Pneumatic tubes(orcapsule pipelines,also known aspneumatic tube transportorPTT) are systems that propel cylindrical containers through networks oftubesbycompressed airor by partialvacuum.They are used for transporting solid objects, as opposed to conventional pipelines which transport fluids. In the late 19th and early 20th centuries, pneumatic tube networks gained acceptance in offices that needed to transport small, urgent packages, such as mail, other paperwork, or money, over relatively short distances, within a building or, at most, within a city. Some installations became quite complex, but have mostly been superseded. However, they have been further developed in the 21st century in places such as hospitals, to send blood samples and the like toclinical laboratoriesfor analysis.[1]

A small number of pneumatic transportation systems were built for larger cargo, to compete with train and subway systems. However, they never gained popularity.
History
editHistorical use
editPneumatic transportation was invented byWilliam Murdocharound 1799.[2]Capsule pipelineswere first used in theVictorian era,to transmittelegramsfrom telegraph stations to nearby buildings. The system is known as pneumatic dispatch.[3]
In 1854,Josiah Latimer Clarkwas issued a patent "for conveying letters or parcels between places by the pressure of air and vacuum". In 1853, he installed a 220-yard (200 m) pneumatic system between theLondon Stock ExchangeinThreadneedle Street,London, and the offices of theElectric Telegraph CompanyinLothbury.[3]The Electric Telegraph Company used the system to acquire stock prices and other financial information to pass to subscribers of their service over their telegraph wires. The advantage of the pneumatic system was that, without it, the company would have had to employ runners to carry messages between the two buildings, or else employ trained telegraph operators within the Stock Exchange. In the mid-1860s, the company installed similar systems to local stock exchanges in Liverpool, Birmingham, and Manchester.[4]After the telegraphs were nationalised in Britain, the pneumatic system continued to be expanded under Post Office Telegraphs. That expansion was due to Joseph William Willmot (previously employed at theElectric & International Telegraph Company) improving Latimer-Clark's invention in 1870 with the "double sluice pneumatic valve" and, in 1880, the "intermediate signaller/quick break switch for pneumatic tubes", which dramatically sped up the process, and made it possible for a number of carrier messages to be in the tube at any one time.[5]By 1880, there were over 21 miles (34 km) of tube in London.[6]A tube was laid between the Aberdeen fish market office and the main post office, to facilitate the rapid sale of the very perishable commodity.[7]
While they are commonly used for small parcels and documents, includingcash carriersatbanksorsupermarkets,[8]in the early 19th century, they were proposed for transport of heavy freight. It was once envisaged that networks of massive tubes might be used to transport people.[9]
Contemporary use
editThe technology is still used on a smaller scale. While its use for communicating information has been superseded by electronics, pneumatic tubes are widely used for transporting small objects, where convenience and speed in a local environment are important.[1]
In the United States, drive-up banks often used pneumatic tubes to transport cash and documents between cars and tellers; by the 2020s some of these have been removed, obviated by the rise of mobile banking apps and the increasing sophistication ofATMs.Many hospitals have a computer-controlled pneumatic tube system to deliver drugs, documents, and specimens to and from laboratories and nurses' stations.[1]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.[10]They are used in casinos to move money, chips, and cards quickly and securely. Japaneselove hotelsuse them to allow customers to settle bills anonymously (no face-to-face contact).[11]NASA's originalMission Control Centerhad pneumatic tubes connecting controller consoles with staff support rooms.Mission Operations Control Room 2,was last used in its original configuration in 1992 and then remodeled for other missions. Because the room was designated aNational Historic Landmarkin 1985, it was decided in 2017 to restore it to its 1960s condition.[12]The pneumatic tubes were removed and sent to theCosmospherein Kansas for restoration.[13]
Pneumatic tube systems have been used innuclear chemistryto transport samples duringneutron activation analysis.Samples must be moved from the nuclear reactor core, in which they are bombarded with neutrons, to the instrument that measures the resulting radiation. As some of the radioactive isotopes in the sample can have very short half-lives, speed is important. These systems may be automated, with a magazine of sample tubes that are moved into the reactor core in turn for a predetermined time, before being moved to the instrument station and finally to a container for storage and disposal.[14]
Until it closed in early 2011, aMcDonald'sinEdina, Minnesotaclaimed to be the "World's Only Pneumatic Air Drive-Thru," sending food from their strip-mall location to a drive-through in the middle of a parking lot.[15]
Technology editor Quentin Hardy noted renewed interest as of 2015[update]in transmission of data by pneumatic tube accompanied discussions of digital network security,[16]and he cited research into London's forgotten pneumatic network.[17]
Related applications includefish cannons[18]which use mechanisms very similar to pneumatic tube systems.
