The Pneumatic Post

It was envisaged in 17th century by Denis Papin, French physicist and mathematician who also invented the pressure cooker. Two centuries later the idea has been materialized by the Scottish engineer William Murdoch in the 19th century and was later developed by the London Pneumatic Dispatch Company. In 1859 Thomas Webster Rammell and Latimer Clark proposed the development of an underground tube network within central London "for the more speedy and convenient circulation of despatches and parcels". It seems the engineers had aspirations for the system to eventually transport all kinds of general freight, and passengers. The company initially raised £25,000 in order to test the technology and construct a pilot route. Early experiments were conducted at the Soho works of Boulton and Watt in Birmingham.
A permanent line was constructed between the Euston station of the London and North Western Railway (beneath platform one), and the North West District Post Office in Eversholt Street (1/3 mile), using a 30 inch diameter tube and similar technology to that tested at Battersea. The line was tested from 15th January 1863, and put into operation on 20th February 1863. A single capsule, conveying up to 35 bags of mail could make the short journey between terminals in one minute, twice the speed of mailcarts. 13 journeys were operated each day, with a daily operating cost of £1 4s 5d. The Post Office were charged a nominal fee for use of the service, presumably to encourage them to accept the technology.
Construction was re-started in 1868, when additional finance was found for the route, and it was completed to Newgate Street in 1869. The Newgate Street terminus was 1,658 yards from Holborn and 4,738 yards from Euston. The journey time from the General Post Office was 17 minutes, at speeds of up to 60 mph.
The company obtained further powers to construct additional routes in London from Parliament in August 1872.
At the beginning of 1874 the Post Office agreed to use the system for traffic from the Central Post Office to Euston. However it found only a 4 minute time saving to be achieved, and doubted the system's reliability or ability to convey heavier loads. In October 1874 the Post Office informed the company that there was no long term prospect of Post Office traffic on the system, and the system was shut.
The tubes were retained for at least 20 years, while the Post Office considered electric traction. The company was restored in 1895, in the belief that the Post Office would wish to use the old tunnels. Finally, the tunnels were purchased by the Post Office in 1921, to run telephone cables in... No wonder that in "Double or Die" by Charlie Higson the young James Bond travels down to the London docks on a disused underground pneumatic railway!
If in London there was only a talk about pneumatic passenger service, in New York such service was pretty close to realization. In January 1867, the Scientific American edited by Alfred Ely Beach ran a frontpage article describing the London parcel tube system and proposing the same thing for New York. This was still for small tubes, for mail and packages. It was later that month that the Senate Select Committee reported in favor of underground passenger railways, if the problem of motive power could be solved.
For the upcoming exhibition of the American Institute, Beach financed two demonstrations of pneumatic dispatch, one of which was large enough for passengers to ride in. The fair ran from September 12 to October 26, 1867. Shortly before the start of the fair, the Times predicted some startling novelties, among them a great pneumatic tube, through which the adventurous will be carried north and south according to the fancy or advice of their physicians.
In October the Scientific Americcan related that the exhibition may now be said to have reached its full glory … The most novel and attractive feature of the exhibition is by general consent conceded to be the Pneumatic Railway, erected by Mr A E Beach, of the Scientific American, and everyone visiting the Fair seems to consider himself specially called upon to visit, and, after actual experience, to pronounce his verdict upon this mode of traveling.
It was a 32.6 m long, 1.8 m diameter pipe that was capable of moving 12 passengers plus a conductor.
Beach published a promotional booklet in January 1868 called The Pneumatic Dispatch. Despite the title it covered both small dispatch tubes and larger passenger railways. The two English pneumatic railways were the models from which he was working. He credited Rammell for the concept of the entire car running in a pneumatic tube. This was what Beach wanted to do. The Rammell patents left many details of design and machinery to be developed, improved, and patented, by Beach and others.
In 1869, the Beach Pneumatic Transit Company of New York secretly constructed a 95 m long, 2.7 m diameter pneumatic subway line under Broadway, to demonstrate the possibilities of the new transport mode. The line only operated for a few months, closing after Beach was unsuccessful in getting permission to extend it - Boss Tweed, an immensely powerful local politician, did not want it to go ahead as he was intending to personally invest into competing schemes for an elevated rail line.
Of course, Beach had his own idea of an elevated:
There were other projects, too:
But the NY elevated was built in a more conventional manner. In the meanwhile, less sensational technology conquered cities and continents: the telegraph conveyor, that became the ultimate instrument of in-city express mail service. In London, it was operated since 1853, i.e. ten years before the Pneumatic Despatch inauguration. The system conveyed messages which had been transcribed from the telegraph. Mr Josiah Latimer Clark (future companion of Rammell) installed 675ft of 1 1/2 inch diameter tube, with messages conveyed in felt bags by pressure differentials generated by a single 6 horse power (hp) engine.
In 1858 the Electric and International Telegraph Company built another tube 3,120 ft long with a diameter of 2 1/4 inches, to an unknown location within London. Other tubes followed. By 1860 the Electric and International Telegraph Company systems had linked their central office in Lothbury with stations at the stock exchange, and at Cornhill. Systems were also installed outside of London, for example, that installed by Mr C. A. Varley in July 1864 in Liverpool.
Continental cities quickly followed suit: in 1865, the Rohrpost (tube mail) was inaugurated in Berlin, in 1866 in Paris, in 1867 in Vienna, in 1887 in Prague.
Parisian Pneumatique deserves a special attention: in the 20th century it became the world's largest with 467 kilometers in total length. The network was commenced by the construction of an experimental line between the telegraph offices at Grand Hotel and place de la Bourse.
Until 1898, the use of official stationary was obligatory - blue cards with imprinted stamp and an inscription Télégramme or Carte-Télégramme (the service was operated by the State Telegraph). The customers could chose between regular and "closed" cards. The latter were double-folded with perforated and glued margins. There were also "Pneumatic envelopes", also with imprinted stamp, and reply-paid postcards (with double tariff, naturally). After the admissibility of private stationery in 1898, many Parisian printers produced light weight envelopes inscribed 'Télégramme Pneumatique' or 'Service Pneumatique'.
For generations the pneumatic letter-card was known affectionately as the petit bleu since it was on blue paper and it was under this name that a 'Télégramme' was a vital piece of evidence in the enquiries which led to the eventual acquittal of Dreyfus. At a court-martial in December 1894 he had been found guilty of passing military secrets to the Germans and was transported to Cayenne. In 1896 the contents of a waste paper basket in the office of Schwartzkoppen, the German military attache in Paris, were taken to the French Intelligence Staff and found to include a torn-up pneu which had never been sent.
When pieced together, it was found that the petit bleu contained a message to another French officer, Esterhazy, implicating him in the offences attributed to Dreyfus. Thus started the chain of events which culminated in 1906 with the ceremonial restoration of his commission to Dreyfus.
Marseille also had its Pneumatique with special stationery:
Berlin tube network was the brainchild of Postmaster General Heinrich von Stephan who was also the Universal Postal Union founder. The Rohrpost was made available to the public in 1876 (before that it delivered only telegrams between the General Post Office and Stock Exchange). In 1900 it had 118 km in total length, connecting 15 post offices and delivering more than 6 million messagesand small parcels annually.
Tube mail was also introduced in Munich, Hamburg, Stuttgart, Frankfurt/Main, Dusseldorf and Chemnitz.
In Vienna, the pneumatic mail was opened to the public in 1875, beginning with modest 14 km line and expanding to 82,5 km in 1913. At its peak it connected 53 post offices, delivering 20,000 capsules per day.
Here's a letter from Serbia that made its final "leg" (between the main and the local post offices) by tube:
* * *
In New York the pneumatic mail service opened only in 1897, when both A E Beach and Boss Tweed were no more than a distant memory.
At the beginning of the 1890s Charles Emory Smith, a former newspaper editor and ambassador to Russia, was appointed Postmaster General. An $8 million pneumatic system was developed in major Eastern US cities. A 6 inch diameter, 3,000 foot long system was constructed in Philadelphia between 1892 and 1893, for the transport of mail between two post offices.
An 8 inch diameter line was added by Congress between 1897 and 1898, along with three new lines in New York and one in Boston. The lines allowed the movement of mail between post offices and neighbourhood post offices, and to railway terminals. In 1902 additional lines were added in New York and Chicago, with an additional lines in St Louis in 1906 taking the entire network to 63 miles of 'double tube'.
Canisters (capsules) containing up to 500 letters travelled at 30mph under the streets of a number of cities. By 1916 systems were in place in Boston (14 miles of tube), Chicago (20 miles), New York (55 miles), St Louis (4 miles) and Philadelphia (20 miles). Extensive use was made of some of the larger systems - typically a third of all first class letters passing through the New York mail system were distributed in part via pneumatic tubes.
In 1918 debate about the relative costs of different systems for moving mail came to the fore. A Congress committee found that use of the pneumatic tubes cost $17,000 per mile per annum, with rental charges for the tubes an 'exorbitant, unjustified and an extravagant waste of public funds'. This combined with the growth of the automobile and traffic control systems in major cities, marked the end of further development for the pneumatic mail networks. However, all but the Philadelphia system operated until the 1950s. In 1900 Charles Emory Smith had predicted that pneumatic tube systems would eventually link every household to the rest of the network. This dream was never to be realised; at least not yet...

