In the white heat of the Victorian age a number of motive powers seemed set to vie for the future. Steam power? Cable? Both were relatively new technologies whose potential seemed endless. Briefly in the 1860s, however, it seemed destined to some that the era we now know as the Steam Age would actually be known as something else – the Pneumatic Age.

To understand how pneumatic traction came to make a mark on London one must first understand its rivals. For whilst with hindsight the supremacy of steam seems preordained, at the time it was by no means guaranteed. No motive mode had yet established superiority or supremacy and the field was still wide open.

Steam traction had a long gestation period and was a maturing technology, but it was also dirty and noisy. It was reliable enough, however, for investors and they funded the mid-century railway mania led to lines all over Great Britain.

Cable traction meanwhile was used in London in 1837 on part of the Euston to Birmingham railway line as well as on the London and Blackwall Railway trains from 1840 to 1848, but the ropes had continuing problems with twisting. In both cases steam traction soon replaced cable haulage.

Cable traction was also used for the short-lived Tower Subway, which was soon converted to a walking tunnel under the Thames and was also initially planned for the City of London and Southwark Subway into King William Street Station, but the rope of the day was not up to the greater forces required thanks to the gradient. The line subsequently opened as the City and South London Railway and used electric locomotives. As a result of this, the gradient would even prove to be problematic when the line was converted to the then-new electric traction, as fully laden electric trains sometimes had to make two or three attempts to climb into King William Street.

Practical Pneumatics Invented

Ce qu’il y a sous le pavé de Londres (Under the pavement of London: top to bottom – gas pipe (small diameter), water pipe (large diameter), Pneumatic Despatch Railway and car, Metropolitan railway tunnel and train.

The principle of air propulsion was first recorded by Hero of Alexandria in his Pneumatics in the second century BC, the Greek root pneuma being the spirit of invisible and almost weightless air. Pneumatic tubes for conveyance of paper and objects were suggested by Frenchman Denis Papin in 1667, and in 1810 London businessman George Medhurst published a paper on ‘conveying letters and goods by air’. Around this time, Medhurst sought financing for three distinct forms of air-propelled transport – a pneumatic tube for transport of capsules, a larger scale tube to carry passengers or freight, then a piston within the pipe moved by air pressure, dragging along a vehicle outside it (later known as an atmospheric railway). Unfortunately he would not see any of them implemented in his lifetime as he could not raise the capital to implement his ideas, but all of them were developed and saw at least experimental trials in the coming decades, being realised in the reverse order of their invention.

Practical pneumatic despatch of objects however was developed by engineer William Murdoch in the 1830’s. These were tubes a few inches in diameter, designed to carry small, light items like letters in cylinders, blown or sucked by steam powered higher or lower air pressures respectively. In 1836 he demonstrated a working, small scale fast delivery message system, but that did not interest investors either.

Initial Experiments in Atmospheric Railways

Building upon George Medhurst’s last proposal, a number of individuals developed functioning atmospheric railway propulsion systems from the 1820’s to the 1840’s, notably the London & Croydon in 1846 and Isambard Kingdom Brunel’s 1847 South Devon Railway in Exeter. However this branch of pneumatic motive power was a technological dead end and will be shunted off to a separate article.

Pneumatics Supplement the Electric Telegraph

The first half of the 19th century saw the introduction of the electric telegraph, principally used for business on the stock exchanges for advance information and hence fortune, but the gain in speed from the telegraph could be lost if a message took a long time to be transcribed then sent by hand from the telegraph office to the Stock Exchange.

To avoid this delay that engineer J. Latimer Clark, using Murdoch’s pioneering ideas, designed and installed in 1853 the world’s first commerial pneumatic message tube using cylindrical carriers, between the London Stock Exchange on Threadneedle Street with the Electrical and International Telegraph Station 220 yards away on Lothbury Street. The evolution and success of this technology is explored over on our sister site, Lapsed Historian, in Get Him on the Blower – London’s Lost Pneumatic Messaging Network. By 1897, London’s pneumatic tube network included 42 stations and covered 34 miles. Similar systems were installed in Manchester, Birmingham, Dublin, Glasgow, Liverpool, and Newcastle, as well as in Paris, Berlin and New York. Such tubes were seen as essential for effective communication in any large city.

