International Transportation (67) 1 | 2015 40 PRODUCTS & SOLUTIONS Urban Ropeways Aerial ropeways for urban mass transportation Gondola lift, cableway, cable cars, traic noise reduction, electric mobility, city traic, local transport The CO 2 problem, dwindling crude oil reserves, dramatically rising air pollution and increasingly congested roads should be enough reasons to adopt new paths in mass transportation. Individual traic using electric cars ofers no real solution. But what about rethinking urban transportation and considering the deployment of urban gondola lifts, where a gondola for up to 10 passengers arrives every 10 seconds and leaves the station just seconds later. - A plea for urban ropeways. Author: Günther Ecker T he strong trend towards reinventing cable-car systems for commuter mass transportation and for everyday use was triggered by Alfredo J. Brillembourg and Hubert Klumpner in Caracas (Venezuela): In the scope of their “Urban Think Tank Project”, the two architects proposed to open the Caracas hills slums with better transportation systems. The project was delayed and, while there were some small-scale earlier applications, it was only in 2004 that the Metrocablé de Medellín (Colombia) opened as the irst urban gondola lift for everyday traic. Cable car systems are cheaper to build and operate than trams or subways. It is said that the irst cable car line of the Metrocablé de Medellín paid for itself within a year [1] - thanks to more than seven million passengers in the irst year and the sale of emissiontrade certiicates. This is the reason why, these days, so many new cable car lines are scheduled to be built in South America: three in Rio de Janeiro, ive in Colombia, ive new cable car lines in Bolivia’s seat of government La Paz. The rapid payback turns urban cable car lines into a proitable investment business, almost a “license to print money”. Especially in developing countries, where urban and transport planning was neglected for a long time and newly arriving rural migrants used to build their shelters in the wasteland on the outskirts of cities, there is a lack of good roads and streets. People mostly use winding walking paths. In the megacities of developing countries, slums and favelas dominate the urban area, “wild construction” is gradually covering slopes, and this substandard housing is accessible only by footpaths and/ or stairs made from concrete slabs. The chief means of “public” transport are taxis, and the abundance of minibuses further slows down traic in the typically narrow streets, leading to extended travel times. Main benefits of using cable car systems for public transport Because of the favorably low capital investment needed for aerial ropeways, the available investment sums can pay for a transport system that covers a much larger urban area than with subways or trams (figure 1, data from [2]). If people have to walk or bike no further than 350 meters (half the diagonal of a 500 x 500 m square) to reach local transport, they do not need to know the timetable, but can enter the next gondola without waiting and reach any destination in the city in a short time. At night it is not necessary to run empty gondolas. If needed, users simply start a gondola parked in the station. 20 hours a day, 7 days a week, passengers can travel to the city center and back, to work, to educational institutions, to shopping venues, to the sports center and so on. The gondolas are also a safe way for people to travel home after dinner or a visit to the club - without fearing to be stopped for an alcohol test. In addition, this environment-friendly transport system contributes substantially to reducing traic noise as well as CO 2 -, NO x -, and particulate matter emissions. Fast realization As the cable car line operates “in the air”, its construction requires neither expensive acquisition of land, nor house demolitions, nor months of road works. A cable car line is quickly designed and deployed, the erection of pillars is done without signiicant disruption to businesses or interference with the daily lives of the resident population (see figure 2). The fully automated operation has a favorable efect on operating costs. Low investment and low operating costs (even on Sundays) either make for faster amortization or can be used to keep ticket prices low. More expensive transportation systems lead to expensive fares, but on balance public transport should be cheaper for the users than transport by car. Figure 1: Comparison of subway, tramway and ropeway investment costs Source: Ecker, data [2] International Transportation (67) 1 | 2015 41 Urban Ropeways Products & solutions To compete with the transport capacity of a gondola lift (3,600 passengers per hour and direction), a tramway with seats and standing room for a total of 290 passengers would have to run at intervals of about ive minutes; for an articulated large-capacity bus with 145 seats and standing places the interval would be two and a half minutes. To assure service at these time intervals for a ten kilometer double-track tramway line with 20 km/ h maximum speed (average speed for short distances) you need about twelve vehicles; with large-capacity buses about 25 vehicles and drivers would be required. A comparable fully automated gondola lift system