Applications
editIn postal service
editPneumatic postorpneumatic mailis a system to deliver letters through pressurized air tubes. It was invented by the Scottish engineerWilliam Murdochin the 19th century and was later developed by theLondon Pneumatic Despatch 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 and large enough to transport humans during trial runs – though not intended for that purpose),[19]but later were largely abandoned.
A major network of tubes inParis(theParis pneumatic post) was in use until 1984, when it was abandoned in favor of computers and fax machines. ThePrague pneumatic postcommenced for the public in 1889 inPrague,now in theCzech Republic,and the network extended approximately 60 kilometres (37 mi).
Pneumatic post stations usually connect post offices, stock exchanges, banks and ministries. Italy was the only country to issuepostage stamps(between 1913 and 1966) specifically for pneumatic post. Austria, France, and Germany issuedpostal stationeryfor pneumatic use.
Typical applications are inbanks,hospitals,andsupermarkets.Many large retailers used pneumatic tubes to transport cheques or other documents from cashiers to the accounting office.
- Historical use
- 1853: linking the London Stock Exchange to the city's main telegraph station (a distance of 220 yards (200 m) )
- 1861: in London with theLondon Pneumatic Despatch Companyproviding services fromEuston railway stationto theGeneral Post OfficeandHolborn
- 1864: inLiverpoolconnecting theElectric and International Telegraph Companytelegraph stations in Castle Street, Water Street, and the Exchange Buildings[20]
- 1864: inManchesterto connect theElectric and International Telegraph Companycentral offices at York Street, with branch offices at Dulcie Buildings and Mosley Street[21]
- 1865: inBirmingham,installed by theElectric and International Telegraph Companybetween the New Exchange Buildings in Stephenson Place and their branch office in Temple Buildings, New Street.[22]
- 1865: in Berlin (until 1976), theRohrpost,a system 400 kilometers in total length at its peak in 1940
- 1866: in Paris (until 1984, 467 kilometers in total length from 1934).John Steinbeckmentioned this system inThe Short Reign of Pippin IV:A Fabrication:"You pay no attention to the pneumatique."
- 1871: inDublin[23]
- 1875: in Vienna (until 1956) - including the unrealised corpse network of Zentralfriedhof[24]
- 1887: in Prague (until 2002 due to flooding), thePrague pneumatic post[25]
- 1893: the first North American system was established inPhiladelphiabyPostmaster GeneralJohn Wanamaker,who had previously employed the technology at hisdepartment store.The system, which initially connected the downtown post offices, was later extended to the principal railroad stations, the stock exchanges, and many private businesses. It was operated by theUnited States Post Office Departmentwhich later opened similar systems in cities such asNew York(connectingBrooklynandManhattan),Chicago,Boston,andSt. Louis.The last of these closed in 1953.[26]
- Other cities: Munich, Rio de Janeiro, Buenos Aires, Hamburg, Rome, Naples, Milan, Marseille, Melbourne, Tokyo, Osaka, Nagoya, Kobe,[27]Zurich, Lausanne, Geneva, Bern, Basel
- 1950s-1989:CIA headquarters(now known as the Old Headquarters Building)[29]
In public transportation
edit- 19th century
In 1812,George Medhurstfirst proposed, but never implemented, blowing passenger carriages through a tunnel.[30]Precursors of pneumatic tube systems for passenger transport, theatmospheric railway(for 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:[31]
- 1844–54:Dublin and Kingstown Railway'sDalkey Atmospheric Railwaybetween Kingstown (Dún Laoghaire) andDalkey,Ireland(1.75 mi [2.82 km])
- 1846–47:London and Croydon RailwaybetweenCroydonandNew Cross,London,England(7.5 mi [12.1 km])
- 1847–48:Isambard Kingdom Brunel'sSouth Devon RailwaybetweenExeterandNewton Abbot,England(20 mi [32 km])
- 1847–60:Paris–Saint-Germain railway between Bois de Vésinet andSaint-Germain-en-Laye,France(2 km [1.2 mi])
In 1861, theLondon Pneumatic Despatch Companybuilt a system large enough to move a person, although it was intended for parcels. The inauguration of the newHolbornStation on 10 October 1865 was marked by having theDuke of Buckingham,the chairman, and some company directors blown through the tube toEuston(a five-minute trip).