Based on these successful pneumatic tube developments, the Secretary to the Post Office Rowland Hill (noted for his successful postal reform and Penny Black 1d stamp in 1840) in 1855 commissioned two engineers (Gregory and Cowper) to investigate the possibility of constructing a larger pneumatic tube, up to 15 inch in diameter, to convey more substantial mail loads and parcels underground between the General Post Office and the future site of their West Central District Office (WCDO) at Little Queen Street and Holborn. They reported in 1856 that such a line was possible but at significant capital and running costs, so the Post Office dropped the idea.

London Pneumatic Despatch Company Formed

Whilst the Post Office dropped the pneumatic parcel tube idea, two men didn’t – engineers Thomas Webster Rammell and the same Latimer Clark. Both were part of the group that incorporated the Pneumatic Despatch Company Ltd. in June 1859 to build an underground pneumatic tube railway of an even larger diameter. This was a step up in scale, and would use air to propel small railcars (as the cylinders) in tunnels to carry standard mail bags and small parcels between main railway termini and post offices. A stationary steam engine turning a reversible fan would blow or suck the cars along.

The Company was a powerful one, the board being headed by Richard Temple-Nugent-Brydges-Chandos-Grenville, 3rd Duke of Buckingham and Chandos (and son of the 2nd Duke who featured in the London Reconnections 2014 Christmas Quiz), a close friend of Benjamin Disraeli (soon to be Chancellor of the Exchequer and then Prime Minister), and included William Henry Smith (who ran railway bookstalls) and Thomas Brassey, an engineer and key player in the era’s “railway mania”. One of the notable engineers that supported the venture was Robert Stephenson, but he had no known engineering or operational role, and he died within four months of the company being incorporated.

By that time railways were the main form of mail distribution across the country, but the railway termini in London were often not at the same locations as the postal sorting office (the latter being constructed in the day of the mail coach). The Pneumatic Despatch railway was to be the missing connector.

The Company’s plan was also for key government buildings – like Parliament, India House, Custom House, the Tower of London, the Royal Mint and the Bank of England, as well as commercial enterprises like the Stock Exchange – to all be linked up, and that the government and companies would pay well for the expedited and secure service. Rammell’s 1858 map shows where he planned the Pneumatic Despatch Railway to originally and eventually run, linking Paddington, Waterloo, London Bridge, Charing Cross and Victoria.

Rammell’s 1858 map of original Pneumatic Despatch Railway routes and terminii (Credit: Royal Mail Group Ltd. 2013, courtesy BPMA)

In 1859 the Company obtained the necessary Act of Parliament to dig up roads and lay down tubes, and raised £25,000 to construct a pilot route.

Prototype and Trials

The first pneumatic railway trial was conducted successfully at the Boulton and Watt manufactory in Birmingham in about 1860. After this success, nine foot cast iron pipe segments of a tube 2ft 9in high, 2ft 6in wide in a railway tunnel cross-section was manufactured by the Staveley Coal and Iron Co. works in Derbyshire. A century later the castings for the Victoria Line tube were made at these same works, which were shortly to become part of the Tubes Division of British Steel.

The first working pneumatic railway prototype was tested in 1861 on land owned by Vauxhall Waterworks and the London Brighton & South Coast Railway at Battersea (Nine Elms). The cast iron segments were joined to create a quarter mile long tube on the surface, with curves up to 300 foot in radius and gradients up to 1 in 22 to simulate the expected underground line profile.

Battersea Fields Pneumatic Despatch Railway testing [WikiFree]

Motive power was provided by a 30 horse-power engine with a massive 21 foot diameter fan providing pressures of 1 to 6 oz/sq inch. The tube contained 2 ft gauge track upon which the 3 ton 8 ft 4 in long cars ran, which fit the tunnel to within an inch all around, and had indiarubber flanges to create an airtight seal. It was hoped that this would provide a tighter seal than the atmospheric railways of the 1840’s, and the test runs achieved speeds of up to 40 mph. The cars resembled the shape and colours of 1930’s tubular but bull-nosed racing cars. Weights simulating mail and even human passengers were successfully sent through it. The system was deemed a success, and plans to build the underground parcels railway (as it was also known) were put into action.