Sources: Capsu.org, Beach Pneumatic by Joseph Brennan, The Pneumatic Post of Paris by J.D. Hayhurst O.B.E., Wikipedia, Wikimedia Commons, Library of Congress.

More stamps & stationery in our Tube Mail album. Browse it or enjoy the slideshow:

How does it work?" Let us see.
The best example is the tube system in the capital of Czech Republic. The Prague pneumatic post (Pražská potrubní pošta) is the world's last preserved municipal pneumatic post system. It is an underground system of metal tubes under the wider centre of Prague, totaling about 55 kilometres (34 mi) in length. Known as the Old Lady of Czech telecommunications, the system started service in 1889 and remained in use by the government, banks and the media until it was rendered inoperative by the August 2002 European floods. The current owner, Telefónica O2 Czech Republic gradually is repairing and conserving the system; due to limited funding the system remained inoperative as of March 2007.
The system initially was employed mainly for sending telegrams. Only three stations had been connected between the Prague post and the telegraph office as of 1901.
The system was established for those desiring to send a document fast. The document would be taken to the post office and rolled up into a metal capsule. The clerk would then drop the metal capsule down a hatch leading to a predestined location. After the clerk pressed a button, the capsule would be moved by compressed air along a network of tubes beneath the pavement.
The main growth of the network dates to the economically prosperous era of 1927–1932. In those years, new lanes were constructed and tens of thousands of capsules transported per month.
During the Prague Uprising (1945) the pneumatic post played a role in supplying the besieged building of the Czech radio. Below: a "tube" postcard mailed in occupied Prague, 1942.
In the late 1990s, the system was used by over 20 subscribers and operating at a loss, so kept rather for prestigious reasons. The traffic weakened gradually and the 2002 floods seriously damaged it, flooding 5 of the 11 underground engine rooms.
The lanes consist of steel pipes of 65 mm bore and wall thickness of 2.5–3 mm. The pipes are connected with tight couplers 14 cm long to ensure perfect coaxial alignment and then welded together, ensuring air-tightness. To prevent dispersion current from causing excess corrosion, ceramic insulators are inserted between the pipe segments at some places. Pipes buried underground are protected from the outside by a layer of fiberglass, wound around at increased temperature and coated with hot asphalt. The pipeline is typically buried under the Prague sidewalks 80–120 cm deep. Inside buildings and in the Prague trunk conduit network the pipes simply are coated with anti-corrosive paint.
The minimum bend radius is 250 cm for underground pipes, but 300 cm is the most commonly used radius. Inside buildings a bend radius as low as 200 cm is allowed. The bends are made of special annealed pipes at normal temperature, using a custom-made bender. A signaling cable is laid along with the pipe, enabling communication with the track components. The lane segments are equipped with dumb wells, where the pipeline can be opened and inspected, or a stuck capsule removed. For this purpose a heavier capsule can be sent at a pressure of up to 30 atm, knocking the stuck capsule out.
The current lane state was indicated by indicator lights on the lane's controller. Up to 10 packages in 30-second intervals could be sent on the same lane at once, although this was rarely used in practice.
When sending capsules to switched lanes, the capsules had to be sent out in a predefined order, as the switches could only be activated before commencing the transfer. The first capsule would be diverted, after which the switch would automatically slide back to its neutral position, sending the remaining capsules in the straight direction. Therefore, the capsule that was meant to branch off had to be sent first.
The system uses aluminium capsules measuring 48 mm in outer-diameter and 200 mm in length. On the rear end they are fitted with a plastic circlet, preventing friction against walls of the pipe and a soft plastic skirt, sealing air behind the capsule. The diameter of the rear circlet is 57 mm. The remaining 8 millimeters of the bore are sealed just by the skirt, allowing for excellent airtightness and low friction at the same time.
Each lane is equipped with a dedicated propulsion unit, consisting of an electrically-powered air pump. One pump can service at most 3 kilometers of pipeline, so it's necessary to use several pumps on longer lanes.
The pumps must be reversible, creating either pressure or vacuum. The pumps are connected to the pipes with tee-fittings. On both sides of the tee the pipe is equipped with switches activated by a passing capsule.

At first the pump is set to intake mode, pulling the capsule towards the tee. Before reaching it, the capsule hits the first switch, causing the pump to start reversing. Meanwhile the capsule reaches the tee-fitting. As it passes the tee, the pump is already fully reversed and starts to push the capsule away.

The older pumps were bladed, having a single blade, mounted eccentrically inside a 300 mm high cylinder. More recent pumps employ a rotating piston instead.

