Sunday, November 2, 2008

Pneumatic tube

Pneumatic tubes (or capsule pipelines; Lamson tubes) are systems in which cylindricaltubes by compressed air or by vacuum. They are used for transporting physical objects, solid objects, compared to the more generic pipelines which transport gases or fluids. containers are propelled through a network of

Pneumatic tube networks gained great prominence in the late 19th and early 20th century for businesses or administrations that needed to transport small but urgent packages (such as mail or money) over relatively short distances (within a building, or, at most, within a city). Some of these systems grew to great complexity, but they were eventually superseded by more modern methods of communication and courier transport, and are now much rarer than before.

A small number of pneumatic transportation systems were also built for larger cargo, to compete with more standard train and subway systems. However, these never really took off as practical systems.

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[edit] History

Pneumatics can be traced back to Hero of Alexandria in the 1st century AD, though there was apparently no thought of using them to move objects through pipes.

Pneumatic capsule transportation was originally invented by Phineas Balk in 1806.[citation needed] Though a marvel of the time, and a successful sideshow, it was considered little more than a novelty until the invention of the capsule in 1836.[citation needed] The Victorians were the first to use capsule pipelines to transmit telegraph messages, or telegrams, to nearby buildings from telegraph stations.

While they are commonly used for small parcels and documents — now most often used at bankssupermarkets[1] — they were originally proposed in the early 1800s for transport of heavy freight. It was once envisioned that networks of these massive tubes might be used to transport people. or

[edit] For postal service

Pneumatic tube letter from Berlin, Germany, 1902
Italian pneumatic post stamp, 1945

Pneumatic post or pneumatic mail is a system to deliver letters through pressurized air tubes. It was invented by the Scottish engineer William Murdoch in the 1800s and was later developed by the London Pneumatic Dispatch Company. Pneumatic post systems were used in several large cities starting in the second half of the 19th century (including an 1866 London system powerful enough to transport humans)[2], but were largely abandoned during the 20th century.

It was also speculated that a system of tubes might deliver mail to every home in the US. A major network of tubes in Paris was in use until 1984, when it was finally abandoned in favor of computers and fax machines. In Prague, Czech Republic, a network of approximately 60 kilometers for delivering mail and parcels still exists. However, due to damage sustained during the 2002 European floods the service has been put on indefinite hold.

Typical current applications are in banks and hospitals. Many large retailers use pneumatic tubes to transport cheques or other documents from cashiers to the accounting office. One system lists a speed of 10 meters per second. [1]

Pneumatic post stations usually connected post offices, stock exchanges, banks and ministries. Italy was the only country to issue postage stamps (between 1913 and 1966) specifically for pneumatic post. Austria, France, and Germany issued postal stationery for pneumatic use.

[edit] Historical use

  • 1853: linking the London Stock Exchange to the city's main telegraph station (a distance of 220 yards)
  • 1865: in Berlin (until 1976), the Rohrpost, a system 400 kilometers in total length at its peak in 1940
  • 1866: in Paris (until 1984, 467 kilometers in total length from 1934)
  • 1875: in Vienna (until 1956)
  • 1887: in Prague (until 2002 due to flooding), the Prague pneumatic post, [2]
  • 1897: in New York City (until 1953)
  • other cities: Munich, Rio de Janeiro, Hamburg, Rome, Naples, Milan, Marseilles, Melbourne, Boston, New York City, Philadelphia, Chicago, St. Louis

[edit] For transportation

(Pneumatic Transportation here in general refers to the transporting of people inside pneumatic tubes.)

In 1812, George Medhurst first proposed, but never implemented, blowing passenger carriages through a tunnel.

Atmospheric railways, on which the tube was laid between the rails, with a piston running in it suspended from the train through a sealable slot in the top of the tube, were operated as follows:[3]

In 1861, the Pneumatic Despatch Company built a system large enough to move a person, although it was intended for parcels. The October 10, 1865 inauguration of the new HolbornDuke of Buckingham, the chairman, and some of the directors of the company blown through the tube to Euston (a five minute trip). Station was marked by having the

The 550-meter Crystal Palace pneumatic railway was exhibited at the Crystal Palace in 1864. This was a prototype for a proposed Whitehall Pneumatic Railway that would have run under the River Thames linking Waterloo and Charing Cross. Digging commenced in 1865 but was halted in 1868 due to financial problems.