First Operational Pneumatic Railway Tunnel

The tube cast-iron sections and steam pump were reused from the Battersea trial and laid from the sorting room at the North West District Office, under Eversholt Street to beneath platform one at Euston Station a third of a mile to the south, with additional cast-iron sections ordered.

Wills’ Cigarettes Inauguration of Pneumatic Tube (Credit: Royal Mail Group Ltd. 2013, courtesy BPMA)

This first operational tunnel was tested from January 17, 1863, and following inspection by the Post Office the first mail was carried on February 20, 1863. Two or three cars could carry up to 14 tonnes equivalent of mail at an average speed of 30mph – more than twice as fast as the 12mph trains on the brand new Paddington-Farringdon Underground line that had opened just a month before. In fact the London Pneumatic Despatch Railway was the second underground railway in the world, albeit not in passenger carrying revenue operation.

Mouth of First Pneumatic Railway Tunnel (Credit: IanVisits)

Many local notables and visitors made the journey in the Pneumatic Dispatch Company tunnel, including Prince Napoleon, son of Napoleon III. Most of the tunnel was just under the road surface so horse hooves and vehicles could be heard, such that repeat passengers could tell what corner they were at and the streets above at any moment.

The tunnel air was cool, clean and fresh even on the hottest summer’s day. And there was no vibration, jolting or dangerous steam, and very little chance of collision, so the potential for this new motive power seemed large, and hopes were high.

The Times of February 10th, 1863 wrote:

Between the pneumatic dispatch and the subterranean railway the days ought to be fast approaching when the ponderous goods vans which now ply between station and station shall disappear for ever from the streets of London.

The London Journal of the time added:

Not only have letters and parcels been transmitted, through the tube but we hear also that a lady, whose courage or rashness – we know not which to call it – astonished all spectators, was actually shot the whole length of the tube, crinoline and all, without injury to person or petticoat.

The service which started on 20 February 1863 included 13 trips each day, with a daily operating cost of £1 4s 5d. The rail car conveying up to 35 bags of mail made the short journey in one minute. The testing process continued until some 4,000 journeys had been made with little delay or incident. The Company estimated that five times the number of trains could have been run without incurring appreciable additional expense.

First Dispatch of Mailbags from Eversholt [WikiFree]

The Post Office was charged a nominal carriage fee to encourage them to trial the line – priced to be equivalent to the cost of sending the mail bags by cab. At the time the Company believed that the Post Office was satisfied with the Railway’s operations.

This first pneumatic railway tube’s life would not prove to be a long one, with its last run coming in October 1866, just after the financial crisis of May 1866 that was initiated by a London bank failure that kicked off an international financial downturn. La plus ça change. By the time the economy recovered in 1868 the Post Office had realised that the tube didn’t provide significant time savings due to access times and transfer of mail bags at each terminal, so they declined to enter into an agreement to restore it to operation.

Even though this initial line was under-powered and leaked air, however, it had at least shown commercial potential. Construction was soon proceeding on a second pneumatic railway tunnel line as the Pneumatic Despatch Company sought to develop further lines within London, attempting to raise an additional £125,000 (£10M in 2014), of capital after the economy recovered and the resumption of lower interest rates.

Second Pneumatic Railway Tunnel

When work began on the first pneumatic railway in 1863, construction had actually started concurrently on a larger 3ft 8 1⁄2in narrow gauge line in a side by side pair of 4ft 6in by 4ft 1in tunnels, one for up traffic, the other for down, from Euston to Holborn. Straight portions of the tunnel were constructed of 9 foot long cast iron sections, similar in profile but larger than the first tube’s, and the bends were built of brick. The steam power was located at the central station in Holborn.

