Sumit Singhal loves modern architecture. He comes from a family of builders who have built more than 20 projects in the last ten years near Delhi in India. He has recently started writing about the architectural projects that catch his imagination.
Metro Cable in Caracas, Venezuela by Urban-Think Tank
October 19th, 2013 by Sumit Singhal
Article source: Urban-Think Tank
In July of 2003, UTT organized an informal, but very public, presentation and symposium at Caracas’ central university to protest the government plan and begin the process of exploring alternatives. Attended by architects, planners, various other experts, university activists, and barrio leaders, the meeting stunned government planners: speakers from San Agustín were not only vehement in their objections, they were eloquent and well-informed.
In rejecting the plan, they also articulated very specific demands, among them the preservation of a pedestrian-oriented community; mixed-use development; expanded parks, and attractive, safe streetscapes; sources of employment, including entrepreneurial opportunities; and various other community amenities.
This was a watershed moment in land-use planning and development: never before had a “slum” community asserted the right to shape its own future; never before had stake-holders demanded a role in the decision-making. The government backed down.
More significantly for the ensuing exploration and planning process, the symposium resulted in the creation of a task force consisting of an organized group of community volunteers and the UTT team. In relatively short order, the task force selected from among several alternatives the cable car system as having the greatest potential: ideally suited to the terrain, minimally invasive into and destructive of the existing fabric, highly sustainable, and flexible.
Following an intensive one-day charrette, during which the task force refined the concept, UTT undertook a six-month analysis and planning initiative, enlisting the participation of our colleagues in what became Caracas MetroCable: a collaboration between Austrian ropeway manufacturer Doppelmayr, climate engineers Transolar, and the US civil structural engineering firm Silman& Associates. With the plans well established and community support overwhelming, UTT launched a media campaign and program of presentations to influential constituencies, to build wider support for the project and exert pressure on the government. The “official” planners responded to the inescapable: abandoning their scheme, they adopted the UTT/San Agustín approach.
A Connect-the-Dots System
Integrated with Metro Systems of Caracas, the public transit system provided in the “formal” city, Caracas MetroCable is 2.1km in length and employs gondolas that hold eight passengers each. The total capacity of the system allows for moving 1,200 people per hour in each direction. Of its five stations, two are in the valley and connect directly with the existing public transit system; three additional stations are located along the mountain ridge on sites that meet the demands of community access, established pedestrian circulation routes, and suitability for construction with minimal demolition of existing housing.
The idea of the a MetroCable has been proven and tested in Barrios in Medellin, Colombia, but what is more here is that the MetroCable Stations provide more than just transport but are hubs for social services and other community activities.
Though the five stations share in common a basic set of components and designs – platform levels, ramps for access, circulation patterns, materials, and structural elements – they differ in configuration and the possibility of additional functions that address other community needs. While not all of these additional purposes are being constructed at this initial stage of the project, the opportunities of integration of the stations with the community include.
The San Agustín and Parque Central stations, at the base of the hillside, include social, cultural, and system administrative functions.
At Los Mangitos, 40 units of housing will be built, replacing homes whose demolition is an inevitable necessity for station construction. The station structure also includes public spaces for community gatherings, out-patient health care facilities, and other similar amenities as well as a playing field on top.
In addition to the station itself, the La Ceibita site has a second structure that links the station to ground level, 16 meters below, and includes a gym and government-sponsored supermarket and day-care center. The station is also connected to an existing housing complex and to a roadway with a municipal bus stop.
Hornos de Cal, the third of the ridge-line stations, affords unique opportunities, as it is the least-densely developed neighborhood and offers the planners more space to work with. It is also the site of a large water tank, which has long been a barrio icon of sorts.
The tank will be demolished and the station built on its foundations, taking the tank’s place both literally and symbolically: the new station is intended to function as a beacon and look-out tower with a viewing platform, from which all of Caracas can be seen spread out in the valley below. The development of this site also includes the restoration and expansion of an existing soccer pitch and the implementation of a major open-space and streetscape plan.
This connect-the-dots scheme has the considerable virtue of being minimally invasive of the community fabric, weaved into it only at five discrete points. The hilltop stations, set into densely-built neighborhoods, rest on stilts to avoid all but the absolutely essential demolition of homes. Like the gondolas themselves, the stations float above the ground, a near-perfect expression of an ideal intervention: one that facilitates and connects without imposing, that emerges literally and figuratively from the community it serves.