Alfred Ely Beach's experimental pneumatic elevated subway on display in 1867

In 1867 at the American Institute exhibition in New York, Alfred Ely Beach demonstrated a 32.6 m long, 1.8 m diameter pipe that was capable of moving 12 passengers plus a conductor. In 1869, the Beach Pneumatic Transit Company of New York constructed in secret a 95 m long, 2.7 m diameter pneumatic subway line under Broadway. The line only operated for a few months, closing after Beach was unsuccessful in getting permission to extend it.

In the 1960s, Lockheed and MIT with the United States Department of Commerce conducted feasibility studies on a vactrain system powered by ambient atmospheric pressure and "gravitational pendulum assist" to connect cities on the East Coast of the US. They calculated that the run between Philadelphia and New York City would average 174 meters per second, that is 626 km/h (388 mph).

When those plans were abandoned as too expensive, Lockheed engineer L.K. Edwards founded Tube Transit, Inc. to develop technology based on "gravity-vacuum transportation". In 1967 he proposed a Bay Area Gravity-Vacuum Transit for California that would run alongside the then-under construction BART system. It was never built.

[edit] Current usage

The technology is still used on a smaller scale. In North America, a large number of drive-up banks use pneumatic tubes to transport cash and documents between cars and tellers. Most hospitals have a computer-controlled pneumatic tube system to deliver drugs, documents and specimens to and from laboratories and nurses' stations. Many factories use them to deliver parts quickly across large campuses. Many larger stores use systems to securely transport excess cash from checkout stands to back offices, and to send change back to cashiers. NASA's original Mission Control Center in Houston, Texas had pneumatic tubes connecting controller consoles with staff support rooms. Denver International Airport is noteworthy for the large number of pneumatic tube systems, including a 25 cm diameter system for moving aircraft parts to remote concourses, a 10 cm system for United Airlines ticketing, and a robust system in the parking toll collection system with an outlet at every booth.

[edit] In fiction

The pneumatic tube train from Albert Robida's The Twentieth Century.

When pneumatic tubes first came into use in the 19th century, they symbolized technological progress and it was imagined that they would be common in the future. Jules Verne's Paris in the 20th Century (1863) includes suspended pneumatic tube trains that stretch across the oceans. Albert Robida's The Twentieth Century (1882) describes a 1950s Paris where tube trains have replaced railways, pneumatic mail is ubiquitous, and catering companies compete to deliver meals on tap to people's homes through pneumatic tubes. Edward Bellamy's Looking Backward (1888) envisions the world of 2000 as interlinked with tubes for delivering goods. Michel Verne's An Express of the Future (1888) questions the sensibility of a transatlanticsubway. In Michel & Jules Verne's The Day of an American Journalist in 2889aero-trains and the Society for Supplying Food to the Home allows subscribers to receive meals pneumatically. pneumatic (1889) submarine tubes carry people faster than

Later, because of their use by governments and large businesses, tubes began to symbolize bureaucracy. In George Orwell's Nineteen Eighty-Four, pneumatic tubes in the Ministry of Truth deliver newspapers to Winston's desk containing articles to be "rectified". The movie Brazil, which has similar themes, also used tubes (as well as other by 1985 anachronistic-seeming technologies) to evoke the stagnation of bureaucracy. At the start of each episode of the 1999 television series Fantasy Island, a darker version of the original, bookings for would-be visitors to the Island were sent to the devilish Mr. Roarke via a pneumatic tube from a dusty old travel agency, making the tube seem not so much bureaucratic as sinister.

The failure of pneumatic tubes to live up to their potential as envisioned in previous centuries has placed them in the company of flying cars and dirigibles as ripe for ironic retro-futurism. The 1960s cartoon series The Jetsons featured pneumatic tubes that people could step into and be sucked up and swiftly spit out at their destination. In the animated television series Futurama, set in the 31st century, large pneumatic tubes are used in cities for transporting people, whilst smaller ones are used to transport mail. The tubes in Futurama are also used to depict the endless confusion of bureaucracy: an immense network of pneumatic tubes connects all offices in New New York City to the "Central Bureaucracy", with all the capsules being deposited directly into a huge pile in the main filing room, with no sorting or organisation.

[edit] See also

[edit] References

  1. ^ Buxton, Andrew (2004). Cash Carriers in Shops. Princes Risborough: Shire Publications. ISBN 978-07478-0615-8.
  2. ^ NEW YORK’S SECRET SUBWAY - American Heritage
  3. ^ Hadfield, Charles (1967). Atmospheric Railways. Newton Abbot: David & Charles. ISBN 0-7153-4107-3.

[edit] External links

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Posted by muhyi at 5:43 AM

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