The 550-metre (1,804 ft)Crystal Palace pneumatic railwaywas exhibited atthe Crystal Palacein 1864. This was a prototype for a proposedWaterloo and Whitehall Railwaythat would have run under theRiver ThameslinkingWaterlooandCharing Cross.Digging commenced in 1865 but was halted in 1868 due to financial problems.
In 1867 at theAmerican Institute FairinNew York,Alfred Ely Beachdemonstrated a 100-foot (30 m) long, 6-foot (1.8 m) diameter pipe that was capable of moving 12 passengers plus a conductor.[32]One year afterNew York City's first-ever elevated rail linewent into service; in 1869, theBeach Pneumatic Transit Companyof New York secretly constructed a 312-foot (95 m) long, 8.9-foot (2.7 m) diameter pneumatic subway line underBroadway,to demonstrate the possibilities of the new transport mode.[32]The line only operated for a few months, closing after Beach was unsuccessful in getting permission to extend it –Boss Tweed,acorruptinfluential politician, did not want it to go ahead as he was intending to personally invest into competing schemes for an elevated rail line.[33]
- 20th century
In the 1920s, the Canadian Pacific and Canadian National Railways cooperated together to lay an elaborate system of 4,500 metre pneumatic tubing between four of their offices to Postal Station A at Union Station in Toronto, Canada. There was also a connection to the mail room at the Royal York Hotel. The newspapers the Star and Telegram joined into the system, laying pipes.[34] In the 1960s,LockheedandMITwith theUnited States Department of Commerceconducted feasibility studies on avactrainsystem powered by ambient atmospheric pressure and "gravitational pendulum assist" to connect cities on the country's East Coast.[32]They calculated that the run betweenPhiladelphiaandNew York Citywould average 174meters per second,that is 626 km/h (388 mph). When those plans were abandoned as too expensive, Lockheed engineerL.K. EdwardsfoundedTube Transit, Inc.to develop technology based on "gravity-vacuum transportation". In 1967 he proposed aBay Area Gravity-Vacuum TransitforCaliforniathat would run alongside the then-under constructionBARTsystem. It was never built.
- 21st century
Research into trains running in partially evacuated tubes, such as theVactrainandHyperloop,is continuing.
Pneumatic elevator
editA pneumatic elevator[1]consists of a cylindrical vertical shaft (typically made of transparent plastic), and a passenger capsule (also transparent) within the shaft which moves vertically by means of differential air pressure above and below. The main advantage that it requires neither a pit below or a loft above the shaft.
For ascending operations, a vacuum pump at the top of the elevator shaft creates a low pressure by drawing air from above the capsule while below the greater normal atmospheric pressure is permitted to enter at the lower (ground floor) level below the capsule providing lift.
To descend, electronically controlled valves inside the tubular shaft regulate the entry and exit of air within the cylinder lowering the car smoothly by means of programmed operation. In the event of a failure of the vacuum pump or electronically controlled valves, the trapped volume of air below the capsule acts as a cushion that is allowed to slowly escape by means of a mechanical valve, gently returning the capsule to the lowest level.
In money transfer
editIn large retail stores, pneumatic tube systems were used to transport sales slips and money from the salesperson to a centralized tube room, wherecashierscould make change, reference credit records, and so on.[35]
Many banks withdrive-throughsalso use pneumatic tubes.[8]
In medicine
editMany hospitals have pneumatic tube systems which sendsamplestolaboratories.[1][36]Blood preservations are transported, where weight and transport duration matter as well as preventing haemolysis caused by centrifugal and accelerating forces. Pneumatic tube systems are also used in hospitals to transportX-rays,patient documents, general documents, drugs and test results.
6-inch (152 mm) pneumatic tube systems have been shown to handle heavy liter-capacityIV bagswith significantly fewer jams compared to the 4-inch (102 mm) systems.