Plug In, Flow Around, Float Over
The entire system is designed on modular principles, effectively a kit-of-parts, using pre-fabricated components. The stations, essentially shed buildings, are inexpensive to manufacture and erect, producing economies of scale and meeting the functional and aesthetic objectives. Critically, the structural and architectural design enables simple, low-cost, and rapid alteration and expansion of each station, to adapt to future needs and objectives. In this, as in other features, the UTT design team borrowed from the organic nature of the barrio itself, a process of unending growth and change, of potential and accommodation.
In addition to minimizing the impact on the built environment, elevating the stations above ground serves significant climatic and geographic purposes. Air-flow at pedestrian level is preserved, and adjacent homes continue to benefit from the cleansing and cooling effects of the prevailing winds. Erosion from the typically heavy annual rains is minimized, protecting the station structures themselves as well as the surroundings. And the stilt-like legs greatly simplify compliance with seismic requirements. Additionally, the structural support for the platforms and cable car system is independent of that for the station shell, which is thus unaffected by the inevitable vibrations from system operations and pedestrian movement.
The barrio-dwellers of San Agustín and of the rest of Caracas’s informal city live officially off-the-grid, though they can and do “borrow” power from municipal lines. The heavy rains notwithstanding, there is no supply of potable water. And residents make extensive use of recycling in the construction of their homes. Thus, all of UTT’s work in the Caracas barrios rests on the fundamental principle of sustainability. No project is of any value to barrio-dwellers if it relies upon resources beyond their means or reach or depends for its completion and operation on promises of future assistance. Moreover, key features of sustainability are at the heart of the community’s culture and way of life, making it vital for a project that has arisen from the community’s will.
The primary materials used in the construction of Caracas MetroCable are steel and concrete – very durable, appropriate to climatic conditions, and requiring little if any maintenance and repair. The stations are skinned with corrugated steel sheets, fiberglass cladding, and a factory-applied gel coat that resists delamination[AL1] . The platforms and footings are concrete and connected with steel columns. The woven wire screening ramps and pedestrian bridges will, in time, support indigenous vines, providing shade and softening the hardscape.
While the cable system itself will draw power from the municipal source, each station is energy-independent. What is more the underground METRO stations in the valley are designed to use energy collected from solarpanels placed on the roof of the METROCABLE stations located above creating a symbiosis of energy flow. In the short term, a single wind-driven turbine will provide sufficient power for station needs. In the long term, the shell of the stations has been designed to accommodate solar panels, which will eventually provide sufficient power for the energy needs of the entire San Agustín barrio. The stations and adjacent structures require no mechanical HVAC of any kind. Each station is designed to incorporate a “wind-catcher,” which directs the prevailing breezes into the interior. Louvered walls enable fresh air to enter and exhaust the stations.
Plans for public restrooms are still under consideration, but are likely to make use of dry toilets, a solution previously proposed by UTT and adopted in several barrios for residential purposes. The two valley stations will use groundwater. At the hilltop stations, cisterns are being constructed to hold rainwater, for toilets and/or the irrigation of residents’ kitchen gardens and of the streetscape, which will be “greened” as part of the project.
During daylight hours, the station interiors will rely exclusively on natural light, admitted both from the sides and through translucent portions of the shell. After dark, LED lights will brighten the stations and the public streetscape. The lighting design for the stations contemplates more than functionality: the stations are conceived as beacons for the community with welcoming glowing lanterns that provide safety, and the fundamentals of what it means to come home.
The View From Here
A key criterion underlying the award to the UTT task force for the Caracas MetroCable project was the question from which our proposal arose: what kind of city do we want to see in 2025? Merely inquiring into the anticipated system capacity, for instance, made no sense. We recalled the lessons of the much-heralded Long Island Expressway in New York, obsolete before it was completed: you cannot “build for tomorrow” – you can only build in such a way as to be able to “build tomorrow.” Moreover, the changes underway in the informal city – in Caracas, as elsewhere – are not only extraordinarily rapid, they are truly transformational.
What we did seek, on the other hand, was to put in place the means for change in relation to the fundamental needs of the barrio of San Agustín, those its inhabitants themselves identified:
Safe, accessible, and cost-effective public transportation for barrio residents
The growth of work opportunities and of the economy of the barrios
The development of a sustainable infrastructure to give permanence and stability to the community
Improvement of the health, education, employment opportunities, and quality of life for barrio-dwellers
Improved safety and reduction in crime
For UTT, we look forward to 2025, even earlier perhaps, with two particular aspirations: that the San Agustín scheme will be translated to other Caracas barrios, eventually effecting the physical, economic, social, and cultural integration of formal and informal cities; and that the empowerment of the barrio communities will be perpetuated and grow stronger, giving them permanent ownership of their destiny.
In April 2009, the first line going from Parque Central station up to La Ceiba was formally inaugurated. The completed Metro Cable system is expected to open in December 2009.
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Category: Metro Cable