Search This Blog

Loading...

20 July 2012

Aerial tramway

An aerial tramway (U.S. English), cable car (British English), ropeway (Japanese) or aerial tram is a type of aerial lift which uses one or two stationary ropes for support while a third moving rope provides propulsion.[1] With this form of lift, the grip of an aerial tramway cabin is fixed onto the propulsion rope and cannot be decoupled from it during operations.

Aerial tramway suspended on two track cables with an additional haulage rope.

An aerial tramway in Italy

Terminology

Because of the proliferation of such systems in the Alpine regions of Europe, the French and German language names of téléphérique and Seilbahn, respectively, are often also used in an English language context. Cable car is the usual term in British English, as in British English the word tramway generally refers to a railed street tramway while in American English, cable car is most often associated with a type of cable-pulled street tramway with detachable vehicles; e.g., San Francisco's cable cars. As such, careful phrasing is necessary to prevent confusion. It is also sometimes called a ropeway or even incorrectly referred to as a gondola lift. A gondola lift has cabins suspended from a continuously circulating cable whereas aerial trams simply shuttle back and forth on cables. In Japan, the two are considered as a same vehicle and called ropeway, while the term cable car means Cable car (railway) and funicular.

Overview

An aerial tramway consists of one or two fixed cables (called track cables), one loop of cable (called a haulage rope), and two passenger cabins. The fixed cables provide support for the cabins while the haulage rope, by means of a grip, is solidly connected to the truck (the wheel set that rolls on the track cables). An electric motor drives the haulage rope which provides propulsion. Aerial tramways are constructed as reversible systems; vehicles shuttling back and forth between two end terminals and propelled by a cable loop which stops and reverses direction when the cabins arrive at the end stations. Aerial tramways differ from gondola lifts in that gondola lifts are considered continuous systems (cabins attached onto a circulating haul rope that moves continuously).[2]
Two-car tramways use a jig-back system: A large electric motor is located at the bottom of the tramway so that it effectively pulls one cabin down, using that cabin's weight to help pull the other cabin up. A similar system of cables is used in a funicular railway. The two passenger cabins, which carry from 4 to over 150 people, are situated at opposite ends of the loops of cable. Thus, while one is coming up, the other is going down the mountain, and they pass each other midway on the cable span.
Some aerial trams have only one cabin, which lends itself better for systems with small elevation changes along the cable run.

History

The first aerial tram was built in 1644 by Adam Wiebe[citation needed]. It was used to move soil to build defences. Other mining systems were developed in the 1860s by Hodgson, and Andrew Smith Hallidie. Hallidie went on to perfect a line of mining and people tramways after 1867 in California and Nevada. See Hallidie ropeway

In mining


Ore bucket on the aerial tramway leading from the Mayflower mine, near Silverton, Colorado, USA

Cableway from abandoned coal mine just south of Longyearbyen, Svalbard
Tramways are sometimes used in mountainous regions to carry ore from a mine located high on the mountain to an ore mill located at a lower elevation. Ore tramways were common in the early 20th century at the mines in North and South America. One can still be seen in the San Juan Mountains of the US state of Colorado. Over one thousand mining tramways were built around the world—Spitsbergen, Russia, Alaska, Argentina, New Zealand and Gabon. This experience was replicated with the use of tramways in the First World War particularly on the Isonzo Front in Italy. The German firm of Bleichert built hundreds of freight and military tramways. Strangely, Bleichert even built the first tourist tramway at Bolzano/Bozen, in then Tyrolian Austria in 1913.
Other firms entered the mining tramway business- Otto, Leschen, Breco Ropeways Ltd., Ceretti and Tanfani, and Riblet for instance. The perfection of the aerial tramway through mining lead to its application in other fields including logging, sugar fields, beet farming, tea plantations, coffee beans and guano mining. A resource on the history of aerial tramways in the mining industry is "Riding the High Wire, Aerial Tramways in the West", by Robert A. Trennert, University Press of Colorado, 2001.

Moving people

In the 1920s the rise of the middle class and the leisure industry allowed for investment in sight seeing machines. The cable car to the top of high peaks in the Alps of Austria, Germany and Switzerland resulted. They were much cheaper to build than the earlier rack railway. One of the first trams was at Chamonix, while others in Switzerland and Garmisch soon followed. From this, it was a natural transposition to build ski lifts and chairlifts. The first cable car in America was at Franconia, New Hampshire in 1938. After the Second World War installations proliferated in Europe, America, Japan, Canada and South Africa. Many hundreds of installations have emerged in mountainous and seascape areas.
The aerial tram evolves again in latter decades—one tram in Costa Rica was built to move tourists above a rainforest, while one in Portland, Oregon, was built to move commuters. Presently, the mining role of tramways has lessened, though some still work, and moving people remains a starring role for the device.
Many aerial tramways were built by Von Roll Ltd. of Switzerland, which has since been acquired by Austrian lift manufacturer Doppelmayr. Other German, Swiss, and Austrian firms played an important role in the cable car business: Pohlig, PHB, Garaventa, and Mueller. Now there are three groups dominating the world market: Doppelmayr Garaventa Group, Leitner Group, and Poma, the latter two being owned by one person.
An escape aerial tramway is a special form of the aerial tramway that allows a fast escape from a dangerous location. They are used on rocket launching sites to offer the launch staff or astronauts a fast retreat. The tramway consists of a rope which runs from the launch tower downward to a protection shelter. On the launch supply tower several small cabs can be occupied by the launch staff or the astronauts. After a barrier is loosened these roll downward to the protection shelter. An escape aerial tramway exists on launch pads 39A and 39B at Cape Canaveral.
Some aerial tramways have their own propulsion, such as the Lasso Mule or the Josef Mountain Aerial Tramway near Merano, Italy.