The capsules can be loaded with packages up to 5 cm in diameter and 30 cm in length. Their weight can be up to 3 kg. Generally these were rolled-up telegrams, but any package within the set limits could be transported.
The Prague pneumatic post network consists of five main lanes arranged in a star topology, fitted with switches and concentrators, and of subscriber's lines. Originally there were 16 subscriber's lines, but only 7 have been preserved up till today. A total of 24 pneumatic post stations remain today. The network crosses the river Vltava in three spots making use of bridges.
All the lanes converge to the main post office in Jindřišská st. Here all the packages were carefully recorded and from here the network was controlled and monitored. This is also the place where the packages were forwarded from one lane to another. The capsule was picked up from a receiving pocket by a member of the staff, recorded and inserted into the inlet of another lane.

Text & images: Wikipedia (EN)

After a Steampunk-flavored historic overview and an inevitable "How does it work?" article, it's time to concentrate on pneumatic communications of the Diesel Era and also on the part played by these glorious tubes in fiction, Utopian and Dystopian.
Here's an article from the Modern Mechanix, Apr. 1935:
New idea? Not so new: In Michel & Jules Verne's The Day of an American Journalist in 2889 (1889) the Society for Supplying Food to the Home allows subscribers to receive meals pneumatically. In the same story, submarine tubes carry people faster than aero-trains. Seven years earlier, in 1882, Albert Robida described 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, the author of Looking Backward (1888) envisioned the world of 2000 as interlinked with tubes for delivering goods.
Another article, published in the Modern Mechanics and Inventions (March 1931), warned us that "messenger boys are put out of business by pneumatic message carriers". Too bad, too sad - but why do I still see these poor boys on their scooters, delivering pizza... and messages, too, 7-24?
Pneumatic mail, doomed by the US Congressional committee, was quite busy in the States.
In Europe, it continued to grow. Look at 1930s pneumatic post terminal in London:
No wonder that in George Orwell's Nineteen Eighty-Four, newspapers are delivered to Winston Smith's desk by pneumatic tubes.
Paris Pneumatique, world's largest pneumatic mail system (467 km in total length), went through a major upgrade in 1931, receiving new capsules fitted with electric contacts:
In a sequence from the 1968 film Baisers volés (Stolen Kisses), François Truffaut shows the fast transportation of a letter through the underground pneumatic tubes system in Paris. (This scene was later parodied in The Simpsons episode "Marge Gets a Job"). Paris tube mail was closed only in 1984.
In Berlin, the Rohrpost continued to grow through 1940, reaching total length of 440 km:
It was damaged during WWII, suffered additional damage in course of Berlin Blockade (1948-1949) but continued to operate till 1955 in the Eastern part of the city and till 1963 in West Berlin.

December 1, 1951: Berliner Rohrpost still alive, celebrating its 75th birthday!
In Soviet Russia, pneumatic tubes installed in the main post offices of Moscow and Leningrad as well as in large government buildings and libraries, were used well into 1970s. It's interesting that Alexander Belyayev, the most prominent Russian sci-fi author of the Interbellum years, was very sceptical about the tube mail. In 1926, he wrote: "Pneumatic mail is more expensive, its capacity is limited, making it unfit for delivery of cheap bulk correspondence like newspapers, parcels, etc. City express mail is gradually replaced by the telephone, that also serves for telegram delivery. Even inside the post offices tube mail is considered less practical than a transporter (conveyor). "
In Italy, pneumatic mail was in use as late as in 1977. Special "Posta Pneumatica" stamps were issued before and after WWII:
Now back to the States. Do you know that every large and self-respecting US Navy warship had its own pneumatic mail system? Here's one aboard USS Midway (photographed by vovsun @ LJ):
During WWII, pneumatic tubes were used by the military as well by the US Weather Bureau and commercial bodies like railroads and Western Union. Three photographs from the Library of Congress vaults, 1942-1943:
Tube mail (often called PCP) is still used by banks, libraries and airports (most notably, the Denver International). But you can not send a postcard by tube from your post office.
Finally, to the future that never was. In 1985, the movie Brazil used tubes (as well as other anachronistic-seeming technologies) to evoke the stagnation of bureaucracy.other anachronistic-seeming technologies) to evoke the stagnation of bureaucracy. At the start of each episode of the 1998 television series Fantasy Island, a darker version of the original, bookings for would-be visitors to the Island were sent to Mr. Roarke via a pneumatic tube from a dusty old travel agency. 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. Ironic, but not pathetic. I believe it could still serve us today, much better than scooterboys. Is it so hard to develop a pizza that would fit in a capsule?

Wiki text used.