Every transportation which is or will be more attractive than another, will be used by many people. This is an advantage, but also a disadvantage.


At times when few passengers are on the move
, in the intervals between the rush hours, in the evenings, on weekends, public transportation should also be usable. Evenings and weekends are overtime for the drivers and possibly unprofitable in operation. And overcrowded vehicles enable the half-empty trips, the mix makles the money's right.

Aerial trams provide with correspondingly large dimensions per line a transportation capacity of up to 5,000 people per hour and per direction, so they are suitable only in areas where the capacity is sufficient, unless the passengers accept waiting times. It is conceivable to implement fares with lower rates during off-peak times to stop the rush.


Stopover destinations


An urban aerial tram of the future might not have only a starting station and a terminal station, but have a chain of stations.


Viele Zweischenstationen könnten eine Gondelbahn zum Verkehrsmittel machen, das Autos und Autobussse ersetzen kann



Ropeway crossings and network nodes


Because of space reasons, crossing stations will be built on each other (in theory it would be possible to cross only the ropes and let the gondolas cross the pathway on rails, but such a station would require large space. ( see the section >crossings< [page still in progress, not yet linked] ).

A reasonable design would be the following:
Third Floor: Aerial tram destination stop "North-South" (for example),
Second floor: Waiting area and crossroad for passengers,
First Floor: Aerial tram destination stop "West-East"
Ground floor: Stairs, escalators, elevators, shops, bicycle parking, lockers for full shopping bags
Basement: Drives,
Inner core: Slots for the ropes,
Exterior shell: Stairs and platforms

You could move one station to the ground floor and the floor above the crossing station. The area of entrance and exit on the ground floor must be structurally separated, so that no accidents can happen to pedestrians, cars, etc. An argument against it is, that urban ropeway gondolas rides often horizontally - apart from the catenary, the sagging of the ropes - and don't need thick track cables to lift up the cabins (and the gondolas don't drive diametrically opposed) and the next destination have to be located on the third floor, thereby the gondolas float above the traffic.

Also a lift down by means of a ramp conveyor would be considered.

About a ramp conveyor have a look here, page 18, English language.
[external link to http://www.doppelmayr.com/uploads/media/WIR_2010_09_EN.pdf]




Lowering of gondolas in stations?


In principle it would be user-friendly, when gondolas are lowered to the pedestrian level to help elderly or disabled persons, wheelchair users and people with prams.

Arguments against the lowering of gondolas in stations are:


1) It requires less energy to lift this user group in an elevator but to lift a much heavier gondola each time to start it, the majority of users reach the cable car on (sloping) stairways.

2) The lowering and followed lifting costs too much time. Perhaps this fits at a central station or launch (starting) station or terminal, but rather not to an intermediate destination stop.

3) Another major argument against the (first proposed by me) lowering the gondolas at destination stops are also the necessary braking distances and speed tracks!


A gondola of a a fast Tricable Ropeway Detachable requires in a station (with a delay or acceleration of 1m / s ²) 34 m (=111_ft.) of track for braking and 32 m (=105_ft.) for acceleration. [ here is a chart with calculated lengths of destination stops ], in sum about 66 m minimal (217 ft.) [it's probably possible to develop a shorter route, but on this below in the text ]. And these 66 meters are better on the first floor than on ground floor to provide the space to other traffic. Below the aerial tram station bike racks, luggage lockers or stores can be positioned. Shorter stations are only designated starting stations and terminals, if space is not reserved for future expansion.


There are some interesting regularities [ ] for an urban ropeway in the city:

[A] Increasing the number of destination stops on a route, this imposes (by reducing travel distances and increasing the station lines) far longer total travel time per added station to just 30 seconds [ although the additional station stay seconds is 40 seconds ! This strange paradox can be explained, that with every additional destination stop the track becomes 66 meters (217 ft.) shorter, at speed 6 m/s (=13,4_mph) driving time are reduced by 11 seconds. For this 66 m (217 ft.) 40 seconds more are required, the sum is about 30 seconds (table and calculation here ) ]


Those 30 seconds are the time, that can be calculated as the delay through a stop instead of riding through a station. In other words, a gondola riding through at an intermediate station without stopping drives 11 seconds. More in the text below.

An increase of stops effectively extending the total travelling time by 30 seconds per station. Nevertheless you must take care of a accessibility of the stations by walking with a distance to the next destination stop of max. 300 m (985 ft.) walk, this means a recommended maximum average distance of 600 m (1,970 ft.) between stations.

[B] On the other hand increasing in speed from 6.0 to 7.5 m / s (from 21.6 to 27 km / h, 3.4 to 16.8 mph) at a distance of three kilometers (1.9 miles) results just a saving of about 1 ½ minutes. Gondolas rides but for all that in 30-second intervals and therefore the ropeway transports no more passengers per hour ! ! !


[C] In opposition to this, a gondola riding 7.5 m/s ( =26 km/h =16 mph) needs for braking (-1 m/s²) and acceleration (+1m/s²) 66 m ( 216 ft.), riding 6 m/s ( 21.6 km/h = 13.4 mph) it needs only 46 meters (151 ft.). To make a station compact and small as possible you need a lower speed (it could be a problem to build a new ropeway station "on the first floor in front of building facades" with a length or diameter of 66 m (216 ft.) ! calculation of station lengths of destination stops depending on total travel times

To make stations more compact, you must shorten it. More in the text below.