Department stores
editTo manage its mail order business the department store Sears built "massive warehouses, like its central facility in Chicago, in which messages to various departments and assembly workers were sent through pneumatic tubes".[37]Many other department stores had pneumatic tube systems in the 20th century, such as Jacksons of Reading and Myer in Melbourne, Australia. TheNational Library of Australia's building (opened 1968), incorporates a pneumatic tube system for sending book requests from the reading rooms to the book stacks. The system is no longer used, but remains partially operational, and is demonstrated on behind the scenes tours.
Waste disposal
editThe use of pneumatic tubes in waste disposal units include theMasjid al-Haram,Mecca,[38]GlashusEtt in the Hammarby Sjöstad area of Stockholm (Sweden), Old Montreal (Canada), Disney World (US) and Roosevelt Island and Hudson Yards (US).
In production
editPneumatic tube systems are used in production plants. Uses include conveying spare parts, measuring instruments, tools, or work pieces alongsideconveyor beltsor in the production process. In industrial laboratories samples are transported through the pneumatic tube systems. These can be conveyed in any physical state (solid, liquid, gas) and at any temperature. For example, the industrial companyThyssenKruppsends 900 °C (1,650 °F) steel samples through pneumatic tubes at a rate of 22 m (72 ft) per second from the furnace to the laboratory.[39]
Technical characteristics
editModern systems (for smaller, i.e. “normal”, tube diameters as used in the transport of small capsules) reach speeds of around 7.5 m (25 ft) per second, though some historical systems already achieved speeds of 10 m (33 ft) per second.[1][40]At the same time, varying air pressures allow capsules to brake slowly, removing the jarring arrival that used to characterise earlier systems and make them unsuitable for fragile contents.[1]
Very powerful systems can transport items with a weight of up to 50 kg (110 lb) and a diameter of up to 500 mm (20 in).[39]More than 100 lines and 1000 stations can be connected.
Further, modern systems can be computer-controlled for tracking of any specific capsule and managing priority deliveries as well as system efficiency. With this technology, time-critical items can be transported, such astissue samplestaken during asurgeryin a hospital.RFID chipswithin the capsules gather data – e. g. about the location of the carrier, its transport speed or its destination.[41]The systems collect and save these data to help users optimize their internal processes and turnaround times. The facilities can be linked to the company's software systems, e.g. laboratory information systems, for full integration into company logistical management and production chains.
See also
edit- Automated vacuum collection
- C1 Espresso
- Lamson Engineering Company Ltd
- Pipeline transport
- Prague pneumatic post,the world's last preserved pneumatic mail system
- Vactrain
- Cash carrier
References
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- ^Horst O. Hardenberg, The Middle Ages of the I.C. engine (Warrendale, 1999, 41)
- ^ab"Pneumatic Networks".Museum of Retrotechnology. 23 July 2008.Retrieved4 January2016.
- ^Kieve, Jeffrey L.,The Electric Telegraph: A Social and Economic History,p. 82, David and Charles, 1973OCLC655205099.
- ^"How has pneumatic tube transport changed over the years?".air-log.Retrieved2022-10-10.
- ^Kieve, p. 235
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- ^abBuxton, Andrew (2004).Cash Carriers in Shops.Princes Risborough: Shire Publications.ISBN978-0-7478-0615-8.
- ^Edwards, Phil (2015-06-24)."The golden era of the pneumatic tube — when it carried fast food, people, and cats".Vox.Retrieved2023-12-29.
- ^Woodford, Chris(8 October 2010)."How pneumatic tube transport works".Explain that Stuff.Retrieved2020-05-27.
- ^Janell L. Carroll,Sexuality Now: Embracing Diversity,p. 248, Cengage Learning, 2015ISBN1305446038.
- ^"The historic Apollo Mission Control Center will be restored",Round Up Reads,NASAJohnson Space Center,29 November 2017, retrieved and archived 3 November 2021.
- ^Sandra Jones,"Five things to know about the restoration of the Apollo MCC",Round Up Reads,NASA Johnson Space Center, 16 April 2018, retrieved and archived 3 November 2021.
- ^Becker, D.A. (22 June 1998)."Characterization and use of the new NIST rapid pneumatic tube irradiation facility".Journal of Radioanalytical and Nuclear Chemistry.233(1–2):155–160.Bibcode:1998JRNC..233..155B.doi:10.1007/bf02389664.S2CID95502740.