The first section of this second tunnel started at the Arrival Parcels Office of Euston Station, proceeded under platforms 1 and 2, then ran south under platform 3. At the southern end it turned west under Drummond Street then south on Hampstead Road. The route unfortunately had to take a dog-leg detour down Tottenham Court Road as the Duke of Bedford, who owned most of the land between Euston and Holborn, refused the Pneumatic Despatch Company permission to disrupt his streets. The line proceeded from Tottenham Court Road until New Oxford Street, and under Holborn.

Map of the Pneumatic Despatch Railway route (Credit: Derek Bayliss)

When this second tube opened in October 1865, London’s political and business class turned out at Holborn station to watch the first mail bags arrive from Euston. The Pneumatic Despatch Railway, just two years after the surprisingly successful Metropolitan underground railway, looked like The Next Big Thing.

Note the two gents in the first car (Credit: IanVisits)

Train of Cars Holborn (Credit: IanVisits)

The second section of this second pneumatic tunnel also started construction in 1865 from Holborn, dropping down under the Viaduct and Farringdon Street, Newgate Street to Gresham Street via the General Post Office on St Martin’s le Grand. By the time of the 1866 financial crisis, a ⅜ mile tube from Holborn to Hatton Garden had been constructed. Construction restarted in 1868 after the financial crisis passed, and the tube was completed to St. Martin’s le Grand for the General Post Office in 1869. Telegraph wires were run inside the tunnel to the three stations, Euston, Holborn and the GPO to signal dispatch of a mail car. The journey time between Euston and the GPO was 17 minutes, covering 4,738 yards and included a section with two gradients of 1 in 15 (steeper than found on any steam railway) across the Fleet Valley where it reached sixty miles an hour.

The General Post Office (GPO), Communications Hub of the Greatest Empire the World has Ever Seen

In the 19th Century, the GPO in London was one of the wonders of the age. As Julian Stray, the senior curator of the British Postal Museum & Archive (BPMA) explained to Ian Steadman in a New Statesman article:

“The General Post Office (GPO) was the routing hub of the whole country. You would have had the foreign mails, the inland mails, the country mails, the mails to the provinces. Speed is everything. A loss of two minutes required a written explanation to one of the directors or the Postmaster General.”

The British Empire’s communications were being constrained however by the crowded, narrow streets between the railway stations at the periphery of central London and the GPO sorting office in the centre near St Paul’s – horse and carriage traffic jams could delay communications, thereby affecting events on the other side of the world. You can read more about the GPO in Get him on the Blower.

Problems with the Technology

This would seem to have represented a perfect opportunity for The Pneumatic Despatch Company railway to impress, yet despite proving a hit as a novelty it was not terribly reliable at actually transporting mail. The stations at each end were in basements, and it took valuable time and labour to transfer the heavy mail sacks in and out of the railcars, which ate up the time savings gained. This became a bigger problem when times sometimes slipped beyond nine minutes for each leg to 20 minutes from the loss of pressure. As British Postal Museum Senior Curator Stray explains:

“Occasionally there would be complete breakdowns [in the pneumatic tube] where someone would have to crawl into the tube with a length of rope, tie it around the carriages and draw them out. Also there was an ingress of water, and occasionally wet bags, and the last thing you wanted was damaged mail.”

The main difficulty lay in maintaining the tunnel sufficiently airtight, even after engine power had been increased six-fold, and mechanical faults began to develop. The Pneumatic Despatch Company considered further efforts useless.

Start of Iron Tube (Credit: IanVisits)

Manually lugging the mail bags out of the rail cars and up from the basement negated the most of the time advantage of the pneumatic railway. The infrastructure to take full advantage of the Despatch Railway had not been built, nor had even been foreseen. There was no precedent to follow. Mechanisation was being attempted on individual segments of what we now call the work flow, and the modern, mechanised and integrated processing operations pioneered by Henry Ford’s car factory assembly line were still 50 years in the future.

The LPDC obtained further powers from Parliament to construct additional routes in August 1872 to St Pancras, Kings Cross and Liverpool Street stations, and to Pickford’s parcel depot on Gresham Street in the City. None of these were started though due to a shortage of funds.