An increase in speed results only at Reversal Ropeways with an increase of the transport capacity, because the cabins are faster back at the starter station and thus the time interval of the vehicles is reduced. To increase transport capacity at detachable ropeways you also have to reduce the time distance of the gondolas (and you can scale up the cabin size too). The whole system (the track cables or the haulage rope, carrying capacity of the supports, drives, brakes, steering, stations, number of gondolas, etc.) must be designed to this capacity expansion or must have reserves.
Calculation of the transport capacity according to the gondola distances (in German language)

30-second intervals mean, that per hour and per direction a maximum of only 120 gondolas of any size are transported. If we take an aerial tram for a maximum speed of 6 m / s (21.6 km / h or 13.4 mph) we get a gondola spatial distance of 210 m, then you need per kilometer in each direction approximately 5 gondolas.


[D] A reduction of idle time in the station does not lead to an increase in transport capacity, but it leads to a reduction in travel time!



gondola riding through stations


My original idea in 1997 for an urban ropeway (network) was, that gondolas also can ride through a destination stop or to stop for passenger entering and leaving, the same system like buses. This however results in a different distance of the gondolas and more complex logistics, when waiting gondolas have to merge at a gap.
A general drive through would be possible at season stops (ice rink in summer, outdoor pool in winter, meeting halls) or is in rush hour useful (to travel faster). Normally a gondola station stops at a station, it slows down the travel time. But travel time slows down at every kind of transportation.

Braking, stopping, accelerating at a destination stop you have at each transportation. Calculated as above, a gondola needs (with a downtime of 20 seconds) about 30 seconds more than without stopping (11 seconds). It really makes sense to disconnect gondolas only if it's necessary or to ride through the station in just under eleven seconds (instead of 40 seconds), provided that it is technically possible to do this.

Such stations, where gondolas can ride through without braking don't exist, developments still are needed. In At stations in principle the gondolas uncoupled from the traction cable (to brake the gondolas in an emergency too) and they are again coupled to the rope after the destination stop. Inside a station gondolas are driving on rails (hanging!). The rail wheels are rigidly connected to the suspension bar (to prevent commuting by braking and acceleration, commuting disturbs to turn at curves also). Therefore you need at least curve-going support wheels on two vehicle axles.

Riding through a station shortened the distance between the first riding through gondola and the previous gondola, shortened by these saved 30 seconds. Assuming a normal cable distance from 30 seconds, it means that the cable would make a collision. The reult is that one gondola is too much on the way.


To switch the system from stopping at every station to ride through every station, the control system must bring a gondola into the garage, the system must make a slot, right from the very beginning into the traffic (one gondola doesn't start). Therefore a distances between two starting gondolas is 2 x 30 seconds and is later shortened to 1 x 30 seconds. To move an already propelled gondola from the system, this gondola must "end" at the previous station, the passengers would have the consequence of change to the next one. Then the empty gondola goes straight into the garage (and increases the distance to the following gondola to 2 x 30 seconds).

The passengers of the first riding through gondola have no time savings, since thea have to wait the saved 30_seconds for the next gondola. Either a gondola didn't start (to make a distance of 2 x 30 seconds) and they have to wait this lost 30 seconds or the ride ended and they have to wait 30 seconds for the following gondola. Only later travellers save time by riding through a station.

The opposite case, to switch from general riding through to stop at a destination stop is no problem, because the next gondola follows at the right distance. So a "stop button" in the gondola makes sense. But whether following gondolas can ride through at this station is only possible, if one gondola is moved out of the traffic. At times with lower passenger traffic longer gondola distances are possible, because of the longer distances it is easy possible to shorten a distance to the previous gondola (up to minimum 30 seconds). There are shorter gondola distances than 30 seconds possible, but then you have to reduce the downtime at the station.

More difficult is to stop/call of a gondola by pressing a hold button
in the station. If the gondolas riding in a distance / intervals od 2 x 30 seconds or longer, it is no problem. Then a gondola starts from the gondola-garage at the station or the next following gondola stops. If the gondolas (in the 30-second-intervals) pass this station without a stop (such as during rush hour) the waiting passenger have to wait until the automatic control removed a gondola from the system. A delicate matter: Boarding at such (riding through) stops brings sometimes 5 minutes waiting time associated with the sight of gondolas, passing without stopping.

That's why it would be clever, if the gondola will start from the garage the time interval of the gondolas will be reduced by reducing downtime. But this could lead to a ...


...gondola traffic jam.
Remedial action: overtaking of gondolas




In a gondola traffic jam (problems at closing the doors, etc.) the following gondola stops at the second destination stop of the station and has the option of overtaking the jamming gondola. If necessary, it could be better to use the second stop just as an exit point.