needs just ive people to operate - if the entry and exit points are monitored by cameras, as it is usual in subway systems (based on data from [2]). Energy eiciency On mountain-to-valley lines, the system is particularly efective. The weight of the gondolas traveling downhill and uphill balances out, so that only little energy for moving and braking is required. Modern tramways can feed braking energy back into the grid, but only at a loss. Also in level sections of the line, cable cars can be operated economically, because the same energy-saving balancing principle allows lowering the gondolas to pedestrian level and later raising them again with only minimum energy requirements. As the gondolas carry neither motor nor brake systems, kinetic energy is saved. Cable cars can be powered by electricity from renewable energy sources, they operate very quietly and emit neither noxious gases nor particulates. For cable cars to be an attractive means of transport also for level sections, they need only to be faster than pedestrians or than cars in congested streets or on detours, which can be guaranteed most of the time. Cable cars are not much slower than subways or tramways. Railways undoubtedly achieve higher top speeds, but they cannot reach maximum velocity on short stretches between stations. What is more, cable cars need not drive detours like tramways or buses. Since the relevant criterion is overall travel time for passengers from their starting point to their destination, lower maximum speed is not a problem. Easy and quick crossing of hills, canyons, rivers, parks, gardens, historic town quarters (igure 3) and parking areas, and no need to cut tracks through agricultural land or pedestrian zones - these are as many arguments in favor of cable car lines. The establishment of a line along an existing road or street simpliies the approval process and facilitates any rescue operations - modern urban cable cars are even equipped with spare engines to bring passengers safely to the next station in case of an emergency. urban cable cars - diferent from touristic cable cars Touristic cable cars are stopped during storms and lightning (and are equipped with extra earthing conductors), which does not present a problem, because in such bad weather, no one likes to go skiing or hiking anyway. In urban contexts, authorities try to avoid interrupting transport service for weather reasons because this will disrupt urban life. This is why a city must choose the most suitable cable car system for the prevailing weather conditions, namely storm frequency. Gondolas on a monocable haul rope can move safely in crosswinds with a speed of up to about 60 km/ h (37-mph). Cable cars traveling on wheels on one or two ropes are safe in crosswinds of up to 100 km/ h (62 mph), but this technology is more expensive. Just like high-voltage power lines, urban cableways should also be equipped with an earthing cable. While the passengers in the gondolas are safe when lightning strikes a cable, a lightning strike in the stations might paralyze crucial systems. In more than a century of operation and continuous evolution, cable car technology has proven to be the safest means of transport overall, based on the number of passengers carried. Accidents are excluded since there is no point of contact with other transport means. Modern gondolas are equipped with WLAN devices, loudspeakers, lighting, heating and ventilation, and in some cases even surveillance cameras. Crime is rare because criminals have little chance to escape. In the stations platform screen doors ensure safe passenger entrance and exit: The platform doors open only when a gondola is in the station, so nobody can accidentally step in front of arriving gondolas. The cabins are well ventilated so that the windows can remain closed and nobody can throw out waste or burning cigarette butts. Blinds with horizontal slats, partially opaque window glass or other structural measures can be used to keep visitors from looking into the gardens and backyards that the gondolas are traveling over. Every cable car must be checked and serviced at regular intervals. About one week per year the gondolas are not available for transportation. This revision can be done in Figure 2: Construction without significant disruption of daily routine in La Paz, Bolivia Photo: Marlene Ecker Figure 3: Ropeway crossing old urban quarter of Funchal, Madeira Photo: Günther Ecker International Transportation (67) 1 | 2015 42 Products & solutions Urban Ropeways the main holiday period. Another possibility is to build circular lines with separate drives for each direction. Then one direction can be taken out of service for revision purposes (or to save energy at low-traic times) while the other line allows passengers to reach every station. If one drive is damaged, it can be coupled with the other one. Likewise, in an emergency, one line can be used to rescue passengers stuck on the other line. In systems consisting of several lines crossing each other, two or four drives can be centrally installed in the same building as the control center (figure 4). In overcrowded informal slums, the lack of roads is one of the reasons for aboveaverage violence and crime levels. In Medellín (and later in Caracas and Rio) the cable car stations in the