Post Office Loses Interest

Soon after the LPDC realised the Post Office were also losing interest in the pneumatic railway. They were not impressed with the system, only realising a 4 minute time savings on average on this second line, and they doubted the system’s reliability and ability to convey heavier loads. The lack of infrastructure and machinery to move the mail vertically quickly at each terminal cut into the time savings, and the possibility of soggy mail did not help. So in October 1874 the Post Office informed the Company that there was no long term prospect of Post Office traffic on the system. The last mails were carried on 31 October 1874 and the Company stopped paying rent for the station site at the GPO.

Shortly thereafter the company opened the pneumatic system to the public for the carriage of parcels, ‘in the face of a Post Office monopoly’. There was little uptake. The company directors also sought other means of recouping part of their considerable investment. In 1874 the Pneumatic Despatch Company tube was used to try to extract the smoke produced by trains in the Metropolitan Railway’s tunnels between Gower Street and Great Portland Street. Whilst the immediate effect appeared favourable, later reports suggested there had been little benefit and the experiment was ended.

The company went into liquidation in June 1875, having spent £200,000 (£1.9m nowadays) on the system which was now closed for good. A winding up order was issued, however difficulties were encountered in identifying the persons responsible for the debt. The Secretary to the Company handed over the keys to the office on 26 May 1876 requesting that the Post Office forego the rent arrears. On 7 March 1882 the London Gazette carried the notice that the Pneumatic Despatch Co. had dissolved.

Soon the pneumatic railway was all but forgotten amidst the burgeoning Underground network and other amazing inventions like the telephone and electric traction.

Rediscovery of the Pneumatic Despatch Railway in 1895

As no original records or plans still exist for the LPDR, only press articles and lithographs from the period, we are fortunate that the Pneumatic Despatch Railway tube was rediscovered in a basement of Euston Station in 1895 by engineer George Threlfall. Over a five year period he explored the tunnels in detail (save below Holborn Viaduct which was full of water), finding that the 30 year old tube often had gaps between tunnel segments, and that the railcars had in some cases rubbed the solder right off the joints. But he found the rails in good condition and determined they could be still used. Undeterred and confident of being able to repair the tubes, he set up a revived London Despatch Company and, on 6th June 1896, by order of the Court of Chancery, the name of Pneumatic Despatch Company was restored to the list of Joint Stock Companies, with the goal of selling its reprised and improved services to the Post Office.

Tube before Cleaning (Credit: IanVisits)

Much of the mail to the north of Great Britain still passed through Euston Station, with 11 tons leaving the GPO for North-Western Central (Post) Office at the busiest hour. Vans carrying up to two tons each took 24 minutes in the best case, but heavy traffic, fog, and greasy pavements could double the time. The contract for the delivery of mail to stations at the time specified eight miles an hour, and attaining this speed was one of the GPO’s chief difficulties. For a time new-fangled motor-cars were tried, but they were unreliable and were stuck in traffic as well.

To proceed Threlfall had no details, maps or documents, so he searched extensively but found neither the original company owners, their contractors, nor details or plan of the route. It was not until he found Mrs. Frances Rammell, widow of the late T W Rammell, that some of the original company papers and plans were recovered.

British Workmen Once More In Possession of the Pneumatic Despatch Railway (Credit: IanVisits)

Threlfall planned to reseal the tunnels for water ingress and convert the cars to electric traction. A copper strip was to be laid between the rails, from which cars would have a roller to pick up the current, sufficient to power a maximum of seven fully loaded cars. The current would be supplied by the electric lighting companies, sparing the expense of a dedicated electricity supply. About forty miles an hour, or under two minutes for the journey, was planned. As each car would carry a ton of mail and parcels, a seven car train carrying seven tons of mail would silently swoosh from post office to station in a twelfth of the time taken by horses and vans.

With the preliminary work done, shares in the new London Dispatch Company were sold in 1899, with an American named Batcheller acquiring the rights of the Company, and Threlfall reportedly making a profit.

However despite The Windsor Magazine of April 1900 noting that:

“Over thirty-six years have passed, and the railway van is to-day more ponderous, ten times more numerous and a hundred times greater danger to those who use the streets.”

The Post Office was even less interested in the revived Pneumatic Despatch Railway than it had been the first time around. As a result no supporting funds were forthcoming for even a trial run, and no tunnel repairs or electrification were started.