Urban transport


A new Roosevelt Island Tram car in operation.
While typically used for ski resorts, aerial tramways have been ported over for usage in the urban environment in recent times. The Roosevelt Island Tramway in New York City and the Portland Aerial Tram are examples where this technology has been successfully adapted for public transport purposes. In comparison to gondola lifts, aerial tramways provide lower line capacities, higher wait times and are unable to turn corners.[3]

Telpherage

One interesting offshoot of the aerial tram was the telpher system. This was an overhead railway, which was electrically powered. The carrier basket had a motor and two contacts on two rails. They were primarily used in English railway and postal stations. The original version was called telpherage. Smaller telpherage systems are sometimes used to transport objects such as tools or mail within a building or factory.
The telpherage concept was first publicised in 1883 and several experimental lines were constructed. It was not designed to compete with railways, but with horses and carts.[4]
The first commercial telpherage line was in Glynde, which is in Sussex, England. It was built to connect a newly-opened clay pit to the local railway station and opened in 1885.[4]

Double deckers

There are aerial tramways with double deck cabins. The Vanoise Express cable car carries 200 people in each cabin at a height of 380 m (1,247 ft) over the Ponturin gorge in France. The Shinhotaka Ropeway carries 121 people in each cabin at Mount Hotaka in Japan. The CabriO cable car to the summit of the Stanserhorn in Switzerland carries 60 persons, with the upper floor accommodating 30 people in the open air[5].

Records

  • Longest (at time of building) and years operated:
  • Second longest:
  • Longest over water:
    • 1.0 km (0.62 mi) 1906 – the same century; Thio, New Caledonia. ship loading.
    • 2.4 km (1.5 mi) Since 1941 (decommissioned in 1997, still operational) Forsby-Köping limestone cableway, Sweden. crossing of Hjälmaren strait. 42 km system.[8]

World's longest functioning aerial tramway: Forsby-Köping

List of accidents

Despite the introduction of various safety measures (back-up power generators, evacuation plans, etc.) there have been several serious incidents on aerial tramways, some of which were fatal.
  • August 29, 1961: A military plane split the hauling cable of the Vallee Blanche Aerial Tramway on the Aiguille du Midi in the Mont Blanc massif: six people killed.
  • March 9, 1976: In the Italian Dolomites at Cavalese, a cab fell after a rope break, killing 42. (See Cavalese cable car disaster (1976))
  • April 15, 1978: In a storm, two carrying ropes of the Squaw Valley Aerial Tramway in California fell from the aerial tramway support tower. One of the ropes partly destroyed the cabin. Four killed, 32 injured.
  • June 1, 1990: Tbilisi, Georgia. After hauling rope brake the lower car rolled back and slammed on the wall of lower station injuring people, the upper car rolled down generating higher speed (brakes didn't work), on reaching lower cable car support mast it slammed ona broken hauling rope which tore a cabin apart and caused people to fall from 20 meters of height onto rooftops and ground, 21 were killed[citation needed] and many injured after jumping from accelerating cabin. Most of them were children celebrating "Children's day". Days before, the standard Soviet gondolas were changed to bigger ones brought from Finland without any precautions.
  • February 3, 1998: U.S. military aircraft severed the cable of an aerial ropeway in Cavalese, Italy, killing 20 people. (See Cavalese cable car disaster (1998))
  • October 19, 2003: Four were killed and 11 injured when three cars slipped off the cable of the Darjeeling Ropeway.
  • October 9, 2004: Crash of a cabin of the Grünberg aerial tramway in Gmunden, Austria. Many hurt.
  • April 18, 2006: New York's Roosevelt Island Tramway experienced a power failure, leaving 69 passengers in two trams stranded over the East River for approximately seven hours, just eight months after a similar incident in which trams were stranded for 90 minutes. No injuries or fatalities occurred in either incident.

Gallery

Cable cars pass mid-stream on the Sandia Peak Tramway in Albuquerque, New Mexico.  
Plateau Rosa aerial tramway in Cervinia, Italy, moves skiers to 3480m glacier.  
The rotating construction of the Titlis gondola provides passengers better view  
The rotating Table Mountain Aerial Cableway is designed to give passengers a 360° view.  
Ropeway conveyor for limestone transportation in Sweden  
The lowest cable is used for pulling. The middle cable supports the weight of gondola.  
Aerial Tramway in Ordu Province, Northeast Turkey  

Cableways in fiction

Comments
0 Comments

No comments:

Post a Comment

Please double post in this blog is up to you

SILAHKAN COPY PASTE SEPUAS MU

Related Posts Plugin for WordPress, Blogger...