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- ^Hardy, Quentin (March 6, 2015)."The Mechanical World".What We're Reading.The New York Times.RetrievedMarch 7,2015.
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- ^Kirby, David (2014-09-24)."Watch This 'Salmon Cannon' Shoot Endangered Fish Through a Tube—to Save Them".TakePart.Archived fromthe originalon 2014-09-26.Retrieved2020-08-05.
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- ^"Pneumatics applied to Telegraphy".Cumberland and Westmorland Advertiser, and Penrith Literary Chronicle.England. 13 December 1864.Retrieved14 February2016– viaBritish Newspaper Archive.
- ^"The Pneumatic Desptach System".Birmingham Daily Gazette.England. 1 March 1865.Retrieved14 February2016– viaBritish Newspaper Archive.
- ^"Postal Telegraph in Ireland".Clare Journal,and Ennis Advertiser.Ireland. 23 February 1871.Retrieved14 February2016– viaBritish Newspaper Archive.
- ^Austrian Philatelic Society."The Vienna Pneumatic Post".austrianphilately.Retrieved13 November2023.
- ^"Prague's pneumatic post".Telefónica O2 Czech Republic.2002. Archived fromthe originalon 2010-01-09.Retrieved12 February2010.
- ^Kyriakodis, Harry (11 April 2014)."Pneumatic Philadelphia".Hidden City Philadelphia.
- ^Bush, Charles (April 2017). "Letters in a Tube: the Rise and Demise of Pneumatic Mail".History Magazine.18(4): 33.
- ^Rachele Delucchi (2020).Nischenangelegenheit - Zur Geschichte der Stadtrohrpost in der Schweiz (ca. 1920-1927)(PDF).Zürich: ETH Zürich.
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- ^George Medhurst(1812).Calculations and Remarks, Tending to Prove the Practicability, Effects and Advantages of a Plan for the Rapid Conveyance of Goods and Passengers: Upon an Iron Road Through a Tube of 30 Feet in Area, by the Power and Velocity of Air.London, England: D.N. Shury.OCLC1000841084.
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{{cite magazine}}
:CS1 maint: multiple names: authors list (link) - ^abSchreibelmayer, Stefan (24 October 2012)."Hörtig schaut (gar nicht) in die Röhre".Wirtschaftsmagazin(in German). No.10–2012. Nordbayerischer Kurier. p. 11.Retrieved11 July2018.
- ^"Capsule Pipelines – Mainland Europe".Capsu.org website.Archived fromthe originalon 11 January 2010.Retrieved12 February2010.
- ^Fleet, Nadja (21 August 2017)."New Royal Adelaide Hospital: Futuristic NRAH features robots, state-of-the-art hi-tech equipment".The Advertiser.Retrieved11 July2018.
- M. Marcu-Pipeline conveyors(pneumatic wheeled pipeline conveyors-state of the art/photos-1990) at page 45 in the "Material handling in pyrometallurgy": proceedings of the International Symposium on Materials Handling in Pyrometallurgy, Hamilton, Ontario, August 26–30, 1990
- Twigge-Molecey, T. Price, Metallurgical Society of CIM. Non-Ferrous Pyrometallurgy Section Pergamon Press, Sep 30, 1990 - Technology & Engineering - 227 pages
Further reading
edit- Archibald Williams, "Pneumatic Mail Tubes", inThe Romance of Modern Mechanism,Philadelphia: Lippincott, 1907. Reprinted by Nabu Press, 2010.ISBN1-146-99537-7.
External links
edit- Site describing Pneumatic Trash and Linen Systems, with photos
- Describes Paris pneumatic post, also mentions others
- "Dial Switches Message Tubes"1951 article that describes with photos and drawing the basics of how the system operates
- Site describing pneumatic post systems in England, France, Berlin, the US, and Prague, with photos
- Article describing the pneumatic post system in Prague
- Pneumatic mail articlefrom the U.S.National Postal Museum
- The pneumatic dispatch...(1868) by Alfred Beach (scanned pages)
- Beach PneumaticAlfred Beach's Pneumatic Subway and the beginnings of rapid transit in New York
- Futuristics: Pneumatic Transportation(contains historical illustrations)
- Capsule Pipelines:good historical information, original author of info found on "capsu.org" pages.
- Pneumatic Tube System - How it works
- Cash Railway Website:pneumatic tubes used for cash handling in shops