Large Diameter Pneumatic Message Tubes

Birney C Batcheller was not to be dissuaded. A mechanical engineer who designed and built pneumatic tube mail systems in Philadelphia and other US cities, using larger diameter tubes for greater capacity, he had taken over the company he worked for in 1892 and renamed it the Batcheller Pneumatic Tube Company. He eyed the lucrative UK market and became a main competitor of London’s successful Lamson Pneumatic Tube Company.

Batcheller submitted a proposal to the British Post Office in 1901 to install larger diameter pneumatic mail tubes (with carriers, not a railway) similar to those his company had developed and installed in the US, but the Post Office rejected them as too costly.

The new head of the Pneumatic Tube Company, John Milholland, then developed a separate plan for a network of yet larger parcel pneumatic tubes for London with British electrical engineer Col. Crompton. Their plan was to incorporate as the Metropolitan Pneumatic Despatch Company and raise £4M of capital for a 95 mile network of double 12in pneumatic tubes to interlace the City and slightly beyond in a 4km radius. However the Post Office, London County Council and other local authorities rejected this as the required street excavation would have been far too disruptive. The Parliamentary Bill was rejected in 1905, as was a modified Bill shortly thereafter. London Despatch Company was finally liquidated and dissolved in October 1905.

GPO Builds Its Own Mail Rail Tube

The Empire was booming, and as The Windsor Magazine of 1900 noted, traffic was getting even worse, even with several new passenger Underground lines in operation.

The British Post Office was aware of narrow-gauge underground railways in Berlin and in Chicago, the latter of which had begun revenue operation as an electric freight railway in 1906. So in 1909 a Post Office Departmental Committee was set up evaluate a number of options, including refurbishing the Pneumatic Despatch Company tunnels.

However the Post Office determined that the 40 year old Pneumatic Despatch Railway tunnels did not run along the ideal route and were too small for the size of trains required for its system. Furthermore advances in tunnelling with the Greathead shield meant it would be easier for the Post Office to dig tunnels along a more optimal route and develop its own electric powered tube railway. Parliament approved the creation and development of the Post Office Railway in 1913.

Construction soon started, with elevators and chutes at each district and central post office as an integrated system to streamline mail transfer. It was completed in 1927 (after war delays and funding problems) between Paddington and Whitechapel via several key London post offices. The London Reconnections article In Pictures: Moving the Mail Rail looks at this system in more detail.

Although the Rail Mail system was closed in 1993, a segment of it is scheduled to reopen operationally for public rides in 2016 on a 1 km ride section of track around the Mount Pleasant station and depot. Featuring descriptive displays of the railway, mail processing equipment and the heavy iron flood gates, Mail Rail will be a key part of the new British Postal Museum, something we’ve looked at before in Reopening London’s Mail Rail.

Post Office Belatedly Interested – For an Even Newer Technology

By 1920, the Post Office realised it could re-use the old pneumatic railway tunnels, by then known as the Parcels Tube, but for running telephone cables, so under the Post Office Tube Acquisition Act 1922 it purchased them from Batcheller’s company. Detailed plans of the tunnels were not available, so when the Post Office did some digging, it found that some tunnel sections had been destroyed by road work, construction projects or used illegally by other companies for telegraph cables or for storage.

Provision of 2-3″ Pneumatic Tubes to WCDO – Route Plan – 2·3·21. Copyright Unknown but thought to be BT Archive.

The following is the key text from this blueprint:

“Note: The possibility of rebuilding the Parcel’s Tube [the Pneumatic Despatch Railway] at this point is under investigation. Failing this it will be necessary to lay a line of ducts & if so two tubes will be laid at the same time.”

Handwritten in feint red ink and pointing to the subways at High Holborn and Kingsway:

“It may be necessary to lay tubes here [illegible] space”

Further handwritten ink just above the duct Legend states:

“[illegible] Parcels [illegible]”

Note that ‘2-3″ tubes’ likely means ‘two 3″ tubes’, as the GPO tubes were 2 1/4″ diameter not 2″.