In the rare event that the following gondola jams too,
the third following gondola should ride through without stopping (an exit is then only at the next station posssible, required return is better than to hang on the rope at a system stop between the stations). Because the possibility of overtaking, a system stop can be avoided, including any related inconveniences, such as swinging of the rope with the gondolas, frustration among passengers, etc.


An Urban Ropeway should be an acceptable transportation and a longer stop hanging on the rope must be avoided at all. Speakers and intercoms in the cabins are helpful, but emergency stops or even rescues must avoided any on.
Destination stops, allowing to overtake jamming gondolas and redundant drives (direction and opposite direction are separate driven with, but necessary, together coupleable drives) should avoid involuntary stops in the air and should make delays to an extremely rare exception.

Jammed gondolas must ride in a shorter time distance, to remedy the jam (the complete system must be designed and constructed for this). It is not a problem, if the gondolas ride in a longer time distance. Otherwise time distances and downtimes must be reduced and a gondola must drive into the gondola garage. Or the jamming gondola ends at this station. Perhaps this method brings up the passengers to avoid jams? If a door at the platform opens only when it is time to enter the gondola, probably problems with the doors of the gondola (and following jams) could be avoided too.

At ropeway systems of presence gondolas riding with 12-seconds-distances, have no downtime and creeping throuh the destination stop with a velocity of 0,1 m/s. Or you stop such a gondola only for about 10 seconds, it could be enough.



The entry and exit points on cable cars in the city should be designed, that the gondola stops at defined points, the car doors open,the passengers go to the exit and then a sliding door opens automatically on the platform to enter the gondola. Larger (longer) Gondolas could have separated entrance door and exit door, to guide the passengers and to minimize the downtimes at a station.

[E] The grapic above shows a third example of a station at which the braking section and the acceleration section be merged with (like an aircraft runway), whereby you only need for a station a length of 25 m. A 30-second or a 12-seconds time window as the distance between the gondolas must be sufficient to share braking and acceleration section. This requires ...




...shortened destination stops (stations)

66 m long stops (at 7,5 m/s velocity) could be reduced to 11 meters by:

  • limiting the travel speed (rope speed) to 4 m/s


  • or increase decelerating asnd acceleration


  • merging the braking section with the acceleration section or to have braking section and acceleration section at different floors, one above the other


  • return of the gondolas to the starting point of the acceleration section


  • situating the stopping place at this return section


  • partitioning of the braking distance between the braking section( from 4 m/s to 1m/s) and the stopping place section (from 1m/s to standstill)


It could be better, if braking track and acceleration track are not are not the same way. After braking, the gondola are raised with a ramp conveyor one floor lower or higher to the destination stop with a ramp conveyor, and at this level is the acceleration track too. But that also means, that every gondola rides this way, without riding through the station (only riding through at the point of the destination stop).
About a ramp conveyor have a look here,
page 18.
[external link to http://www.doppelmayr.com/uploads/media/WIR_2010_09_EN.pdf]



If gondolas ride with 4 m/s and 30-second intervals and stand around 30 seconds in the station, so the following is currently in the braking section, when a gondola wants to start. On the braking distance the gondola rides about 3 seconds, the disengaging expects further 2 seconds. In the 25-second gap to the next following gondola the "runway" is free to get the lane and to accelerate.



Travel speed affects strongly on the required length of the stations. At about 4 m/s will probably the optimum speed. Faster transportations (with larger passenger capacity) usually have other station distances (and longer stations, which must be reached by foot, for which a lot of time is required ! ). Cable cars in the city will not replace faster transportations (but just fast transportation jammed in the traffic jam to and therefore slow transportations) , because ropeways don't need own tracks and don't get stuck at jams. They offer advantages in the transportation of future.




gondola garages in each intermediate station:



In each intermediate station gondolas should be garaged and started fully automated so that ...

  • In the morning the system can be set in operation as soon as possible,
  • during storms and at the end of operations the system can be emptied as quick as possible,
  • in each station empty gondolas are ready on call at all times (such as at night)
  • gondolas can drive to the gondola garage as soon as possible to enable following gondolas to ride through the station
  • and to avoid large condola garages, although they are cost effective.




At the entry and exit point the gondolas are weighed on a weighing rail (or the internal drive system measures the moment of inertia of the moved gondola). An empty gondola can automatically drive into the gondola garage. To transport empty gondolas on the rope costs unnecessarily energy. Ropeways in the plane are not in balance, as ropeways up/downhill, where down-propelled gondolas lift up the other leading up gondolas. Furthermore "direction and opposite direction" should be driven with separated drives.


During the evening, if generally less gondolas are on the rope and only the empty haulage rope is moved, an empty gondola can quickly retrieved from the gondola garage to start it.

As with escalators, reduced velocity saves energy at night. It's cheaper than to move an empty rope with full speed. If necessary, the speed is increased.


Turning points at each intermediate station:


In each station gondolas can change the direction on a circuit.

That has advantages,

  • if different sections are closed ( for repairs, at accidents, fire, etc.)
  • to garage empty gondolas there, wherever space is available
  • to garage empty gondolas, where they wait to be on call



„Our head is round, enabling us to change the direction of our mind“
Francis Picabia
French writer, painter and graphic artist
1879 - 1953


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