favelas were equipped to house police stations and public facilities (libraries, health centers and rooms with free internet access) in addition, ensuring that now more police oicers are on the spot [3]. Barrier-free and easy access, even-for freight transport Gondolas ofer barrier-free, easy access for people with wheelchairs, prams, bicycles, roller skates, luggage carts or hand trucks because there are no thresholds or steps, and the gap between the vehicle and the platform edge is very small (figure 5). Entering is no problem for young children, invalids or disabled persons. Depending on the system the gondola moves through the station at crawling speed (slower than an escalator) or stops completely. In larger gondolas, bicycles can be transported easily. In addition, cable cars are suitable for transporting goods, either in separate gondolas, or in combination gondolas with folding seats for passengers, or in two-tier cabins. A few - solvable problems In cableway construction, curves are a problem. The sophisticated technology is suitable for straight lines only, in curves gondolas have to drive on rails. As gondolas drive on rails in stations anyway, stations should be built where curves are required. The “CURVO-System” (Conveyor & Ropeway Services, India) promises improved operation in curves, but there is probably higher load and more wear on the ropes. The optimum length for cable car rides as mass transportation is a maximum of about seven kilometers (4.3 miles), for longer distances faster transportation systems are better. The reason: The number of stops and the resulting braking and reacceleration procedures are a crucial factor in overall travel time. Urban cable car lines recently built in South America and Ankara (Turkey) have intermediate stops. In practice, the sections are structurally separated, so that the passengers need to transfer by foot from one line to the other within the stations. Continuous lines with intermediate stops or passing gondolas are of course feasible. Although some technical innovations would be necessary for the construction of entire networks - e.g. to enable passing intermediate stations without stopping, crossing stations, or modular stations built for subsequent extension - all customer requests from gondola heating to rooless gondolas can be met by the cable car manufacturers. Intervals between gondolas can of course be longer than 10 seconds, for instance at night. It is desirable that, before starting their trip, users should inform the system how far they intend to go. This will enable more targeted control of traic low, for instance by inserting additional gondolas on high-usage sections. Gondolas could also be parked at every intermediate station so that at night the rope will run empty and gondolas will only latch on on demand. Although ropeways can be constructed and operated at quite low costs, they will face resistance in cities with extensive public transportation systems. But in towns or cities where eicient public transport is lacking and traic jams are an every day phenomenon, cable cars would be an efective way to reduce car dependency and promote the switch from cars to public transport. Seven days a week, 20 hours a day, cable car lines are an inexpensive and proitable mass transport system and in many respects the only true alternative to the car: “Go to the stop, get on without waiting time, start immediately and arrive on time”, could be the new motto for public transportation. ■ SOURCES: [1] Seeber, Anton: The Renaissance of the Cableway - Innovative Urban Solutions from Leitner Technologies - Innovative urban passenger transport systems of Leitner Technologies - Innovativi sistemi di trasporto urbano di Leitner Technologies (English/ German/ Italian), ISBN 978-88-6069-006-7, Publisher Prokopp & Hechensteiner [2] Forschungsgesellschaft für Straßen- und Verkehrswesen e.V. (FGSV): Hinweise zu Systemkosten von Busbahn und Straßenbahn bei Neueinführung, Köln 2008 [3] http: / / www.theguardian.com/ world/ 2013/ jun/ 09/ medellin-colombia-worlds-most-dangerous-city Günther Ecker Chairman abcde-institute.org, Wels (AT) info@abcde-institute.org BACKGROUND INFORMATION Language confusion “Urban ropeways” is the technical term in the English language spoken in the (former) Commonwealth States, Japan and Southeast Asia. “Urban cable cars” or “urban aerial lifts” mean the same in the English variety used in Europe. “Cable propelled transit” is the term used in Canada and the United States where “cable car” refers only to cable-propelled streetcars on rails. In French the technology is called “télécabine urbaine”, “télépherique urbain” or “transport urbain par câble“. The Spanish term is “teleférico urbano” while the Germans call the system “Urbane Seilbahn”. Ropeways with ixed or detachable vehicles are “gondola lifts”, “télécabine” (French), “telecabina” (Spanish), “Gondelbahn” (German). Ropeways with one or two “cabins” (not gondolas) that commute between station 1 and station 2 are called “reversible ropeway” (Europe), “aerial tram(way)” or “jig-back ropeway” (both Northern America), “téléphérique” (French), “teleférico” (Spanish) and “Pendelbahn” (German). Figure 4: Efects of a combination of several ropeway lines Draft: Ecker Figure 5: Barrier-free access Photo: Günther Ecker