Gas Buildup

In the early twentieth century gas used for heating/lighting had a tendency to build-up in the city’s sewers and underground voids, sometimes causing pavement explosions. In 1928 an explosion attributed to the ignition of a built-up mixture of coal gas and air in the old Pneumatic Despatch Railway tunnel near High Holborn and Kingsway caused one of the most serious of the era, known at the time as the “Holborn Explosion”.

“It lifted the ground for hundreds of metres in each direction,” said Stray, “It blew in shop fronts. There were flames that were 30 feet high in the air, that burned for hours on end. Below ground, where a lot of premises had cellar space, the walls were blown in a few inches.” One man was killed, and thousands of pounds of damage was recorded. Though the cause of the explosion was never conclusively determined, the Post Office was forced to fill in or ventilate its Pneumatic Despatch Railway tunnels.

Demise of the Pneumatic Railway

The demise of the pneumatic railway technology was due to a number of factors. It didn’t scale up well and was too expensive to maintain. Steam, although far dirtier, was far more reliable, although it could not be operated remotely.

One wonders why cable traction wasn’t tried in the Pneumatic Despatch Railway. Cable traction would have provided direct energy transfer from motive power to vehicle with little or no loss. Perhaps it was the lack of sufficiently robust ropes or cables, as experienced by the cable traction attempts.

But given the efforts to increase pneumatic engine power six fold to overcome air leaks, there must have been another limitation – a political one. The GPO had no love of either the technology or a solution foisted upon them by politically connected individuals such as Disraeli. Further it seems the GPO had lost patience with the reliability problems and occasional soggy mail in the trials.

A pneumatic railway has a large contact surface – not just the rails but the rubber flange all around the vehicle. And not just one but two kinds of leaks were problematic, air out and water in. The investors had tired of sinking money into a doubly leaky tunnel with no returns.

Competing directly with better established and understood steam railways, pneumatic railways were a new technology, and the latter’s shortcomings gave it no advantage over the former.

Electric traction was developed near the end of the 19th century, and was ideal for underground rail lines for obvious reasons – clean, with no smoke or soot, and did not require constant attention on board. Furthermore electric traction scaled up and down very well, lending itself well to the later unmanned Post Office Railway.

Remains and Legacy

The Pneumatic Despatch Railway tunnels were progressively removed by subsequent road and Underground construction, filled in by the Post Office, or caved in from bombing.

All that remains of the railway are two of the rail cars from the initial, smaller 2ft gauge tunnel between Euston Station and the North West District Post Office. They were discovered in 1930 during construction work at Euston, and are currently kept at the British Postal Museum Store in Debden, Essex, where they can be seen on the regular tours.

Of the many requirements of a successful transport/motive power mode, adaptability, affordability, scalability, maintainability, capacity, recoverability in case of malfunction, quietness, simplicity and velocity, pneumatic railways only offered the latter three, but not all of the time. Electric traction soon proved to be far better but even that couldn’t save the Post Office Railway, as gas and diesel power in surface vehicles and eventually email replacing letters left far less demand for it.

Of the three pneumatic communication technologies developed in England in the nineteenth century, atmospheric railways, pneumatic railways and pneumatic message tubes, the latter is the only one still in use today. The London Pneumatic Despatch Railway was the last gasp and the end of the line for urban pneumatic railway technology.

If you’re interested in finding out more about London’s history of pneumatic networks, then you can read Get Him on the Blower – London’s Lost Pneumatic Messaging Network over on Lapsed Historian

An article of this depth and history is due to the efforts of many, from the papers of the Newcomen Society, which specialises in the history of engineering and technology since 1920, to the modern day assistance of history and technology professionals such as John Liffen, Curator of Communications at the Science Museum, Andrew Emmerson, author of numerous excellent books on subterranean London, and Julian Stray, Curator of the British Postal Museum & Archive.

Many thanks as well to Ian Mansfield of IanVisits for the use of his scans of The Windsor Magazine article of 1900, and to the British Postal Museum & Archive for some of their images.

And finally to passionate enthusiasts Graham Feakins and David Holt who have assisted greatly with resources, papers, technical details and suggestions.